ASSOCIATION OF INSULIN AND INSULIN PROPEPTIDES WITH AN ATHEROGENIC LIPOPROTEIN PHENOTYPE

A characteristic lipoprotein phenotype, including hypertriglyceridemia . a low high density lipoprotein (HDL) cholesterol concentration, and a predominance of small, dense low-density lipoprotein (LDL) particles , is linked to insulin resistance and hyperinsulinemia. Individuals wi th these characteristics are supposed to be at increased risk of devel oping coronary heart disease (CHD). To address this issue further, rel ations between basal and postload glucose, insulin and insulin propept ide concentrations, and subfractions of apolipoprotein (apo) B-contain ing lipoproteins were examined in 62 consecutive Swedish nondiabetic m en who had experienced a first myocardial infarction before the age of 45. A total of 41 age-matched, population-based healthy men were inve stigated as controls. Highly specific immunoradiometric assays were us ed for measuring intact proinsulin and des 31,32proinsulin levels. In all, 39% of the patients were found to be glucose-intolerant. and basa l and postload hyper(pro)insulinemia were characteristic features irre spective of glucose tolerance category. Hypertriglyceridemic (HTG) lip oprotein phenotypes with a low HDL cholesterol concentration dominated among the patients, and hyperinsulinemia was linked to hypertriglycer idemia and putatively atherogenic lipoprotein traits, such as increase d particle numbers of small very-low-density lipoprotein (VLDL) and in termediate-density lipoprotein (IDL) and triglyceride enrichment of LD L. The corollary of these findings is that insulin resistance is a cha racteristic feature of young postinfarction patients and is accompanie d by a complex atherogenic lipoprotein phenotype, new components of wh ich are an abundance of small cholesteryl ester-rich VLDL and an eleva ted LDL triglyceride concentration. Copyright (C) 1995 by W.B. Saunder s Company