Do Different Metabolic Syndrome Definitions Predict Cerebrovascular Events and Coronary Heart Disease Independent of Their Components?: 9 Years Follow-Up of the Tehran Lipid and Glucose Study

The purpose of this study was to examine whether metabolic syndrome (MetS), applying different definitions, predicts incident coronary heart disease (CHD) and cerebrovascular events (CVAs) independent of its components. Among 2548, aged ≥ 50 years, World Health Organization, International Diabetes Federation, and Joint Interim Statement criteria were used to define MetS. Cox proportional hazards regression was implemented to estimate hazard ratios of incident CVA and CHD. During 9.3 years of follow-up, 72 and 343 cases of CVA and CHD events occurred. The multivariate hazard ratios (95% CI) of incident CVA and CHD were 2.71 (1.57-4.68) and 2.07 (1.63-2.64) for MetS as defined by the Joint Interim Statement, respectively. There was no difference among the 3 definitions of MetS regarding the prediction of the CVA incidence. However, MetS as defined by the Joint Interim Statement predicted CHD better than the International Diabetes Federation definition. After adjustment for components, MetS lost its association with CHD and CVA; in this model, the elevated blood pressure and high fasting plasma glucose (International Diabetes Federation definition) showed significant risk for CVA events; regarding CHD events, the elevated blood pressure, high fasting plasma glucose, and, for World Health Organization definition, obesity and dyslipidemia remained as predictors. All definitions of MetS were associated with CVA and CHD events. After adjusting its components, MetS lost its association with incident CVA and CHD; however, elevated blood pressure for both CVA and CHD events and high fasting plasma glucose for CHD events remained as independent predictors in all definitions.