Comparison of definitions of metabolic syndrome in relation to risk for coronary artery disease and stroke.

OBJECTIVES: To compare definitions of metabolic syndrome (MS) in relation to their association with coronary artery disease (CAD) and stroke. METHODS: We performed a cross-sectional study in a primary care setting, involving 719 general practitioners and based on stratified distribution proportional to the population density. The first two adult patients scheduled for an appointment on a given day were invited to participate, irrespective of the reason for the consultation. A questionnaire was applied to record sociodemographic, clinical and laboratory data. A diagnosis of MS was defined according to NCEP-ATP III 2001, NCEP-ATP III 2004, IDF and AHA/NHLBI criteria. Multivariate logistic regression analysis was used to assess the risk of CAD and stroke according to gender, age, body mass index, waist circumference, HDL cholesterol, triglycerides, hypertension, diabetes and MS according to each definition. RESULTS: The study included 16,856 individuals (age 58.1 +/- 15.1 years). The prevalence of MS adjusted for gender, age and region size according to the 2001 and 2004 NCEP-ATP III, IDF and AHA/NHLBI definitions was 28.4%, 32.8%, 65.5% and 69.4%, respectively. The degree of agreement according to k statistics was modest and only 60.3% simultaneously fulfilled the criteria of all definitions. Hypertension was the treatable risk factor most strongly associated with CAD and stroke. Only the IDF and AHA/NHLBI definitions of MS were independently associated with CAD (OR: 1.74 and 2.26, respectively). Regarding stroke, only the AHA/NHLBI criteria showed a statistically significant association (OR: 1.85). CONCLUSIONS: MS as defined according to the AHA/NHLBI criteria appears to be the best predictor of CAD and stroke in the Portuguese population, and remains an independent risk factor for CAD and stroke after adjustment for its individual components.