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High CholesterolCholesterol is a waxy, fatlike substance that your body needs to function normally. Cholesterol is naturally present in cell walls or membranes everywhere in the body, including the brain, nerves, muscles, skin, liver, intestines, and heart. Your body uses cholesterol to produce many hormones, vitamin D, and the bile acids that help to digest fat. It takes only a small amount of cholesterol in the blood to meet these needs. If you have too much cholesterol in your bloodstream, the excess may be deposited in arteries, including the coronary (heart) arteries, where it contributes to the narrowing and blockages that cause the signs and symptoms of heart disease. Coronary heart disease (CHD) is caused by cholesterol and fat being deposited in the walls of the arteries that supply nutrients and oxygen to your heart. Like any muscle, the heart needs a constant supply of oxygen and nutrients, which are carried to it by the blood in the coronary arteries. Fixed narrowing that is often calcified (hardened) usually cause angina (chest pain). Less severe narrowing may contain unstable blockages called atherosclerotic or fatty plaque. Unstable atherosclerotic plaque can rupture, resulting in clot formation, no blood flow, and a heart attack. If enough oxygen-carrying blood is blocked from reaching your heart, you may experience a type of chest pain called angina. If the blood supply to a portion of the heart is completely cut off by total blockage of a coronary artery, the result is a heart attack. This is usually due to a sudden closure of the artery from a blood clot forming on top of unstable plaque. A simple blood test checks for high cholesterol. Simply knowing your total cholesterol level is not enough. A complete lipid profile measures your LDL (low-density lipoprotein [the bad cholesterol]), total cholesterol, HDL (high-density lipoprotein [the good cholesterol]), and triglycerides—another fatty substance in the blood. Government guidelines say healthy adults should have this analysis every 5 years. A desirable total cholesterol level is 200 mg/dL or lower. A desirable LDL is 100 mg/dL (130-159 is borderline high; 160 is high; 190 is very high). HDL, the "good cholesterol," should be around 40 mg/dL or greater. With HDL, the higher the number, the better, and 60 mg/dL is protective against heart disease. Too many people have high levels of total cholesterol and LDL (the bad cholesterol). A diet high in saturated fat (a type of fat found mostly in foods that come from animals and certain oils) raises LDL levels more than anything else in your diet. You also eat cholesterol in your diet, although the effect of saturated fat in the diet is greater than the effect of dietary cholesterol. Trans-fatty acids (seen in processed foods and many "fast foods") can also increase LDL levels. Dietary cholesterol is found only in foods from animal products. Genetic factors combined with eating too much saturated fat and cholesterol are the main reasons for high levels of cholesterol that lead to heart attacks. Reducing the amount of saturated fat and cholesterol you eat is an important step in reducing your blood cholesterol levels. Research confirms the dangers when your cholesterol levels are too high. The Framingham Heart Study established that high blood cholesterol is a risk factor for coronary heart disease (CHD). Results of the Framingham study showed that the higher your cholesterol level, the greater your risk. Several studies have confirmed a direct link between high blood cholesterol and CHD. The Lipid Research Clinics-Coronary Primary Prevention Trial (LRC-CPPT) first showed that lowering total and LDL (bad) cholesterol levels significantly reduces coronary heart disease. A series of more recent trials of cholesterol-lowering using statin drugs have conclusively demonstrated that lowering total cholesterol and LDL cholesterol reduces your chance of having a heart attack, needing bypass surgery or angioplasty, and dying of CHD-related causes. Recent studies have shown that lowering cholesterol in people without heart disease greatly reduces their risk for developing heart disease in the first place. This is true for those with high cholesterol levels and for those with average cholesterol levels. In 1994, the Scandinavian Simvastatin Survival Study (4S) was the first study to show that people who took the cholesterol-lowering class of drugs called statins (in this case, simvastatin) reduced their risk for major CHD events (such as a heart attack) by 34%, CHD deaths by 42%, and all deaths by 30% in people with known coronary heart disease and high blood