OBJECTIVETo explore the factors affected insulin sensitivity index (ISI) and the effects of superior fiber complex (SFC) on ISI and blood lipids in non-insulin dependent diabetes mellitus (NIDDM) rats.

METHODSTwenty-six male Wistar rats were injected with low dose of streptozotocin and fed a diet with high calorie and high fat for ten weeks and glucose tolerance (GTT), fasting insulin (FINS), total cholesterol (TC) and triglyceride (TG) were measured while area under curve (AUC) and insulin sensitivity index (ISI) were also calculated. The results were compared with those from 7 normal control rats. Multi-factor regression analysis was used to analyze those factors affected ISI. In the same experiment, 13 rats with diabetes mellitus were treated with Superior Fiber Complex (SFC) for 8 weeks and the results were compared with the pre-treated data.

RESULTSCompared with the control group, AUC in the diabetic group was larger, and FINS, TC and TG were higher; but ISI was lower. Therefore, The TG and AUC was the major factor affected ISI. TC and TG were lowered and AUC was reduced and ISI increased.

CONCLUSIONHigh TG and impaired glucose tolerance (IGT) are main risk factors of ISI in the rat model, and SFC could increase ISI, decrease high blood lipids and prevent IGT.