As mentioned previously, 5% of people with hypertension have what is called secondary hypertension. This means that the hypertension in these individuals is secondary to (caused by) a specific disorder of a particular organ or blood vessel, such as the kidney, adrenal gland, or aortic artery.
Renal (kidney) hypertension
Diseases of the kidneys can cause secondary hypertension. This type of secondary hypertension is called renal hypertension because it is caused by a problem in the kidneys. One important cause of renal hypertension is narrowing (stenosis) of the artery that supplies blood to the kidneys (renal artery). In younger individuals, usually women, the narrowing is caused by a thickening of the muscular wall of the arteries going to the kidney (fibromuscular hyperplasia). In older individuals, the narrowing generally is due to hard, fat-containing (atherosclerotic) plaques that are blocking the renal artery.
How does narrowing of the renal artery cause hypertension? First, the narrowed renal artery impairs the circulation of blood to the affected kidney. This deprivation of blood then stimulates the kidney to produce the hormones, renin and angiotensin. These hormones, along with aldosterone from the adrenal gland, cause a constriction and increased stiffness (resistance) in the peripheral arteries throughout the body, which results in high blood pressure.
Renal hypertension is usually first suspected when high blood pressure is found in a young individual or a new onset of high blood pressure is discovered in an older person. Screening for renal artery narrowing then may include renal isotope (radioactive) imaging, ultrasonographic (sound wave) imaging, or magnetic resonance imaging (MRI) of the renal arteries. The purpose of these tests is to determine whether there is a restricted blood flow to the kidney and whether angioplasty (removal of the restriction in the renal arteries) is likely to be beneficial. However, if the ultrasonic assessment indicates a high resistive index within the kidney (high resistance to blood flow), angioplasty may not improve the blood pressure because chronic damage in the kidney from long-standing hypertension already exists. If any of these tests are abnormal or the doctor's suspicion of renal artery narrowing is high enough, renal angiography (an x-ray study in which dye is injected into the renal artery) is done. Angiography is the ultimate test to actually visualize the narrowed renal artery.
A narrowing of the renal artery may be treated by balloon angioplasty. In this procedure, the physician threads a long narrow tube (catheter) into the renal artery. Once the catheter is there, the renal artery is widened by inflating a balloon at the end of the catheter and placing a permanent stent (a device that stretches the narrowing) in the artery at the site of the narrowing. This procedure usually results in an improved blood flow to the kidneys and lower blood pressure. Moreover, the procedure also preserves the function of the kidney that was partially deprived of its normal blood supply. Only rarely is surgery needed these days to open up the narrowing of the renal artery.
Any of the other types of chronic kidney disease that reduces the function of the kidneys can also cause hypertension due to hormonal disturbances and/or retention of salt.
It is important to remember that not only can kidney disease cause hypertension, but hypertension can also cause kidney disease. Therefore, all patients with high blood pressure should be evaluated for the presence of kidney disease so they can be treated appropriately.
Adrenal gland tumors
Two rare types of tumors of the adrenal glands are less common, secondary causes of hypertension. The adrenal glands sit right on top of the kidneys. Both of these tumors produce excessive amounts of adrenal hormones that cause high blood pressure. These tumors can be diagnosed from blood tests, urine tests, and imaging studies of the adrenal glands. Surgery is often required to remove these tumors or the adrenal gland (adrenalectomy), which usually relieves the hypertension.
One of the types of adrenal tumors causes a condition that is called primary hyperaldosteronism because the tumor produces excessive amounts of the hormone aldosterone. In addition to the hypertension, this condition causes the loss of excessive amounts of potassium from the body into the urine, which results in a low level of potassium in the blood. Hyperaldosteronism is generally first suspected in a person with hypertension when low potassium is also found in the blood. (Also, certain rare genetic disorders affecting the hormones of the adrenal gland can cause secondary hypertension.)
The other type of adrenal tumor that can cause secondary hypertension is called a pheochromocytoma. This tumor produces excessive catecholamines, which include several adrenaline-related hormones. The diagnosis of a pheochromocytoma is suspected in individuals who have sudden and recurrent episodes of hypertension that are associated with flushing of the skin, rapid heart beating (palpitations), and sweating, in addition to the symptoms associated with high blood pressure.
Coarctation of the aorta
Coarctation of the aorta is a rare hereditary disorder that is one of the most common causes of hypertension in children. This condition is characterized by a narrowing of a segment of the aorta, the main large artery coming from the heart. The aorta delivers blood to the arteries that supply all of the body's organs, including the kidneys.
The narrowed segment (coarctation) of the aorta generally occurs above the renal arteries, which causes a reduced blood flow to the kidneys. This lack of blood to the kidneys prompts the renin-angiotensin-aldosterone hormonal system to elevate the blood pressure. Treatment of the coarctation is usually the surgical correction of the narrowed segment of the aorta. Sometimes, balloon angioplasty (as described above for renal artery stenosis) can be used to widen (dilate) the coarctation of the aorta.
The metabolic syndrome and obesity
Genetic factors play a role in the constellation of findings that make up the "metabolic syndrome." Individuals with the metabolic syndrome have insulin resistance and a tendency to have type 2 diabetes mellitus (non-insulin-dependent diabetes).
Obesity, especially associated with a marked increase in abdominal girth, leads to high blood sugar (hyperglycemia), elevated blood lipids (fats), vascular inflammation, endothelial dysfunction (abnormal reactivity of the blood vessels), and hypertension all leading to premature atherosclerotic vascular disease. The American Obesity Association states the risk of developing hypertension is five to six times greater in obese Americans, age 20 to 45, compared to non-obese individuals of the same age. The American Journal of Clinical Nutrition reported in 2005 that waist size was a better predictor of a person's blood pressure than body mass index (BMI). Men should strive for a waist size of 35 inches or under and women 33 inches or under. The epidemic of obesity in the United States contributes to hypertension in children, adolescents, and adults.
Sunday, August 31, 2008
Monday, August 25, 2008
CORONARY ARTERY BYPASS GRAFT
WHAT IS CORONARY ARTERY BYPASS GRAFT?
Just like every other part of the body, the heart itself needs a blood supply; in fact it needs a very good one in view of the constant and vital work it does throughout our lives. The coronary arteries are the blood vessels that lie on the surface of the heart and supply it with the blood it needs. Frequently these arteries become narrowed or 'furred up' with fatty deposits. This means that less blood is able to get through to the part of the heart supplied by that particular coronary artery and this is particularly a problem when the heart needs a lot of blood, for example during exercise. This usually causes pain from the heart called angina.
If the artery blocks completely, no blood is able to get through, causing an area of the heart muscle to die. This is called a myocardial infarction or heart attack.
A coronary artery bypass graft (CABG) is an operation which uses a blood vessel from another part of the body to bypass the narrowing, thereby relieving the angina pains and reducing the risk of a heart attack.
WHEN IS IT USED?
A CABG is usually suggested when someone is suffering from angina that is not controlled by medication. In this situation a CABG will aim to relieve the angina and may prevent a heart attack from occurring. The operation is also sometimes done after someone has had a heart attack in order to prevent another one or to treat remaining angina. In these circumstances the specialist will usually arrange further investigations to assess how many coronary arteries are narrowed and by how much. These investigations usually include an exercise ECG(a heart trace performed while the person is exercising on a treadmill) and an angiogram(a special x-ray of the arteries of the heart). The results of these tests help the doctor to decide if a CABG would be beneficial.
WHAT DOES IT INVOLVE?
A CABG is a major operation but these days it is quite a common one. The patient's chest is opened via a cut down the middle of the breastbone extending into the upper part of the abdomen. At the same time a second surgeon removes a length of vein from the patient's leg, which will be used to bypass the narrowed section of coronary artery. A heart-lung machine is then used to take over the work of the heart and lungs so that the heart can be stopped whilst the surgeon operates on it.
The surgeon then uses the vein removed from the leg, or an artery called the internal mammary artery from inside the chest wall, to form new coronary arteries where they are needed to bypass the furred up ones. The patient is then taken off the heart-lung machine and blood is then able to flow through the newly-formed arteries to supply the parts of the heart which were previously starved of blood. The operation usually lasts between three and five hours.
After the operation, the patient is taken to the Intensive Care Unit (ICU) until their condition has stabilised enough to allow them back to the ward.
ARE THERE COMPLICATIONS?
Generally speaking, most CABG operations are very successful, leading to a relief of symptoms for at least five years in 80 per cent of people. They have been shown to improve the life expectation in some groups of patients. However, like any major operation there are possible complications. These include irregularities of the heartbeat, infection of the chest or leg wound, and post-operative bleeding, requiring a return to the operating theatre.
WHAT IS THE RECOVERY PERIOD?
A day or two after the operation the patient is usually taken from ICU to the ward and is usually discharged home a week or so later. An out-patient follow-up appointment will usually be arranged for them, but the timing of this varies between hospitals. They will be advised by the consultant about resuming activities. Normally it is suggested that they gradually increase what they do over the next three months after which all normal activities should resume. The timing of return to work will vary from one person to another but on average someone will need between two to three months off work following a CABG.
Driving is not allowed for one month after a CABG but it may be sensible to leave it until about six weeks after the operation before driving again depending on how the individual feels. One of the most troublesome symptoms afterwards tends to be pain at the site where the chest was opened in the middle of the breastbone, but this will gradually subside.
IS SPECIAL MEDICATION NEEDED?
Many people who have this operation will come out of hospital on less medication than they went in with. This is because they may have needed tablets to control their angina, which they will not need after bypass surgery. However, they may still need to remain on some medication according to the specialist's instructions. This often includes having to take a certain amount of aspirin each day and medication to lower the level of cholesterol (a type of fat) in the blood to help to prevent further narrowing of the arteries.
HOW LONG WILL A CABG LAST?
It is difficult to answer how long the new blood vessels will last for because the useful life of the newly formed coronary arteries is very variable. As mentioned above 80 per cent of people who have this operation are symptom free for at least five years and many of those will have no trouble for a lot longer than this. Some people do need a repeat operation after a few years and this depends to some extent on whether or not they look after themselves and their new arteries by following the advice of the doctors.
WHAT SELF HELP STRATEGIES ARE THERE?
Probably the most important measure for the person to take from the moment they know that they are going to have the operation is to give up smoking for the rest of their lives. This will not only reduce their chances of having a complication following surgery but will also help to stop the new arteries from furring up, thereby preventing the need for a repeat operation, which tends to be riskier than the first. Stopping smoking will also significantly reduce the chances of a heart attack.
Another worthwhile measure to take is to start a food diet, which is low in fat, because this will also help to keep the new heart vessels healthy and open. The patient's physician or specialist will probably measure the level of fat (called cholesterol) in the blood so that they can advise on how best to keep this down to a safe level. As mentioned above, this may involve taking medication to reduce the cholesterol level. Regular exercise is recommended, as is routine blood pressure measurement since high blood pressure contributes to narrowing of the arteries. A positive attitude and a determination to return to a normal life after the operation are also important factors in speeding recovery.
ARE THERE ANY NEW DEVELOPMENTS?
Surgeons in certain specialised hospital units have begun pioneering CABG operations via keyhole surgery. Delicate instruments allow them to work inside the body through small holes in the skin, enabling them to view their surgery through special narrow telescopes. This method allows patients to leave hospital after only three days although it is not yet widely available.
In cases where bypass surgery is not thought to be suitable, a procedure called an angioplasty may be recommended. This involves the insertion of a special catheter (thin tube) into the narrowed artery at the end of which is a balloon that is inflated, thereby opening up the narrowing. This is not a new development in itself but it has recently been shown that the placing of a tube called a 'stent' (which is left inside the constriction in the artery) during the angioplasty procedure frequently prevents the narrowing from returning and may be in some cases a more suitable procedure for the patient.
Just like every other part of the body, the heart itself needs a blood supply; in fact it needs a very good one in view of the constant and vital work it does throughout our lives. The coronary arteries are the blood vessels that lie on the surface of the heart and supply it with the blood it needs. Frequently these arteries become narrowed or 'furred up' with fatty deposits. This means that less blood is able to get through to the part of the heart supplied by that particular coronary artery and this is particularly a problem when the heart needs a lot of blood, for example during exercise. This usually causes pain from the heart called angina.
If the artery blocks completely, no blood is able to get through, causing an area of the heart muscle to die. This is called a myocardial infarction or heart attack.
A coronary artery bypass graft (CABG) is an operation which uses a blood vessel from another part of the body to bypass the narrowing, thereby relieving the angina pains and reducing the risk of a heart attack.
WHEN IS IT USED?
A CABG is usually suggested when someone is suffering from angina that is not controlled by medication. In this situation a CABG will aim to relieve the angina and may prevent a heart attack from occurring. The operation is also sometimes done after someone has had a heart attack in order to prevent another one or to treat remaining angina. In these circumstances the specialist will usually arrange further investigations to assess how many coronary arteries are narrowed and by how much. These investigations usually include an exercise ECG(a heart trace performed while the person is exercising on a treadmill) and an angiogram(a special x-ray of the arteries of the heart). The results of these tests help the doctor to decide if a CABG would be beneficial.
WHAT DOES IT INVOLVE?
A CABG is a major operation but these days it is quite a common one. The patient's chest is opened via a cut down the middle of the breastbone extending into the upper part of the abdomen. At the same time a second surgeon removes a length of vein from the patient's leg, which will be used to bypass the narrowed section of coronary artery. A heart-lung machine is then used to take over the work of the heart and lungs so that the heart can be stopped whilst the surgeon operates on it.
The surgeon then uses the vein removed from the leg, or an artery called the internal mammary artery from inside the chest wall, to form new coronary arteries where they are needed to bypass the furred up ones. The patient is then taken off the heart-lung machine and blood is then able to flow through the newly-formed arteries to supply the parts of the heart which were previously starved of blood. The operation usually lasts between three and five hours.
After the operation, the patient is taken to the Intensive Care Unit (ICU) until their condition has stabilised enough to allow them back to the ward.
ARE THERE COMPLICATIONS?
Generally speaking, most CABG operations are very successful, leading to a relief of symptoms for at least five years in 80 per cent of people. They have been shown to improve the life expectation in some groups of patients. However, like any major operation there are possible complications. These include irregularities of the heartbeat, infection of the chest or leg wound, and post-operative bleeding, requiring a return to the operating theatre.
WHAT IS THE RECOVERY PERIOD?
A day or two after the operation the patient is usually taken from ICU to the ward and is usually discharged home a week or so later. An out-patient follow-up appointment will usually be arranged for them, but the timing of this varies between hospitals. They will be advised by the consultant about resuming activities. Normally it is suggested that they gradually increase what they do over the next three months after which all normal activities should resume. The timing of return to work will vary from one person to another but on average someone will need between two to three months off work following a CABG.
Driving is not allowed for one month after a CABG but it may be sensible to leave it until about six weeks after the operation before driving again depending on how the individual feels. One of the most troublesome symptoms afterwards tends to be pain at the site where the chest was opened in the middle of the breastbone, but this will gradually subside.
IS SPECIAL MEDICATION NEEDED?
Many people who have this operation will come out of hospital on less medication than they went in with. This is because they may have needed tablets to control their angina, which they will not need after bypass surgery. However, they may still need to remain on some medication according to the specialist's instructions. This often includes having to take a certain amount of aspirin each day and medication to lower the level of cholesterol (a type of fat) in the blood to help to prevent further narrowing of the arteries.
HOW LONG WILL A CABG LAST?
It is difficult to answer how long the new blood vessels will last for because the useful life of the newly formed coronary arteries is very variable. As mentioned above 80 per cent of people who have this operation are symptom free for at least five years and many of those will have no trouble for a lot longer than this. Some people do need a repeat operation after a few years and this depends to some extent on whether or not they look after themselves and their new arteries by following the advice of the doctors.
WHAT SELF HELP STRATEGIES ARE THERE?
Probably the most important measure for the person to take from the moment they know that they are going to have the operation is to give up smoking for the rest of their lives. This will not only reduce their chances of having a complication following surgery but will also help to stop the new arteries from furring up, thereby preventing the need for a repeat operation, which tends to be riskier than the first. Stopping smoking will also significantly reduce the chances of a heart attack.
Another worthwhile measure to take is to start a food diet, which is low in fat, because this will also help to keep the new heart vessels healthy and open. The patient's physician or specialist will probably measure the level of fat (called cholesterol) in the blood so that they can advise on how best to keep this down to a safe level. As mentioned above, this may involve taking medication to reduce the cholesterol level. Regular exercise is recommended, as is routine blood pressure measurement since high blood pressure contributes to narrowing of the arteries. A positive attitude and a determination to return to a normal life after the operation are also important factors in speeding recovery.
