Normolipidemic subjects with low HDL cholesterol levels have altered HDL subpopulations

Abstract

Epidemiological studies have established that plasma concentration of HDL is inversely correlated with the risk of coronary heart disease, even in the absence of increased LDL cholesterol levels. We postulate that specific HDL sub-populations may be responsible for antiatherogenic properties of HDL. HDL subpopulations were quantitated by two-dimensional gel electrophoresis in 79 normolipidemic healthy male subjects. To eliminate the influence of diet, volunteers consumed an average American diet for 6 weeks. After the diet period, subjects were stratified according to their HDL cholesterol (HDL-C) levels to low HDL-C <0.91 mmol/L (<35 mg/dL), medium >0.91<1.30 mmol/L (>35 <50 mg/dL), and high ≤1.30 mmol/L (≤50 mg/dL) groups. Plasma triglycerides and insulin levels were in the normal range, but subjects with low HDL-C levels had higher concentrations of plasma triglycerides and insulin than subjects with medium or high HDL-C concentrations. The absolute concentration (mg/dL) of apoA-I in the largest α-migrating HDL subpopulation (α1) was (P