Abstract: Objective  To explore the impact of  exenatide  combined with metformin on islet function in patients with newly diagnozed type 2 diabetes mellitus. Methods  A total of 120 patients with newly diagnozed T2DM were randomly divided into four groups: diet and exercise group 30 cases（group A），  metformin group  30  cases （group B），exenatide group 30 cases（group C）  and metformin and exenatide group 30  cases （group D）. Blood glucose， insulin， glucagon (GC) and glucagonlike peptide1  （GLP1） were measured. Insulin secretion index（HOMAβ） and insulin resistance index（HOMAIR）  were calculated. Results  HOMAIR after treatment was significantly reduced in group B， C and D (P＜0.05)， HOMAβ  was significantly increased in group B， C and D (P＜0.05). After treatment， group B showed no significant difference compared with group A; the HOMAIR in group C and D after treatment was significantly decreased (P<0.05)， and the HOMAβ  was significantly increased (P<0.05); Compared with group B， the HOMAIR in group C and D after treatment was significantly decreased (P<0.05)， and the HOMAβ  was significantly increased (P<0.05); Compared with group C， the HOMAIR in group D after treatment was significantly decreased (P<0.05)， and the HOMAβ  was significantly increased (P<0.05). Conclusion   Exenatide combined with metformin could effectively improve the islet function in newly diagnozed T2DM， and the effect was better than monotherapy of exenatide or metformin.

Key words: diabetes mellitus, type 2； metformin;  , islets of langerhans