Aim: To compare exenatide and sitagliptin glucose and glucoregulatory measures in subjects with type 2 diabetes.
Methods: An 8‐week, double‐blind, randomized, crossover, single‐centre study. Eighty‐six subjects (58% female, body mass index 35 ± 5 kg/m2, haemoglobin A1c 8.3 ± 1.0%) received either exenatide 10 µg (subcutaneous) twice daily or sitagliptin 100 mg (oral) daily for 4 weeks and crossed to the other therapy for an additional 4 weeks. Main outcome was time‐averaged glucose during the 24‐h inpatient visits.
Results: Both treatments decreased average 24‐h glucose, but exenatide had a greater effect [between‐group difference: −0.67 mmol/l, 95% confidence interval (CI): −0.9 to −0.4 mmol/l]. Both treatments decreased 2‐h postprandial glucose (PPG), area under the curve of glucose above 7.8 mmol/l (140 mg/dl) and 11 mmol/l (200 mg/dl) and increased the time spent with glucose between 3.9 and 7.8 mmol/l (70 and 140 mg/dl) during 24 h, but exenatide had a significantly greater effect (p < 0.05). Both treatments decreased postprandial serum glucagon, with exenatide having a greater effect (p < 0.005). Both treatments decreased fasting blood glucose to a similar degree (p = 0.766). Sitagliptin increased, while exenatide decreased, postprandial intact glucagon‐like peptide‐1. Both drugs improved homeostasis model assessment of β‐cell function (HOMA‐B), with exenatide having a significantly greater effect (p = 0.005). Both exenatide and sitagliptin decreased 24‐h caloric intake, with exenatide having a greater effect (p < 0.001). There was no episode of major hypoglycaemia. Adverse events were mild to moderate and mostly gastrointestinal in nature with exenatide. No study withdrawals were due to an adverse event.
Conclusion: Compared to sitagliptin, exenatide showed significantly lower average 24‐h glucose, 2‐h PPG, glucagon, caloric intake and improved HOMA‐B.