Indexed on: 12 Sep '14Published on: 12 Sep '14Published in: The Journal of clinical endocrinology and metabolism
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).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.A double-blind randomized trial was conducted.Community-dwelling residents attended a clinical research laboratory.Ten healthy "older" subjects (9 male, 1 female; age 73.2 ± 1.5 y) were studied.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.BP, HR, superior mesenteric artery (SMA) flow, blood glucose, and serum insulin were measured.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).In healthy older subjects, acute administration of GLP-1 attenuates the hypotensive response to ID glucose, and potentiates the increase in SMA flow.