Effects of Exogenous Glucagon-Like Peptide-1 on the Blood Pressure, Heart Rate, Mesenteric Blood Flow, and Glycemic Responses to Intraduodenal Glucose in Healthy Older Subjects

• Published in: The journal of clinical endocrinology and metabolism Vol. 99; no. 12; pp. E2628 - E2634
• Main Authors: Trahair, Laurence G., Horowitz, Michael, Hausken, Trygve, Feinle-Bisset, Christine, Rayner, Christopher K., Jones, Karen L.
• Format: Journal Article
• Language: English
• Published: United States Oxford University Press 01.12.2014; Copyright by The Endocrine Society
• Subjects: Aged; Autonomic Nervous System - drug effects; Blood flow; Blood Glucose - metabolism; Blood pressure; Blood Pressure - drug effects; Cardiovascular system; Clinical trials; Double-Blind Method; Duodenum - metabolism; Fasting; Female; Gastric emptying; Glucagon; Glucagon-like peptide 1; Glucagon-Like Peptide 1 - pharmacology; Glucose; Glucose - administration & dosage; Glucose - pharmacology; Heart rate; Heart Rate - drug effects; Humans; Insulin - blood; Intubation, Gastrointestinal; Male; Mesenteric Arteries - drug effects; Peptides; Splanchnic Circulation - drug effects
• ISSN: 0021-972X; 1945-7197; 1945-7197
• DOI: 10.1210/jc.2014-2475

Context:Studies relating to the cardiovascular effects of glucagon-like peptide-1 (GLP-1) and its agonists, which slow gastric emptying, have not discriminated between fasting and postprandial, blood pressure (BP) and heart rate (HR).Objective:To determine whether exogenous GLP-1 modulates the effects of an intraduodenal (ID) glucose infusion on BP, HR, and splanchnic blood flow in healthy older subjects.Design:A double-blind randomized trial was conducted.Setting:Community-dwelling residents attended a clinical research laboratory.Patients:Ten healthy “older” subjects (9 male, 1 female; age 73.2 ± 1.5 y) were studied.Interventions:Intravenous infusion of GLP-1 (0.9 pmol/kg/min), or saline (0.9%) for 90 min (t = −30–60 min). Between t = 0–60 min, ID glucose was infused at 3 kcal/min.Main Outcome Measures:BP, HR, superior mesenteric artery (SMA) flow, blood glucose, and serum insulin were measured.Results:During the fasting period (t = −30–0 min), GLP-1 had no effect on BP or HR. In response to ID glucose (t = 0–60 min), systolic BP decreased (P < .001), and both HR (P < .001) and SMA flow (P < .05) increased, on both days. GLP-1 attenuated the maximum decrease in systolic BP (P < .05), tended to increase HR (P = .09), and increased SMA flow (P < .01). GLP-1 diminished the glycemic response (P < .05).Conclusions:In healthy older subjects, acute administration of GLP-1 attenuates the hypotensive response to ID glucose, and potentiates the increase in SMA flow.