Cholesterol is the waxy substance in fats. It's used in some body functions and in the formation of cell membranes. Generally, the liver produces most of the cholesterol needed by the body. We also get cholesterol from some of the foods we eat. In the blood, cholesterol is carried in little packages, called lipoproteins. Low-density lipoprotein (LDL) is the main carrier of cholesterol. If too much LDL cholesterol circulates in the blood, excess cholesterol remains on the walls of the arteries. Over time, a build-up of cholesterol and other substances can form a hardened deposit, called plaque. Enough plaque can build on the artery to slow or stop the flow of blood, leading to a loss of blood flow through the area.
In the heart, a blockage can cause a heart attack. A blocked artery in the brain can cause a stroke. High density lipoprotein (HDL) is often called the "good" cholesterol. It is believed to pick up deposits of excess cholesterol and carry them back to the liver for processing and elimination from the body.
High levels of HDL cholesterol are believed to reduce the risk of a heart attack. Another important component of heart disease risk is triglyceride level. Triglycerides are a type of fat which can be stored by the body for energy. Hormones trigger the release of triglycerides from the fat cells. High levels of triglycerides are associated with an increased risk for heart disease.
The Numbers Breakdown
Last year, the National Cholesterol Education Panel issued some new guidelines for screening, evaluating, and treating adults with high cholesterol. The Panel recommends all people 20 and older have a fasting blood cholesterol test every five years. The test should measure total cholesterol as well as LDL, HDL, and triglycerides. The guidelines suggest an optimal LDL as less than 100 mg/dL. The higher the HDL, the better. Patients should have an HDL level of at least 40 mg/dL and a level of 60 mg/dL or higher is considered to be protective against heart disease. Optimal triglyceride levels are less than 100 mg/dL.
Health experts also advise aggressive treatment for some patients. While high LDL levels continue to be important risk factors for heart disease, the new recommendations take into account multiple risk factors (such as age, family history, smoking, diabetes, obesity, and high blood pressure) in the complex relationship between cholesterol levels and heart disease risk. Under the guidelines, as many as 35.6 million Americans would be eligible for cholesterol-lowering medications.
For general information on cholesterol or heart disease:
American Heart Association, contact your local chapter, or visit their website at www.americanheart.org