High Cholesterol
medical conditions

High Cholesterol

Explore the available health information, treatment context, and integrative evidence for High Cholesterol.

Background
  • High cholesterol, or hypercholesterolemia, is a condition in which there are unhealthy high levels of cholesterol in the blood. It is also called dyslipidemia, hyperlipidemia, and lipid disorder.
  • Too much cholesterol in the blood is a major risk for heart disease, which may lead to a heart attack, heart failure (cannot pump enough blood to the body), and death. High cholesterol levels are also a risk factor for stroke (lack of blood and oxygen to the brain), causing nerve damage.
  • Cholesterol is a soft, waxy, fat-like substance found within the bloodstream and cells of the body. Cholesterol synthesis is a naturally-occurring process that functions to produce membranes for all cells in the body, including those in the brain, nerves, muscles, skin, liver, intestines, and heart. Cholesterol is also converted into steroid hormones, such as the male and female sex hormones (androgens and estrogens) and the adrenal hormones (cortisol, corticosterone, and aldosterone). In the liver, cholesterol is the precursor to bile acids that aid in the digestion of food, especially fats. Cholesterol is also used in making vitamin D.
  • The body obtains cholesterol in two ways, producing the majority of it in the body, and consuming the rest in the diet in the form of animal products, such as meats, poultry, fish, eggs, butter, cheese and whole milk. Plant foods, like fruits, vegetables, and grains, do not contain cholesterol. Fat that occurs naturally contains varying amounts of saturated and unsaturated fat.
  • High cholesterol can cause the formation and accumulation of plaque deposits in the arteries. Plaque is composed of cholesterol, other fatty substances, fibrous tissue, and calcium, normal substances in the blood that become deposited on the artery walls if the blood does not flow properly. When plaque builds up in the arteries, it results in atherosclerosis (hardening of the arteries), or coronary heart disease (CHD). Atherosclerosis can lead to plaque ruptures and blockages in the arteries, which increase the risk for heart attack, stroke, and death, as well as circulation problems such as Raynaud's disease and high blood pressure.
  • The development of plaques and blockages in the arteries involves several steps. When the innermost lining of the arteries (endothelium) is damaged by oxidation, cholesterol particles, proteins and other substances deposit into the damaged wall and form plaques. More cholesterol and other substances incorporate into the plaque and the plaque grows, narrowing the artery. Over time, plaque deposits may grow large enough to interfere with blood flow through the artery (called a blockage). When the arteries supplying the heart with blood (coronary arteries) are blocked, chest pain (angina) may occur; when arteries in the legs are blocked, leg pain or cramping may occur; and when arteries supplying the brain with blood are blocked, stroke may occur.
  • The platelets collecting on the plaque deposit are forming a clot as they try to rush by and get caught because the lining of the artery is rough and the platelets are sticky. Then the clot can break off and travel through the body, getting lodged in vessels of the leg or brain and less commonly the lungs. If a plaque ruptures or tears, a blood clot (thrombus) may develop. If a blood clot completely blocks blood flow through a coronary artery, heart attack (myocardial infarction) occurs; if an artery supplying blood to the brain is completely blocked, stroke occurs.
  • Blood clots can break loose and travel through the bloodstream (called an embolus) and lodge in blood vessels in other parts of the body, including the lungs, heart, brain, and legs. A thromboembolus is when the blood clot lodges in vessels.
  • According to current estimates, 71.3 million people in America have one or more forms of heart disease. High cholesterol affects about 20% of adults over the age of 20 in the United States. The highest prevalence occurs in women between the ages of 65 and 74. The World Health Organization (WHO) reports that high cholesterol contributes to 56% of cases of coronary heart disease worldwide and causes about 4.4 million deaths each year.
  • 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 (such as diet, heredity, and smoking) also influence risk for coronary heart disease.
  • Evidence is accumulating that eating more carbohydrates, especially simpler, more refined carbohydrates such as white breads, sugar, and pasta, may increase levels of triglycerides in the blood, lower high density lipoprotein (HDL or "good" cholesterol), and may increase low density lipoprotein (LDL or "bad" cholesterol). Thus a low fat diet, which often means a higher carbohydrate intake, may actually be an unhealthy change.
Risk Factors and Causes
  • Diet: Saturated fat and cholesterol in foods makes total cholesterol and low density lipoprotein (LDL) levels rise. Cholesterol is consumed in the diet in the form of animal products, such as meats, poultry, fish, eggs, butter, cheese and whole milk. Plant foods, like fruits, vegetables, and grains, do not contain cholesterol. Fat that occurs naturally contains varying amounts of saturated and unsaturated fat.