cholesterol levels, compared with people who were given a placebo (a dummy pill that looks exactly like the medication being tested). This has been called "secondary prevention," or prevention of a second heart attack, because the study involved people with known heart disease, many of whom had already had at least one heart attack. A 1995 study called the West of Scotland Coronary Prevention Study (WOSCOPS) found that lowering cholesterol reduced the number of heart attacks and deaths from cardiovascular causes in men with high blood cholesterol levels who had not had a heart attack. For 5 years, more than 6,500 men with total cholesterol levels of 249-295 mg/dL were given either a cholesterol-lowering drug or a placebo along with a cholesterol-lowering diet. The drug that was given is known as a statin (pravastatin), and it reduced total cholesterol levels by 20% and LDL (bad) cholesterol levels by 26%. The study found that the overall risk of having a nonfatal heart attack or dying from CHD was reduced by 31% in those who received the statin. The need for bypass surgery or angioplasty was reduced by 37%, and deaths from all cardiovascular causes were reduced by 32%. A very important finding was that deaths from causes other than heart disease were not increased, and overall deaths from all causes were reduced by 22%. This is called primary prevention because the study subjects had not previously had a heart attack. In 1996, the CARE study of CHD patients with "normal" cholesterol (LDL average of 138 mg/dL) values and a recent heart attack was associated with 24% reduction in CHD events. Overall death rates were not affected. The drug used was pravastatin. In 1998, the results of the Air Force/Texas Coronary Atherosclerosis Prevention Study (AFCAPS/TexCAPS) showed that lowering cholesterol in generally healthy men and women (no previous heart disease) with average cholesterol levels reduced their risk for a first-time major coronary event (such as a heart attack) by 37%. Lovastatin was the drug used in this study. In the 1998 LIPID study, men and women with known CHD and mild-to-moderate elevations of LDL lowered their risk of death by 22%, CHD deaths by 24%, and death by CHD or nonfatal heart attack by 24%. Pravastatin was the drug used in this study. The Heart Protection Study, published in 2002, examined men and women of all ages at high risk for heart disease irrespective of their cholesterol levels. Simvastatin treatment reduced CHD events by 24%. This study has caused some experts to suggest that everyone at high risk for CHD would benefit from statin therapy, regardless of their blood cholesterol levels. The National Health and Nutrition Examination Survey III (NHANES III), carried out from 1988-1991, discovered that 26% of American adults had high blood cholesterol concentrations, and 49% had desirable values. Who has high cholesterol? Throughout the world, cholesterol levels (measured in the blood) vary widely. Generally, people who live in countries where blood cholesterol levels are lower, such as Japan, have lower rates of heart disease. Countries with very high cholesterol levels, such as Finland, have very high rates of coronary heart disease. However, some populations with similar total cholesterol levels have very different heart disease rates, suggesting that other factors also influence risk for coronary heart disease. High cholesterol is more common in men younger than 55 years and in women older than 55 years. The risk for high cholesterol increases with age. High Cholesterol Causes Several drugs and diseases can bring about high cholesterol, but, for most people, a high-fat diet and inherited risk factors may be the main causes. Your doctor will rule out the possibility that you have an underactive thyroid or kidney or liver disease. Heredity: Your genes influence how high your LDL (bad) cholesterol is by affecting how fast LDL is made and removed from the blood. One specific form of inherited high cholesterol that affects 1 in 500 people is called familial hypercholesterolemia, which often leads to early heart disease. But even if you do not have a specific genetic form of high cholesterol, genes play a role in influencing your LDL cholesterol level. Weight: Excess weight may modestly increase your LDL (bad) cholesterol level. If you are overweight and have a high LDL cholesterol level, losing weight may help you lower it. Weight loss especially helps to lower triglycerides and raise HDL (good) cholesterol levels. Physical activity/exercise: Regular physical activity may lower triglycerides and raise HDL cholesterol levels. Age and sex: Before menopause, women usually have lower total cholesterol