High-density lipoprotein cholesterol and angiographic coronary artery disease in black patients.

The clinical epidemiology of coronary artery disease (CAD) among black patients has not been well described, particularly in relation to the impact of the major risk factors. Lipoprotein profiles and other risk factors were measured in 114 black patients undergoing cardiac catheterization for probable CAD. Patients (coronary narrowing of 50% or greater; n = 63) were compared to those without significant stenoses (n = 51). Total cholesterol and low-density lipoprotein cholesterol (LDLC) were both significantly associated with the presence of CAD in men and women; however, high-density lipoprotein cholesterol (HDLC) had discriminatory value only for women. The ratio of total cholesterol to HDLC (TC:HDL) separated patients from control subjects in both sexes, most efficiently among women, and was the only lipid variable associated with CAD in the age group over 55 years. Hypertension and angina were frequent in both groups and did not identify those with disease. In summary, LDLC was the best predictor among the lipids for men (likelihood ratio = 9.4) and TC:HDL was the best indicator of disease among women (likelihood ratio = 15.7). Low HDLC levels may, in part, account for the increased incidence of CAD among black women. Further population studies of factors leading to reduced HDLC, namely, obesity and diabetes, are needed.