  • Weight: Being overweight may increase "bad" cholesterol levels and is a risk factor for heart disease. Losing weight may help lower LDL, triglyceride, and total cholesterol levels, as well as raise HDL. Individuals with a large waist measurement (more than 40 inches for men and more than 35 inches for women) are at high risk for heart disease.
  • Physical activity: A lack of physical activity is a risk factor for heart disease. Exercise helps strengthen the heart and blood vessels. Exercising regularly can help lower LDL (bad) cholesterol and raise HDL (good) cholesterol levels. Being physically active for at least 30 minutes on most, if not all, days may help with reducing the risk of developing high cholesterol and coronary heart disease.
  • Age and gender: Cholesterol levels rise with age, due to various factors including hormonal changes, diet, and general health. Before the age of menopause, women have lower total cholesterol levels than men of the same age. After the age of menopause, women's LDL levels tend to rise due to hormonal imbalances. As a rule, women have higher HDL cholesterol levels than men do. The female sex hormone estrogen tends to raise HDL cholesterol, which may help explain why pre-menopausal women are usually protected from developing heart disease. Estrogen production is highest during the childbearing years (20s to 40s). Women also tend to have higher triglyceride levels. As people get older and/or gain weight, their triglyceride and cholesterol levels tend to rise. Evidence reports that the atherosclerotic process (buildup of fatty plaque in arteries) begins in childhood and progresses slowly into adulthood. Then it often leads to coronary heart disease, the single leading cause of death in the United States. Eating patterns and genetics affect blood cholesterol levels in children and increase the risk of developing heart disease later in life.
  • Heredity: Genetics partially determine how much cholesterol is produced endogenously. High blood cholesterol can run in families. If a parent or sibling developed heart disease before age 55, high cholesterol levels place an individual at a greater than average risk of developing heart disease.
  • Smoking: Cigarette smoking damages the walls of blood vessels through a process called oxidation, making them prone to build up fatty deposits. Smoking may also lower levels of HDL cholesterol.
  • High blood pressure: Increased pressure on the blood vessel walls damages arteries, which can speed the accumulation of plaque.
  • Diabetes: High blood sugar contributes to high LDL cholesterol and low HDL cholesterol. High blood sugar can also damage the lining of the arteries, making it easier for plaque (protein, fat, and cholesterol) to deposit.
  • Others: Kidney disease (nephrotic syndrome), hypothyroidism (low thyroid levels), anorexia nervosa (eating disorder), and Zieve's syndrome (a condition that causes high cholesterol during withdrawal from long term alcohol abuse) can all contribute to high cholesterol.
Signs and Symptoms
  • High cholesterol does not lead to specific symptoms unless it has been chronic (long-term). High cholesterol levels may lead to specific physical findings such as xanthoma (thickening of tendons due to accumulation of cholesterol), xanthelasma (yellowish patches around the eyelids), and arcus senilis (white discoloration of the outer edges of the cornea due to cholesterol deposits).
  • A high level of blood cholesterol causes the arteries to narrow and can slow, or even block, blood flow to the heart. This reduced blood supply prevents the heart from receiving enough oxygen. Chronic (long-term) high cholesterol can lead to atherosclerosis (hardening of the arteries), angina (chest pain), heart attack, transient ischemic attacks (TIAs, or temporary lack of blood flow and oxygen to the brain), cerebrovascular accidents/strokes (lack of blood and oxygen in the brain), and peripheral artery disease (PAD).
Complications
  • Possible complications of high cholesterol include atherosclerosis (hardening of the arteries), coronary artery disease (CAD) or coronary heart disease (CAD), stroke (lack of blood flow to the brain), heart attack, and death. As discussed, high cholesterol levels can lead to plaque deposits in blood vessels. Plaque is composed of cholesterol, other fatty substances, fibrous tissue, and calcium, normal substances in the blood that become deposited on the artery walls if the blood does not flow properly. Over time, plaque deposits may grow large enough to interfere with blood flow through the artery (called a blockage). When the arteries supplying the heart with blood (coronary arteries) are blocked, chest pain (angina) may occur; when arteries in the legs are blocked, leg pain or cramping may occur; and when arteries supplying the brain with blood are blocked, stroke may occur.