ARE THERE ANY NEW DEVELOPMENTS?
Surgeons in certain specialised hospital units have begun pioneering CABG operations via keyhole surgery. Delicate instruments allow them to work inside the body through small holes in the skin, enabling them to view their surgery through special narrow telescopes. This method allows patients to leave hospital after only three days although it is not yet widely available.
In cases where bypass surgery is not thought to be suitable, a procedure called an angioplasty may be recommended. This involves the insertion of a special catheter (thin tube) into the narrowed artery at the end of which is a balloon that is inflated, thereby opening up the narrowing. This is not a new development in itself but it has recently been shown that the placing of a tube called a 'stent' (which is left inside the constriction in the artery) during the angioplasty procedure frequently prevents the narrowing from returning and may be in some cases a more suitable procedure for the patient.
HEADACHE, MIGRAINE
WHAT IS IT?
Migraine is a severe and disabling headache that results from dilation of arteries in the head. The headaches usually begin in adolescence or early adulthood and are more common in women. Many migraine sufferers are perfectionists and worriers. The headaches interfere greatly with the individual's life. Migraines may be triggered by a variety of factors including emotional or physical stress, alcohol, certain foods (chocolate, cheese, or MSG), missed meals, too much or too little sleep, or menstruation. Estrogen pills for birth control or menopause can precipitate the headaches. The underlying cause of migraine is unknown. It may have a hereditary predisposition, as individuals often have a family history of migraine.
HOW IS IT DIAGNOSED?
History is of gradual onset of the headache over an hour. The headache is usually one sided, but can be generalized. Migraine is most often present on awakening. It is usually throbbing in quality, and may vary in intensity and duration, lasting from several hours to three days. It is often accompanied by nausea, vomiting, and sensitivity to light and sound. In some individuals, the headache is preceded by a warning (aura) such as visual disturbances (light flashes or decreased vision), difficulty speaking, or numbness or weakness of one side of the body. These symptoms often disappear as the headache begins.
Physical exam is not helpful in this diagnosis.Tests are similarly not helpful, but may be done to explore anatomic causes of headache like brain tumor or bleeding.
HOW IS IT TREATED?
During an acute episode, the individual may be helped by resting in a quiet, darkened room. A non-narcotic analgesic sometimes is effective, when it is taken as soon as the symptoms begin. Once the headache is underway, treatment usually requires a vasoconstrictor (e.g., an ergot alkaloid) to stop the attack. A new type of vasoconstrictor has become available, and pain relief may begin within a few minutes of the injection or ingestion.
If nausea and vomiting are present, medication may have to be administered under the tongue, by injection, or rectally. Prevention of migraine is an important part of treatment. The frequency of acute episodes may be decreased by avoiding precipitating factors. If episodes occur more than two or three times a month, a variety of drugs can be taken for prevention. These include beta-blockers, tricyclic antidepressants, ergot alkaloids, and calcium channel blockers. The person may have to try several of these before the headaches are brought under control. Once an effective drug is found, it should be continued for several months. If the individual remains free of headaches, the drug may be tapered gradually off.
WHAT MIGHT COMPLICATE IT?
There are complications of frequent use of ergot drugs or the newer vasoconstrictor. Vertigo can be a complicating symptom. Motion sickness frequently is another complaint in migraine sufferers.
PREDICTED OUTCOME
Some individuals see the headaches disappear in their 30s or 40s. The headaches may persist if precipitating causes are not identified and avoided including issues of lifestyle.
ALTERNATIVES
Other possibilities are high blood pressure, infections or tumors of the sinuses, dental pain (which can radiate to the head), cold substances in contact with the palate, coital headaches at climax, headache following closed head injury, and post-lumbar puncture headache.
APPROPRIATE SPECIALISTS
Neurologist.
Migraine is a severe and disabling headache that results from dilation of arteries in the head. The headaches usually begin in adolescence or early adulthood and are more common in women. Many migraine sufferers are perfectionists and worriers. The headaches interfere greatly with the individual's life. Migraines may be triggered by a variety of factors including emotional or physical stress, alcohol, certain foods (chocolate, cheese, or MSG), missed meals, too much or too little sleep, or menstruation. Estrogen pills for birth control or menopause can precipitate the headaches. The underlying cause of migraine is unknown. It may have a hereditary predisposition, as individuals often have a family history of migraine.
HOW IS IT DIAGNOSED?
History is of gradual onset of the headache over an hour. The headache is usually one sided, but can be generalized. Migraine is most often present on awakening. It is usually throbbing in quality, and may vary in intensity and duration, lasting from several hours to three days. It is often accompanied by nausea, vomiting, and sensitivity to light and sound. In some individuals, the headache is preceded by a warning (aura) such as visual disturbances (light flashes or decreased vision), difficulty speaking, or numbness or weakness of one side of the body. These symptoms often disappear as the headache begins.
Physical exam is not helpful in this diagnosis.Tests are similarly not helpful, but may be done to explore anatomic causes of headache like brain tumor or bleeding.
HOW IS IT TREATED?
During an acute episode, the individual may be helped by resting in a quiet, darkened room. A non-narcotic analgesic sometimes is effective, when it is taken as soon as the symptoms begin. Once the headache is underway, treatment usually requires a vasoconstrictor (e.g., an ergot alkaloid) to stop the attack. A new type of vasoconstrictor has become available, and pain relief may begin within a few minutes of the injection or ingestion.
If nausea and vomiting are present, medication may have to be administered under the tongue, by injection, or rectally. Prevention of migraine is an important part of treatment. The frequency of acute episodes may be decreased by avoiding precipitating factors. If episodes occur more than two or three times a month, a variety of drugs can be taken for prevention. These include beta-blockers, tricyclic antidepressants, ergot alkaloids, and calcium channel blockers. The person may have to try several of these before the headaches are brought under control. Once an effective drug is found, it should be continued for several months. If the individual remains free of headaches, the drug may be tapered gradually off.
WHAT MIGHT COMPLICATE IT?
There are complications of frequent use of ergot drugs or the newer vasoconstrictor. Vertigo can be a complicating symptom. Motion sickness frequently is another complaint in migraine sufferers.
PREDICTED OUTCOME
Some individuals see the headaches disappear in their 30s or 40s. The headaches may persist if precipitating causes are not identified and avoided including issues of lifestyle.
ALTERNATIVES
Other possibilities are high blood pressure, infections or tumors of the sinuses, dental pain (which can radiate to the head), cold substances in contact with the palate, coital headaches at climax, headache following closed head injury, and post-lumbar puncture headache.
APPROPRIATE SPECIALISTS
Neurologist.
Wednesday, August 20, 2008
Diabetes Mellitus
Put very simply, diabetes mellitus is a condition in which the body is unable to keep the amount of sugar in the blood down to normal levels.
When we eat, some of the food is broken down to sugar within the body. This sugar travels in the bloodstream to every part of the body to provide energy necessary for life and activity.
A hormone called insulin is produced in a gland in the abdomen, called the pancreas, and it is this hormone that keeps the amount of sugar in the blood at normal levels. Without insulin, the blood sugar levels will rise. Insulin is also vital in helping to �push' the sugar in the blood into the cells of the body, thus allowing the cells to use this as 'fuel'.
The pancreas produces varying amounts of insulin depending on the level of blood sugar, therefore regulating the blood sugar level and keeping it within quite narrow limits. Normal non-diabetic people control their blood sugar between about 4 and 7 (mmol/litre of blood).
HOW DOES IT OCCUR?
When someone develops diabetes they have either a complete or a partial lack of insulin. This has two main effects. Firstly the blood sugar level rises and secondly, without insulin, the sugar is unable to enter the cells, which are therefore starved of energy. This is why diabetes is sometimes referred to as 'starvation in a sea of plenty', since there is plenty of sugar in the blood (in fact too much) but the cells are unable to make use of it without the help of insulin.
ARE THERE DIFFERENT TYPES OF DIABETES MELLITUS?
There are two types of diabetes mellitus, which have changed their names over the years. Although the two types have certain things in common, they are very different in many ways as can be seen from the features described below.
Type 1 diabetes: This used to be called 'insulin-dependent diabetes'.
This type results from an almost complete lack of insulin and therefore treatment comes in the form of insulin injections. It is the least common of the two types, occurring in only about 10 to 15 per cent of all diabetics. It tends to start early in life (which is why it also used to be referred to as juvenile onset diabetes). The reason for the change of name is that older people can develop type 1 diabetes and type 2 diabetics often require treatment with insulin, so the old names are no longer seen as appropriate.
Type 2 diabetes: This used to be called 'non insulin-dependent diabetes'.
This form is the more common type of diabetes, making up about 85 to 90 per cent of all cases and it is this form that is on the increase for reasons that are explained below. In the last few years, a lot more is understood about type 2 diabetes than before. Type 2 diabetes is generally found in adults, which is why it used to be called �maturity onset diabetes�, but unfortunately it is increasingly found in younger people as well as adults. This has occurred as a result of the increase in obesity in the general population, since the development of type 2 diabetes is strongly associated with being overweight. It tends to be slower to develop than type 1 diabetes and often the individual has had the condition for months or years before it is diagnosed because the symptoms are often less obvious.
WHY DOES IT OCCUR?
The causes of type 1 and type 2 diabetes are different, which is one reason why doctors think that the two types are probably completely different conditions with the only similarities being some shared symptoms and similar long-term effects on the body.
Type 1 diabetes: This is due to a failure of the insulin-making cells of the pancreas (called the Islet cells), leading to an almost total lack of insulin production. Consequently, the blood sugar increases without any control. The condition is thought to develop because of a mixture of a susceptible individual (ie a genetic predisposition) and possibly a viral infection that triggers a process in the body where the body destroys its own insulin-making cells. As mentioned, there is a slight inherited factor so, for instance, an identical twin of a person with type 1 diabetes has a 50 per cent chance of also having the condition.
Type 2 diabetes: This seems to be a little bit more complicated. There is a strong tendency to inherit type 2 diabetes, to the extent that an identical twin of a person with this condition has a 100 per cent chance of developing it as well. The first link in the chain that results in someone with this inherited tendency developing type 2 diabetes is something called 'insulin resistance'. This means that the individual makes the normal amount of insulin to begin with (in contrast to type 1) but that the tissues of the body become resistant to the effects of the insulin. Therefore to keep the blood sugar levels down and to push the sugar into the tissues (see above) the body has to produce more insulin.
Another effect of insulin resistance is that the liver produces more sugar. This further increases the blood sugar levels which means that even more insulin is needed to try to keep the sugar levels down and so on. At this stage, the individual's blood sugar levels, if measured, could be normal but to achieve these normal levels the pancreas has to work increasingly hard.
Two things then happen to cause type 2 diabetes finally to occur. Firstly, the pancreas can no longer keep pace with the increased demand for insulin. Secondly, any increases in blood sugar actually begin to 'poison' the insulin-making cells of the pancreas. The levels of sugar in the blood therefore begin to gradually increase through a phase which doctors call 'glucose intolerance', and then to true type 2 diabetes when the blood sugars become abnormally high.
Insulin resistance, and therefore type 2 diabetes, is strongly linked to obesity. This explains why the condition is becoming so common, as the level of obesity in the Western World is increasing. In a study of adults in the USA it was found that 24 per cent had insulin resistance mainly as a result of being overweight. Although not all of these will go on to develop diabetes, a significant proportion will.
Other types of diabetes: There are other causes of diabetes, some of which are temporary, but which may highlight an underlying tendency to insulin resistance. These include something called gestational diabetes that is diabetes occurring in pregnancy, which then tends to get better once the baby has been born. Another is diabetes caused by high doses of steroids, either in the form of medication or as a result of a condition called 'Cushing's disease' where the body produces too much of its own steroid. A type of diabetes can also be caused by destruction of the pancreas, either by its removal during an operation or as the result of excessive alcohol consumption.
WHAT ARE THE SYMPTOMS?
Although the symptoms of both type 1 and type 2 diabetes are similar, type 1 diabetes tends to progress more rapidly, and generally speaking the symptoms are worse.
Someone can have type 2 diabetes for a long time without realising it or it may even be picked up coincidentally during a medical check-up, whereas type 1 diabetes is usually detected fairly early due to the severity of the symptoms it produces.
The main symptoms of diabetes include:
• excessive thirst
• excessive urine production
• weight loss
• hunger
• tiredness and weakness
• blurred vision
• low resistance to infection, especially skin infections such as boils and also
hrush
• dehydration and coma in severe untreated cases.
Many type 2 diabetics will not have any of these symptoms, but unfortunately this does not mean that they do not have the illness. It also does not mean that the condition is not affecting the body, for example the blood vessels as described below.
WHAT ARE THE TESTS FOR DIABETES?
The tests for diabetes are usually very simple. The doctor may start by testing a sample of urine for sugar. Normally there should be no sugar detectable in urine, so if sugar is present it usually indicates the presence of diabetes. Sugar usually only appears in the urine if the level of sugar in the blood is greater than about 10 mmol/litre of blood. However, occasionally this is not the case so to truly confirm or exclude diabetes a blood test should be done.
A far more accurate test is to measure the blood sugar directly using a blood test that measures the glucose (sugar) level in millimoles per litre of blood. Over the years the accepted level of sugar in the blood that determines whether someone is diabetic has changed. However, at the time of writing the best test is a fasting blood sugar measurement. This is taken when the individual has had nothing to eat or drink (apart from water) for at least eight hours. If the blood sugar level is less than 6.1 mmol/litre, the person does not have diabetes or glucose intolerance. If the fasting blood sugar level is 7 mmol/litre or more, the person has diabetes. Between these levels the person is said to be �glucose intolerant�, which means they have a high chance of developing type 2 diabetes in the subsequent years.
If the result of these tests is uncertain then the doctor may ask for a 'glucose tolerance test�, that involves taking blood tests for sugar levels after fasting and then two hours after a drink containing 75 grams of glucose.
WHAT ARE THE COMPLICATIONS?
It is very important to treat diabetes, because if left untreated it can cause a variety of problems. These can be divided into acute and long-term effects.
Acute effects: Acute effects are generally only seen in type 1 diabetes, as this tends to come on more quickly and the levels of blood sugar can rise quickly. If diabetes remains untreated, the blood sugar level can continue to increase and the 'starvation' of the cells becomes worse, leading to dehydration and the build up of substances called �ketones'. This can eventually result in something called ketoacidotic coma, which is a life-threatening condition and needs urgent treatment.
Long-term effects: The long-term effects of both types 1 and 2 diabetes are similar, although there are some differences. Untreated mild diabetes or poorly controlled diabetes can contribute towards damage to blood vessels throughout the body. The blood vessels that cause particular concern are those of the eyes, kidneys, feet and heart. Damage to the blood vessels could lead to visual problems (including bleeding into the eye), kidney problems (sometimes leading to kidney failure), circulatory problems to the legs and feet and an increased risk of angina and heart attacks.
These complications are more likely if the individual has other factors that could damage the arteries such as smoking, high blood pressure or a high cholesterol level. Complications tend to occur more often when diabetes is poorly controlled. The nerves can also be affected causing loss of feeling especially in the feet, and diabetics are more prone to tooth and gum problems.
Generally speaking, kidney problems and problems with small blood vessels, such as those at the back of the eye, are more likely in type 1 diabetics. Problems such as 'furring up' of the large blood vessels such as those in the heart, those to the legs and those to the brain, are more likely to occur in type 2 diabetics. There seems to be a link between developing type 2 diabetes and also suffering from high blood pressure and an increased level of certain fats such as cholesterol or other fats called triglycerides in the blood. These all increase dramatically the chances of artery blockage in type 2 diabetes, since this combination is a nasty cocktail for the large arteries of the body. The result is a significantly higher risk of having a heart attack, a stroke or problems with the circulation to the legs. For this reason it is particularly important that diabetics do not smoke, since this multiplies these risks still further.
WHAT IS THE TREATMENT?
The aim of diabetes treatment is not just to control the blood sugar but also to reduce the symptoms associated with it. In practice, this involves controlling any high blood pressure, reducing the complications of the condition and in particular minimising the risk of heart and blood vessel related problems as described above.
TREATMENT OF TYPE 1 DIABETES
Type 1 diabetes is treated with the correct diet and injections of insulin. Insulin has to be given as an injection because it is destroyed in the stomach and therefore cannot, so far, be given by mouth.
