Obesity indexes and cutoff values for diagnosis of metabolic syndrome

Objective To evaluate predictive value of various obesity indexes in the identification of metabolic syndrome(MS) and to calculate optimal cutoff values of the obesity indexes. Methods Anthropometric measurements,physiological parameters and blood sample tests were taken among 1 907 in-service and retired staff in a university in Shenyang.The diagnostic criteria for MS defined by the International Diabetes Federation(IDF) and the Chinese Diabetes Society(CDS) were used.The receiver operating characteristic(ROC) curve analyses were performed to determine the best obesity index among waist circumference(WC),body mass index(BMI),waist-to-stature ratio(WSR),and waist-to-hip ratio(WHR) in diagnosis of MS.The optimal cutoff values were determined by the maximal Youden's indexes. Results Based on the IDF criteria,the optimal WC cutoff values were 90 cm in men and 80 cm in women.Based on the CDS criteria,the optimal BMI cutoff values were 24.6 in men and 25.6 in women.WSR had the highest area under the ROC curve and showed significantly better predictive value than BMI to identify MS(all P0.05).The optimal WSR cutoff values were 53 for men and 51 for women.Risks of clustering MS risk factors were significantly higher in subjects with WSR above the cutoff value than those in normal range(P0.05).Reducing the WSR to the normal range could prevent 41.3%-44.6% clustering of MS risk factors. Conclusion WSR is the simplest and best effective obesity index in the diagnosis of metabolic syndrome.