Treatment
  • The main goal of cholesterol-lowering treatment is to lower low density lipoprotein (LDL) levels enough to reduce the risk of developing heart disease or having a heart attack. The higher the risk, the lower the LDL goal should be. There are two main ways to lower cholesterol, including therapeutic lifestyle changes (TLC) and drug therapy. TLC includes a cholesterol-lowering diet (called the TLC diet), physical activity, and weight management. TLC is for anyone whose LDL is above their target number and goal. Drug treatment with cholesterol-lowering drugs can be used together with TLC treatment to help lower LDL. Prevention of elevated cholesterol is started if the individual is at risk for high cholesterol levels or heart disease, or a previous heart attack or stroke has occurred.
  • Category I, highest risk: In those with highest risk, the LDL goal is less than 100mg/dL. They will begin the TLC diet to reduce high risk even if the LDL is below 100mg/dL. If the LDL is 100 or above, drug treatment will be started at the same time as the TLC diet. If the LDL is below 100mg/dL, drug treatment may also be started together with the TLC diet if the doctor finds the risk is very high, for example if the individuals has had a recent heart attack or has both heart disease and diabetes.
  • Category II, next highest risk: The LDL goal is less than 130mg/dL. If the LDL is 130mg/dL or above, treatment with the TLC diet should be started. If the LDL is 130mg/dL or more after 3 months on the TLC diet, drug treatment is started along with the TLC diet. If the LDL is less than 130mg/dL, individuals should follow the heart healthy diet for all Americans, which allows a little more saturated fat and cholesterol than the TLC diet.
  • Category III, moderate risk: The LDL goal is less than 130mg/dL. If the LDL is 130mg/dL or above, the TLC diet is started. If the LDL is 160mg/dL or more after having tried the TLC diet for 3 months, drug treatment may be started along with the TLC diet. If the LDL is less than 130mg/dL, the heart healthy diet for all Americans (low saturated fat and cholesterol) is used.
  • Category IV, low-to-moderate risk: The LDL goal is less than 160mg/dL. If the LDL is 160mg/dL or above, the TLC diet is started. If the LDL is still 160mg/dL or more after three months on the TLC diet, drug treatment may be started along with the TLC diet to lower LDL, especially if the LDL is 190mg/dL or more. If the LDL is less than 160mg/dL, the heart healthy diet for all Americans is used.
  • Diet: Individuals with high risk associated with developing heart disease will be started on the therapeutic lifestyle changes (TLC) diet. The TLC diet is a low-saturated-fat, low-cholesterol eating plan that calls for less than 7% of calories to come from saturated fat (such as in animal products) and less than 200 milligrams of dietary cholesterol daily. The TLC diet recommends only enough calories to maintain a desirable weight and avoid weight gain. If the LDL is not lowered enough by reducing saturated fat and cholesterol intakes, the amount of soluble fiber, such as psyllium, oat bran, and beta-glucan, in the diet can be increased (found in cereals, breads, and supplements), thereby helping to raise HDL and lower LDL. Certain food products that contain plant sterols (a cholesterol lowering component in many plants) can also be added to the TLC diet to boost its LDL-lowering power. Examples include cholesterol-lowering margarines (containing Benecol®, a plant sterol) and sterol supplements in capsule and tablet form. Plant sterols are found naturally in fruits, vegetables, nuts, seeds, cereals, legumes (beans), and vegetable oils (particularly soybean oil).
  • Weight management: When the body mass index (BMI, or fat content) is greater than 25, an individual is considered overweight. BMI uses an equation based on height and weight to determine the level of obesity. Losing weight can help lower LDL and is especially important for those with a cluster of risk factors that includes high triglyceride and/or low HDL levels.
  • Physical activity: Regular physical activity (at least 30 minutes on most, if not all, days) is recommended for those that can tolerate exercise. Taking a brisk 30-minute walk, three to four times a week can positively impact cholesterol levels. Patients with chest pain and/or known or suspected heart disease should talk to their doctor before beginning any exercise program. Exercise can help raise HDL and lower LDL and is especially important for those with high triglyceride and/or low HDL levels who are overweight with a large waist measurement. Individuals with a large waist measurement (more than 40 inches for men and more than 35 inches for women) are at high risk for heart disease.
  • Medication therapy: There are several medications that may help lower cholesterol, including total cholesterol, lipoproteins, and triglycerides. Medications can reduce LDL cholesterol levels by 20-40%. They also can modestly increase HDL ("good") cholesterol levels, usually by about 5-10%. Available drugs include 5-hydroxy-3-methylglutaryl-coenzyme A reductase inhibitors (HMG-CoA reductase inhibitors), bile-acid-binding resins, cholesterol absorption inhibitors, fibrates, and niacin.