The insulin regimes come in a variety of forms since there are many different types of insulin. The doctors involved will advise on the type and frequency of these injections. The insulin regime is given in association with a diet, the aim being to sustain a normal body weight and to balance the calorie intake with the amount of insulin given throughout the day.
Too much food will result in blood sugars being too high and too much insulin can cause the blood sugar to become too low, so the balance for each individual needs to be found.
In addition, high blood pressure should be treated with the appropriate medication, as should any evidence of abnormally high blood lipids (the fats in the blood-cholesterol and triglycerides) and any early signs of kidney or eye problems.
TREATMENT OF TYPE 2 DIABETES
Type 2 diabetes is treated in a variety of ways. The starting point is the correct diet, especially since at least 80 per cent of type 2 diabetics are overweight. Reduction of weight to normal can slow the process of the development or worsening of the condition as well as reducing the risks associated with it. In some cases type 2 diabetes can be treated with diet alone, at least for a period of time.
If diet alone is not sufficient, the next step will be to add in medication in the form of tablets. There are now three main groups of oral medication for type 2 diabetes, and these are outlined below.
Biguanides: The most commonly prescribed drug in this group is metformin. This is particularly useful for overweight diabetics, as it does not increase the appetite. It works by decreasing the amount of glucose produced by the liver, and by making muscle tissues of the body more sensitive to the effects of insulin.
Sulphonylureas: The second group of drugs given for type 2 diabetes are called the sulphonylureas, the most commonly prescribed of which is a tablet called glibenclamide. The sulphonylureas work by boosting the insulin output of the pancreas and are usually given to the few diabetics who are of normal weight, especially as one of the side effects is a possible increase in weight.
Glitazones: This is a relatively new group of drugs for type 2 diabetes, and includes rosiglitazone and pioglitazone. These work in a complex way to make the tissues more sensitive to insulin and are given in combination with either metformin or a sulphonylurea. Since it works by making the tissues of the body more sensitive to the effects of insulin, it acts directly against the insulin resistance chain of events, which causes type 2 diabetes in the first place.
There are other oral drugs that are occasionally used for the treatment of type 2 diabetes but those mentioned above are by far the most common.
In many cases, type 2 diabetes will eventually become resistant to treatment even with maximum doses of tablets, at which point insulin may be introduced either instead of, or as well as, a tablet. Although diabetics may see this as a backward step, in fact it often permits better control of their condition with subsequent improvement in their symptoms and a lower risk of complications.
As important as the control of blood sugar is the treatment of the other factors that make the complications of diabetes more likely such as high blood pressure and high blood lipids, as well as the giving up of smoking. In addition many type 2 diabetics will be advised by their physician or specialist to take a small dose of aspirin daily, since this has been shown to reduce the chances of artery narrowing in some diabetic individuals.
WHAT DIET IS RECOMMENDED?
Firstly it should be noted that diabetics do not need special 'diabetic foods'; they should eat the ordinary food obtainable from local shops and supermarkets. Secondly, it is a myth that diabetics should avoid sugar completely, but it is true that the sugars in the diet should be in a form where they are released slowly into the body. In practical terms this means that sugary foods should be limited and that the carbohydrates (starchy foods) in the diet should be what are called complex carbohydrates. Examples of complex carbohydrates are potatoes and bread, because these release sugar into the body gradually and avoid sudden increases in the level of glucose in the blood.
In general diabetics should:
• eat a diet that brings them down to their correct weight and keeps them there
• eat regular meals and try to eat similar amounts of starchy foods from day to day
• try to eat high fibre foods, especially beans, peas, lentils and fruit
• cut down on fried and fatty food such as butter, margarine, cheese, chips etc.
• reduce their sugar intake by swapping high sugar foods for low sugar foods
• be careful not to use too much salt
• be aware that alcohol is a source of sugar in the diet and therefore should be included in any dietary considerations. In practical terms, a moderate intake in keeping with a balanced diet is not a problem, but excessive intake will affect the blood sugar levels and the individual will risk an increase in weight.
It is advisable for a newly diagnosed diabetic to see a dietician for more detailed and specialist advice regarding the correct diet for their condition.
WHAT ARE THE SIDE EFFECTS OF TREATMENT?
The most frequently experienced side effect of both insulin and some diabetic tablets is that they can cause the blood sugar to go too low (2 mmol/l or less), which causes the person to become 'hypoglycaemic' or 'hypo' for short. The symptoms of a hypo are intense hunger, feeling shaky and sweaty, and finally a hypoglycaemic coma may result. This needs urgent medical attention.
Before the coma happens, a hypo can be treated by eating something high in sugar such as a glucose tablet or sugar lump. Diabetic tablets can occasionally cause other side effects including nausea and diarrhoea.
WHAT HAPPENS AFTER TREATMENT?
Once treatment has been established, the most important thing for a diabetic to do is to follow the advice of the doctor and/or diabetic nurse in terms of taking the prescribed treatment and following the dietary guidelines. They will also be taught how to monitor their treatment through regular checks on their own urine or blood sugar levels, which they can do very easily at home.
They will usually have regular check-ups, either in their doctor's surgery or at the hospital diabetic clinic. It is important that such check-ups are attended. Monitoring of a number of things will take place, including their diabetic control, their blood pressure, blood tests for cholesterol, triglyceride (see above) and sugar levels, and advice about foot care and regular eye checks. A blood test now exists, called an HbA1C, that gives an average of the blood sugar readings over the previous two to three months and provides the doctors and nurses with a very good indicator of the blood sugar control over that period.
In the meantime, it is important that people with diabetes monitor their own diabetic control. It is also important to have regular eye checks with an optician (so that early signs of diabetic eye disease can be detected and referred for early treatment) and to take good care of the feet, since these can suffer from damage if the diabetes affects sensation in that area. As mentioned above, a person with diabetes should also give up smoking and follow any dietary advice. Although this sounds very restrictive, in fact it can easily develop into a manageable routine and will allow the individual to continue a normal life in almost every respect with the knowledge that they are doing everything possible to limit the long-term effects of the condition on their health.
ARE THERE ANY DEVELOPMENTS IN THE TREATMENT OF DIABETES?
In the last few years, several new groups of drugs have been developed for the treatment of type 2 diabetes, which are adding to the combinations of treatment on offer.
A method of continuously monitoring blood sugar levels is also being researched, which could provide more accurate information about the blood sugar fluctuations that occur in the bloodstream of a diabetic. This could be helpful for diabetics who are finding their diabetic control especially difficult and may eventually lead on to an 'artificial pancreas' that would react to the glucose levels by injecting more or less insulin into the body in a similar way to a normal pancreas.
Progress is also being made into Islet cell transplantation. It is the Islet cells of the pancreas which produce insulin and which fail to work in diabetes and, by transplanting a diabetic patient with new Islet cells, it may be possible to cure type 1 and some cases of type 2 diabetes. Barriers to the progress of this treatment include a shortage of donors for Islet cells and prevention of tissue rejection (which occurs because the body recognises the transplanted tissue as 'alien').
When we eat, some of the food is broken down to sugar within the body. This sugar travels in the bloodstream to every part of the body to provide energy necessary for life and activity.
A hormone called insulin is produced in a gland in the abdomen, called the pancreas, and it is this hormone that keeps the amount of sugar in the blood at normal levels. Without insulin, the blood sugar levels will rise. Insulin is also vital in helping to �push' the sugar in the blood into the cells of the body, thus allowing the cells to use this as 'fuel'.
The pancreas produces varying amounts of insulin depending on the level of blood sugar, therefore regulating the blood sugar level and keeping it within quite narrow limits. Normal non-diabetic people control their blood sugar between about 4 and 7 (mmol/litre of blood).
HOW DOES IT OCCUR?
When someone develops diabetes they have either a complete or a partial lack of insulin. This has two main effects. Firstly the blood sugar level rises and secondly, without insulin, the sugar is unable to enter the cells, which are therefore starved of energy. This is why diabetes is sometimes referred to as 'starvation in a sea of plenty', since there is plenty of sugar in the blood (in fact too much) but the cells are unable to make use of it without the help of insulin.
ARE THERE DIFFERENT TYPES OF DIABETES MELLITUS?
There are two types of diabetes mellitus, which have changed their names over the years. Although the two types have certain things in common, they are very different in many ways as can be seen from the features described below.
Type 1 diabetes: This used to be called 'insulin-dependent diabetes'.
This type results from an almost complete lack of insulin and therefore treatment comes in the form of insulin injections. It is the least common of the two types, occurring in only about 10 to 15 per cent of all diabetics. It tends to start early in life (which is why it also used to be referred to as juvenile onset diabetes). The reason for the change of name is that older people can develop type 1 diabetes and type 2 diabetics often require treatment with insulin, so the old names are no longer seen as appropriate.
Type 2 diabetes: This used to be called 'non insulin-dependent diabetes'.
This form is the more common type of diabetes, making up about 85 to 90 per cent of all cases and it is this form that is on the increase for reasons that are explained below. In the last few years, a lot more is understood about type 2 diabetes than before. Type 2 diabetes is generally found in adults, which is why it used to be called �maturity onset diabetes�, but unfortunately it is increasingly found in younger people as well as adults. This has occurred as a result of the increase in obesity in the general population, since the development of type 2 diabetes is strongly associated with being overweight. It tends to be slower to develop than type 1 diabetes and often the individual has had the condition for months or years before it is diagnosed because the symptoms are often less obvious.
WHY DOES IT OCCUR?
The causes of type 1 and type 2 diabetes are different, which is one reason why doctors think that the two types are probably completely different conditions with the only similarities being some shared symptoms and similar long-term effects on the body.
Type 1 diabetes: This is due to a failure of the insulin-making cells of the pancreas (called the Islet cells), leading to an almost total lack of insulin production. Consequently, the blood sugar increases without any control. The condition is thought to develop because of a mixture of a susceptible individual (ie a genetic predisposition) and possibly a viral infection that triggers a process in the body where the body destroys its own insulin-making cells. As mentioned, there is a slight inherited factor so, for instance, an identical twin of a person with type 1 diabetes has a 50 per cent chance of also having the condition.
Type 2 diabetes: This seems to be a little bit more complicated. There is a strong tendency to inherit type 2 diabetes, to the extent that an identical twin of a person with this condition has a 100 per cent chance of developing it as well. The first link in the chain that results in someone with this inherited tendency developing type 2 diabetes is something called 'insulin resistance'. This means that the individual makes the normal amount of insulin to begin with (in contrast to type 1) but that the tissues of the body become resistant to the effects of the insulin. Therefore to keep the blood sugar levels down and to push the sugar into the tissues (see above) the body has to produce more insulin.
Another effect of insulin resistance is that the liver produces more sugar. This further increases the blood sugar levels which means that even more insulin is needed to try to keep the sugar levels down and so on. At this stage, the individual's blood sugar levels, if measured, could be normal but to achieve these normal levels the pancreas has to work increasingly hard.
Two things then happen to cause type 2 diabetes finally to occur. Firstly, the pancreas can no longer keep pace with the increased demand for insulin. Secondly, any increases in blood sugar actually begin to 'poison' the insulin-making cells of the pancreas. The levels of sugar in the blood therefore begin to gradually increase through a phase which doctors call 'glucose intolerance', and then to true type 2 diabetes when the blood sugars become abnormally high.
Insulin resistance, and therefore type 2 diabetes, is strongly linked to obesity. This explains why the condition is becoming so common, as the level of obesity in the Western World is increasing. In a study of adults in the USA it was found that 24 per cent had insulin resistance mainly as a result of being overweight. Although not all of these will go on to develop diabetes, a significant proportion will.
Other types of diabetes: There are other causes of diabetes, some of which are temporary, but which may highlight an underlying tendency to insulin resistance. These include something called gestational diabetes that is diabetes occurring in pregnancy, which then tends to get better once the baby has been born. Another is diabetes caused by high doses of steroids, either in the form of medication or as a result of a condition called 'Cushing's disease' where the body produces too much of its own steroid. A type of diabetes can also be caused by destruction of the pancreas, either by its removal during an operation or as the result of excessive alcohol consumption.
WHAT ARE THE SYMPTOMS?
Although the symptoms of both type 1 and type 2 diabetes are similar, type 1 diabetes tends to progress more rapidly, and generally speaking the symptoms are worse.
Someone can have type 2 diabetes for a long time without realising it or it may even be picked up coincidentally during a medical check-up, whereas type 1 diabetes is usually detected fairly early due to the severity of the symptoms it produces.
The main symptoms of diabetes include:
• excessive thirst
• excessive urine production
• weight loss
• hunger
• tiredness and weakness
• blurred vision
• low resistance to infection, especially skin infections such as boils and also
hrush
• dehydration and coma in severe untreated cases.
Many type 2 diabetics will not have any of these symptoms, but unfortunately this does not mean that they do not have the illness. It also does not mean that the condition is not affecting the body, for example the blood vessels as described below.
WHAT ARE THE TESTS FOR DIABETES?
The tests for diabetes are usually very simple. The doctor may start by testing a sample of urine for sugar. Normally there should be no sugar detectable in urine, so if sugar is present it usually indicates the presence of diabetes. Sugar usually only appears in the urine if the level of sugar in the blood is greater than about 10 mmol/litre of blood. However, occasionally this is not the case so to truly confirm or exclude diabetes a blood test should be done.
A far more accurate test is to measure the blood sugar directly using a blood test that measures the glucose (sugar) level in millimoles per litre of blood. Over the years the accepted level of sugar in the blood that determines whether someone is diabetic has changed. However, at the time of writing the best test is a fasting blood sugar measurement. This is taken when the individual has had nothing to eat or drink (apart from water) for at least eight hours. If the blood sugar level is less than 6.1 mmol/litre, the person does not have diabetes or glucose intolerance. If the fasting blood sugar level is 7 mmol/litre or more, the person has diabetes. Between these levels the person is said to be �glucose intolerant�, which means they have a high chance of developing type 2 diabetes in the subsequent years.
If the result of these tests is uncertain then the doctor may ask for a 'glucose tolerance test�, that involves taking blood tests for sugar levels after fasting and then two hours after a drink containing 75 grams of glucose.
WHAT ARE THE COMPLICATIONS?
It is very important to treat diabetes, because if left untreated it can cause a variety of problems. These can be divided into acute and long-term effects.
Acute effects: Acute effects are generally only seen in type 1 diabetes, as this tends to come on more quickly and the levels of blood sugar can rise quickly. If diabetes remains untreated, the blood sugar level can continue to increase and the 'starvation' of the cells becomes worse, leading to dehydration and the build up of substances called �ketones'. This can eventually result in something called ketoacidotic coma, which is a life-threatening condition and needs urgent treatment.
Long-term effects: The long-term effects of both types 1 and 2 diabetes are similar, although there are some differences. Untreated mild diabetes or poorly controlled diabetes can contribute towards damage to blood vessels throughout the body. The blood vessels that cause particular concern are those of the eyes, kidneys, feet and heart. Damage to the blood vessels could lead to visual problems (including bleeding into the eye), kidney problems (sometimes leading to kidney failure), circulatory problems to the legs and feet and an increased risk of angina and heart attacks.
These complications are more likely if the individual has other factors that could damage the arteries such as smoking, high blood pressure or a high cholesterol level. Complications tend to occur more often when diabetes is poorly controlled. The nerves can also be affected causing loss of feeling especially in the feet, and diabetics are more prone to tooth and gum problems.
Generally speaking, kidney problems and problems with small blood vessels, such as those at the back of the eye, are more likely in type 1 diabetics. Problems such as 'furring up' of the large blood vessels such as those in the heart, those to the legs and those to the brain, are more likely to occur in type 2 diabetics. There seems to be a link between developing type 2 diabetes and also suffering from high blood pressure and an increased level of certain fats such as cholesterol or other fats called triglycerides in the blood. These all increase dramatically the chances of artery blockage in type 2 diabetes, since this combination is a nasty cocktail for the large arteries of the body. The result is a significantly higher risk of having a heart attack, a stroke or problems with the circulation to the legs. For this reason it is particularly important that diabetics do not smoke, since this multiplies these risks still further.
WHAT IS THE TREATMENT?
The aim of diabetes treatment is not just to control the blood sugar but also to reduce the symptoms associated with it. In practice, this involves controlling any high blood pressure, reducing the complications of the condition and in particular minimising the risk of heart and blood vessel related problems as described above.
TREATMENT OF TYPE 1 DIABETES
Type 1 diabetes is treated with the correct diet and injections of insulin. Insulin has to be given as an injection because it is destroyed in the stomach and therefore cannot, so far, be given by mouth.
