Relation of High TG–Low HDL Cholesterol and LDL Cholesterol to the Incidence of Ischemic Heart Disease

High triglyceride (TG) and low HDL cholesterol (HDL-C) is the characteristic dyslipidemia seen in insulin-resistant subjects. We examined the role of this dyslipidemia as a risk factor of ischemic heart disease (IHD) compared with that of high LDL cholesterol (LDL-C) in the Copenhagen Male Study. In total 2910 white men, aged 53 to 74 years, free of cardiovascular disease at baseline, were subdivided into four groups on the basis of fasting concentrations of serum TG, HDL-C, and LDL-C. "High TG-low HDL-C" was defined as belonging to both the highest third of TG and the lowest third of HDL-C; this group encompassed one fifth of the population. "High LDL-C" was defined as belonging to the highest fifth of LDL-C. A control group was defined as not belonging to either of these two groups. "Combined dyslipidemia" was defined as belonging to both dyslipidemic groups. Age-adjusted incidence of IHD during 8 years of follow-up was 11.4% in high TG-low HDL-C, 8.2% in high LDL-C, 6.6% in the control group, and 17.5% in combined dyslipidemia. Compared with the control group, relative risks of IHD (95% confidence interval), adjusted for potentially confounding factors or covariates (age, body mass index, alcohol consumption, physical activity, non-insulin-dependent diabetes, hypertension, smoking, and social class), were 1.5 (1.0-2.1), P < .05; 1.3 (0.9-2.0), P = .16; and 2.4 (1.5-4.0), P < .01, in the three dyslipidemic groups, respectively. In conclusion, the present results showed that high TG-low HDL-C, the characteristic dyslipidemia seen in insulin-resistant subjects, was at least as powerful a predictor of IHD as isolated high LDL-C. The results suggest that efforts to prevent IHD should include intervention against high TG-low HDL-C, and not just against hypercholesterolemia.