Accumulation of visceral adipose tissue is associated with metabolic complications such as noninsulin-dependent diabetes mellitus. The aim of this study was to evaluate the effect of abdominal adipose tissue on insulin sensitivity in subjects with noninsulin-dependent diabetes mellitus (NIDDM). Areas of abdominal fat were calculated from axial magnetic resonance images obtained at the level of the umbilicus in 21 men with NIDDM [age, 45.6+/-8.3 (+/-SD) yr; body mass index, 29.3+/-4.5 kg/m(-2); total body fat (skinfold thickness), 26.8+/-5.4%; waist to hip ratio, 0.97+/-0.07; duration of diabetes, 59+/-47 months; hemoglobin A(1c), 8.1+/-1.5%]. Insulin sensitivity was evaluated by an insulin tolerance test. The areas of deep abdominal fat and sc abdominal fat were, respectively, 135.3+/-55.1 and 211.8+/-99.1 cm(2). The blood glucose disappearance rate was 2.11+/-0.87%/min and was negatively related to deep abdominal fat (r = 0.72; P = 0.0025). In contrast, areas of sc abdominal fat, total body fat, body mass index, and waist to hip ratio were not related to the blood glucose disappearance rate. Plasma triglyceride concentrations averaged 1.8+/-0.8 mmol/L and were positively related to deep abdominal fat (r = 0.69; P = 0.0018). We conclude that insulin sensitivity is strongly related to visceral adipose tissue accumulation NIDDM.