Beating high cholesterol
Over the past few decades, doctors and scientists have come to understand high cholesterol (hypercholesterolemia) as a major health issue and identified it as a major underlying cause of heart disease.
High cholesterol is generally defined as a blood cholesterol level of 240 milligrams per deciliter (mg/dL) or higher. It can result from dietary and lifestyle habits, diseases that affect the endocrine organs, or your genetic makeup. Even though a person with high cholesterol levels may have no symptoms, over time the condition can lead to serious medical problems, including heart attacks and stroke.
Fortunately, through the education efforts of physicians and researchers, Americans have begun to take better care of their bodies, adopting healthy diets and exercising regularly. Effective new drugs are available to treat this condition, and deaths related to high cholesterol have decreased in the past three decades. High cholesterol can now be effectively treated.
To understand high cholesterol, it helps to know a little bit about what happens in your body. Cholesterol and fatty acids, in the form of triglycerides, are transported through your bloodstream wrapped in proteins. This combination molecule makes up a lipoprotein, of which there are several varieties with specific tasks in the body. Major lipoproteins include the following:
- Chylomicrons: large particles that transport dietary fat and cholesterol to muscles (for energy), to fat tissue (for storage), and to breasts (for milk production).
- Very low-density lipoproteins (VLDL): particles synthesized by the liver that deliver triglycerides to muscles (for energy) and to fat tissue (for storage). As the triglycerides are removed from these VLDL particles, they collect cholesterol; the majority become converted to LDL particles.
- Low-density lipoproteins (LDL): particles that carry about 70% of the blood's cholesterol. They are small enough to cross the blood vessel walls and enter tissue. LDL can be harmed by oxidation, a natural process that nevertheless can damage blood vessel walls. For this reason, LDL is known as the "bad cholesterol."
- High-density lipoproteins (HDL): are transported out of the intestines and liver in quantities greater than the body's tissue can use, so the excess is returned to the liver for elimination in bile or to be remade into VLDL. HDL is crucial for this reverse transport of cholesterol, which is why it is nicknamed the "good cholesterol." High HDL is associated with a lowered risk of coronary artery disease.
A high level of LDL in the bloodstream corresponds to a high level of cholesterol. LDL tends to deposit its cholesterol on artery walls. These deposits, known as plaques, harden the arterial wall and obstruct blood flow. When arteries become so congested that tissues begin to lose their blood supply, the condition is called atherosclerosis, a serious, progressive condition that can lead to heart attack, stroke, and gangrene of the extremities. LDL has been justly nicknamed "bad cholesterol."
HDL has been called "good cholesterol" because it transports cholesterol to the liver, where it is broken down and removed from the blood stream. High levels of HDL are associated with lower levels of cholesterol and lower chances of heart attack and stroke.
How Common Is High Cholesterol?
High cholesterol is a common health risk in the United States. The American Heart Association estimates that 98.1 million American adults (51.9%) have total blood cholesterol values of 200 mg/dL and higher, and about 39.4 million American adults (about 20%) have levels of 240 or higher.
Goals of Treatment
High cholesterol is a treatable condition. Dietary changes and exercise are often successful in bringing moderately elevated cholesterol levels back to desirable levels. If you are at high risk, your doctor may prescribe a cholesterol-lowering drug in addition to diet and exercise. Proper treatment can even help reduce atherosclerotic plaque buildup to some extent. The goals of treatment to prevent the worsening of atherosclerosis and reduce the risk of heart attack and stroke can be effectively accomplished.
Many at-risk people never need to take prescription medications to lower their cholesterol levels. Simply making some informed choices may be all you need to restore your circulatory system to its former glory:
- Eat a healthy diet low in saturated fat and cholesterol, and aim to include five to six servings of fruits and vegetables. The American Heart Association recommends you limit your daily intake of cholesterol to 300 mg on a prevention program (what the AHA calls Step I), 200 mg per day on a reversal regimen (what the AHA calls Step II). In addition, no more than 30% of your daily caloric intake should be from fats, and no more than 10% of that should be from saturated fats. Every 1% drop in overall cholesterol reduces your chances of dying of cardiovascular disease by 2%.
- If you drink, do so moderately. Although moderate use of alcohol seems to increase HDL levels, the damage alcohol can do to your liver could compromise the LDL receptors' ability to filter out the bad cholesterol. Stick to no more than one glass for women, two glasses for men, per day.
