Study on the relation between insulin resistance and total and regional body fat in overweight and obese individuals

Objective To use the extended hyperinsulinemic euglycemic clamp technique for the study of insulin sensitivity in normal weight and normal glucose tolerant obese Chinese, and also, for the study of insulin sensitivity in relation to body adipose depots and distribution. Methods Twenty two Chinese 〔9 with normal weight (BMI25 kg/m 2) and 13 with overweight/obese (BMI≥25 kg/m 2)〕 from Shanghai area were included. Extended hyperinsulinemic euglycemic clamp experiment was performed on them, and the regional body adipose depots were measured by MRI. Results (1) Compared with normal weight group, the overweight/obese group showed the decrease in tissue glucose utilization 〔(3.37±0.15)mg·kg -1 ·min -1 vs (5.86±0.65)mg·kg -1 ·min -1 ,P0.01〕,mainlyduetodefect in glycogen synthesis 〔(1.51±0.15)mg·kg -1 ·min -1 vs (3.17±0.62)mg·kg -1 ·min -1 ,P0.01〕. (2) The overweight/obese group showed the decrease in the insulin inhibition of lipid oxidation and blood free fatty acid levels. (3) The increase in intra abdominal adipose tissue depots was the major regional body adipose abnormality in relation to insulin sensitivity (r=-0.80,P0.01). Conclusion The decreased insulin sensitivity is observed in overweight/obese Chinese with normal glucose tolerance, indicating increased intra abdominal fat mass affects insulin sensitivity in Chinese.