Effect of baseline body mass index on glycemic control and weight change with exenatide monotherapy in Chinese drug-naive type 2 diabetic patients

Background The weight-reducing effect of exenatide has been proved, but too much weight loss in normal-weight patients may concern physicians. This study evaluated the effects of exenatide monotherapy on glycemic control and weight change in normal-weight, overweight, and obese patients with newly diagnosed type 2 diabetes (T2D). Methods In this multicenter prospective study, 29 normal-weight, 54 overweight, and 27 obese newly diagnosed and drug-naive patients with T2D were treated with exenatide for 48 weeks. The primary efficacy endpoint was the effect of baseline body mass index (BMI) on glycemic control, measured as the change in HbA1c from baseline to Week 48 compared among different BMI groups. Other endpoints included comparisons of the effects of exenatide on fasting plasma glucose (FPG), postprandial plasma glucose (PPG), body weight, and other metabolic indices. Results After 48-week treatment, the estimated mean changes in HbA1c in normal-weight, overweight, and obese patients were -1.9%, -1.8%, and -1.5%, respectively (P = 0.290 among groups after adjustment for baseline values). There were similar declines in FPG and 0.5- and 2-hour PPG among groups. There were non-significant trends from normal-weight to overweight to obese patients for increased weight reduction (decreases of 2.2, 3.9, and 4.0 kg, respectively; P = 0.104) and changes in waist circumference (decreases of 2.2, 3.2, and 5.6 cm, respectively; P = 0.078). Conclusions Baseline BMI had no effect on glycemic control, weight change, or other metabolic indices with exenatide monotherapy. Normal-weight patients with T2D would benefit from exenatide as much as overweight or obese patients on glucose control, without increased risk of excess weight loss.