Comparison Of The Effects Of Treatment With Insulinotropic Drugs-Repaglinide Or Gliclazide MR On Insulin Secretion And Lipid Metabolism In Patients With Newly-diagnosed Type 2 Diabetes Mellitus

Aims A loss of early-phase insulin secretion is an early marker of type 2 diabetes(T2D),and the restoration of it can improve insulin sensitivity,β-cell function,and lipid metabolism.The aim of this study was to evaluate the effects of treatment with Repaglinide(Rg)or Gliclazide(Gli)on glucose control,insulin secretion,and lipid profile in patients with T2D.Methods In the 4-week open-labelled parallel study,40 patients newly diagnosed with T2D were randomized 1:1 to Rg t.i.d or Gli qd treatment,and 34 patients completed the study.Both drugs were titrated to achieve a fasting blood glucose target of≤7 mmol/l.No lipid regulators were given during the study.A standard mixed meal tolerance test was performed at baseline and end of study.Plasma glucose(PG), serum true insulin concentration,proinsulin concentration,lipid profile and free fatty acid profile were measured at fasting and 7 points after meal(30',45',60' 90',120',180',and 240').Results Demographic and baseline characteristics were comparable between the two groups.At week 4,fasting and postprandial PG decreased significantly,and postprandial insulin concentrations increased significantly in both groups(all points,p＜0.05).The time to maximum insulin concentration occurred earlier in Rg group than in Gli group(90' vs.120').AUCins increased significantly in both groups(p＜0.05),and no difference was found between groups.Early-phase insulin secretion index(ΔI30/ΔG30)increased significantly in both groups(p＜0.05), especially in Rg group(p＜0.05 vs.Gli).There was no significant difference in HOMA-IR during the study.In Rg group the proinsulin/insulin ratio was improved at fasting and 5 points after meal(30',45',60' 90',180').In Gli group,the proinsulin/insulin ratio was not changed at fasting,and improved at 2 points after meal(60',180').TG,CHOL and free fatty acids decreased significantly in Rg group (p＜0.05),while no change was observed in Gli group.In Rg group decrease in serum CHOL levels correlated with the increase in true insulin secretion(r=0.484,P=0.036).Conclusion No significant differences were observed in glucose control and total insulin secretion after treatment between the two groups. However,treatment with Rg was associated with significantly greater improvements in early-phase insulin secretion,the quantity and quality of insulin secretion and lipid metabolism.In Rg group decrease in serum CHOL levels correlated with the increase in true insulin secretion.