- Toss the cigarettes. If you smoke, stop. Smoking does so much damage to the cardiovascular system that it practically rolls out the red carpet for atherosclerosis. Cigarettes are also linked with increased LDL and decreased HDL. Smokers will gain immediate benefits from quitting and should see significant decreases in LDL and total cholesterol.
- Get moving. One of the biggest favors you can do for your bloodstream is get up off the couch and exercise. You don't have to train like a marathon runner; half an hour of brisk walking a few times a week will boost your HDL levels almost immediately and lower your LDL. The more you do, the better you will feel, and the healthier your cardiovascular system will become.
For some people, diet and exercise aren't enough to bring down dangerous cholesterol levels. They may need to take prescription medications to reduce or even halt the production of cholesterol in the liver. All cholesterol-lowering medications should be taken only with the advice of and under the supervision of your physician.
Four types of medications are available for the treatment of high cholesterol: HMG-CoA reductase inhibitors, bile acid sequestrants, nicotinic acid, and fibric acid derivatives. The class of drug your physician prescribes will depend on a variety of factors, including your HDL and LDL levels and your family medical history, age, and gender.
|HMG-CoA reductase inhibitors|
This is a class of drug that has demonstrated significant effectiveness in lowering cholesterol levels. Drugs in this class are probably the most frequently prescribed for high cholesterol, but they do have side effects, including muscle aches and pains, joint pain, and gastrointestinal upset. These drugs can cause increases in liver enzymes, although they rarely cause liver damage. This class of drug has also been associated with decreased cholesterol production and increased LDL receptors in the liver.
|Bile acid sequestrants|
These are drugs that convert more of the cholesterol in the bloodstream into bile acids, which are more easily eliminated from the body. These drugs can also increase the number of LDL receptors in the liver. Side effects of this class of drug can include bloating, diarrhea, constipation, and elevated triglyceride levels. The most commonly prescribed drugs in this class include Colestid (colestipol hydrochloride) and LoCholest or Questran (cholestyramine). You should have periodic cholesterol and bleeding time function tests while on this type of medication to make sure it is working well and to monitor any side effects.
This is another word for niacin, or vitamin B-3, and is commonly used to lower cholesterol by decreasing VLDL (very low density lipoproteins). Nicontinic acid can reduce total and LDL cholesterol and triglycerides while raising HDL cholesterol. As with other classes of cholesterol-lowering drugs, this drug requires liver-enzyme monitoring to guard against liver damage. The most common side effects include gastrointestinal upset, skin flushing, and elevations in glucose, uric acid, and liver enzymes. Symptoms of flushing, itching, and headache caused by dilation of blood vessels are especially troublesome. These symptoms can be eased by taking an aspirin 30 minutes beforehand, or taking B-3 with food.
|Fibric acid derivatives|
These drugs inhibit cholesterol production in the liver and lower VLDL levels. They are primarily effective in lowering triglycerides, but also increase HDL. Although these drugs are well tolerated by most patients and two large studies have demonstrated their effectiveness, the drugs' use has declined in the United States after a large World Health Organization study failed to prove their effectiveness. Some patients who take these drugs have gastrointestinal problems; they may cause a higher incidence of gallstones.
Monitoring the Condition
Your doctor will want to keep close tabs on your condition if you have high cholesterol levels. Monitoring often involves periodic laboratory tests to measure total blood cholesterol, LDL, and HDL levels, as well as liver-enzyme monitoring if you are taking some types of cholesterol-lowering drugs. Based on the laboratory findings, your doctor may recommend or adjust cholesterol-lowering medications as well as exercise and diet.
The most serious complications that can result from high cholesterol are those associated with atherosclerosis:
- Coronary artery disease
- Angina pectoris and unstable angina
- Congestive heart failure
- Heart attack
- Stroke/transient ischemic attack (TIA)
- Blood clots and arterial obstruction
Quality of Life
High cholesterol itself doesn't affect your quality of life, but the diseases that can result from it can. It is never too late to seek the assistance of a physician in heading off the dangers of high cholesterol. Lowering your cholesterol means making some changes in the way you live, but most people aren't facing anything too radical mainly just some dietary adjustments and exercise. You're in charge, and many lifestyle choices you make directly affect your cholesterol levels for the better, some virtually right away.
