Effect of islet β cell function and insulin resistance in patients of new-onset type 2 diabetes mellitus with different treatment

Abstract

Objective To compare effect on islet β cell function and insulin resistance(IR)by insulin(INS)injection and oral hypoglycemic agent(OHA)therapy in patients of new-onset type 2 diabetes mellitus.And estimate better treatment for patients of new-onset type 2 diabetes mellitus.Methods 62 patients of new-onset type 2 diabetes mellitus were randomly divided into two groups(INS therapy group and oral OHA therapy group).In OHA therapy group,sulphonylureas(SUs)and(or)dimethyl biguanide were the first choices of drugs.Thiazolidinediones(TZDs)might be also applied in combination if the patient's blood glucose level could not reach the anticipated goal(FBG＜6.0 mmol/L and 2h PG＜8.0 mmol/L).Two or three drugs in combination were used to most of the patients.The dosage of drugs or insulin was aoljusted according to the blood glucose level.After three months of treatment,fast blood glucose(FBG),fast insulin(FINS),2-hour postchallenge glucose(2h PG),glycoslyted hemoglobin(HbA1C),fast C peptide(FCP),2-hour postprandial C peptide(2 h CP)were observed.Islet β cell function index[Homaβ=20×FINS/(FBG-3.5)]and insulin resistance index[HomaIR=(FBG×FINS)/22.5]were calculated by the homeostasis model assessment(Homa).The level of C peptide(CP)level,Homa β and Homa IR etc.of two groups after treatment were compared in order to evaluate the effect on the islet β cell function and peripheral insulin resistance.Results (1)After treatment,FBG,2 h PG,HbA1C of both groups decreased significantly(P＜0.01),there was no statistical significance between two groups.(2)Mter treatment,FINS,FCP,2h CP,Homaβ in INS therapy groups increased(P＜0.05),and these was no significantly change in OHA therapy group(P＞0.05).There was statistical significance between two groups(P＜0.05).(3)After treatment,HomaIR in INS therapy group significantly decreased(P＜0.05),and there was no significantly change in OHA therapy group(P＞0.05).There was statistical significance between two groups(P＜0.05).Conclusions Early administrated insulin therapy Can improve the islet β cell function and peripheral insulin resistance.Compared with OHA therapy,INS therapy can protect the islet β cell function preferably. Key words: Diabetes mellitus, type 2; Insulin; Hypoglycemic agents; islet function; insulin resistance