levels than men of the same age. As women and men age, their blood cholesterol levels rise until about 60-65 years of age. After about age 50 years, women often have higher total cholesterol levels than men of the same age. Alcohol use: Moderate (1-2 drinks daily) alcohol intake increases HDL (good) cholesterol but does not lower LDL (bad) cholesterol. Doctors don't know for certain whether alcohol also reduces the risk of heart disease. Drinking too much alcohol can damage the liver and heart muscle, lead to high blood pressure, and raise triglyceride levels. Because of the risks, alcoholic beverages should not be used as a way to prevent heart disease. Mental stress: Several studies have shown that stress raises blood cholesterol levels over the long term. One way that stress may do this is by affecting your habits. For example, when some people are under stress, they console themselves by eating fatty foods. The saturated fat and cholesterol in these foods contribute to higher levels of blood cholesterol. High Cholesterol Symptoms High cholesterol is usually discovered on routine screening and has no symptoms. It is more common if you have a family history of it, but lifestyle factors (such as eating a diet high in saturated fat) clearly play a major role. If you have a routine blood test during a physical exam or while attending a health fair or screening at a shopping center, your blood may reveal a high total cholesterol level, which would require further testing to determine your LDL, HDL, and triglyceride levels (this is known as a lipid panel). The National Cholesterol Education Program guidelines suggest that everyone aged 20 years and older should have their blood cholesterol level measured at least once every 5 years. It is best to have a blood test called a lipoprotein profile to find out your cholesterol numbers. This blood test is done after a 9- to 12-hour fast and gives information about the following items: Total cholesterol is the sum of all the cholesterol in your blood (serum cholesterol). The higher your total cholesterol, the greater your risk for heart disease. Less than 200 mg/dL is a desirable level that puts you at lower risk for heart disease. A cholesterol level of 200 mg/dL or greater increases your risk. A level of 200-239 mg/dL is termed borderline high. A level of 240 mg/dL and above is considered high blood cholesterol. Your risk at this level is twice the risk of heart disease compared with someone whose total cholesterol level is 200 mg/dL. Low-density lipoprotein (LDL) is considered the "bad" cholesterol. Cholesterol travels in the blood in packages called lipoproteins. Just like oil and water, cholesterol, which is not soluble in water, and blood, which is watery, do not mix. In order to be able to travel in the bloodstream, the cholesterol made in the liver is combined with protein and other substances, making a lipoprotein. This lipoprotein then carries the cholesterol through the bloodstream. LDLs carry most of the cholesterol in the blood, and the cholesterol from LDL is the main source of damaging buildup and blockage in your arteries. Thus, the more LDL cholesterol you have in your blood, the greater your risk of heart disease. Reducing your LDL cholesterol is the main goal of cholesterol-lowering treatment. The lower, the better. Less than 100 mg/dL is considered optimal (best). A level of 100-129 mg/dL is near optimal/above optimal. A level of 130-159 mg/dL is borderline high. A level of 160-189 mg/dL is high. A level of 190 mg/dL and above is very high. High-density lipoprotein (HDL) is called the "good" cholesterol. HDLs carry cholesterol in the blood from other parts of the body back to the liver, which leads to its removal from the body. In this way, HDL helps keep cholesterol from building up in the walls of the arteries. If it is not possible to have a lipoprotein profile done, knowing your total cholesterol and HDL cholesterol can give you a general idea about your cholesterol levels. If your total cholesterol is 200 mg/dL or more, or if your HDL is less than 40 mg/dL, you will need to have a fasting lipoprotein profile done. Less than 40 mg/dL is considered a major risk factor for heart disease. A level of 40-59 mg/dL is better. A level of 60 mg/dL and above is thought to protect you against heart disease. Triglycerides are a form of fat carried through the bloodstream. Most of your body's fat is in the form of triglycerides stored in fat tissue. Only a small portion of your triglycerides is found in the bloodstream. High blood triglyceride levels alone do not necessarily cause atherosclerosis (the buildup of cholesterol and fat in the walls of arteries). But