Analysis of waist circumference in Japanese subjects with type 2 diabetes mellitus: Lack of propriety to define the current criteria of metabolic syndrome

A necessary condition of advocated criteria to determine the metabolic syndrome (MetS) in Japan is waist circumference (WC), which varies among races. In this study, we measured WC and visceral fat area (VFA) in subjects with type 2 diabetes (T2DM) and assessed the propriety of new criteria of MetS in Japan. Four hundred and nineteen patients (M/F: 258/161, age: 60.4 ± 0.7 years, BMI: 24.4 ± 0.2 kg/m2) who received abdominal CT examination were analyzed, and 178 (M/F: 111/67) subjects sufficed the criteria of MetS. Average VFA was significantly larger in subjects with MetS (162 ± 3 cm2 versus 82 ± 3 cm2, p < 0.01). The WC and VFA were correlated significantly in both male (r = 0.78, p < 0.001) and female (r = 0.82, p < 0.001), and corresponding VFA at 85 cm of WC in male and at 90 cm in female were 125 cm2 and 120 cm2. Incidence of cardio- and cerebro-vascular diseases (CVD) was not different between subjects with and without MetS. The present cross-sectional study strongly suggests that the recommended WC is not suitable to define the current criteria of MetS (VFA, ≧100 cm2) and its criteria is not appropriate to segregate a risk of CVD in Japanese T2DM subjects. Further prospective analysis should be required to validate the criteria and clinical significance of MetS in T2DM.