Optimal cut-off levels of body mass index and waist circumference in relation to each component of metabolic syndrome (MetS) and the number of MetS component.

AIMS: There is an ethnic difference of obesity index to diagnose metabolic syndrome. The authors explored the optimal cut-off levels for body mass index (BMI) and waist circumference (WC) in relation to each component of metabolic syndrome.
MATERIALS AND METHODS: Receiver operating characteristics (ROC) analysis was used to determine the optimal cut-off levels for each component of metabolic syndrome. This study included 4572 workers aged 42.5±9.9 years.
RESULTS: The optimal BMI cut-off values for diabetes mellitus, hypertension or dyslipidemia varied from 23.0 to 24.3 kg/m(2). As for WC, the optimal cut-off values varied from 83.0 to 83.7 cm. The optimal BMI cut-off values relating with one to three components of metabolic syndrome varied from 23.2 to 25.3 kg/m(2). As for WC, the optimal cut-off values varied from 83.0 to 85.0 cm. Pair-wise comparison of ROC curves showed that WC has an advantage in relation to metabolic syndrome and its components compared with BMI. By logistic regression analysis, odds ratios of obesity indices for hypertension, dyslipidemia or the number of metabolic component were all significantly increased. As for diabetes mellitus, odds ratios of BMI ≥25 and WC ≥85 significantly increased, respectively.
CONCLUSIONS: Japanese criteria of obesity in metabolic syndrome in man may be appropriate for diabetes mellitus. Ethnic difference in criteria of obesity in Asian metabolic syndrome exists, and mutual comparisons in the prevalence of metabolic syndrome have a difficulty to conduct.