SERUM-INSULIN IS A RISK MARKER FOR CORONARY HEART-DISEASE MORTALITY IN MEN BUT NOT IN WOMEN

Serum insulin 1 h post-glucose load is examined in this prospective st udy of 2971 Caucasoid subjects aged > 20 years in 1966 and followed to 1989. The serum insulin levels as a continuous variable show no signi ficant linear association with coronary heart disease (CHD) deaths in either sex after accounting for age by Cox proportional hazards analys is. In males the quintile classes of serum insulin show a striking U-s haped pattern with both the highest and lowest quintiles having signif icant associations with CHD deaths. In females the insulin quintiles s how no direct association. Analysis for interactions of risk variables indicate that in females the relative protection df low cholesterol l evels is abolished by hyperinsulinaemia after 12 years, Thus, serum in sulin is not a direct aetiological risk factor for CHD. The findings s uggest that the associations are likely to be due to confounding effec ts of unmeasured variables including lipid subfractions.