The insulin regimes come in a variety of forms since there are many different types of insulin. The doctors involved will advise on the type and frequency of these injections. The insulin regime is given in association with a diet, the aim being to sustain a normal body weight and to balance the calorie intake with the amount of insulin given throughout the day.
Too much food will result in blood sugars being too high and too much insulin can cause the blood sugar to become too low, so the balance for each individual needs to be found.
In addition, high blood pressure should be treated with the appropriate medication, as should any evidence of abnormally high blood lipids (the fats in the blood-cholesterol and triglycerides) and any early signs of kidney or eye problems.
TREATMENT OF TYPE 2 DIABETES
Type 2 diabetes is treated in a variety of ways. The starting point is the correct diet, especially since at least 80 per cent of type 2 diabetics are overweight. Reduction of weight to normal can slow the process of the development or worsening of the condition as well as reducing the risks associated with it. In some cases type 2 diabetes can be treated with diet alone, at least for a period of time.
If diet alone is not sufficient, the next step will be to add in medication in the form of tablets. There are now three main groups of oral medication for type 2 diabetes, and these are outlined below.
Biguanides: The most commonly prescribed drug in this group is metformin. This is particularly useful for overweight diabetics, as it does not increase the appetite. It works by decreasing the amount of glucose produced by the liver, and by making muscle tissues of the body more sensitive to the effects of insulin.
Sulphonylureas: The second group of drugs given for type 2 diabetes are called the sulphonylureas, the most commonly prescribed of which is a tablet called glibenclamide. The sulphonylureas work by boosting the insulin output of the pancreas and are usually given to the few diabetics who are of normal weight, especially as one of the side effects is a possible increase in weight.
Glitazones: This is a relatively new group of drugs for type 2 diabetes, and includes rosiglitazone and pioglitazone. These work in a complex way to make the tissues more sensitive to insulin and are given in combination with either metformin or a sulphonylurea. Since it works by making the tissues of the body more sensitive to the effects of insulin, it acts directly against the insulin resistance chain of events, which causes type 2 diabetes in the first place.
There are other oral drugs that are occasionally used for the treatment of type 2 diabetes but those mentioned above are by far the most common.
In many cases, type 2 diabetes will eventually become resistant to treatment even with maximum doses of tablets, at which point insulin may be introduced either instead of, or as well as, a tablet. Although diabetics may see this as a backward step, in fact it often permits better control of their condition with subsequent improvement in their symptoms and a lower risk of complications.
As important as the control of blood sugar is the treatment of the other factors that make the complications of diabetes more likely such as high blood pressure and high blood lipids, as well as the giving up of smoking. In addition many type 2 diabetics will be advised by their physician or specialist to take a small dose of aspirin daily, since this has been shown to reduce the chances of artery narrowing in some diabetic individuals.
WHAT DIET IS RECOMMENDED?
Firstly it should be noted that diabetics do not need special 'diabetic foods'; they should eat the ordinary food obtainable from local shops and supermarkets. Secondly, it is a myth that diabetics should avoid sugar completely, but it is true that the sugars in the diet should be in a form where they are released slowly into the body. In practical terms this means that sugary foods should be limited and that the carbohydrates (starchy foods) in the diet should be what are called complex carbohydrates. Examples of complex carbohydrates are potatoes and bread, because these release sugar into the body gradually and avoid sudden increases in the level of glucose in the blood.
In general diabetics should:
• eat a diet that brings them down to their correct weight and keeps them there
• eat regular meals and try to eat similar amounts of starchy foods from day to day
• try to eat high fibre foods, especially beans, peas, lentils and fruit
• cut down on fried and fatty food such as butter, margarine, cheese, chips etc.
• reduce their sugar intake by swapping high sugar foods for low sugar foods
• be careful not to use too much salt
• be aware that alcohol is a source of sugar in the diet and therefore should be included in any dietary considerations. In practical terms, a moderate intake in keeping with a balanced diet is not a problem, but excessive intake will affect the blood sugar levels and the individual will risk an increase in weight.
It is advisable for a newly diagnosed diabetic to see a dietician for more detailed and specialist advice regarding the correct diet for their condition.
WHAT ARE THE SIDE EFFECTS OF TREATMENT?
The most frequently experienced side effect of both insulin and some diabetic tablets is that they can cause the blood sugar to go too low (2 mmol/l or less), which causes the person to become 'hypoglycaemic' or 'hypo' for short. The symptoms of a hypo are intense hunger, feeling shaky and sweaty, and finally a hypoglycaemic coma may result. This needs urgent medical attention.
Before the coma happens, a hypo can be treated by eating something high in sugar such as a glucose tablet or sugar lump. Diabetic tablets can occasionally cause other side effects including nausea and diarrhoea.
WHAT HAPPENS AFTER TREATMENT?
Once treatment has been established, the most important thing for a diabetic to do is to follow the advice of the doctor and/or diabetic nurse in terms of taking the prescribed treatment and following the dietary guidelines. They will also be taught how to monitor their treatment through regular checks on their own urine or blood sugar levels, which they can do very easily at home.
They will usually have regular check-ups, either in their doctor's surgery or at the hospital diabetic clinic. It is important that such check-ups are attended. Monitoring of a number of things will take place, including their diabetic control, their blood pressure, blood tests for cholesterol, triglyceride (see above) and sugar levels, and advice about foot care and regular eye checks. A blood test now exists, called an HbA1C, that gives an average of the blood sugar readings over the previous two to three months and provides the doctors and nurses with a very good indicator of the blood sugar control over that period.
In the meantime, it is important that people with diabetes monitor their own diabetic control. It is also important to have regular eye checks with an optician (so that early signs of diabetic eye disease can be detected and referred for early treatment) and to take good care of the feet, since these can suffer from damage if the diabetes affects sensation in that area. As mentioned above, a person with diabetes should also give up smoking and follow any dietary advice. Although this sounds very restrictive, in fact it can easily develop into a manageable routine and will allow the individual to continue a normal life in almost every respect with the knowledge that they are doing everything possible to limit the long-term effects of the condition on their health.
ARE THERE ANY DEVELOPMENTS IN THE TREATMENT OF DIABETES?
In the last few years, several new groups of drugs have been developed for the treatment of type 2 diabetes, which are adding to the combinations of treatment on offer.
A method of continuously monitoring blood sugar levels is also being researched, which could provide more accurate information about the blood sugar fluctuations that occur in the bloodstream of a diabetic. This could be helpful for diabetics who are finding their diabetic control especially difficult and may eventually lead on to an 'artificial pancreas' that would react to the glucose levels by injecting more or less insulin into the body in a similar way to a normal pancreas.
Progress is also being made into Islet cell transplantation. It is the Islet cells of the pancreas which produce insulin and which fail to work in diabetes and, by transplanting a diabetic patient with new Islet cells, it may be possible to cure type 1 and some cases of type 2 diabetes. Barriers to the progress of this treatment include a shortage of donors for Islet cells and prevention of tissue rejection (which occurs because the body recognises the transplanted tissue as 'alien').
MULTIPLE SCLEROSIS
WHAT IS IT?
Multiple sclerosis (MS) is a slow progressive disease of the central nervous system. It is the most common cause of neurologic disability in young adults. In MS, local areas of myelin, the fatty substance that surrounds nerve processes, is lost. This demyelination can cause slowed or blocked nerve impulse conduction and can occur at any site where "white matter" (nerves encased in myelin) occurs. Because it can disrupt function in any area of the central nervous system (CNS), symptoms are varied and numerous.
Although the exact cause of MS is unknown, it is considered to be an autoimmune disease (condition in which the body's defense system reacts against its own tissue). There seems to be a genetic factor as well, since relatives of affected people are eight times more likely than others to contract the disease. Since it is five times more common in temperate zones (such as the US and Europe) than in the tropics, environment may also play a part. Spending the first fifteen years of life or more in a particular area seems to increase the risk. This suggests that a virus picked up during this early period of life may be responsible for a susceptible person to later develop the disease MS generally occurs between 20 and 40 years of age. In high-risk areas, the incidence is about one in every 1,000 people. Women outnumber the men at a ratio of three to two.
HOW IS IT DIAGNOSED?
History: MS can have many different signs and/or symptoms. Approximately 50% of individuals will present with visual problems (usually the loss of vision in one eye). Other common symptoms include severe fatigue, weakness, numbness, tingling, unsteadiness of limb movements, loss of coordination, loss of equilibrium, prominent gait, impaired dexterity, urinary problems, disturbed speech patterns, mental disturbances, impairment of temperature sensation and abnormal sense of limb position.Although painless, the symptoms can last from several days to weeks. Remission (period of time during which the symptoms of a disease lessen or disappear) may be partial or complete. The next attack may come with new symptoms and may not occur until years later. In females, relapses are common in the first two to three months following pregnancy. Diagnosis is often a considerable challenge because of the potential for an infinite array of signs and symptoms. After exclusion of all other causes, criteria for diagnosis is generally that there must be at least two neurologic events, separate in time (by at least a month), and separate in location within the central nervous system.
Physical exam are variable depending on which region of the CNS is involved. Clumsiness, muscle weakness, and unsteady gait may be due to damage to the white matter in the brain. When the inflammation occurs in the portion of the brain involved with vision, the eye's pupillary response to light is often diminished. Inflammation of the spinal cord can cause extremity weakness or stiffness (spasticity). Urinary incontinence indicates that the nerve fibers to the bladder may be involved.
Tests: There is no specific diagnostic test for MS. But the accuracy of the diagnosis can be improved with three indicators. A spinal tap to obtain a sample of cerebrospinal fluid may be used to confirm the presence of an inflammatory lesion or to rule out other possible CNS diseases or infections. Recording of nerve responses to various stimuli (evoked potential) are routinely employed. Absence of response or an abnormality in a response is useful in detecting and localizing lesions in the CNS. MRI is used to both diagnose and monitor the disease. It can also be helpful in excluding other CNS disorders.
HOW IS IT TREATED?
Search for a cure is still in progress. Treatment is designed to suppress the disease, to lessen the symptoms, and/or to improve day-to-day lifestyle.
Treatment is directed at modification of the course of the disease and primarily includes the use of corticosteroids (anti-inflammatory), immunosuppressant drugs (which interfere or suppress the body's immune response), or a combination of corticosteroid with immunosuppressant drugs. Treatment may include the use of beta-interferon (anti-inflammatory) and plasmapheresis (immunosuppressant).The symptoms of MS are treated with drugs to address muscle weakness and muscle spasticity, physical therapy to strengthen weakened muscles, and occupational therapy to teach individuals how to deal with stress in the workplace and at home. Treatment also targets bladder dysfunction and pain management.
One of the most difficult aspects for the individual with MS is the sense of uncertainty about the course of the disease. Psychiatric or psychological counseling may be necessary to provide support.
MEDICATIONS
Brand Name Active Ingredient
Lioresal Baclofen Order Baclofen
WHAT MIGHT COMPLICATE IT?
Complications include those related to symptoms such as extreme fatigue, deteriorating general health, urinary incontinence or frequent urinary tract infections, constipation, skin ulceration, painful muscle spasms, and paralysis. Although MS is not in itself fatal, those who are severely disabled may die from the complications of being bedridden or from recurrent infections.
PREDICTED OUTCOME
The course of the disease and the rate of disability varies considerably from person to person. Approximately twenty percent of individuals experience long symptom-free periods throughout life with a few mild relapses and very few permanent effects. Others may have a series of flare-ups, leaving some residual disability, but further deterioration ceases. While most individuals at least partially recover from the first attack, there are others who gradually become more disabled, becoming bedridden and incontinent by early middle life. A small group of individuals suffer gross disability within the first year. Although MS is not in itself fatal, those who are disabled may die from the complications of being bedridden or from recurrent infections.
ALTERNATIVES
Conditions with similar symptoms include neoplasms (tumors) or infections (labyrinthitis, meningovascular syphilis, or encephalitis).
APPROPRIATE SPECIALISTS
Neurologist, urologist, ophthalmologist, psychiatrist, psychologist and physical therapist.
WHAT IS IT?
Multiple sclerosis (MS) is a slow progressive disease of the central nervous system. It is the most common cause of neurologic disability in young adults. In MS, local areas of myelin, the fatty substance that surrounds nerve processes, is lost. This demyelination can cause slowed or blocked nerve impulse conduction and can occur at any site where "white matter" (nerves encased in myelin) occurs. Because it can disrupt function in any area of the central nervous system (CNS), symptoms are varied and numerous.
Although the exact cause of MS is unknown, it is considered to be an autoimmune disease (condition in which the body's defense system reacts against its own tissue). There seems to be a genetic factor as well, since relatives of affected people are eight times more likely than others to contract the disease. Since it is five times more common in temperate zones (such as the US and Europe) than in the tropics, environment may also play a part. Spending the first fifteen years of life or more in a particular area seems to increase the risk. This suggests that a virus picked up during this early period of life may be responsible for a susceptible person to later develop the disease MS generally occurs between 20 and 40 years of age. In high-risk areas, the incidence is about one in every 1,000 people. Women outnumber the men at a ratio of three to two.
HOW IS IT DIAGNOSED?
History: MS can have many different signs and/or symptoms. Approximately 50% of individuals will present with visual problems (usually the loss of vision in one eye). Other common symptoms include severe fatigue, weakness, numbness, tingling, unsteadiness of limb movements, loss of coordination, loss of equilibrium, prominent gait, impaired dexterity, urinary problems, disturbed speech patterns, mental disturbances, impairment of temperature sensation and abnormal sense of limb position.Although painless, the symptoms can last from several days to weeks. Remission (period of time during which the symptoms of a disease lessen or disappear) may be partial or complete. The next attack may come with new symptoms and may not occur until years later. In females, relapses are common in the first two to three months following pregnancy. Diagnosis is often a considerable challenge because of the potential for an infinite array of signs and symptoms. After exclusion of all other causes, criteria for diagnosis is generally that there must be at least two neurologic events, separate in time (by at least a month), and separate in location within the central nervous system.
Physical exam are variable depending on which region of the CNS is involved. Clumsiness, muscle weakness, and unsteady gait may be due to damage to the white matter in the brain. When the inflammation occurs in the portion of the brain involved with vision, the eye's pupillary response to light is often diminished. Inflammation of the spinal cord can cause extremity weakness or stiffness (spasticity). Urinary incontinence indicates that the nerve fibers to the bladder may be involved.
Tests: There is no specific diagnostic test for MS. But the accuracy of the diagnosis can be improved with three indicators. A spinal tap to obtain a sample of cerebrospinal fluid may be used to confirm the presence of an inflammatory lesion or to rule out other possible CNS diseases or infections. Recording of nerve responses to various stimuli (evoked potential) are routinely employed. Absence of response or an abnormality in a response is useful in detecting and localizing lesions in the CNS. MRI is used to both diagnose and monitor the disease. It can also be helpful in excluding other CNS disorders.
HOW IS IT TREATED?
Search for a cure is still in progress. Treatment is designed to suppress the disease, to lessen the symptoms, and/or to improve day-to-day lifestyle.
Treatment is directed at modification of the course of the disease and primarily includes the use of corticosteroids (anti-inflammatory), immunosuppressant drugs (which interfere or suppress the body's immune response), or a combination of corticosteroid with immunosuppressant drugs. Treatment may include the use of beta-interferon (anti-inflammatory) and plasmapheresis (immunosuppressant).The symptoms of MS are treated with drugs to address muscle weakness and muscle spasticity, physical therapy to strengthen weakened muscles, and occupational therapy to teach individuals how to deal with stress in the workplace and at home. Treatment also targets bladder dysfunction and pain management.
One of the most difficult aspects for the individual with MS is the sense of uncertainty about the course of the disease. Psychiatric or psychological counseling may be necessary to provide support.
MEDICATIONS
Brand Name Active Ingredient
Lioresal Baclofen Order Baclofen
WHAT MIGHT COMPLICATE IT?
Complications include those related to symptoms such as extreme fatigue, deteriorating general health, urinary incontinence or frequent urinary tract infections, constipation, skin ulceration, painful muscle spasms, and paralysis. Although MS is not in itself fatal, those who are severely disabled may die from the complications of being bedridden or from recurrent infections.
PREDICTED OUTCOME
The course of the disease and the rate of disability varies considerably from person to person. Approximately twenty percent of individuals experience long symptom-free periods throughout life with a few mild relapses and very few permanent effects. Others may have a series of flare-ups, leaving some residual disability, but further deterioration ceases. While most individuals at least partially recover from the first attack, there are others who gradually become more disabled, becoming bedridden and incontinent by early middle life. A small group of individuals suffer gross disability within the first year. Although MS is not in itself fatal, those who are disabled may die from the complications of being bedridden or from recurrent infections.
