Cholesterol Knowledge

Cholesterol is a lipidic, waxy alcohol found in the cell membranes and transported in the blood plasma of all animals. It is an essential component of mammalian cell membranes where it is required to establish proper membrane permeability and fluidity. Cholesterol is the principal sterol synthesized by animals, but small quantities are synthesized in other eukaryotes, such as plants and fungi. It is almost completely absent among prokaryotes, which include bacteria. Cholesterol is classified as a sterol (a contraction of steroid and alcohol).

Although cholesterol is essential for life, high levels in circulation are associated with atherosclerosis. Cholesterol is synthesized in virtually all cells, and significant amounts of it can be absorbed from the diet.

Function

Cholesterol is required to build and maintain cell membranes; it regulates membrane fluidity over a wide range of temperatures. The liver produces about 1 gram of cholesterol per day, in bile

Cholesterol level

>200mg/dl or less than 5.0 mmol/l Low heart attack risk

200-240mg/dl or 5.2-6.2mmol/l Borderline

>240mg/dl or >6.2mmol/l High risk

High blood cholesterol and triglycerides

The medical term for high blood cholesterol and triglycerides is lipid disorder. Such a disorder occurs when you have too many fatty substances in your blood. These substances include cholesterol and triglycerides.

Causes, incidence, and risk factors

High cholesterol and other lipid disorders can be inherited (passed down through families) or associated with:

* Fatty diets

* Disease such as diabetes, hypothyroidism, Cushing syndrome, and kidney failure

* Certain medications, including birth control pills, estrogen, corticosteroids, certain diuretics, and beta-blockers

* Lifestyle factors, including inactivity and regular, excessive alcohol use

If you smoke and also have high cholesterol you have an even greater risk for heart disease.

Lipid disorders are more common in men than women.

Signs and tests

Tests to diagnose a lipid disorder may include:

* Lipoprotein test

* Lipoprotein(a) analysis

* HDL test

* LDL test

Treatment

How you are treated depends on your age, health history, if you smoke, and other risk factors for heart disease, such as:

* Diabetes

* Poorly controlled high blood pressure

* Family history of heart disease

There are steps that everyone can take to improve their cholesterol levels, and help prevent heart disease and heart attack. Here are the most important ones:

* Choose foods low in saturated fat. (See cholesterol for more information.)

* Exercise regularly.

* Lose weight if you are overweight.

* Get routine health checkups and cholesterol screenings.

If lifestyle changes do not help or your cholesterol level remains very high, your doctor may may recommend medication. There are several types of drugs available to help lower blood cholesterol levels, and they work in different ways. Some are better at lowering LDL cholesterol, some are good at lowering triglycerides, while others help raise HDL cholesterol.

The most commonly used drugs for treating high LDL cholesterol are called statins. Other drugs that may be used include bile acid sequestering resins, cholesterol absorption inhibitors, fibrates, and nicotinic acid (niacin).

Expectations (prognosis)

If you are diagnosed with high cholesterol, you will probably need to continue lifestyle changes and drug treatment throughout your life. Periodic monitoring of your cholesterol blood levels is necessary. Reducing high cholesterol levels will slow the progression of atherosclerosis.

Complications

Possible complications of high cholesterol include:

* Atherosclerosis

* Coronary artery disease

* Stroke

* Heart attack or death

Prevention

To help prevent high cholesterol:

* Keep a healthy body weight

* Eat a well-balanced, low-fat diet