High-density lipoprotein subfractions in normolipidemic patients with coronary atherosclerosis.

High-density lipoprotein (HDL) levels were studied in 10 male patients with severe coronary atherosclerosis and in 10 well-matched controls. All subjects were normolipidemic, and the presence of a disease or other factor influencing HDL levels were excluded. Very low density lipoprotein and low-density lipoprotein levels were similar in both groups, but HDL concentration was significantly lower in the patient group. Analysis of HDL subfractions revealed that both HDL2 and HDL3 concentrations were significantly lower in the patient group. The composition of both HDL subfractions was also altered in the patient group: an increased cholesterol-to-protein ratio was found. These data strengthen the evidence in support of an important and independent role for HDL in the pathogenesis of coronary atherosclerosis. It appears that both HDL2 and HDL3 are implicated and that both the concentration and composition of HDL are important.