Aims/hypothesis: Information on the association of hyperinsulinaemia with coronary heart disease (CHD) in patients with Type II (non-insulin-dependent) diabetes is limited and controversial. Therefore, we carried out a prospective study to examine the predictive value of fasting plasma insulin and "hyperinsulinaemia cluster" with regard to the risk of CHD mortality.
Methods: At baseline risk factors for CHD were determined in 902 patients aged 45 to 64 years with Type II diabetes not treated by insulin (499 men and 403 women). These patients were followed up to 7 years for CHD mortality.
Results: Coronary heart disease mortality (16.2% in men, 9.2% in women) increased significantly in men with increasing plasma insulin tertiles (p = 0.006) and in both sexes combined (p = 0.010) but not in women (p = 0.090). The predictive value of hyperinsulinaemia with regard to death from CHD was independent of conventional cardiovascular risk factors but not of risk factors clustering with hyperinsulinaemia. By applying factor analysis and principal component analysis we showed that "hyperinsulinaemia cluster" (a factor having high positive loadings for body mass index, triglycerides and insulin; and a high negative loading for high-density lipoprotein cholesterol) was predictive of death from CHD in patients with Type II diabetes (hazard ratio with 95% confidence intervals 1.43 (1.18, 1.73), p < 0.001).
Conclusion/interpretation: Our results support the notion that cardiovascular risk factors clustering with endogenous hyperinsulinaemia increase the risk of death from CHD in patients with Type II diabetes not treated with insulin.