INSULIN IN ISCHEMIC-HEART-DISEASE - ARE ASSOCIATIONS EXPLAINED BY TRIGLYCERIDE CONCENTRATIONS - THE CAERPHILLY PROSPECTIVE-STUDY

Objective-To investigate the predictive value of fasting insulin conce ntrations for subsequent fatal or non-fatal ischaemic heart disease at five year follow up and to examine the associations between insulin a nd other indicators of risk. Design-A prospective population study amo ng 2512 men aged 45 to 59 at recruitment. Setting-A whole population s ample of men resident in Caerphilly, South Wales. Measurements-At recr uitment fasting blood samples were taken for measurement of plasma lip ids and serum insulin. Men were re-examined at a five year follow up a nd ischaemic heart disease events during this period were assessed fro m hospital notes, death certificates, and electrocardiograms. Main res ults-Diabetic men and those men with a fasting blood glucose of greate r than or equal to 8 mmol/l were excluded from all analyses. In a univ ariate analysis the incidence of ischaemic heart disease increased wit h increasing concentration of fasting insulin, such that for men in th e top 20% of the insulin distribution the odds of developing ischaemic heart disease were 1.87 relative to men in the bottom 20%. On multiva riate analysis this relation disappeared on adjusting for plasma trigl ycerides, body mass index, and evidence of ischaemic heart disease at recruitment. Conclusion-In this population in South Wales there was no evidence that the fasting insulin concentration is an independent ris k factor for ischaemic heart disease. The univariate association betwe en insulin and incident disease was almost entirely explained by the a ssociation of both with triglycerides and body mass index.