A crossover study of the combination therapy of metformin and exenatide or biphasic insulin aspart 30 in overweight or obese patients newly diagnosed with type 2 diabetes mellitus.

The aim of the present study was to explore the effects of various combinations of exenatide, metformin (MET) and biphasic insulin aspart 30 (BIA30) on type 2 diabetes mellitus (T2DM). Two hundred overweight or obese patients newly diagnosed with T2DM were evenly randomized into two groups: A (twice daily for all: Phase I, 5 µg exenatide + 0.5 g MET for 4 weeks, then 10 µg exenatide + 0.5 g MET for 8 weeks; Phase II, 0.5 g MET for 12 weeks; Phase III, 0.3-0.4 U/kg/day BIA30 + 0.5 g MET for 12 weeks) and B (Phases I, II, III matched the phases III, II and I in group A). In groups A and B a significant decrease and increase, respectively, in glycated hemoglobin (HbAlc) and body mass index (BMI) was noted during Phase I. A 3.2±0.4-kg decrease in body weight in group A and a 2.6±0.3-kg increase in group B was observed. In Phase II, HbAlc was significantly increased in both groups (P<0.05). In Phase III, the BMI was increased in group A and reduced in group B (P<0.05). There was a 3.8±0.4-kg weight decrease in group B and 4.2±0.5-kg increase in group A (P<0.05). The combination of exenatide and MET promoted weight loss, glycemic control, β-cell function index, C peptide and adiponectin levels. These results suggested that the combination of exenatide and MET is better than the combination of BIA and MET for the therapy of overweight or obese patients newly diagnosed with T2DM.