some lipoproteins that are rich in triglycerides also contain cholesterol, which causes atherosclerosis in some people with high triglycerides; plus, high triglyceride levels are often accompanied by other factors (such as low HDL and/or a tendency toward diabetes) that raise heart disease risk. Therefore, high triglycerides may be a sign of a lipoprotein problem that contributes to heart disease. Less than 150 mg/dL is normal. A level of 150-199 mg/dL is borderline high. A level of 200-499 mg/dL is high. A level of 500 mg/dL or above is very high. Medical Treatment If following a low-saturated fat, low-cholesterol diet, increasing your physical activity, and losing weight have not lowered your risk for developing coronary heart disease after about 3 months, your doctor may consider prescribing a cholesterol-lowering medication. If your doctor prescribes medicine, you must still (1) follow your cholesterol-lowering diet, (2) be more physically active, (3) lose weight if you are overweight, and (4) control or stop all of your other coronary heart disease risk factors (including high blood pressure, diabetes, and smoking). Taking all these steps together may lessen the amount of medicine you need or make the medicine work better, which reduces your risk for developing coronary heart disease. Your doctor may prescribe medication for you from the following categories: Statins: Statins lower LDL cholesterol levels more than other types of drugs. Statins inhibit an enzyme, HMG-CoA reductase, that controls the rate of cholesterol production in the body. These drugs lower cholesterol by slowing down the production of cholesterol and by increasing the liver's ability to remove the LDL cholesterol already in the blood. Statins were used to lower cholesterol levels in many of the clinical trials discussed previously. The large reductions in total and LDL cholesterol produced by these drugs resulted in significant reductions in heart attacks and coronary heart disease deaths. Thanks to their safety and to their ability to lower LDL cholesterol the number of coronary heart attacks and heart disease deaths, statins have become the drugs most often prescribed for lowering cholesterol. Studies using statins have reported 20-60% lower LDL cholesterol levels in people taking them. Statins also reduce high triglyceride levels modestly and produce a mild increase in HDL cholesterol. The statins are most often given in a single dose at the evening meal or at bedtime. It is important that these medications be given in the evening to take advantage of the fact that the body makes more cholesterol at night than during the day. Newer, long-acting statins, such as atorvastatin (Lipitor), may be administered in the morning. You should begin to see results from the statins after several weeks, with a maximum effect in 4-6 weeks. After about 6-8 weeks, your doctor can do the first check of your LDL cholesterol while you are on the medication. A second measurement of your LDL cholesterol level must be averaged with the first for your doctor to decide whether your dose of medicine should be changed to help you meet your goal. The statins are well tolerated, and serious side effects are rare (liver problems, muscle soreness, pain, weakness). If this happens, or if you have brown urine, contact your doctor right away to get blood tests for possible muscle problems. Rarely, widespread muscle breakdown, known as rhabdomyolysis, can occur, usually in people who are taking other drugs that interfere with the breakdown of the statin and in people with advanced kidney problems. This is a medical emergency. So, if you have diffuse muscle pain and weakness, or brown urine (a possible sign of muscle breakdown), contact your doctor immediately and stop taking the statin medication. Some people experience an upset stomach, gas, constipation, and abdominal pain or cramps. These symptoms are usually mild to moderate and generally go away as your body adjusts. Monitoring of liver function tests is usually done in patients taking statins. Statin drugs include the following: Atorvastatin (Lipitor): Atorvastatin is a highly effective drug in lowering LDL cholesterol when used in large doses (though high doses are not commonly used). Atorvastatin has been shown to reduce coronary heart disease events in people with hypertension. Fluvastatin (Lescol): Fluvastatin is the least potent statin drug. Fluvastatin has been shown to reduce coronary heart disease events in people after percutaneous coronary intervention or balloon angioplasty. Lovastatin (Mevacor, Altocor): Lovastatin is the first statin to be approved by the FDA. Lovastatin is proven to reduce coronary heart