ALTERNATIVES
Conditions with similar symptoms include neoplasms (tumors) or infections (labyrinthitis, meningovascular syphilis, or encephalitis).
APPROPRIATE SPECIALISTS
Neurologist, urologist, ophthalmologist, psychiatrist, psychologist and physical therapist.
WHAT IS CANCER?
People tend to think of cancer as one particular disease but in fact there are more than 200 different kinds of cancer. What all types of cancer have in common is an abnormality of the way in which cancer cells behave. All the tissues of the body such as skin, muscle, lung etc are made up of millions of building blocks called cells. Normally these cells divide and grow in a controlled way to replace ageing tissue and replace it with new tissue. However, cancer cells divide rapidly and in an uncontrolled way that does not tend to stop unless it is treated.
In some cases these cancer cells break away from the main area of growth and spread through the blood or lymphatic (fluid drainage system) to other parts of the body where they continue to multiply. These areas are called 'metastases' or 'secondaries'. Other words that tend to be used in relation to cancer are the word 'tumour' which means an abnormal lump of tissue usually made up of cancerous cells (although occasionally the word tumour is used to mean any abnormal mass of tissue even if the cells are not cancerous) and 'malignant' which is another word for cancerous.
WHY DOES CANCER OCCUR?
The reason why some cells become cancerous is not properly understood but a great deal of research is being done into this area. It seems that it is something to do with an alteration to, or abnormality of, the genetic blueprint called DNA inside the cells that tells the cells to continue to divide and multiply instead of switching this process off.
We do know that in some cases this DNA abnormality is inherited so, for instance, there is a degree of inheritance in some cases of bowel and breast cancer and it is also known that the cell DNA can be damaged by certain environmental factors making certain cancers more likely. For instance, certain types of skin cancer are recognised to be strongly related to over exposure to ultraviolet rays from the sun which damage the DNA in the cells, and smoking cigarettes in some way affects the cells inside the lung resulting in a higher risk of lung cancer.
However, in many cases, there is no known reason why one person develops cancer and another doesn't. In other words most cancers do not seem to have either an inherited or known environmental cause for them.
WHAT TYPES OF CANCER ARE THERE?
In theory any tissue of the body can become cancerous. However, cancer is more likely to occur in tissues that have to multiply themselves rapidly as part of normal life. For instance, skin cells have to constantly multiply to replace those that are lost from the surface of the body. Partly as a result of this and partly because the skin is exposed to ultraviolet light, skin cancer is the most common malignancy although most types of skin cancer (called non-melanoma skin cancer) are nearly always curable.
Therefore, about 85 per cent of cancers are due to malignancy of the cells that line the body (ie the skin) or the organs (such as lung lining or the tissues that line the bowel). About six per cent of cancers arise in what is called connective tissue (such as muscle, bone and fat) and about five per cent occur in the blood (leukaemia) or lymphatic system (such as a type of cancer called lymphomas). Rarer cancers make up the remainder.
The most common cancers in men are, in order: cancer of the prostate, lung cancer, bowel cancer and cancer of the bladder. In women they are: breast cancer, bowel cancer, lung cancer and cancer of the ovary.
WHO GETS CANCER?
Anyone can get cancer. In most cases there is no particular reason why a particular person develops it. One in three of us will develop cancer at some stage. Although this sounds very frightening it must be remembered that cancer is more common in the elderly, ie we unfortunately must all die of something and heart disease and cancer are the two most common causes in developed countries. Also, not all cancers are fatal since advances in treatment mean many types of cancer can be controlled or even cured.
Obviously there are some people who are more likely to develop cancer. As mentioned, cancer is more likely to occur the older you get probably because the DNA inside the cells becomes corrupted and increasingly likely to send out the 'wrong signals' which then lead to uncontrolled cell multiplication. Exposure to certain substances also makes an individual more liable to develop certain types of cancer. Hence a cigarette smoker is at greater risk of not only lung cancer but also a large number of other cancers including cancer of the throat, stomach and tongue. People who have been exposed to asbestos are at greater risk of a type of malignancy of the lining of the lung called 'mesothelioma'. It is now well known that high doses of radiation can increase the chances of blood disorders such as leukaemia (cancer of the blood) and over exposure of the skin to the sun is a factor in the development of skin cancer.
HOW IS CANCER DIAGNOSED?
This is a hard question to answer since, as explained above, there are many different types of cancer. It is a bit like asking 'how is illness diagnosed?' For each type of cancer there are symptoms which may cause the person to consult a doctor and for the doctor to consider cancer as a possible cause for these symptoms.
Some types of cancer are detected as part of a screening procedure. The best known of these is the national cervical smear programme which screens for early signs of abnormal cells which may lead to cervical cancer (cancer of the neck of the womb). Another example is the national breast-screening programme, which involves all women between the ages of 55 and 64 being offered a mammogram to detect early breast cancer.
If cancer is suspected the patient will almost certainly have further investigations which may include blood tests, x-rays and scans such as ultrasound, CT (computerised tomography) or MRI (magnetic resonance imaging) scans which all give images of the inside of the body. If a tumour exists, the doctors may try to obtain a biopsy (a small sample) of the tissue inside the tumour, which is then examined under a microscope to assist in diagnosis.
Further tests may be done even after a diagnosis of cancer has been made. These are often done to so-called 'stage' the cancer. Staging is now an important part of the management of many cancers and essentially means doing tests to establish how bad the cancer is both in terms of the type of cancer cells involved and how far they have spread by the time the cancer is diagnosed. This can be important both in terms of helping to decide what the best treatment regime will be and in relation to the likely outlook (prognosis) for the patient.
HOW IS CANCER TREATED?
There are many different treatments for cancer depending on the type of cancer involved and how far it has or has not spread at the time of diagnosis.
The main types of treatment fall into the following groups:
• surgery
• radiotherapy
• chemotherapy
• hormone therapy
• immunotherapy
• gene therapy
• bone marrow and stem cell transplants.
People with certain types of cancer may have more than one of these. For instance, someone with breast cancer may have surgery to remove the breast lump, followed by chemotherapy and radiotherapy.
Each of these will be explained more fully below.
Surgery: Surgery is perhaps the oldest treatment for many cancers but it still has a large part to play in the modern treatment of many malignancies. For instance, treatment of skin cancers, bowel cancer and breast cancer usually (but not always) involves the removal of the cancer, often in association with other forms of treatment such as radiotherapy. Surgery is also sometimes used as part of the treatment of cancer recurrence (the return of cancer in an individual). For example, it is now not unusual to remove a secondary deposit in the liver from a bowel cancer by excising it, usually along with other forms of treatment.
Chemotherapy: Chemotherapy is the use of powerful drugs in order to attempt to kill the cancer cells. In the same way as radiotherapy, it may be given on its own or as one of a number of different types of treatment. It can be given to destroy the tumour, to shrink it before surgery or to reduce the chances of the cancer returning.
Chemotherapy is usually given in the form of carefully measured doses of a number of drugs given either intravenously (directly in a vein) or by mouth.
The side effects associated with chemotherapy vary according to the drugs given and alter from one individual to another. However, common side effects include nausea, hair loss (which usually recovers once the treatment is completed) and sometimes soreness of the mouth. Many of the side effects can themselves be treated with anti-sickness drugs etc.
Radiotherapy: Radiotherapy is the treatment of cancer by using high doses of x-rays directed at the cancer cells in order to kill those cells. It can be used either:
• on its own to try to destroy the cancer
• in association with chemotherapy
• to try to shrink the size of a cancerous tumour before surgery to remove it
• in an attempt to prevent the cancer cells from returning.
Radiotherapy is usually given 'externally' with the patient being given a carefully calculated dose of radiation from a machine in a special unit. However, it is occasionally given internally ie from inside the body. This can come in the form of a radioactive drink, an injection or radioactive rods or wires placed into the tumour.
Side effects of radiotherapy include general effects such as tiredness or nausea and local effects such as burning or soreness of the skin over the area exposed to the radiation.
Hormone therapy: Certain types of cancer 'feed' on the existence of particular hormones in the blood. For instance, some forms of breast cancer grow faster if the female hormone oestrogen is in the bloodstream and prostate cancer thrives if the male hormone testosterone is present. Therefore if the effect of these hormones can be blocked, this in turn slows the progression of the cancer.
One of the most successful anti cancer drugs of all time is one called tamoxifen, which acts by blocking the effect of oestrogen on breast cancer and has improved the outlook for many women with this condition. Similarly, there are a number of drugs used in the treatment of prostate cancer, such as one called goserulin that blocks the effect of testosterone on these cancer cells.
Immunotherapy: Immunotherapy is the general name given to treatment that uses or assists the body's own immune system to attack the cancer cells. It comes in many different forms. One form is a drug called interferon which is injected into the body and which 'boosts' the body's defences against certain types of cancer such as a skin cancer called malignant melanoma and cancer of the kidney.
Another type of immunotherapy that is being researched is called monoclonal antibody treatment, which is sometimes referred to in the media as the 'magic bullet'. This involves the laboratory manufacture of antibodies (substances that the body naturally produces to fight off infection) that are designed to attach themselves to certain types of cancer cells. They can either be used to attack the cancer cell or to carry a radioactive or toxic substance to the cells, which are then destroyed by the targeted radiation or toxin.
The concept of monoclonal antibody treatment is a good one but it is an area of treatment that is still being developed. It cannot be seen as a miracle cure and at the moment is only likely to be offered to a small number of carefully selected patients. It is important that someone with cancer only considers monoclonal antibody treatment on the advice of their lead specialist.
Another area of development in the field of immunotherapy is the production of vaccines to certain types of cancer. This is really a progression of the way vaccines are currently given to stimulate the body to produce its own antibodies to infection, eg the BCG vaccine to protect against tuberculosis. However, anti-cancer vaccines are still in the developmental stage.
Gene therapy: Gene therapy is an exciting area of therapy for cancer, but one that is still only in the early stages of development. This works on the idea that, as mentioned above, cells are thought to become cancerous when part of the DNA message inside the cells becomes damaged. Gene therapy involves somehow either preventing the DNA from becoming damaged or by repairing it. One idea is to use special viruses as messengers to get inside the cells and carry a gene repair therapy with them into the cells.
Bone marrow transplantation: Most people are familiar with the idea of organ transplantation such as kidney and heart transplants but may not know that bone marrow transplantation is also sometimes used in the treatment of certain cancers. The bone marrow is soft tissue found in the middle of many of the bones of the body and it is this that makes the blood cells.
Bone marrow transplantation is used in blood related cancers such as in leukaemia or the lymphomas (which are a type of cancer in the lymph system).
The transplant can either be the patient's own bone marrow that was harvested (removed) before the chemotherapy was given and which is then given back to them or can be a donor bone marrow from a relative or close genetic match.
Stem cell transplantation: Stem cells are cells that develop into blood cells. Stem cell transplantation is similar in principal to bone marrow transplantation. High doses of cancer therapy that are toxic to the patient's bone marrow are given initially. The bone marrow can then be repopulated with healthy blood cells by giving the patient a transplant of stem cells, which were either removed from the individual before the cancer treatment or are donated by a suitable donor.
WHAT HAPPENS IF THE CANCER COMES BACK
Sometimes, despite correct treatment, cancer can come back. This is called a recurrence of the cancer and can mean the cancer cells appearing either in the same place as they were originally (something called 'local recurrence') or in an area away from the original site of the cancer ('distant recurrence').
All the methods of treatment of the original cancer are sometimes used to treat the recurrence (ie surgery, chemotherapy etc) depending, of course, on the type of cancer involved and whether the specialists feel that treatment would be beneficial to the patient.
WHAT IF THE CANCER OR THE RECURRENCE CANNOT BE TREATED?
There may come a point where further treatment with the aim of curing the cancer may not be possible. However, a host of different treatments now exist with the aim of treating the symptoms of the cancer and improving the quality of life of the individual. This sort of treatment is called palliative therapy and is now a specialist area in itself with doctors and nurses who have particular training in palliative care.
HOW CAN CANCER BE PREVENTED?
There is nothing an individual can do to guarantee that they will never develop cancer since, as mentioned above, the causes of most malignancies are not known. However, there are certain things that someone can do to reduce their chance of getting some types of cancer or to detect them early at a stage when treatment is likely to be more successful. These measures include:
• Not smoking, since many cancers, not only lung cancer, are related to smoking tobacco. It is important to emphasise that it is almost never too late to give up smoking since it has been shown that people who stop even well into middle age avoid most of their subsequent risk of developing lung cancer.
• Eating a healthy diet since certain malignancies such as cancer of the oesophagus (the gullet) and ovarian cancer are thought to have a link with a diet high in alcohol and fat respectively. There is also increasing evidence that healthy food such as green vegetables and fruit contain substances called anti-oxidants which have a protective effect against certain cancers. It is recommended that people eat at least five portions of fruit a day and have a diet low in fat and high in fibre.
• Avoiding over-exposure to the sun's rays to reduce the chance of developing skin cancer.
• Having regular cervical smears as part of the national cervical smear screening programme for cancer of the neck of the womb in women. This programme has been partly responsible for a fall in the number of cases and the death rate from cervical cancer.
• Attending regular mammogram appointments as arranged as part of the national breast cancer-screening programme for women. Also, all women need to be 'breast aware' and be alert to any changes in their breasts or development of breast lumps either of which should prompt medical advice.
• Regular testicular self-examination by all men so that any lumps can be reported to a doctor for further examination to exclude testicular cancer.
• Seeking medical advice for any persistent or unusual symptoms.
It is worth remembering that advances in the prevention, detection and treatment of various cancers are being made all the time which are altering the outlook for people with these conditions for the better. It has been estimated that if the current rates of improvement in survival from common cancers continues at its present rate, about 24,000 deaths within five years of diagnosis would have been avoided in patients under the age of 75 by the year 2010.
People tend to think of cancer as one particular disease but in fact there are more than 200 different kinds of cancer. What all types of cancer have in common is an abnormality of the way in which cancer cells behave. All the tissues of the body such as skin, muscle, lung etc are made up of millions of building blocks called cells. Normally these cells divide and grow in a controlled way to replace ageing tissue and replace it with new tissue. However, cancer cells divide rapidly and in an uncontrolled way that does not tend to stop unless it is treated.
In some cases these cancer cells break away from the main area of growth and spread through the blood or lymphatic (fluid drainage system) to other parts of the body where they continue to multiply. These areas are called 'metastases' or 'secondaries'. Other words that tend to be used in relation to cancer are the word 'tumour' which means an abnormal lump of tissue usually made up of cancerous cells (although occasionally the word tumour is used to mean any abnormal mass of tissue even if the cells are not cancerous) and 'malignant' which is another word for cancerous.
WHY DOES CANCER OCCUR?
The reason why some cells become cancerous is not properly understood but a great deal of research is being done into this area. It seems that it is something to do with an alteration to, or abnormality of, the genetic blueprint called DNA inside the cells that tells the cells to continue to divide and multiply instead of switching this process off.
We do know that in some cases this DNA abnormality is inherited so, for instance, there is a degree of inheritance in some cases of bowel and breast cancer and it is also known that the cell DNA can be damaged by certain environmental factors making certain cancers more likely. For instance, certain types of skin cancer are recognised to be strongly related to over exposure to ultraviolet rays from the sun which damage the DNA in the cells, and smoking cigarettes in some way affects the cells inside the lung resulting in a higher risk of lung cancer.
However, in many cases, there is no known reason why one person develops cancer and another doesn't. In other words most cancers do not seem to have either an inherited or known environmental cause for them.
WHAT TYPES OF CANCER ARE THERE?
In theory any tissue of the body can become cancerous. However, cancer is more likely to occur in tissues that have to multiply themselves rapidly as part of normal life. For instance, skin cells have to constantly multiply to replace those that are lost from the surface of the body. Partly as a result of this and partly because the skin is exposed to ultraviolet light, skin cancer is the most common malignancy although most types of skin cancer (called non-melanoma skin cancer) are nearly always curable.
Therefore, about 85 per cent of cancers are due to malignancy of the cells that line the body (ie the skin) or the organs (such as lung lining or the tissues that line the bowel). About six per cent of cancers arise in what is called connective tissue (such as muscle, bone and fat) and about five per cent occur in the blood (leukaemia) or lymphatic system (such as a type of cancer called lymphomas). Rarer cancers make up the remainder.
The most common cancers in men are, in order: cancer of the prostate, lung cancer, bowel cancer and cancer of the bladder. In women they are: breast cancer, bowel cancer, lung cancer and cancer of the ovary.
