Poster Presentation Australian Diabetes Society and the Australian Diabetes Educators Association Annual Scientific Meeting 2017

POSTER DISCUSSION: Effects of sitagliptin on gastric emptying of, and the blood pressure response to, a carbohydrate meal in type 2 diabetes (#332)

Madeline Buttfield 1 , Julie E Stevens 2 3 , Seva Hatzinikolas 3 , Tongzhi Wu 3 , Hung Pham 3 , Kylie Lange 3 , Chris K Rayner 3 , Michael Horowitz 3 , Karen L Jones 1 3
  1. School of Health Sciences, University of South Australia, Adelaide, SA, Australia
  2. School of Pharmacy, University of South Australia, Adelaide, SA, Australia
  3. The University of Adelaide, Adelaide, SA, Australia

Introduction: A substantial postprandial fall in blood pressure (BP), postprandial hypotension (PPH), occurs frequently in type 2 diabetes (T2DM) and the fall is greater when gastric emptying (GE) is relatively more rapid (1). There is no satisfactory treatment for PPH. We have shown that intravenous administration of glucagon-like peptide-1 (GLP-1), slows GE and attenuates the postprandial fall in BP in T2DM (2). Dipeptidyl peptidase-4 (DPP-4) inhibitors, which prevent the degradation of GLP-1 and thereby increase plasma levels of active GLP-1, are used widely in the management of T2DM.

Objectives: To determine the effects of the DPP-4 inhibitor, sitagliptin, on GE of, and the BP response to, a high carbohydrate meal in T2DM.

Methods: Fourteen patients with T2DM (9M, 5F; age: 67.8±1.5yr; BMI: 31.2±0.9kg/m2; diabetes duration: 4.2±0.9yr; HbA1c: 6.35±0.2%), managed by diet ± metformin, underwent simultaneous measurements of GE, BP, heart rate (HR) and blood glucose for 240 min after a mashed potato meal labelled with 20MBq 99mTc-Calcium Phytate on two separate days. Subjects received sitagliptin (100mg) or placebo in randomised, double-blind, crossover fashion on 2 consecutive days; the last dose was given 60 min before the meal. Data are mean values ± SEM.

Results: There was no difference in GE (T50) between the two days (sitagliptin:71.5±3.9min vs placebo: 71.1±4.3min; P=0.88. There was a fall in systolic BP (max fall sitagliptin: 16.2±3.2mmHg; placebo: 16.9±1.9mmHg; P<0.01 for both) and a rise in HR (max rise sitagliptin: 17.1±1.7BPM; placebo: 15.2±1.4BPM; P<0.01 for both) following the meal without any difference between the two days. The blood glucose response was reduced by sitagliptin (AUC 0-240 min: sitagliptin: 2392±169mmol/L*min vs placebo: 2539±160mmol/L*min; P<0.05).

Conclusion: Sitagliptin has no effect on GE or postprandial BP in T2DM. DPP-4 inhibitors are, accordingly, unlikely to be useful in the management of PPH.

  1. Jones KL, Tonkin A, Horowitz M, Wishart JM, Carney BI, Guha S, Green L. Rate of gastric emptying is a determinant of postprandial hypotension in non-insulin-dependent diabetes mellitus. Clin Sci 1998;94:65-70.
  2. Trahair LG, Horowitz M, Stevens JE, Feinle-Bisset C, Standfield S, Piscitelli D, Rayner CK, Deane AM, Jones KL. Effects of exogenous glucagon-like peptide-1 on blood pressure, heart rate, gastric emptying, mesenteric blood flow and glycaemic responses to oral glucose in older individuals with normal glucose tolerance or type 2 diabetes. Diabetologia 2015;58:1769-78.