Minimum Waist and Visceral Fat Values for Identifying Japanese Americans at Risk for the Metabolic Syndrome

OBJECTIVE — Japanese American is an ethnic group with a high risk for type 2 diabetes, which is linked to the metabolic syndrome. Central adiposity is considered to play a key role in the metabolic syndrome. Not known are the optimal cut point values for central and visceral adiposity to identify Japanese Americans at risk for the metabolic syndrome. RESEARCHDESIGNANDMETHODS — Study subjects included 639 Japanese Amer-icans. The nonadipose variables of the metabolic syndrome were defined using modified Inter-national Diabetes Federation criteria, and the accuracy of identifying at least two of these by intra-abdominal fat area (IAFA) as measured by computed tomography and waist circumference was cross-sectionally assessed using area under receiver operating characteristic (ROC) curves. The values for IAFA and waist circumference that resulted in maximizing the Youden index were defined as “optimal.” RESULTS — The area under the ROC curve for IAFA exceeded that for waist circumference (men 0.787 vs. 0.686; women 0.792 vs. 0.721). For women, the optimal cut points for IAFA and waist circumference were 51.5 cm2 and 80.8 cm (age56 years) and 86.3 cm2 and 89.0 cm (age 56 years). For men, the optimal cut points for IAFA and waist circumference were 88.6 cm2 and 90.0 cm (age 57 years) and 96.1 cm2 and 87.1 cm (age 57 years). CONCLUSIONS — These results argue that current Japanese waist circumference cut points for the metabolic syndrome need to be revised. Moreover, the waist circumference and IAFA cut points should be age specific, especially in women. Appropriate waist circumference cut point