WHO GETS CANCER?
Anyone can get cancer. In most cases there is no particular reason why a particular person develops it. One in three of us will develop cancer at some stage. Although this sounds very frightening it must be remembered that cancer is more common in the elderly, ie we unfortunately must all die of something and heart disease and cancer are the two most common causes in developed countries. Also, not all cancers are fatal since advances in treatment mean many types of cancer can be controlled or even cured.
Obviously there are some people who are more likely to develop cancer. As mentioned, cancer is more likely to occur the older you get probably because the DNA inside the cells becomes corrupted and increasingly likely to send out the 'wrong signals' which then lead to uncontrolled cell multiplication. Exposure to certain substances also makes an individual more liable to develop certain types of cancer. Hence a cigarette smoker is at greater risk of not only lung cancer but also a large number of other cancers including cancer of the throat, stomach and tongue. People who have been exposed to asbestos are at greater risk of a type of malignancy of the lining of the lung called 'mesothelioma'. It is now well known that high doses of radiation can increase the chances of blood disorders such as leukaemia (cancer of the blood) and over exposure of the skin to the sun is a factor in the development of skin cancer.
HOW IS CANCER DIAGNOSED?
This is a hard question to answer since, as explained above, there are many different types of cancer. It is a bit like asking 'how is illness diagnosed?' For each type of cancer there are symptoms which may cause the person to consult a doctor and for the doctor to consider cancer as a possible cause for these symptoms.
Some types of cancer are detected as part of a screening procedure. The best known of these is the national cervical smear programme which screens for early signs of abnormal cells which may lead to cervical cancer (cancer of the neck of the womb). Another example is the national breast-screening programme, which involves all women between the ages of 55 and 64 being offered a mammogram to detect early breast cancer.
If cancer is suspected the patient will almost certainly have further investigations which may include blood tests, x-rays and scans such as ultrasound, CT (computerised tomography) or MRI (magnetic resonance imaging) scans which all give images of the inside of the body. If a tumour exists, the doctors may try to obtain a biopsy (a small sample) of the tissue inside the tumour, which is then examined under a microscope to assist in diagnosis.
Further tests may be done even after a diagnosis of cancer has been made. These are often done to so-called 'stage' the cancer. Staging is now an important part of the management of many cancers and essentially means doing tests to establish how bad the cancer is both in terms of the type of cancer cells involved and how far they have spread by the time the cancer is diagnosed. This can be important both in terms of helping to decide what the best treatment regime will be and in relation to the likely outlook (prognosis) for the patient.
HOW IS CANCER TREATED?
There are many different treatments for cancer depending on the type of cancer involved and how far it has or has not spread at the time of diagnosis.
The main types of treatment fall into the following groups:
• surgery
• radiotherapy
• chemotherapy
• hormone therapy
• immunotherapy
• gene therapy
• bone marrow and stem cell transplants.
People with certain types of cancer may have more than one of these. For instance, someone with breast cancer may have surgery to remove the breast lump, followed by chemotherapy and radiotherapy.
Each of these will be explained more fully below.
Surgery: Surgery is perhaps the oldest treatment for many cancers but it still has a large part to play in the modern treatment of many malignancies. For instance, treatment of skin cancers, bowel cancer and breast cancer usually (but not always) involves the removal of the cancer, often in association with other forms of treatment such as radiotherapy. Surgery is also sometimes used as part of the treatment of cancer recurrence (the return of cancer in an individual). For example, it is now not unusual to remove a secondary deposit in the liver from a bowel cancer by excising it, usually along with other forms of treatment.
Chemotherapy: Chemotherapy is the use of powerful drugs in order to attempt to kill the cancer cells. In the same way as radiotherapy, it may be given on its own or as one of a number of different types of treatment. It can be given to destroy the tumour, to shrink it before surgery or to reduce the chances of the cancer returning.
Chemotherapy is usually given in the form of carefully measured doses of a number of drugs given either intravenously (directly in a vein) or by mouth.
The side effects associated with chemotherapy vary according to the drugs given and alter from one individual to another. However, common side effects include nausea, hair loss (which usually recovers once the treatment is completed) and sometimes soreness of the mouth. Many of the side effects can themselves be treated with anti-sickness drugs etc.
Radiotherapy: Radiotherapy is the treatment of cancer by using high doses of x-rays directed at the cancer cells in order to kill those cells. It can be used either:
• on its own to try to destroy the cancer
• in association with chemotherapy
• to try to shrink the size of a cancerous tumour before surgery to remove it
• in an attempt to prevent the cancer cells from returning.
Radiotherapy is usually given 'externally' with the patient being given a carefully calculated dose of radiation from a machine in a special unit. However, it is occasionally given internally ie from inside the body. This can come in the form of a radioactive drink, an injection or radioactive rods or wires placed into the tumour.
Side effects of radiotherapy include general effects such as tiredness or nausea and local effects such as burning or soreness of the skin over the area exposed to the radiation.
Hormone therapy: Certain types of cancer 'feed' on the existence of particular hormones in the blood. For instance, some forms of breast cancer grow faster if the female hormone oestrogen is in the bloodstream and prostate cancer thrives if the male hormone testosterone is present. Therefore if the effect of these hormones can be blocked, this in turn slows the progression of the cancer.
One of the most successful anti cancer drugs of all time is one called tamoxifen, which acts by blocking the effect of oestrogen on breast cancer and has improved the outlook for many women with this condition. Similarly, there are a number of drugs used in the treatment of prostate cancer, such as one called goserulin that blocks the effect of testosterone on these cancer cells.
Immunotherapy: Immunotherapy is the general name given to treatment that uses or assists the body's own immune system to attack the cancer cells. It comes in many different forms. One form is a drug called interferon which is injected into the body and which 'boosts' the body's defences against certain types of cancer such as a skin cancer called malignant melanoma and cancer of the kidney.
Another type of immunotherapy that is being researched is called monoclonal antibody treatment, which is sometimes referred to in the media as the 'magic bullet'. This involves the laboratory manufacture of antibodies (substances that the body naturally produces to fight off infection) that are designed to attach themselves to certain types of cancer cells. They can either be used to attack the cancer cell or to carry a radioactive or toxic substance to the cells, which are then destroyed by the targeted radiation or toxin.
The concept of monoclonal antibody treatment is a good one but it is an area of treatment that is still being developed. It cannot be seen as a miracle cure and at the moment is only likely to be offered to a small number of carefully selected patients. It is important that someone with cancer only considers monoclonal antibody treatment on the advice of their lead specialist.
Another area of development in the field of immunotherapy is the production of vaccines to certain types of cancer. This is really a progression of the way vaccines are currently given to stimulate the body to produce its own antibodies to infection, eg the BCG vaccine to protect against tuberculosis. However, anti-cancer vaccines are still in the developmental stage.
Gene therapy: Gene therapy is an exciting area of therapy for cancer, but one that is still only in the early stages of development. This works on the idea that, as mentioned above, cells are thought to become cancerous when part of the DNA message inside the cells becomes damaged. Gene therapy involves somehow either preventing the DNA from becoming damaged or by repairing it. One idea is to use special viruses as messengers to get inside the cells and carry a gene repair therapy with them into the cells.
Bone marrow transplantation: Most people are familiar with the idea of organ transplantation such as kidney and heart transplants but may not know that bone marrow transplantation is also sometimes used in the treatment of certain cancers. The bone marrow is soft tissue found in the middle of many of the bones of the body and it is this that makes the blood cells.
Bone marrow transplantation is used in blood related cancers such as in leukaemia or the lymphomas (which are a type of cancer in the lymph system).
The transplant can either be the patient's own bone marrow that was harvested (removed) before the chemotherapy was given and which is then given back to them or can be a donor bone marrow from a relative or close genetic match.
Stem cell transplantation: Stem cells are cells that develop into blood cells. Stem cell transplantation is similar in principal to bone marrow transplantation. High doses of cancer therapy that are toxic to the patient's bone marrow are given initially. The bone marrow can then be repopulated with healthy blood cells by giving the patient a transplant of stem cells, which were either removed from the individual before the cancer treatment or are donated by a suitable donor.
WHAT HAPPENS IF THE CANCER COMES BACK
Sometimes, despite correct treatment, cancer can come back. This is called a recurrence of the cancer and can mean the cancer cells appearing either in the same place as they were originally (something called 'local recurrence') or in an area away from the original site of the cancer ('distant recurrence').
All the methods of treatment of the original cancer are sometimes used to treat the recurrence (ie surgery, chemotherapy etc) depending, of course, on the type of cancer involved and whether the specialists feel that treatment would be beneficial to the patient.
WHAT IF THE CANCER OR THE RECURRENCE CANNOT BE TREATED?
There may come a point where further treatment with the aim of curing the cancer may not be possible. However, a host of different treatments now exist with the aim of treating the symptoms of the cancer and improving the quality of life of the individual. This sort of treatment is called palliative therapy and is now a specialist area in itself with doctors and nurses who have particular training in palliative care.
HOW CAN CANCER BE PREVENTED?
There is nothing an individual can do to guarantee that they will never develop cancer since, as mentioned above, the causes of most malignancies are not known. However, there are certain things that someone can do to reduce their chance of getting some types of cancer or to detect them early at a stage when treatment is likely to be more successful. These measures include:
• Not smoking, since many cancers, not only lung cancer, are related to smoking tobacco. It is important to emphasise that it is almost never too late to give up smoking since it has been shown that people who stop even well into middle age avoid most of their subsequent risk of developing lung cancer.
• Eating a healthy diet since certain malignancies such as cancer of the oesophagus (the gullet) and ovarian cancer are thought to have a link with a diet high in alcohol and fat respectively. There is also increasing evidence that healthy food such as green vegetables and fruit contain substances called anti-oxidants which have a protective effect against certain cancers. It is recommended that people eat at least five portions of fruit a day and have a diet low in fat and high in fibre.
• Avoiding over-exposure to the sun's rays to reduce the chance of developing skin cancer.
• Having regular cervical smears as part of the national cervical smear screening programme for cancer of the neck of the womb in women. This programme has been partly responsible for a fall in the number of cases and the death rate from cervical cancer.
• Attending regular mammogram appointments as arranged as part of the national breast cancer-screening programme for women. Also, all women need to be 'breast aware' and be alert to any changes in their breasts or development of breast lumps either of which should prompt medical advice.
• Regular testicular self-examination by all men so that any lumps can be reported to a doctor for further examination to exclude testicular cancer.
• Seeking medical advice for any persistent or unusual symptoms.
It is worth remembering that advances in the prevention, detection and treatment of various cancers are being made all the time which are altering the outlook for people with these conditions for the better. It has been estimated that if the current rates of improvement in survival from common cancers continues at its present rate, about 24,000 deaths within five years of diagnosis would have been avoided in patients under the age of 75 by the year 2010.
Friday, August 15, 2008
BEFORE AND AFTER AN OPERATION
Surgical procedures and operations have become so commonplace that it is easy to forget that even relatively minor operations can be a major event in a person's life. Therefore anyone planning to have surgery should be prepared not just physically, but mentally and socially too (meaning domestic and work arrangements). You should only accept surgery if you consider that it is in your, or your child's, interests and that the benefits of the operation will outweigh the risks and disruption.
The term 'minor operation' usually means one that only involves a local anaesthetic (eg removal of a mole or sebaceous cyst from the skin), or one that only requires a quick general anaesthetic (eg removal of tonsils, insertion of grommets into the ears to treat glue ear or bunion operations).
A major operation is any operation requiring a longer anaesthetic or the opening up of the abdomen or chest.
Examples of major operations are:
· hip replacement
· coronary artery bypass grafting
· almost all organ transplants
· hemi-colectomy (removal of part of the large bowel).
Obviously there is a wide range of very different operations but some general principles apply to all, whether an operation is done as a routine (so-called 'elective' surgery) or whether it is an emergency.
Before surgery
Anaesthetic
Local anaesthetics: Local anaesthetics can be used in different ways to allow an operation to take place. For instance, they can be injected directly into the skin to numb an area. This technique is used for the removal of moles or to allow the insertion of a large needle to obtain a biopsy (small piece of tissue for analysis) from an organ inside the body (such as the liver). Local anaesthetic drops are used in a similar way to enable cataract removal without the need for a general anaesthetic.
Alternatively, local anaesthetic can be injected around certain nerves. This technique is most commonly used by dentists to numb part of the mouth but is also used by anaesthetists during some operations on the arm, hands or feet.
Finally, local anaesthetic can be injected into the fluid around the spinal cord (something called a 'spinal anaesthetic') or into a fatty layer around the spinal cord (an 'epidural'). Both of these result in complete numbness of the lower part or section of the body and allow the surgeon to perform certain major operations without the need for a general anaesthetic. Spinal and epidural anaesthetics are used for such operations as Caesarean section deliveries (allowing the mother to be awake during the birth of her child) and are also often preferable for major operations on the frail or elderly.
General anaesthetics: Under a general anaesthetic (GA), a patient is rendered unconscious in a carefully controlled way with the use of anaesthetic drugs given either into the veins and/or as an inhaled gas. This technique is suitable for major operations such as heart and chest surgery and most forms of abdominal surgery (because they require the abdominal muscles to be artificially paralysed for the duration of the operation). Since the stomach can empty involuntarily under GA, fasting is needed before a planned general anaesthetic. Eating and drinking immediately afterwards are not allowed either.
Pre-operative assessment
Pre-existing conditions need to be assessed before surgery to minimise their impact on the patient during and after the operation. Obvious examples are diabetes, heart disease, and thrombosis of the leg veins, but there are many others. This is why the anaesthetist (and/or a doctor from the surgical team) usually examines the patient a day or so before surgery, or sometimes the same day.
Depending on the nature of the operation and the general health of the patient, tests may need to be done, such as:
- chest x-ray for patients with chronic lung disease
- ECG (electrocardiogram) in patients over 65 years of age, or anyone with a history of heart trouble
- blood tests such as full blood count before any major operation.
Drugs and surgery
The surgeon and anaesthetist also need to know which drugs a patient is already on, for instance insulin or diabetic tablets, drugs for high blood pressure, anti-depressants and so on. This is because both prescribed drugs and those bought over-the-counter can affect the anaesthetic or the operation itself. In the case of patients who have needed to take steroid tablets over a length of time for conditions such as asthma or arthritis, a higher dose of steroid may be needed for several days to counteract the effects of surgery. A list of medicines, including any bought over the counter, should be brought into the hospital so that the hospital staff can check with you.
In some cases, women may be advised to discontinue the oral contraceptive pill to reduce the chance of developing a DVT (deep vein thrombosis, or clot in the leg) following surgery. The usual advice is for women on the combined oral contraceptive pill to stop taking it four weeks before any planned major surgery or any surgery to the legs. The pill can then be re-started on the first day of the period which starts at least two weeks after return to full mobility. Obviously it is important for other contraceptive measures to be used during this time. Once in hospital, a sleeping pill may be on offer the night before a routine operation, even if the patient doesn't usually take any.
Social preparations
It's wise to think ahead about going home. On the simplest level, a relative may be needed to provide a lift from the hospital, while a neighbour might be able to shop for fresh groceries. Those who live alone may have to give some thought to security of their home, or to the welfare of any pets, especially if the stay in hospital turns out to be a bit longer than anticipated. It is advisable to stop smoking, as this will increase the chances of a trouble-free recovery.
Special preparations
Some planned operations demand specific preparations. The most obvious example is colon (bowel) surgery, which usually requires an empty bowel. This may involve several days on a low-residue (low fibre) diet, and then an enema or laxatives.
Consent for surgery
Faced with a consent form, patients sometimes joke about signing their life away, and leave most of their questions unasked. It is, however, much better to be well informed before having any surgery.
Although most people probably do not want to hear every single technical detail of the operation they are about to have, a patient must at least know enough to ensure that the consent he or she gives is truly 'informed'.
The most important issue about an operation is what the benefits are likely to be and what the possible risks are. Just as there is no such thing as a risk-free activity in normal life, it is also true that there is no such thing as a risk-free operation. The degree of risk will depend on a number of factors such as the difficulty of the operation, the health of the patient and whether or not it is a planned (elective) operation or is done as an emergency.
Useful questions to ask the surgeon include:
· what type of anaesthetic will be used - local or general?
· how long is the stay in hospital likely to be?
· if the operation involves any form of biopsy, how long will it be before the lab provides the result?
· is a blood transfusion anticipated?
· are there any special dietary requirements afterwards?
· what are the follow-up arrangements?
· will stitches need to be removed, and by whom - hospital staff or physician surgery?
