IS METABOLIC SYNDROME A DISCRETE ENTITY IN THE GENERAL-POPULATION - EVIDENCE FROM THE CAERPHILLY AND SPEEDWELL POPULATION STUDIES

Objective-To examine the clinical and epidemiological utility of the c oncepts of metabolic syndrome and insulin resistance syndrome in two p rospective cohort studies of white men. Methods-Men aged 45-63 years w ere screened for evidence of ischaemic heart disease (IHD) between 197 9 and 1982 and followed up at regular intervals thereafter. Non-fatal coronary events were validated from hospital records and fatal coronar y events from death certificates. Results-Analysis of serum insulin co ncentrations in non-diabetic individuals measured at entry to the stud y showed no independent contribution to the prediction of subsequent I HD at 10 year follow up. Blood glucose concentrations, however, showed a small independent contribution in the combined cohort in the upper fifth of the distribution. Three different models of metabolic syndrom e among non-diabetic individuals were defined based on tertiles, media ns, and clusters. The predictive value of each model was assessed usin g logistic regression before and after adjustment for conventional and metabolic risk factors. After adjustment the odds were non-significan t and close to unity. Conclusions-This study did not detect any comple x relation among the five variables defining metabolic syndrome; the e xcess risk seems to be no greater than can be explained by individual effects of the defining variables in a multiple logistic model.