HETEROGENEITY OF HIGH-DENSITY-LIPOPROTEIN PARTICLES AND INSULIN OUTPUT DURING ORAL GLUCOSE-TOLERANCE TEST IN MEN WITH CORONARY-ARTERY DISEASE

We compared the high-density lipoprotein (HDL) composition and particl e heterogeneity in 60 nonobese (normal body mass index, BMI) men suffe ring from coronary artery disease (CAD) with normolipemia and normoins ulinemia with lower and higher insulin output during the oral glucose tolerance test (silent hyperinsulinemia). The apolipoprotein apoAI, ap oAII, and apoE levels were higher in the high insulin response (HI) gr oup than in low insulin response (LI) group. The ratio of apoAI versus total protein and the ratio of apoAI versus total cholesterol were in creased in HI compared with LI. The lipid components in HDL were highe r in LI than in HI, while for HDL2 they were higher in HI. The fractio ning of HDL by gradient gel electrophoresis revealed a different patte rn of HDL particles in both groups. The larger particles, HDL2b and HD L2a (mean particle diameters 10.6 and 9.2 nm, respectively), occur mor e frequently in HI patients (up to 60%) than in LI patients, whereas t he smaller particles, HDL3a and HDL3b (mean particle diameters 8.6 and 7.8 nm, respectively), predominate in LI patients. Our results demons trate that even in the normoglycemic, normocholesterolemic CAD patient s, a high insulin output observed during the oral glucose tolerance te st may be connected with a different HDL particle pattern, which sugge sts changes in the reverse cholesterol transport.