Distribution of ApoA-I–Containing HDL Subpopulations in Patients With Coronary Heart Disease

Abstract

Abstract —High density lipoproteins (HDLs) and their subspecies play a role in the development of coronary heart disease (CHD). HDL subpopulations were measured by 2-dimensional nondenaturing gel electrophoresis in 79 male control subjects and 76 male CHD patients to test the hypothesis that greater differences in apolipoprotein (apo)A-I–containing HDL subpopulations would exist between these 2 groups than for traditional lipid levels. In CHD subjects, HDL cholesterol (HDL-C) was lower (−14%, P<0.001), whereas total cholesterol and the low density lipoprotein cholesterol/HDL-C ratio were higher (9% [ P <0.05] and 21% [ P <0.01], respectively) compared with control levels. No significant differences were found for low density lipoprotein cholesterol, triglyceride, and apoA-I levels. In CHD subjects, there were significantly ( P <0.001) lower concentrations of the large lipoprotein (Lp)A-I α 1 (−35%), pre-α 1 (−50%), pre-α 2 (−33%), and pre-α 3 (−31%) subpopulations, whereas the concentrations of the small LpA-I/A-II α 3 particles were significantly ( P <0.001) higher (20%). Because α 1 was decreased more than HDL-C and plasma apoA-I concentrations in CHD subjects, the ratios of HDL-C to α 1 and of apoA-I to α 1 were significantly ( P <0.001) higher by 36% and 57%, respectively, compared with control values. Subjects with low HDL-C levels (≤35 mg/dL) have different distributions of apoA-I–containing HDL subpopulations than do subjects with normal HDL-C levels (>35 mg/dL). Therefore, we stratified participants according to HDL-C concentrations into low and normal groups. The differences in lipid levels between controls and HDL-C–matched cases substantially decreased; however, the significant differences in HDL subspecies remained. Our research findings support the concept that compared with control subjects, CHD patients not only have HDL deficiency but also have a major rearrangement in the HDL subpopulations with significantly lower α 1 and pre-α 1–3 (LpA-I) and significantly higher α 3 (LpA-I/A-II) particles.