1412-P: Visceral Adiposity Is an Independent Predictor of Incident Type 2 Diabetes in Japanese

Introduction & Objective: Visceral adiposity has been reported to be an important risk factor for type 2 diabetes (T2D). However, whether directly measured visceral adiposity is associated with the risk of developing T2D independent of other fat depots and insulin resistance and whether this association holds true in normal-weight individuals has not been investigated in a prospective cohort study of native Asians.

Methods: Study participants were 1244 Japanese men and women without diabetes at baseline. Intra-abdominal fat area (IAFA) and abdominal, thoracic, and thigh subcutaneous fat areas (SFA) were measured by CT. Total fat area (TFA) was calculated as the sum of these fat areas and total SFA as TFA minus IAFA. T2D was defined as a fasting plasma glucose level ≥126 mg/dL, or an A1c value ≥6.5%, or use of glucose-lowering medications or insulin. Cox proportional hazards model was used to estimate hazard ratios for T2D in relation to exposures.

Results: The mean BMI at baseline was 23.1 kg/m² and the mean age was 50.2 years. During the 10520 person-years of follow-up, we confirmed 112 cases of T2D. IAFA was associated with an increased risk for T2D. The multiple-adjusted hazard ratios of T2D for tertiles of IAFA were 2.76 (95% CI, 1.20-16.36) for tertile 2 and 4.96 (2.07-11.93) for tertile 3 compared with tertile 1 after adjustment for abdominal SFA, age, sex, family history of diabetes, smoking habit, regular physical activity, daily alcohol consumption, and fasting immunoreactive insulin. IAFA remained a significant risk factor for T2D even after adjustment for TFA, total SFA, abdominal SFA, waist circumference, or BMI, but none of these measures of fat area were associated with the risk of T2D in models including IAFA. In individuals with BMI <25 kg/m², these associations did not change.

Conclusions: Greater visceral adiposity increased the risk of T2D independent of other fat depots and insulin resistance in Japanese. These associations were similar in normal-weight individuals.