My HDL cholesterol has been quite low for a number of years, and my wife and I are quite disappointed with my doctor's inability to improve these levels. Do you have any suggestions?
HDL, the so-called "good cholesterol," is one of the complex blood proteins (called lipoproteins) that transport fats, primarily cholesterol and triglycerides, within the blood circulation. Measured by determining the amount of cholesterol they carry, HDL levels are strongly linked to coronary artery disease.
People with high HDL levels are relatively protected against coronary artery disease (CAD); those with low levels are at increased risk.
The average HDL levels are 45 milligrams per deciliter (mg/dl) in men and 55 mg/dl in women. The National Cholesterol Education Program has suggested that levels of HDL cholesterol less than 35 mg/dl constitute a risk factor for CAD, but since cholesterol levels are normally higher in women than in men, an HDL cholesterol less than 42 mg/dl is a risk factor for women.
You should not be upset with your doctor; it is often very difficult to raise HDL cholesterol levels because they are largely determined by inherited factors that cannot be changed.
However, the HDL cholesterol level can sometimes be increased modestly by altering other risk factors.
First, it is important to treat conditions that can lower HDL cholesterol, such as high levels of blood triglycerides (hypertriglyceridemia), diabetes and obesity. HDL cholesterol may also be raised by cessation of cigarette smoking, increased physical activity and estrogen replacement in postmenopausal women. Moderate alcohol intake can raise HDL cholesterol levels too, but it is not a good idea for teetotalers to start drinking for this reason.
Certain drugs can lower HDL cholesterol, sometimes drastically, as with anabolic steroids by athletes and bodybuilders. Progestins, often prescribed along with estrogen in postmenopausal women, thiazide diuretics and beta-blockers can also decrease HDL.
Conversely, several cholesterol-lowering drugs can raise HDL levels. Among these, the "statins" and gemfibrozil can each raise HDL cholesterol levels by 8 percent to 10 percent.
The most effective drug to increase HDL levels is niacin, which can raise levels by 20 percent to 30 percent. But in general, these drugs are used only with people who have other blood abnormalities, such as elevated cholesterol or triglycerides, and not when the only problem is low HDL.
In this regard, let me correct a misconception exemplified by a recent letter to the editor of The Sun.
The writer of this letter stated that "niacin is not a drug. It is available without a prescription and it's much less expensive than prescription drugs with often times harmful side effects."
In fact, niacin, while inexpensive and a readily available vitamin, is a drug when taken in the amounts needed to lower blood cholesterol and triglycerides, or to increase HDL cholesterol.
And taking niacin to treat a blood lipid abnormality should be done only under the care of a doctor, because niacin has more dangerous side effects than any of the other drugs used to treat these disorders. These side effects include nausea, abdominal pain, peptic ulcer, liver abnormalities, gout and an increase in blood sugar levels in those with diabetes.
Dr. Margolis is professor of medicine and biological chemistry at the Johns Hopkins School of Medicine.
Pub Date: 8/06/96