OVERVIEW THE EFFECT OF HDL LEVELS ON CARDIOVASCULAR DISEASE

High-density lipoprotein (HDL), also known as good cholesterol, is a strong and independent risk factor for coronary artery disease (CAD). Persons with high HDL levels are relatively protected from atherosclerosis, and those with low HDL levels exhibit increased cardiovascular morbidity and mortality. Raising the level of HDL cholesterol leads to reduction in heart disease risk by an order of magnitude higher than that achievable by lowering the levels of low-density lipoprotein (LDL), known as bad cholesterol. For example, lowering the LDL level by 1 mg/dL reduces CAD risk by 1%, but raising the HDL level by 1 mg/dL results in a risk reduction of 2% in men and 3% in women. Thus, to decrease the risk of CAD, modifying HDL levels is as effective as, if not more effective than, modifying LDL levels.

In the Third Report of the National Cholesterol Education Program (NCEP) Expert Panel on Detection, Evaluation, and Treatment of High Blood Cholesterol in Adults (Adult Treatment Panel [ATP] III), a low HDL level for both men and women is defined as an HDL level <40 mg/dL, while a high HDL level is defined as an HDL level of ≥60 mg/dL. HDL level is also one of the five components that define metabolic syndrome, and a level <40 mg/dL for men or <50 mg/dL for women is considered the cut-off point. Currently, the NCEP does not specifically recommend that HDL be a primary target of intervention. However, in patients with metabolic syndrome and those with low HDL levels, the HDL level is an appropriate secondary target of intervention that may be modified by medications that raise HDL levels. Finally, in high-risk patients, such as those who have diabetes, those who have established atherosclerotic disease, and those of south Asian origin, treating isolated low HDL cholesterol levels may be reasonable.