Inter-individual variation in gastric emptying is related to GLP-1 response to intraduodenal glucose exposure in health.

Abstract

To determine whether gastric emptying of an oral glucose load is related to the glucagon-like peptide-1 (GLP-1) response to intestinal glucose exposure in healthy individuals. 42 healthy participants (20F/22 M, age: 35.1 ± 2.1 years; BMI 24.5 ± 0.6 kg/m2) were evaluated on 2 days. On Day 1, participants ingested a 75 g glucose drink containing 150 mg 13C-acetate, with the gastric half-emptying time (T50) (breath test) and blood glucose concentrations determined over 180 min. On Day 2, participants received an intraduodenal glucose infusion at 4kcal/min for 30 min. Plasma insulin, C-peptide and total GLP-1 concentrations were measured at frequent intervals. There was a direct relationship between the T50 of oral glucose and the incremental area under the curve (iAUC) for GLP-1 (t = 0-120 min) in response to intraduodenal glucose (r = 0.33, P = 0.03). When participants were stratified into tertiles according to T50, GLP-1 iAUC0-120min in response to intraduodenal glucose infusion was greater in participants with slower vs. faster gastric emptying (P = 0.02). In healthy individuals, gastric emptying of a glucose drink is related to the magnitude of the GLP-1 response to intestinal glucose exposure. This finding supports the concept of intestinal 'sensitivity' to nutrients as a determinant of gastric emptying.