The effect of DPP-4-protected GLP-1 (7–36) on coronary microvascular function in obese adults

Abstract

Objective Glucagon-like-peptide-1 (GLP-1) receptor analogues have been shown to reduce cardiovascular events in patients with type 2 diabetes. However, the mechanism behind is still unknown. The aim of the study was to investigate the effect of intact GLP-1 (7–36) on coronary microcirculation in overweight adults. Design and methods A double-blinded randomized cross-over study was performed, with 12 overweight participants. Effects of intact GLP-1 (7-36) infusion were compared with a saline infusion on separate days. A DPP-4 inhibitor was administered to block degradation of intact GLP-1 (7–36) to the GLP-1 metabolite (9–36). Coronary microcirculation was assessed by Doppler coronary flow velocity reserve (CFVR) before and after 2\u202fh of infusion. Peripheral endothelial function was assessed by flow mediated dilation (FMD) before and after one hour of infusion. Results CFVR was 3.77\u202f±\u202f1.25 during GLP-1 infusion and 3.85\u202f±\u202f1.32 during saline infusion, endothelial function was 16.3\u202f±\u202f15.5\u202f% during GLP-1 infusion and 7.85\u202f±\u202f7.76\u202f% during saline infusion. When adjusting for baseline values no significant differences in CFVR (ΔCFVR\u202f0.38\u202f±\u202f0.92\u202fvs.\u202fΔCFVR\u202f0.71\u202f±\u202f1.03, p\u202f=\u202f0.43) and no difference in peripheral endothelial function (ΔFMD\u202f7.34\u202f±\u202f11.5\u202f%\u202fvs.\u202fΔFMD\u202f–1.25\u202f±\u202f9.23%, p\u202f=\u202f0.14) was found. Conclusions We found no effect of intact GLP-1 (7–36), protected from DPP4 mediated degradation on coronary microcirculation in overweight adults.