Cholesterol is commonly associated with heart disease. Some cholesterol is produced naturally in the body, and other cholesterol comes from the diet. As the American Heart Association notes, not all cholesterol is bad. Understanding the difference between the "good" and "bad" types of cholesterol is important in determining whether a person is at a risk for heart disease, heart attack or a stroke.
Significance
When interpreting what the numbers mean for cholesterol levels, patients must first realize that the total cholesterol level is the sum of low-density lipoprotein, or LDL, plus high-density lipoprotein, or HDL, plus very low-density lipoprotein, or VLDL. Cholesterol is measured in milligrams per deciliter. A total cholesterol of less than 200 mg/dl is healthy. A level between 200 and 230 mg/dl is borderline, and a reading of more than 240 mg/dl is high.
High-Density Lipoprotein
HDL is considered the "good" cholesterol because it seems to have a protective effect by lowering the risk of heart attack and stroke. HDL helps prevent the buildup of plaque in the artery walls by carrying cholesterol to the liver, where it is expelled. HDL is the only type of cholesterol in which a higher number is better. HDL levels should be at least 40 mg/dl for men and at least 50 mg/dl for women. An HDL reading of at least 60 mg/dl is optimal.
Low-Density Lipoprotein
LDL is the "bad" cholesterol because it is the carrier of plaque-building fats. Lower levels of LDL mean the patient is at a lower risk of having a heart attack or stroke. An ideal LDL level is less than 100 mg/dl, according to the American Heart Association. Several levels of risk have been established, with the highest level indicated by LDL readings above 190 mg/dl.
Very Low-Density Lipoprotein
In order to understand VLDL, it's necessary to understand triglycerides. Triglycerides are a type of fat found in the bloodstream and act as a energy source. Less than 150 mg/dl is normal for triglyceride levels, and 500 mg/dl or greater is very high. Above-normal triglyceride levels have been shown to increase the risk of heart disease and stroke. Of the three lipoproteins -- HDL, LDL and VLDL -- the highest amount of triglycerides are found in VLDL. Patients do not usually receive VLDL information when they have cholesterol testing, because VLDL is not a specific test. Instead, it's a percentage of the triglyceride value.
Prevention
Once patients understand what the cholesterol levels mean, they need to know what affects these numbers. Patients whose cholesterol levels indicate they are at a risk for heart disease or stroke can quickly change bad habits in their lifestyle and decrease their risks. Lifestyle changes may relate to diet, exercise, smoking and alcohol consumption.
References
- American Heart Association: About Cholesterol
- "Urologic Nursing"; Cholesterol, Cholesterol-Lowering Agents/Statins and Urologic Disease; Moyad and Merrick; April 2006
- "Patient Care Management"; Teach Meaning Behind Cholesterol Numbers; Randall; August 2008
