Risks of Cholesterol
People with high cholesterol have a higher risk of stroke, heart attack and heart disease. Cholesterol is measured by a blood test called a lipid panel or lipid profile. Cholesterol testing is recommended by the American Heart Association every five years for most adults, more often for people with heart disease, family history of heart disease or those who know their cholesterol is high. Children at risk for developing heart disease, such as diabetics, should be tested as well.
Cholesterol Defined
Cholesterol is a lipid, or fat, that the body uses to form bile, hormones and cell membranes. It joins with proteins, triglycerides and other lipid molecules to form particles called lipoproteins. Lipoproteins are classified as high-density lipoproteins, or HDL; low-density lipoproteins, or LDL; and very low density lipoproteins, or VLDL.
Testing for Cholesterol
You should fast for 12 hours before a cholesterol test. It takes several hours for the body to fully process the food you eat. Fasting before a test ensures that your doctor will get an accurate picture of how your body stabilizes cholesterol, rather than how much fat was in your last meal. A cholesterol test will measure total cholesterol, HDL, LDL and triglycerides. Cholesterol levels are measured in milligrams per deciliter, or mg/dL, of blood.
Total Cholesterol
Total cholesterol is the combination of HDL and LDL. The ideal total cholesterol is under 200 mg/dL. Knowing your total cholesterol is a good starting point, but specific measurements of HDL and LDL give a better picture of your risk for stroke and heart attack.
HDL
HDL is the so-called "good cholesterol." HDL carries cholesterol from the tissues of the body back to the liver. Along the way, it gathers LDL, or "bad cholesterol." An ideal HDL level would be 60 mg/dL or higher. HDL cholesterol levels below 40 mg/dL for men and 50 mg/dL for women puts you at higher risk for heart disease and stroke.
LDL
LDL is known as "bad cholesterol." Low-density lipoproteins carry cholesterol from you liver to the tissues of your body that need it. But when the blood contains more LDL than the body needs, LDL can form plaque along the walls of the arteries. This plaque blocks the flow of blood to your tissues and can eventually rupture, causing heart attack or stroke. LDL cholesterol levels should be below 130 mg/dL. For patients at risk for heart attack, levels should be below 100 mg/dL
HDL/LDL Ratio
The ratio of good cholesterol to bad cholesterol is another indicator that physicians monitor during a cholesterol screening. The HDL/LDL ratio is calculated by dividing the good cholesterol by the bad cholesterol. The preferred range of HDL/LDL ratio is 0.3 or above.
Triglycerides
Triglycerides are the fats that the body stores in fat cells and uses for energy. Most triglycerides come from the diet, but triglycerides can also be manufactured in the liver. If triglyceride levels remain high, extra triglycerides, along with LDL, form plaque on the walls of the arteries. Triglyceride levels should be less than 150 mg/dL.
References
- American Heart Association on Cholesterol
- Basic and Clinical Pharmacology; Bertram Katzung; 2007
- Clinical Pharmacology and Therapeutics; Eric T. Herfindal, Dick R. Gourley and Linda Lloyd Hart; 1992
