Impact of metabolic syndrome, diabetes and prediabetes on cardiovascular events: Tehran lipid and glucose study.

AIMS: To compare the cardiovascular disease (CVD) risk associated with the metabolic syndrome (MetS) and dysglycemia, independent of each other during a median follow-up of 6.7 years.

METHODS: Study population included 4018 Iranian subjects >or=40 years, free of CVD or coronary heart disease (CHD) at baseline. Incidence rates and hazard ratio (HR) were estimated by the presence or absence of MetS and dysglycemia. Considering the glycemic status, the ability of MetS in prediction of CVD after adjustment for age, sex and CVD risk factors was assessed.

RESULTS: The prevalence of MetS, impaired fasting glucose or impaired glucose tolerance (IFG/IGT) and diabetes were 51.4%, 27.3%, and 18.7%, respectively. The addition of MetS to diabetes did not change the CVD risk compared to diabetic subjects without MetS (reference group) after adjustment for age and sex [HR: 1.62 (95% CI 0.93-2.81)] and CVD risk factors [HR: 1.49 (95% CI 0.86-2.60)]. However, addition of MetS to IFG/IGT increased the risk of CVD by 2.5 times compared to those with IFG/IGT without MetS (the risk factor adjusted HR: 2.45 (95% CI 1.32-4.55)).

CONCLUSIONS: In Iranian population, MetS did not add to diabetes to predict incident CVD however, IFG/IGT was a significant predictor only in the presence of MetS.