Decisions on when to lower blood cholesterol should be based on the guidelines from the National Cholesterol Education Program (NCEP). I have regularly used these guidelines and agree with most of them.

Decisions are based on the number of coronary heart disease (CHD) risk factors and your LDL cholesterol level. Risk factors for heart disease, some of which are modifiable, are cigarette smoking, low HDL cholesterol, high blood pressure, and a family history of premature coronary heart disease.

The NCEP guidelines also state that the number of risk factors can be reduced by one if the HDL cholesterol is 60 mg/dL or higher. Neither obesity nor elevated triglycerides is included in this list, even though they are both associated with an increased risk of CHD.

If your LDL cholesterol exceeds the recommended targets, your doctor may first advise you to adopt lifestyle measures such as a low-fat, high-fiber diet, and exercise, and to lose weight if necessary. Here are the LDL cholesterol targets.

For zero or one risk factors, the LDL cholesterol target is 160mg/dL. For two or more risk factors, the LDL cholesterol target is 130 mg/dL (100 mg/dL or lower if you have a history of CHD, stroke, peripheral vascular disease, or diabetes).

The latest revision of these guidelines suggests LDL cholesterol should be even lower - below 70 mg/dL - in people with the above diseases.

If lifestyle measures alone aren't enough to reach the above targets, your doctor may recommend a statin or other medication.

Though I agree with all of these guidelines, I am loath to subtract one risk factor in patients whose HDL cholesterol is 60 mg/dL or greater.

I find it hard to believe that high HDL cholesterol levels can counteract 40 years of cigarette smoking or significant high blood pressure. Furthermore, some of my patients have had heart attacks even though they had a healthy-looking HDL cholesterol level of 90 mg/dL.