· how long before it is safe to drive a car?
· how long is it necessary to stay off work?
· when can sex safely be resumed?
· how soon will it be safe to travel by train/air?
There may well be more questions to ask, depending on the exact operation to be done and each patient's circumstances.
After surgery
The recovery room
Often called simply 'recovery', the recovery room is a ward next to the operating theatre, which provides a high level of care by specially trained nurses while the patient is coming around after surgery. An anaesthetist is close at hand to give support if necessary. Because they may be feeling groggy, not all patients remember it well. After only a minor operation, time spent in the recovery room may be minimal, but it could be an hour or more after hip replacement, for example.
Once patients have recovered from the anaesthetic, they are returned to the ward or, after very large operations, they may be taken to ITU (intensive therapy unit) where an especially close watch is kept on all aspects of their recovery.
Pain relief
Many people who have just had surgery for the first time are surprised to have pain afterwards, as they felt nothing during the operation. New methods of operating, such as laparoscopic (keyhole) surgery, require much smaller cuts in the skin, so pain is less, but the reality is that a surgical wound is usually painful. Most people need some pain relief after surgery, especially for the first 72 hours.
When pain lasts much longer than this, or recurs after it had got better, it can be due to infection in the wound. Infections complicate a small number of operations, mostly those where the patient is debilitated and therefore has a low resistance, or where contamination has occurred, from bowel contents for instance.
Methods of delivering pain relief include:
· drugs that can be given as an injection such as pethidine, morphine and related drugs. The injection may be given either into the muscle of the thigh, into a vein, or sometimes into an epidural if this is already in place.
· drugs which can be given by mouth, like paracetamol and co-dydramol. These are milder painkillers, which are most suitable after minor operations, or after the first 48 hours following surgery.
· suppositories. Pain relief can also be given rectally in the form of suppositories; diclofenac is sometimes used in this way.
Nausea and vomiting
Surgical procedures and operations have become so commonplace that it is easy to forget that even relatively minor operations can be a major event in a person's life. Therefore anyone planning to have surgery should be prepared not just physically, but mentally and socially too (meaning domestic and work arrangements). You should only accept surgery if you consider that it is in your, or your child's, interests and that the benefits of the operation will outweigh the risks and disruption.
The term 'minor operation' usually means one that only involves a local anaesthetic (eg removal of a mole or sebaceous cyst from the skin), or one that only requires a quick general anaesthetic (eg removal of tonsils, insertion of grommets into the ears to treat glue ear or bunion operations).
A major operation is any operation requiring a longer anaesthetic or the opening up of the abdomen or chest.
Examples of major operations are:
· hip replacement
· coronary artery bypass grafting
· almost all organ transplants
· hemi-colectomy (removal of part of the large bowel).
Obviously there is a wide range of very different operations but some general principles apply to all, whether an operation is done as a routine (so-called 'elective' surgery) or whether it is an emergency.
Before surgery
Anaesthetic
Local anaesthetics: Local anaesthetics can be used in different ways to allow an operation to take place. For instance, they can be injected directly into the skin to numb an area. This technique is used for the removal of moles or to allow the insertion of a large needle to obtain a biopsy (small piece of tissue for analysis) from an organ inside the body (such as the liver). Local anaesthetic drops are used in a similar way to enable cataract removal without the need for a general anaesthetic.
Alternatively, local anaesthetic can be injected around certain nerves. This technique is most commonly used by dentists to numb part of the mouth but is also used by anaesthetists during some operations on the arm, hands or feet.
Finally, local anaesthetic can be injected into the fluid around the spinal cord (something called a 'spinal anaesthetic') or into a fatty layer around the spinal cord (an 'epidural'). Both of these result in complete numbness of the lower part or section of the body and allow the surgeon to perform certain major operations without the need for a general anaesthetic. Spinal and epidural anaesthetics are used for such operations as Caesarean section deliveries (allowing the mother to be awake during the birth of her child) and are also often preferable for major operations on the frail or elderly.
General anaesthetics: Under a general anaesthetic (GA), a patient is rendered unconscious in a carefully controlled way with the use of anaesthetic drugs given either into the veins and/or as an inhaled gas. This technique is suitable for major operations such as heart and chest surgery and most forms of abdominal surgery (because they require the abdominal muscles to be artificially paralysed for the duration of the operation). Since the stomach can empty involuntarily under GA, fasting is needed before a planned general anaesthetic. Eating and drinking immediately afterwards are not allowed either.
Pre-operative assessment
Pre-existing conditions need to be assessed before surgery to minimise their impact on the patient during and after the operation. Obvious examples are diabetes, heart disease, and thrombosis of the leg veins, but there are many others. This is why the anaesthetist (and/or a doctor from the surgical team) usually examines the patient a day or so before surgery, or sometimes the same day.
Depending on the nature of the operation and the general health of the patient, tests may need to be done, such as:
- chest x-ray for patients with chronic lung disease
- ECG (electrocardiogram) in patients over 65 years of age, or anyone with a history of heart trouble
- blood tests such as full blood count before any major operation.
Drugs and surgery
The surgeon and anaesthetist also need to know which drugs a patient is already on, for instance insulin or diabetic tablets, drugs for high blood pressure, anti-depressants and so on. This is because both prescribed drugs and those bought over-the-counter can affect the anaesthetic or the operation itself. In the case of patients who have needed to take steroid tablets over a length of time for conditions such as asthma or arthritis, a higher dose of steroid may be needed for several days to counteract the effects of surgery. A list of medicines, including any bought over the counter, should be brought into the hospital so that the hospital staff can check with you.
In some cases, women may be advised to discontinue the oral contraceptive pill to reduce the chance of developing a DVT (deep vein thrombosis, or clot in the leg) following surgery. The usual advice is for women on the combined oral contraceptive pill to stop taking it four weeks before any planned major surgery or any surgery to the legs. The pill can then be re-started on the first day of the period which starts at least two weeks after return to full mobility. Obviously it is important for other contraceptive measures to be used during this time. Once in hospital, a sleeping pill may be on offer the night before a routine operation, even if the patient doesn't usually take any.
Social preparations
It's wise to think ahead about going home. On the simplest level, a relative may be needed to provide a lift from the hospital, while a neighbour might be able to shop for fresh groceries. Those who live alone may have to give some thought to security of their home, or to the welfare of any pets, especially if the stay in hospital turns out to be a bit longer than anticipated. It is advisable to stop smoking, as this will increase the chances of a trouble-free recovery.
Special preparations
Some planned operations demand specific preparations. The most obvious example is colon (bowel) surgery, which usually requires an empty bowel. This may involve several days on a low-residue (low fibre) diet, and then an enema or laxatives.
Consent for surgery
Faced with a consent form, patients sometimes joke about signing their life away, and leave most of their questions unasked. It is, however, much better to be well informed before having any surgery.
Although most people probably do not want to hear every single technical detail of the operation they are about to have, a patient must at least know enough to ensure that the consent he or she gives is truly 'informed'.
The most important issue about an operation is what the benefits are likely to be and what the possible risks are. Just as there is no such thing as a risk-free activity in normal life, it is also true that there is no such thing as a risk-free operation. The degree of risk will depend on a number of factors such as the difficulty of the operation, the health of the patient and whether or not it is a planned (elective) operation or is done as an emergency.
Useful questions to ask the surgeon include:
· what type of anaesthetic will be used - local or general?
· how long is the stay in hospital likely to be?
· if the operation involves any form of biopsy, how long will it be before the lab provides the result?
· is a blood transfusion anticipated?
· are there any special dietary requirements afterwards?
· what are the follow-up arrangements?
· will stitches need to be removed, and by whom - hospital staff or physician surgery?
· how long before it is safe to drive a car?
· how long is it necessary to stay off work?
· when can sex safely be resumed?
· how soon will it be safe to travel by train/air?
There may well be more questions to ask, depending on the exact operation to be done and each patient's circumstances.
After surgery
The recovery room
Often called simply 'recovery', the recovery room is a ward next to the operating theatre, which provides a high level of care by specially trained nurses while the patient is coming around after surgery. An anaesthetist is close at hand to give support if necessary. Because they may be feeling groggy, not all patients remember it well. After only a minor operation, time spent in the recovery room may be minimal, but it could be an hour or more after hip replacement, for example.
Once patients have recovered from the anaesthetic, they are returned to the ward or, after very large operations, they may be taken to ITU (intensive therapy unit) where an especially close watch is kept on all aspects of their recovery.
Pain relief
Many people who have just had surgery for the first time are surprised to have pain afterwards, as they felt nothing during the operation. New methods of operating, such as laparoscopic (keyhole) surgery, require much smaller cuts in the skin, so pain is less, but the reality is that a surgical wound is usually painful. Most people need some pain relief after surgery, especially for the first 72 hours.
When pain lasts much longer than this, or recurs after it had got better, it can be due to infection in the wound. Infections complicate a small number of operations, mostly those where the patient is debilitated and therefore has a low resistance, or where contamination has occurred, from bowel contents for instance.
Methods of delivering pain relief include:
· drugs that can be given as an injection such as pethidine, morphine and related drugs. The injection may be given either into the muscle of the thigh, into a vein, or sometimes into an epidural if this is already in place.
· drugs which can be given by mouth, like paracetamol and co-dydramol. These are milder painkillers, which are most suitable after minor operations, or after the first 48 hours following surgery.
· suppositories. Pain relief can also be given rectally in the form of suppositories; diclofenac is sometimes used in this way.
Nausea and vomiting
Nausea, retching and vomiting are nowadays much rarer after surgery than they once were, because anaesthetics have improved and also because surgical procedures are quicker than they used to be. Even so, these symptoms can occur shortly after an operation, either as a result of the surgery or the effect of drugs given during the anaesthetic.
These symptoms can be treated with anti-emetic medication, which is similar to travel-sickness tablets, but usually given by injection. When a patient is still retching or vomiting, eating and drinking are obviously out of the question for the time being, and fluid intake may have to be given intra-venous through a drip. The stomach may also have to be kept empty via a thin naso-gastric tube passed down through the nose.
Constipation
Many factors can cause constipation after surgery, including:
· bed-rest
· pain-killing drugs
· a low-fibre diet
· the operation itself.
Whatever the cause, the result can be uncomfortable, especially as straining is awkward in the presence of a recent surgical incision. Fortunately, suffering is not necessary and enemas are not always needed either, since there are now many gentler ways to produce a bowel movement. It is always a good idea to let the nurses know about whether the bowels have moved or not.
A less well known symptom in the early days after an abdominal operation is pain from trapped gas. This can cause a strange searing pain that travels from the middle of the belly slowly towards the back passage. It may be a little alarming at the time but is very short-lived. Any more persistent pain should of course be mentioned to the nursing staff or the doctor.
Retention of urine
Inability to pass urine can cause problems after an operation, particularly in men past middle age, when it is often due to a large prostate. However, retention also occurs in women. Simply being in bed, particularly in a strange place, can cause urinary retention and so can constipation.
Acute retention of urine is very uncomfortable because there is an intense desire to pass water, despite an inability to do so. If retention does not respond to simple measures (like being taken to the bathroom and running the taps) and constipation has been excluded, a urinary catheter may be needed as a temporary measure for, say, 24 to 48 hours. Men may rest assured that a little local anaesthetic jelly is first squirted into the tip of the penis to ease the discomfort of having the catheter inserted.
Deep vein thrombosis (DVT)
DVT is a potentially dangerous complication in which a clot forms in a vein, either in the leg or the pelvis. It can cause localised pain and swelling in the leg. More importantly, the clot, or thrombus, can sometimes become detached and travel up into the lungs, resulting in a pulmonary embolus, which can be fatal if it is large.
Reasons why DVT can occur include:
· immobility in bed, causing sluggish blood flow
· pressure on veins, especially from operations in the pelvic area (like hysterectomy)
· the fact that the blood itself becomes stickier and more liable to clot after an operation
· co-existing drug treatment, such as hormone replacement therapy (HRT) or the contraceptive pill
· close family history of a tendency to form blood clots.
Having said that, DVT is relatively rare because of measures to prevent it, such as:
· getting patients out of bed quickly after surgery
· giving anti-coagulant (blood thinning) drugs such as low-dose heparin or even aspirin tablets
· use of anti-embolic stockings which stimulate blood flow in the leg veins
· stopping the combined oral contraceptive pill in appropriate cases.
If despite all this a DVT develops, treatment with anti-coagulants can prevent the more serious complication of pulmonary embolism.
Confusion
Being in hospital can be disorientating, especially for the elderly, who may become confused after surgery.
There are many possible causes, such as:
· temporary lack of oxygen
· dehydration
· chest infection
· retention of urine
· pain
· side-effects of drugs
· other coincidental illnesses.
It is disconcerting for families to have a relative who has suddenly become agitated or even aggressive following surgery, but it is usually a very temporary state of affairs. If there is anything they know about the patient (for instance his drinking habits) that might help the staff treat the episode of confusion, it is useful to share the information.
Emotions
With today's modern anaesthetics, people usually feel well and clear-headed when they come round from a general anaesthetic. All the same, patients may feel they are on an emotional roller-coaster after surgery. Even normally stoical souls can feel low or even weepy, often on the third or fourth day after a major operation. Although the exact cause isn't known, this is usually short-lived. Nurses sometimes maintain that one gets worse before one gets better, and that a patient's tears are a reliable sign of their imminent recovery.
It is also common to be a bit light-headed after a general anaesthetic, possibly because of blood pressure changes. This can last for a couple of weeks, and is often worse if one gets up quickly from a seated or lying position. One can faint if rising too quickly, so, unless symptoms are severe, the convalescent should just take the hint and try not to rush things.
Stitches
There are two main kinds of stitches:
· absorbable, which the body itself breaks down
· non-absorbable, which remain intact unless removed.
Surgeons use absorbable material for much of the internal stitches, although non-absorbable material is used for holding bones or tendons together, and for hernia repairs.
The only stitches that most patients are concerned about are those in the skin. Sometimes these are absorbable, but usually they are not, and have to be removed a few days after the operation. Timing of removal varies according to the operation and to each surgeon's individual habits, but in general, abdominal stitches are taken out a week or more after surgery. Stitches on the face are usually removed much sooner. Either a doctor or a nurse may remove stitches, and the business is usually far quicker and less uncomfortable than most first-time patients imagine it will be.
Other forms of wound closure
In addition to stitches, other forms of wound closure material may be used if appropriate, e.g. surgical staples, glue and steri-strips.
Bedsores
Older patients may have memories of bedsores (more accurately known as pressure sores). These can occur after prolonged immobility in bed, but they are now rare because nursing care has improved dramatically, and because patients are becoming mobile much more quickly after surgery. In fact the whole experience of being a surgical patient has changed in the last few decades. The vast majority of people who have an operation nowadays have very few complications at all, and enjoy a much improved quality of life afterwards.
ESSENTIAL HYPERTENSION
WHAT IS IT?
Hypertension is high blood pressure. Hypertension affects over 50 million Americans between the ages of 25 and 55. Untreated, hypertension affects the heart, the brain and the kidneys. Individuals with hypertension often die prematurely.
A specific cause can rarely be found, though family history is often a precursor. Obesity, high alcohol consumption, cigarette smoking, a high-stress occupation or environment, and the use of certain anti-inflammatory drugs can precipitate or worsen high blood pressure in predisposed individuals. An estimated ten to fifteen percent of white adults and twenty to thirty percent of black adults develop high blood pressure, which is a known contributor to the risk of stroke and heart disease.
HOW IS IT DIAGNOSED?
History: A family history is often present. Individuals can have mild to moderately high blood pressure without being aware of it. As it worsens, high blood pressure can cause headaches, fatigue, confusion, blurred vision, and occasionally nausea and vomiting.
Physical exam: Upper (systolic) and lower (diastolic) blood pressure readings may be elevated. Two blood pressure readings will often be taken in a single visit, one while the individual is standing and the second while the individual is lying down. Other findings may include retinal changes, irregular heartbeats or sounds, irregular pulse, blurred vision.
Tests: Basic laboratory tests for a diagnosis of hypertension typically include a blood count, urinalysis, renal function test and measurement of blood sugar after fasting. Further tests are usually used to rule out possible underlying causes of hypertension. If hypertensive cardiovascular disease is suspected, an echocardiogram or a chest x-ray to closely examine the left ventricle of the heart may be ordered.
HOW IS IT TREATED?
Treatment varies according to the readings obtained in a blood pressure evaluation and whether any risk factors are present. Individuals with high normal or elevated blood pressures can often be treated successfully with individual lifestyle modifications such as weight loss, exercise, decrease in salt intake and alcohol consumption, and stopping smoking.
