Effects of sitagliptin on gastric emptying of, and the glycaemic and blood pressure responses to, a carbohydrate meal in type 2 diabetes

Aims: To determine the effects of the dipeptidyl peptidase-4 inhibitor, sitagliptin, on gastric emptying (GE) of a high-carbohydrate meal and associated glycaemic and blood pressure (BP) responses in type 2 diabetes mellitus (T2DM). Materials and Methods: Fourteen patients with T2DM (nine men, five women; age 67.8 ± 1.5 years; body mass index 31.2 ± 0.9 kg/m²; T2DM duration: 4.2 ± 0.9 years; glycated haemoglobin: 46 ± 1.8 mmol/mol [6.4% ± 0.2%]), managed by diet and/or metformin, underwent concurrent measurements of GE, BP and plasma glucose for 240 minutes after ingestion of a radiolabelled mashed potato meal after receiving sitagliptin (100 mg) or placebo in randomized, double-blind, crossover fashion on 2 consecutive days. Results: Sitagliptin reduced postprandial plasma glucose (P <.005) without affecting GE (P =.88). The magnitude of the glucose-lowering effect (change in incremental area under the curve^{0–240 min} from placebo to sitagliptin) was related to GE (kcal/min) on placebo (r = 0.68, P =.008) There was a comparable fall in systolic BP (P =.80) following the meal, with no difference between the 2 days. Conclusions: In T2DM, while sitagliptin has no effect on either GE or postprandial BP, its ability to lower postprandial glucose are dependent on the basal rate of GE.