Considerations for Women
Estrogen has been shown to have beneficial effects on HDL and LDL levels. As a woman enters menopause, the ovaries stop producing estrogen, putting women at risk of atherosclerotic disease. Menopausal and postmenopausal women may benefit from estrogen replacement therapy. Ask your doctor if this choice is right for you.
Considerations for Older People
Men age 45 and older and women age 55 and older have a higher incidence of high cholesterol and should be screened annually.
Considerations for Children & Adolescents
High cholesterol is not reserved for the middle-aged and self-indulgent. Too many young adults, teens, and even children have plaque deposits on their arteries. Atherosclerosis, for instance, can begin in childhood and progress without symptoms for years. Almost all of these cases is a direct result of a poor diet overloaded with fats. But like their meat-and-cheese-loving elders, young people can control much of the problem with a little common sense, better fitness, and a lot more leafy vegetables.
Last updated 23 May 2012
Diets high in cholesterol and saturated fats can increase cholesterol levels. High-fat diets also seem to encourage the liver to manufacture more cholesterol than is necessary. Saturated fats from meat and dairy products can significantly raise blood cholesterol levels.
Heredity can profoundly influence your cholesterol readings. Researchers believe family-related hypercholesterolemia and other inherited cholesterol disorders are responsible for some 10 million deaths worldwide in middle-aged men and women. Some individuals are born with a shortage of LDL receptors on the liver, so the organ has only a limited filtering capacity. Other inherited liver conditions can compromise its ability to handle even moderate levels of cholesterol and other substances. Some genetic factors, such as certain thyroid disorders and diabetes conditions, may also elevate cholesterol levels
If you have one or more of the following risk factors, you are at increased risk for high cholesterol levels. Consult your doctor regarding the possibility of more careful monitoring. Though some risk factors cannot be changed, you can eliminate or reduce others through changes in your lifestyle.
- Diet high in fat and cholesterol
- Family history of heart disease or cholesterol disorder
- Diabetes mellitus
- Other long-term illnesses such as liver or kidney disease
- Sedentary lifestyle
- Increasing age
- Male gender
Symptoms & Diagnosis
High cholesterol itself has no symptoms. You can have elevated blood cholesterol levels for many years and not know it, which in turn can lead to a silent buildup of plaque within the arteries. However, symptoms may occur as a result of atherosclerosis, a common consequence of continuous high cholesterol levels. The following are symptoms of serious diseases related to atherosclerosis. If you experience any of these symptoms, contact your physician immediately:
- Chest pain (angina)
- Dull pain in the buttock, calf muscle, or thigh during physical exercise or exertion
- Sharp pains in the legs or feet when you are at rest
- Tingling or numbness in an armor leg, partial vision, or speech loss
Conditions That May Be Mistaken for High Cholesterol
High cholesterol is high cholesterol, whether it is caused by poor dietary choices, genetic predisposition, or the effects of drugs or disease.
How Is High Cholesterol Diagnosed?
All it takes is a blood test to find out what your cholesterol levels are. Unless you're in a high-risk group (if you smoke, eat a high-fat diet, are under excessive stress, or have certain chronic illnesses such as diabetes and thyroid or liver dysfunction), testing once every five years is fine. Men over 45 and women over 55 should be tested yearly. People on cholesterol-reducing regimens or medications will require more frequent checks to ensure their cholesterol levels and liver enzymes are within safe limits. The blood for the test is usually drawn after a night of fasting to ensure accuracy.
Your doctor is primarily interested in three values:
- Total blood (serum) cholesterol: This is the overall amount of cholesterol in your bloodstream. A person with total cholesterol greater than 240 milligrams per deciliter (mg/dL) has more than twice the risk of heart disease compared to someone whose cholesterol is 200 mg/dL. Here are the National Cholesterol Education Program guidelines:
- Desirable: less than or equal to 200 mg/dL
- Borderline: 200 to 240 mg/dL
- High: greater than 240 mg/dL
- HDL: The higher your HDL ("good" cholesterol) level, the better. According to the National Cholesterol Education Program, your HDL should be 35 mg/dL or higher. An HDL level less than 35 mg/dL increases your risk for heart disease.
- LDL: LDL ("bad" cholesterol) is a better predictor of heart disease risk than your total blood cholesterol. If your LDL level is high or borderline and you have other risk factors for heart disease, your doctor will likely plan a treatment program for you. Here are the National Cholesterol Education Program guidelines:
- Desirable: less than 130 mg/dL
- Borderline: 130 to 159 mg/dL
- High: 160 mg/dL and above