Subjects With Normal Glucose Tolerance

OBJECTIVE — The purpose of this study was to investigate the association between visceral adiposity or triglyceride (TG) metabolism and insulin resistance in metabolically obese, normal weight (MONW) Japanese individuals with normal glucose tolerance. RESEARCH DESIGN ANDMETHODS — We evaluated body fat areas, lipid profiles, and the glucose infusion rate (GIR) during a euglycemic-hyperinsulinemic clamp study in 20 MONW subjects (BMI25 kg/m2and visceral fat areas 100 cm2) with normal glucose tolerance. Body fat areas were measured by computed tomography scans. Control data were obtained from 20 normal subjects (BMI 25 kg/m2 and visceral fat areas 100 cm2). RESULTS — MONW subjects showed a significant increase in fasting serum levels of TG (P 0.01) and a decrease in GIR (P 0.01) compared with normal subjects. There were significant correlations between visceral fat areas (r 0.563, P 0.01) or serum levels of TG (r 0.474, P 0.05) and GIR in MONW subjects. Multiple regression analyses showed that visceral fat areas (F 7.702, P 0.02) and serum levels of TG (F 7.114, P 0.05) were significantly associated with GIR in all (MONW and normal) subjects. CONCLUSIONS — Increased visceral fat and serum levels of TG are associated with insuli