disease events. Pravastatin (Pravachol): Pravastatin is the most studied statin in clinical trials and is also proven to reduce coronary heart disease events and deaths. Simvastatin (Zocor): Simvastatin is the first drug shown to reduce the total death rate by reducing LDL concentrations in people with coronary heart disease. Simvastatin is proven to reduce coronary heart disease events and deaths. Rosuvastatin (Crestor): Rosuvastatin is the newest statin (cholesterol-lowering drug) approved in the United States and the most potent of the statin drugs. It is particularly effective in lowering very high cholesterol levels or when a cholesterol level has not been decreased with other drugs. Bile acid sequestrants: These drugs bind with cholesterol-containing bile acids in the intestines and are then eliminated in the stool. The usual effect of bile acid sequestrants is to lower LDL cholesterol by about 10-20%. Small doses of sequestrants can produce useful reductions in LDL cholesterol. Bile acid sequestrants are sometimes prescribed with a statin to enhance cholesterol reduction. When these drugs are combined, their effects are added together to lower LDL cholesterol by more than 40%. Cholestyramine (Questran, Questran Light), colestipol (Colestid), and colesevelam (WelChol) are the 3 main bile acid sequestrants currently available. These 3 drugs are available as powders or tablets. They are not absorbed from the gastrointestinal tract, and 30 years of experience with these drugs indicates that long-term use is safe. Bile acid sequestrant powders must be mixed with water or fruit juice and must be taken once or twice (rarely, 3 times) daily with meals. Tablets must be taken with large amounts of fluids to avoid stomach and intestinal problems. Sequestrant therapy may produce a variety of symptoms, including constipation, bloating, nausea, and gas. The bile acid sequestrants are not prescribed as the sole medicine to lower your cholesterol if you have high triglycerides or a history of severe constipation. Although sequestrants are not absorbed, they may interfere with the absorption of other medicines if taken at the same time. You must take other medications at least 1 hour before or 4-6 hours after the sequestrant. You should talk to your doctor about the best time to take this medicine, especially if you take other medications. Cholesterol absorption inhibitors: This new class of drugs was approved in late 2002. The drug inhibits cholesterol absorption in the gut and has few, if any, side effects. Cholesterol absorption inhibitors may rarely be associated with tongue swelling (angioedema). Ezetimibe (Zetia) is the first drug in this class. Ezetimibe reduces LDL cholesterol by 18-20%. It is probably most useful in people who cannot take statins or as an additional drug for people who take statins but who notice side effects when the statin dose is increased. Adding ezetimibe to a statin is equivalent to doubling or tripling the statin dose. Nicotinic acid or niacin: This water-soluble B vitamin improves all lipoproteins when given in doses well above the vitamin requirement. Nicotinic acid lowers total cholesterol, LDL cholesterol, and triglyceride levels, while raising HDL cholesterol levels. There are 2 types of nicotinic acid: immediate release and extended release. The immediate-release form of crystalline niacin is inexpensive and widely accessible without a prescription, but, because of potential side effects, it must not be used for cholesterol lowering without the monitoring of a doctor. (Nicotinamide, another form of niacin, does not lower cholesterol levels and should not be used in place of nicotinic acid.) If you take nicotinic acid to lower cholesterol, your doctor will closely monitor you to avoid complications from this medication. You should not take this medication on your own. You may miss important side effects. Nicotinic acid reduces LDL cholesterol levels by 10-20%, reduces triglycerides by 20-50%, and raises HDL cholesterol by 15-35%. A common and troublesome side effect of nicotinic acid is flushing or hot flashes, which are the result of blood vessels opening wide. Most people develop a tolerance to flushing, which can sometimes be decreased by taking the drug during or after meals or by the use of aspirin or other similar medications prescribed by your doctor 30 minutes prior to taking niacin. The extended-release form may cause less flushing than the other forms. The effect of high blood pressure medicines may also be increased while you are on niacin. If you are taking high blood pressure medication, it is important to set up a blood pressure monitoring system while you are getting used