More severe hypertension with accompanying risk factors typically calls for drug therapy (such as diuretics and beta-blockers, and occasionally calcium channel blockers, ACE inhibitors, and alpha-blockers) to reduce readings to lower, safer levels. The choice of the drug or drugs is usually based on the individual's age, race, sex and lifestyle, and the presence of any other illness or disorder.
WHAT MIGHT COMPLICATE IT?
Complications include heart attack, stroke or renal failure.
PREDICTED OUTCOME
Untreated, hypertension can result in death and is known to shorten lives by ten to twenty years. Approximately 95% of individuals are able to lower their blood pressure at least moderately by making certain lifestyle changes, and often dramatically with drug therapy. If treatment is successful, the individual may be able to lower the drug dosage to maintain a healthy blood pressure.
ALTERNATIVES
Treatable causes of hypertension such as pheochromocytoma, primary aldosteronism, severe cases of Cushing's syndrome and acromegaly should be ruled out.
APPROPRIATE SPECIALISTS
Internist, cardiologist, dietitian, and endocrinologist.
WHAT IS IT?
Hypertension is high blood pressure. Hypertension affects over 50 million Americans between the ages of 25 and 55. Untreated, hypertension affects the heart, the brain and the kidneys. Individuals with hypertension often die prematurely.
A specific cause can rarely be found, though family history is often a precursor. Obesity, high alcohol consumption, cigarette smoking, a high-stress occupation or environment, and the use of certain anti-inflammatory drugs can precipitate or worsen high blood pressure in predisposed individuals. An estimated ten to fifteen percent of white adults and twenty to thirty percent of black adults develop high blood pressure, which is a known contributor to the risk of stroke and heart disease.
HOW IS IT DIAGNOSED?
History: A family history is often present. Individuals can have mild to moderately high blood pressure without being aware of it. As it worsens, high blood pressure can cause headaches, fatigue, confusion, blurred vision, and occasionally nausea and vomiting.
Physical exam: Upper (systolic) and lower (diastolic) blood pressure readings may be elevated. Two blood pressure readings will often be taken in a single visit, one while the individual is standing and the second while the individual is lying down. Other findings may include retinal changes, irregular heartbeats or sounds, irregular pulse, blurred vision.
Tests: Basic laboratory tests for a diagnosis of hypertension typically include a blood count, urinalysis, renal function test and measurement of blood sugar after fasting. Further tests are usually used to rule out possible underlying causes of hypertension. If hypertensive cardiovascular disease is suspected, an echocardiogram or a chest x-ray to closely examine the left ventricle of the heart may be ordered.
HOW IS IT TREATED?
Treatment varies according to the readings obtained in a blood pressure evaluation and whether any risk factors are present. Individuals with high normal or elevated blood pressures can often be treated successfully with individual lifestyle modifications such as weight loss, exercise, decrease in salt intake and alcohol consumption, and stopping smoking.
More severe hypertension with accompanying risk factors typically calls for drug therapy (such as diuretics and beta-blockers, and occasionally calcium channel blockers, ACE inhibitors, and alpha-blockers) to reduce readings to lower, safer levels. The choice of the drug or drugs is usually based on the individual's age, race, sex and lifestyle, and the presence of any other illness or disorder.
WHAT MIGHT COMPLICATE IT?
Complications include heart attack, stroke or renal failure.
PREDICTED OUTCOME
Untreated, hypertension can result in death and is known to shorten lives by ten to twenty years. Approximately 95% of individuals are able to lower their blood pressure at least moderately by making certain lifestyle changes, and often dramatically with drug therapy. If treatment is successful, the individual may be able to lower the drug dosage to maintain a healthy blood pressure.
ALTERNATIVES
Treatable causes of hypertension such as pheochromocytoma, primary aldosteronism, severe cases of Cushing's syndrome and acromegaly should be ruled out.
APPROPRIATE SPECIALISTS
Internist, cardiologist, dietitian, and endocrinologist.
Monday, August 11, 2008
Cholesterol
What is cholesterol?
Cholesterol is a fatty substance that is found throughout the body and circulates in the bloodstream. It is vital to the normal functioning of the body and is an important constituent of body cells. It is an essential ingredient of vital body chemicals such as hormones produced by various glands, eg the thyroid and ovaries. It is also a component of certain chemicals such as bile acids, which help in the natural digestive processes of fat taken in the diet.
However, when the level of cholesterol in the bloodstream is high, it becomes one of the causes of 'furring up' of the arteries of the body (a process more correctly called 'atherosclerosis'). The arteries of most concern are those supplying blood to the heart, the brain and the legs, since these are the ones most likely to cause serious problems for the individual if they become narrowed or blocked.
How is cholesterol formed?
Nearly all of the cholesterol in the body is manufactured by the liver, whilst a small amount is derived from the diet, formed from digesting foods which contain fat. This diet-derived fat is of two types, namely saturated and unsaturated.
Cholesterol is a fatty substance that is found throughout the body and circulates in the bloodstream. It is vital to the normal functioning of the body and is an important constituent of body cells. It is an essential ingredient of vital body chemicals such as hormones produced by various glands, eg the thyroid and ovaries. It is also a component of certain chemicals such as bile acids, which help in the natural digestive processes of fat taken in the diet.
However, when the level of cholesterol in the bloodstream is high, it becomes one of the causes of 'furring up' of the arteries of the body (a process more correctly called 'atherosclerosis'). The arteries of most concern are those supplying blood to the heart, the brain and the legs, since these are the ones most likely to cause serious problems for the individual if they become narrowed or blocked.
How is cholesterol formed?
Nearly all of the cholesterol in the body is manufactured by the liver, whilst a small amount is derived from the diet, formed from digesting foods which contain fat. This diet-derived fat is of two types, namely saturated and unsaturated.
The saturated form is found mainly in the following foods:
- meat and meat products (beef, lamb, pork, suet, lard dripping) derived from animal sources
- dairy products (milk, butter, cream, cheese)
- hard margarine and cooking fat
- cakes, biscuits, puddings and chocolate.
The unsaturated form is found in the following:
- vegetable oils
- soft margarine
- oily fish eg herring, mackerel, tuna, pilchards and sardines.
The more saturated fats that are eaten the higher the blood cholesterol is likely to be, and therefore the higher the risk of developing coronary heart disease (as described later).
Cholesterol is transported around the body in the bloodstream by attachment to specific proteins, called lipoproteins, along with other small chemical substances derived from the breakdown of fat. These substances are known as triglycerides.
There are two main types of lipoproteins, each containing different amounts of protein and cholesterol. These are high-density lipoprotein (HDL), which contains a high amount of protein and a relatively small amount of cholesterol, and low-density lipoprotein (LDL) containing a smaller amount of protein and a high amount of cholesterol. These are the major cholesterol carrying substances in the bloodstream and about 75 per cent of the circulating cholesterol is carried in the form of LDL, whilst HDLs carry about 25 per cent of the circulating cholesterol. The significance of the different types of cholesterol is that LDL is 'bad' since it tends to carry cholesterol around the body, high levels of which then result in the depositing of fat onto the artery walls as described above. On the other hand, HDL cholesterol is thought to be 'good' because this tends to carry fats from the body to the liver where it is broken down into other substances and is eventually eliminated from the body. Therefore, when cholesterol levels are measured, the doctor sometimes asks for the result to be divided into HDL and LDL fractions to assess a more accurate measurement of the harmful LDL type. However, high cholesterol levels are most likely to consist mainly of the LDL type.
What causes high blood cholesterol?
What constitutes a 'high' cholesterol level varies from person to person and is explored later in this fact sheet but there are a number of causes of abnormally raised cholesterol levels. These are set out below.
An inherited tendency: These are called 'familial hyperlipidaemias' and there are many different types but they all result in the inheritance of abnormally high levels of cholesterol or another group of fats carried in the blood called the triglycerides. Familial hyperlipidaemia is to be suspected in anyone who has a close family history of heart disease such as angina or heart attacks at an early age.
Certain conditions which are often, but not always, associated with high cholesterol levels: These include diabetes, under activity of the thyroid gland, excessive alcohol consumption, kidney failure and certain conditions of the pancreas (the gland in the abdomen involved with the production of insulin). These account for about 10 to 20 per cent of high cholesterol levels and are called secondary hyperlipidaemias, as they are secondary to another condition.
Poor diet: A diet rich in fatty food and carbohydrates such as cakes, biscuits, sweets, etc., is liable to increase the cholesterol level. However, as mentioned at the beginning, diet only plays a moderate part in the overall level of cholesterol in the blood.
Why is high blood cholesterol important?
If cholesterol is present in abnormally high quantities in the circulating blood, the body is unable to process this amount of fat and so excess cholesterol builds up in the body. It may be deposited in various parts of the body, especially on the walls of the arteries where it forms clumps, or plaques. These can severely narrow and eventually block off the blood supply in the arteries. This results in a loss of oxygen and glucose supply to tissues and muscles supplied by these arteries, which can then become damaged.
The most important area where this build up can occur is in the coronary (heart) arteries. These arteries form a network of blood vessels around the heart. If they are narrowed from cholesterol deposition, this causes the heart muscle to become starved of oxygen. Oxygen starvation may occur temporarily during exercise (resulting in angina pain on exertion) or there may be permanent loss of blood supply that results in a heart attack due to heart muscle damage. A similar problem can occur in the arteries in the legs, where impaired circulation can lead to pain when walking (called intermittent claudication), and if very severe can actually stop the circulation altogether. The significance of the different types of cholesterol is that LDL is 'bad' since it tends to carry cholesterol around the body, high levels of which then result in the depositing of fat onto the artery walls as described above. On the other hand, HDL cholesterol is thought to be 'good' because this tends to carry fats from the body to the liver where it is broken down into other substances and is eventually eliminated from the body. Therefore, when cholesterol levels are measured, the doctor sometimes asks for the result to be divided into HDL and LDL fractions to assess a more accurate measurement of the harmful LDL type. However, high cholesterol levels are most likely to consist mainly of the LDL type. There is no doubt that lowering of the blood cholesterol level will reduce the risk of developing coronary heart disease but the lowest cholesterol level which is desirable is, as yet, unknown.
When should it be measured?
There are often no symptoms associated with high cholesterol and there is ongoing debate as to whether routine measurement should form part of the health screening examinations. There are, however, groups at risk who should be screened:
- patients with a family history of high cholesterol levels in either parent or siblings. The condition is likely to be inherited as mentioned above.
- patients who have a family history of premature (or early onset) heart disease (heart attacks or angina), or high blood pressure.
- patients who are very overweight, smokers, or who themselves have suffered heart problems such as angina or heart attacks. Lowering of cholesterol levels is especially important in these people.
- those who have other medical conditions such as alcohol problems, diabetes, or kidney disease, all of which can be associated with a high blood cholesterol.
- patients who have received coronary artery bypass surgery or who have had an angioplasty (a procedure to open up the arteries to the heart).
- people who have outward signs of a high cholesterol. These signs are unusual as most people who have a high cholesterol do not develop these and paradoxically, some people with these signs do not have high cholesterol. These signs include a white rim around the outside of the iris (known as 'arcus') and whitish deposits commonly around the eyelids and occasionally in other parts of the body.
How is it measured?
This involves a simple blood test. It is traditional to ask for the sample to be taken when the patient has fasted for at least 12-14 hours. This is partly because the reading is slightly more accurate when it is performed on a fasting blood sample but also because it is almost always done in conjunction with measurement of the other type of fats carried in the blood, the blood level of which is very much affected by whether the person has just eaten or not. These other fats are called triglycerides, which have a similar effect on the arteries as cholesterol if they are found in increased amounts in the blood.
If the cholesterol level is found to be increased, the test is usually repeated to ensure that the original result was an accurate one. At the same time, the doctor may check for any likely contributory causes for the high cholesterol, such as thyroid failure or diabetes as mentioned above. If it is thought to be helpful, the LDL and HDL fractions may also be requested.
What level of cholesterol requires treatment?
Since the discovery of the significance of raised cholesterol levels in the blood, there has been a lot of controversy surrounding this question and over the years the advice seems to have changed. However, a consensus of opinion is forming which is based on the fact that the cholesterol level has to be seen as only one of several risk factors for heart disease and atherosclerosis. There are now methods of assessing each person's level of risk. This is based on such things as a person's age, their sex, whether or not they smoke, their blood pressure and cholesterol level. Whether or not treatment of the cholesterol level is required is now based on that person's level of risk. Therefore, an acceptable level of cholesterol for one person will be a level that requires treatment in another person. There is no longer one single cholesterol level above which everyone would need treatment.
The experts in this field advise that the level of cholesterol should be measured. If the level is above five mmol per litre of blood it should be lowered in the following groups of people:
- diabetics
- people with a previous history of heart disease such as angina, heart attack(s) or procedures to treat these such as coronary artery bypass surgery or angioplasty (to open up the heart arteries)
- people who are estimated to have a 30 per cent or greater risk of developing coronary heart disease (angina or heart attacks) over the next 10 years. (In future this may be widened to include those with a 10 year risk of 15 per cent or more, but this would include about 25 per cent of the adult population and this would cost the country a great deal as a greater number of cholesterol lowering drugs would need to be prescribed).
In those people listed above, the level of cholesterol aimed for is below 5 mmol per litre of blood or a reduction of 30 per cent (whichever is greater). There is some discussion amongst specialists as to whether these levels should be even lower in certain groups of people.
What is the treatment for raised cholesterol?
There is a small group of patients whose raised cholesterol level is due to another condition, as mentioned above, such as thyroid gland failure or excessive alcohol intake. In these people, the initial treatment is of the underlying condition, since this will almost always result in a natural return of the cholesterol level to normal.
In those people with primary hypercholesterolaemia (ie high cholesterol which is not the result of another illness), which make up the majority of cases, treatment involves dietary modification and where necessary, tablets to control obesity and reduce the cholesterol level.
Dietary modification: Research has shown that the amount of fat in the diet, and particularly the amount of saturated fat, has a greater effect on the level of cholesterol in the blood than the actual amount of cholesterol in the food someone eats. Therefore there are some foods which, although high in cholesterol, are alright to eat in moderation. These include eggs and prawns both of which are high in cholesterol but low in saturated fat. Seafood also contains healthy fatty acids called omega 3 fatty acids. Therefore weight reduction and avoidance of saturated fats in the diet are the main factors which will reduce the level of cholesterol in the blood.
The following measures will aid in this:
- Use skimmed or semi skimmed milk.
- Grill, bake or steam foods rather than frying.
- Eat smaller portions of meat and trim off any excess fat.
- Eat low fat cheeses and margarine and spread margarine and butter thinly.
- Do not add fat or oil during cooking.
- Make sure low fat foods are labelled 'low in saturated fat' if a specific low cholesterol diet is required.
Foods high in saturated fats and therefore best avoided or eaten in small amounts include:
- Fatty cuts of meat, black pudding, salami and sausages.
- Butter, lard and cream.
- Hard cheeses.
Food high in unsaturated fats can help to reduce cholesterol levels and include:
- Oily fish.
- Vegetable oils.
- Nuts and seeds.
Medication: This works by lowering the blood cholesterol, the triglyceride level, or both. There is now overwhelming evidence that lowering the blood cholesterol by diet and/or drugs will reduce the chances of patients developing coronary artery disease. Cholesterol lowering tablets are not a substitute for a low fat diet. There are a number of groups of these drugs.
- Anion exchange resins: These are agents which bind bile acids in the bowel and interfere with absorption and digestion of fat and therefore reduce the amount of circulating cholesterol. These include drugs such as cholestyramine. This group of drugs is not often used since they have been generally superseded by the statins.
- Statins: These work by reducing the production of cholesterol in the liver with the result that the level of cholesterol in the blood is reduced. These are now the most commonly prescribed cholesterol-lowering drugs and include such drugs as simvastatin, atorvastatin and pravastatin.
- The fibrates: These tend only to be used if maximum doses of a statin are not producing the required level of cholesterol-lowering effect or if the main problem is a high level of the other type of fat, the triglycerides. Their main action is to reduce the triglycerides in the blood although they do lower cholesterol as well. This group includes such drugs as ciprofibrate.
- Ezetimibe: This is a new drug which works by reducing the absorption of cholesterol from the intestine. It can be given either on its own to those patients who are not suitable for treatment with statins or as an addition to statin treatment if further cholesterol lowering is needed.
All these drugs work by lowering the blood cholesterol, but each may be used appropriately in different circumstances.
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