  • 5-hydroxy-3-methylglutaryl-coenzyme A reductase inhibitors (HMG-CoA reductase inhibitors, or statins): Statins have significantly advanced the treatment of high cholesterol. Statins block a substance (HMG-CoA reductase) that the liver needs to make cholesterol. This decreases cholesterol in liver cells (hepatocytes), which causes the liver to remove cholesterol from the blood, thereby lowering cholesterol levels. Statins may also help the body reabsorb cholesterol from accumulated deposits on artery walls, potentially reversing coronary artery disease. Commonly prescribed statins include atorvastatin (Lipitor®), fluvastatin (Lescol®), lovastatin (Mevacol®), pravastatin (Pravachol®), rosuvastatin calcium (Crestor®), and simvastatin (Zocor®). Statins may also be added to blood pressure lowering drugs for use in protection from coronary heart disease (Caduet® a combination of atorvastatin (Lipitor®) and amlodipine (Norvasc®). Results from statin treatment should be seen after several weeks, with a maximum effect in four to six weeks. After about six to eight weeks, a doctor will check the LDL cholesterol levels while the individual is on the statin. Serious side effects are rare, and include liver problems, and muscle soreness, pain, and weakness. If this happens, or if there is brown urine present, contact a doctor immediately. Although rare, muscle breakdown, known as rhabdomyolysis, can occur. This is a medical emergency and a doctor should be contacted immediately.
  • Bile-acid-binding resins (sequestrants): The liver uses cholesterol to make bile acids, a substance needed for digestion. The medications cholestyramine (Prevalite®, Questran®), colesevelam (WelChol®), and colestipol (Colestid®) lower cholesterol indirectly by binding to bile acids (called sequestrant therapy). This causes the liver to use excess cholesterol to make more bile acids, which reduces the level of cholesterol in the blood. Bile acid sequestrant powders must be mixed with water or fruit juice and must be taken once or twice (rarely, three 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. Although sequestrants are not absorbed, they may interfere with the absorption of other medicines if taken at the same time. Other medications should be taken at least one hour before or four to six hours after taking the sequestrant.
  • Cholesterol absorption inhibitors: The small intestine absorbs the cholesterol from the diet and releases it into the bloodstream. The drug ezetimibe (Zetia®) helps reduce blood cholesterol by limiting the absorption of dietary cholesterol. Zetia® can cause headaches, nausea and fever, and muscle weakness. Zetia® by itself lowers LDL cholesterol levels similar to statins, but when combined with a statin, Zetia® works better to control elevated LDL levels. There is a combination of ezetimibe and simvastatin on the market (Vytorin®).
  • Fibrates: The medications fenofibrate (Lofibra®, Tricor®) and gemfibrozil (Lopid®) decrease triglycerides by reducing the liver's production of very-low-density lipoprotein (VLDL) cholesterol and by speeding up the removal of triglycerides from the blood. VLDL cholesterol contains mostly triglycerides. Some people taking fibrates may have side effects such as stomach or intestinal discomfort. Fibrates may increase the likelihood of developing gallstones and can increase the effect of medications that thin the blood. The dose of fibrates should be reduced if kidney function declines.
  • Niacin: Niacin, also known as nicotinic acid or vitamin B3, decreases triglycerides by limiting the liver's ability to produce low density lipoprotein (LDL) and VLDL cholesterol. There are two types of niacin: immediate release and extended (or slow) release. Niacin can reduce LDL cholesterol levels by 10-20%, reduce triglycerides by 20-50%, and raise HDL cholesterol by 15-35%. A common and troublesome side effect of immediate release niacin is flushing or hot flashes, which are the result of blood vessels opening wide. The causes of this flushing are not well known. 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 30 minutes prior to taking niacin - a doctor will guide the individual. The extended-release form may cause less flushing than the other forms (Niaspan®). Individuals will be started on regular niacin therapy to see how well it is tolerated, then the individual can be started on the extended release products if needed. Blood pressure may also be reduced while taking niacin. Niacin can cause a variety of gastrointestinal symptoms, including nausea, indigestion, gas, vomiting, diarrhea, and the irritation of peptic ulcers.
