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 with these characteristics are supposed to be at increased risk of developing
coronary heart disease (CHD). To address this issue further, relations between basal and postload
glucose,
insulin and
insulin propeptide concentrations and subfractions of
apolipoprotein (
apo) B-containing
lipoproteins were examined in 62 consecutive Swedish nondiabetic men who had experienced a first
myocardial infarction before the age of 45. A total of 41 age-matched, population-based healthy men were investigated as controls. Highly specific immunoradiometric assays were used for measuring intact
proinsulin and des 31,32proinsulin levels. In all, 39% of the patients were found to be
glucose-intolerant, and basal and postload hyper(pro)insulinemia were characteristic features irrespective of
glucose tolerance category. Hypertriglyceridemic (HTG)
lipoprotein phenotypes with a low
HDL cholesterol concentration dominated among the patients, and
hyperinsulinemia was linked to
hypertriglyceridemia and putatively atherogenic
lipoprotein traits, such as increased particle numbers of small
very-low-density lipoprotein (VLDL) and
intermediate-density lipoprotein (IDL) and
triglyceride enrichment of
LDL. The corollary of these findings is that
insulin resistance is a characteristic feature of young postinfarction patients and is accompanied by a complex atherogenic
lipoprotein phenotype, new components of which are an abundance of small
cholesteryl ester-rich VLDL and an elevated
LDL triglyceride concentration.