The Evaluation Of β-cell Secretion Function Of Intial Type2Diabetes Mellitus In Different States

ObjectiveTo investigate isletβcell function of newly diagnosed type2diabetes patients in basicstate, arginine stimulation test and steamed bread meal test.Methods119newly diagnosed type2diabetes patients (NT2DM) and429participants withnormal glucose tolerance (NGT) were recruited, and they were classified into3groupsseparately according to Body Mass Index (BMI). Serum plasma glucose, plasma insulin,Homeostasis model assessment derived HOMA-βand HOMA-IR, insulin/plasma glucoseratio, insulin increment, area under curve of insulin, area under curve of glucose weremeasured in basic statement, arginine stimulation test and steamed bread meal test toevaluate βcell function.Results1. In basic state, fasting insulin, plasma2h-glucose, HOMA-βand HOMA-IR wereall affected by BMI in both type2diabetes group and control group (P<0.05). Thedifference in the fasting and2h values of plasma glucose among3groups in NT2DMshowed no statistical significance (P>0.05). HOMA-βwas significantly higher in NGTthan NT2DM, while HOMA-IR was significantly lower (P<0.05).2. After arginine stimulation test, plasma glucose was slowly increasing while notparalleled with plasma insulin increment in all3groups in NT2DM. The difference ininsulin/plasma glucose ratio had statistical significance among groups (P<0.05). Insulinincrement, area under curve of insulin were higher in obesity group than normal weightand overweight group (P<0.05).3. After standard steamed bread meal test, area under curve of glucose wassignificantly higher in NT2DM than NGT (p<0.05). Area under curve of insulin was higherin obesity than normal weight and overweight group in NGT (P<0.05). The differences in the value of area under curve of glucose and insulin showed no significance among groupsin NT2DM (P>0.05).Conclusions1. Basic state, arginine stimulation test, steamed bread meal test all could evaluateisletβcell function well. isletβcell function of NT2DM is worse than that of controls. Sowe would choose appropriate tests to evaluate βcell function according to differentresearch aims. Appropriate application of isletβcell function evaluation tests and relevantindex could be beneficial for our clinical research work.2. Obesity is related to hyperglycemic, hyperinsulinemia and diabetes. There existsdifference in index of isletβcell function, such as PG, insulin, HOMA-β、HOMA-IR,INS/PG, ΔINS、AUC（INS）, in sub-groups of NT2DM grouped by BMI.