to your new niacin regimen. A variety of gastrointestinal symptoms, including nausea, indigestion, gas, vomiting, diarrhoea, and the activation of peptic ulcers, has been seen with the use of nicotinic acid. Three other major adverse effects include liver problems, gout, and high blood sugar. Risk of the latter 3 complications increases as the dose of nicotinic acid is increased. Your doctor may not prescribe this medicine for you if you have diabetes because of the effect on your blood sugar. Extended-release niacin is often better tolerated than crystalline niacin. However, its liver toxicity (liver damage) is probably greater. Therefore, the dose of extended-release niacin is usually limited to 2 grams per day. If you take niacin, you should increase the dose very slowly. Recently, a combination product of extended-release niacin (Niaspan) and lovastatin has been released (Advicor). The side effects of this combination product mirror those of the 2 drugs taken individually. Fibrates: These cholesterol-lowering drugs are primarily effective in lowering triglycerides and, to a lesser extent, increasing HDL cholesterol levels. Gemfibrozil (Lopid), the fibrate most widely used in the United States, can be effective for people with high triglyceride levels. However, gemfibrozil is not very effective for lowering LDL cholesterol. It is used in some people with heart disease for whom a goal of treatment is lowering triglycerides or raising HDL. Another fibrate is fenofibrate (Tricor), which is more effective at lowering triglycerides and LDL cholesterol. Some people taking fibrates may have side effects such as stomach or intestinal discomfort. Fibrates may increase the likelihood of your developing gallstones and can increase the effect of medications that thin the blood. Your doctor will monitor you. The dose of fibrates should be reduced if your kidney function declines. Hormone replacement therapy: The risk of heart disease is increased in women after menopause. The increasing risk may be related to loss of oestrogen that comes with menopause. Previously, women might have been treated with hormone replacement therapy (replacing the oestrogen and perhaps progestin). Recent studies have found that women on hormone replacement therapy did not benefit by having a lower rate of heart-related events compared with women treated with placebo. Therefore, postmenopausal women who are judged by their doctor to need drug treatment to reduce their risk for heart disease should consider cholesterol-lowering drugs instead of hormones because cholesterol-lowering drugs have been shown to be safe and effective in lowering cholesterol and reducing coronary heart disease risk. Self-Care at Home If you have high lipoproteins and thus high cholesterol, your doctor will work with you to target your levels with dietary and drug treatment. Depending on your risk factors for heart disease, your target goals may differ for lowering your LDL cholesterol. Diet: The National Cholesterol Education Program has created dietary guidelines. NCEP dietary guidelines Total fat - Less than 30% of calories Saturated fat - Less than 7% of calories Polyunsaturated fat - Less than or equal to 10% of calories Monounsaturated fat - Approximately 10-15% of calories Cholesterol - Less than 200 milligrams per day Carbohydrates - 50-60% of calories The new guidelines are more stringent than previous ones, mandating more restriction on saturated fat and dietary cholesterol. Some people are able to reduce fat and dietary cholesterol with vegetarian diets. Dean Ornish and his colleagues have shown the value of a very strict fat-reduction diet in unblocking coronary arteries. Whether these dietary restrictions are realistic for most Americans is debatable. Moreover, such a diet also reduces HDL and raises triglyceride levels. Stanol esters can be included in the diet and may reduce LDL by about 14%. Products containing stanol esters include margarine substitutes (marketed as brand names Benecol and Take Control). People with higher triglycerides may benefit from a diet that is higher in monounsaturated fat and lower in carbohydrates, particularly simple sugars. A common source of monounsaturated fat is olive oil. Activity: Although exercise has little effect on LDL, aerobic exercise may improve insulin sensitivity, HDL, and triglyceride levels and may thus reduce your heart risk. People who exercise and control their diet appear to be more successful in long-term lifestyle modifications that improve their heart risk profile. Aromatherapy essential oils which can be beneficial are Geranium, Juniper and Rosemary. |
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