  • Other: If there are other symptoms of coronary heart disease (CHD) besides high cholesterol, other medications may be used to decrease the risk of stroke (lack of blood and oxygen to the brain) and heart attack. These include platelet inhibitors ("thin" the blood) such as aspirin (81-325mg daily, may cause bleeding) or Plavix® (clogidogrel), beta blockers (decrease the heart rate and blood pressure, reducing the heart's demand for oxygen, may cause fatigue) such as metoprolol (Lopressor®, Toprol®), nitroglycerin (increases the oxygen available to the heart by dilating coronary arteries, may cause headache), calcium channel blockers (slow heart rate and dilate coronary blood vessels, may cause slow heart rate) such as amlodipine (Norvasc®) or diltiazem (Cardizem®), angiotensin inhibiting drugs or ACE inhibitors (dilate blood vessels and increase oxygen to the heart, may cause cough) such as lisinopril (Prinivil®, Zestril®) or ramipril (Altace®), and statins or HMG-CoA reductase inhibitors (help lower cholesterol levels, may cause liver problems or muscle pain) such as atorvastatin (Lipitor®) or lovastatin (Mevacor®). Interventional procedures may also be used to treat CHD, including balloon angioplasty (PTCA or percutaneous transluminal coronary angioplasty) and stent (a wire mesh that opens blocked blood vessels) placement. Coronary artery bypass graft (CABG) surgery may be required to restore normal blood flow to the heart. CABG is a serious surgery, with complications including infection, lowered immunity, memory loss, "fuzzy" thinking, and even death.
Prevention
  • Dietary modification: Minimize cholesterol and fat intake, especially saturated fat, which raises cholesterol levels more than any other substance. Cholesterol and saturated fats are found primarily in foods derived from animals, such as meats and dairy products. Dietary guidelines for reducing cholesterol and fat consumption include eating lean fish, poultry, and meat (remove the skin from chicken and trim the fat from beef before cooking), avoiding commercially prepared and processed food (cakes, cookies, doughnuts) and breaded fried foods, increasing the intake of fruits, vegetables, breads, cereals, rice, legumes (beans, peas), using skim or 1% milk, and using cooking oils that are high in unsaturated fat (corn, olive, canola, safflower oils). Healthcare professionals recommend eating fish, including salmon, tuna, and herring, which are high in omega-3 fatty acids, and therefore proposed to have a heart-protective action. Eggs do contain cholesterol, but may be eaten without negative effects on cholesterol levels.
  • Weight loss: Excess weight contributes to high cholesterol. Losing 5% of the total body weight can have a significant impact on lowering total cholesterol levels. Fad diets such as the Atkin's diet may not give a person the balance of nutrients needed for a healthy heart and body. Exercising and eating the right foods in moderation help to increase weight loss.
  • Smoking cessation: Quitting smoking can improve HDL cholesterol levels, decrease blood pressure, and reduce the risk of a heart attack. Within one year after stopping, the risk of heart disease is half that of a smoker. Within 15 years of stopping, the risk of heart disease is similar to that of someone who has never smoked.
  • Alcohol consumption: In some studies, moderate use of alcohol (particularly red wine) has been linked with increasing levels of HDL cholesterol. No more than two glasses of red wine (four ounces each) should be consumed daily for heart protection. Excessive drinking can have a negative impact on cholesterol levels, actually raising triglyceride levels and increasing blood pressure.
  • Cholesterol screenings: Everyone age 20 and older should have their cholesterol measured at least once every five years.
References
  • American Heart Association. .
  • Boekholdt SM, Sandhu MS, Day NE, et al. Physical activity, C-reactive protein levels and the risk of future coronary artery disease in apparently healthy men and women: the EPIC-Norfolk prospective population study. Eur J Cardiovasc Prev Rehabil. 2006;13(6):970-6. View Abstract
  • Duffey KJ, Gordon-Larsen P, Jacobs DR Jr, et al. Differential associations of fast food and restaurant food consumption with 3-y change in body mass index: the Coronary Artery Risk Development in Young Adults Study. Am J Clin Nutr. 2007;85(1):201-8. View Abstract
  • Harris WS, Assaad B, Poston WC. Tissue omega-6/omega-3 fatty acid ratio and risk for coronary artery disease. Am J Cardiol. 2006 Aug 21;98(4A):19i-26i. Epub 2006 May 30. View Abstract
  • National Heart, Lung, and Blood Institute. .
  • National Institutes of Health. .
  • Natural Standard: The Authority on Integrative Medicine. .
  • U.S. Food and Drug Administration. .