ABSTRACT
Objective To assess the role of the different pancreatic islet β cell function index in the evaluation of glucose metabolism in different duration of type 2 diabetes mellitus (T2DM).Methods Normal glucose tolerance subjects without diabetes family history (NC group,48 cases) and T2DM patients (182 cases) were enrolled.The T2DM patients were divided into three groups:less than 5 years group (DM ＜5 group,74 cases),5-10 years group (DM5-10 group,51 cases) and more than 10 years group ( DM ＞10 group,57 cases).Oral glucose tolerance test (OGTT) and insulin release test were taken in all groups.Insulin resistance index (HOMA-IR) and whole body insulin sensitivity index [ISI(Matsuda)] were used to estimate insulin sensitivity,and early insulin secretion index ( △ I30/ △ G30) and glucose disposition index (DI) were used to evaluate the function of pancreatic islet β cell.Results HOMA-IR was increased and ISI (Matsuda) was decreased in DM ＜5 group,DM5-10 group and DM ＞10 group compared with those in NC group [HOMA-IR:8.78 ± 7.12,8.08 ± 3.67,7.84 ± 5.08 vs.4.76 ± 3.43;ISI(Matsuda):46.78 ± 29.00,36.71 ± 16.67,38.86 ±21.72 vs.61.13 ± 32.08,P ＜ 0.05],however,there was no significant difference among DM ＜5 group,DM5-10 group and DM ＞10 group.△ I30/ △ G30 and DI were decreased in DM ＜5 group,DM5-10 group and DM ＞10 group compared with those in NC group [ △ I30 △ G30:( 68.41 ± 361.52 ),(4.31 ± 3.42 ),(7.70 ± 5.78 ) mU/mmol vs.(92.65 ± 309.29) mU/mmol;DI:0.0421 ± 0.0123,0.0412 ± 0.0123,0.0363 ± 0.0116 vs.0.1151 ± 0.0236,P ＜ 0.05 ],and there was no significant difference in △ I30 / △ G30 among DM ＜5 group,DM5-10 group and DM ＞10 group,however,DI was decreased in DM＞10 group compared with that in DM＜5 group and DM5-10 group (P＜0.05).ConclusionsHOMA-IR,ISI (Matsuda),△I30/△G30 are not sensitive to evaluate the insulin resistance of different duration.DI can reflect the glucose utilization of pancreatic islet β cell earlier and the ability to regulate blood sugar steady state changes.