BACKGROUNDIncretin-based therapies provide additional options for treating type 2 diabetes. We aimed to evaluate the efficacy and tolerability of exenatide monotherapy in obese patients with type 2 diabetes.

METHODSA 26-week, metformin controlled, parallel-group study was conducted among antidiabetic drug-naive obese patients aged > 18 years, and with type 2 diabetes. Participating patients were randomly assigned to receive exenatide or metformin treatments.

RESULTSFifty-nine patients (age (50.5 ± 8.6) years, body mass index (BMI) (30.2 ± 1.6) kg/m(2), and hemoglobin A1C (HbA(1C) (8.2 ± 1.2)%) were enrolled in the study. Glucose control and weight reduction improved in both groups receiving treatment. HbA(1C) and oral glucose tolerance test (OGTT) 2 hour glycemia reduction with exenatide was superior to that obtained with metformin ((-2.10 ± 1.79)% vs. (-1.66 ± 1.38)%, (-5.11 ± 2.68) mmol/L vs. (-2.80 ± 2.70) mmol/L, P < 0.05). Fast plasma glucose (FPG) reduction was not significantly different between the two groups ((-1.8 ± 2.0) mmol/L vs. (-1.6 ± 1.7) mmol/L, P > 0.05). Patients treated with exenatide achieved HbA(1C) of < 7% (97% of patients) and < 6.5% (79%) at end-point, vs. 93% and 73% with metformin (P > 0.05). Greater weight reduction was also achieved with exenatide ((-5.80 ± 3.66) kg) than with metformin ((-3.81 ± 1.38) kg, P < 0.01). Homeostasis model assessment of beta-cell function (HOMA-B) was not significantly increased, but the insulinogenic index and HOMA for insulin sensitivity (HOMA-S) were greatly improved in the exenatide group (P < 0.05). Nausea was the most common adverse effect in exenatide treatment (30% vs. 8%; P < 0.05), but most cases were of mild to moderate intensity. One case in the exenatide group was withdrawn early because of severe nausea. Hypoglycemia events were often observed during the first 4 weeks, with 12% of patients in the exenatide and 3.2% in metformin groups, respectively (P < 0.05). No incidents of severe hypoglycemia were reported.

CONCLUSIONSExenatide demonstrated more beneficial effects on HbA(1C), weight reduction and insulin resistance during 26 weeks of treatment, but there were more hypoglycemic events and mild-to-moderate nausea compared with metformin. These results suggested that exenatide monotherapy may provide a viable treatment option in newly developed type 2 diabetes.