Aims/hypothesis A postprandial fall in BP occurs frequently in older individuals and in patients with type 2 diabetes. The magnitude of this decrease in BP is related to the rate of gastric emptying (GE). Intravenous administration of glucagon-like peptide-1 (GLP-1) attenuates the hypotensive response to intraduodenal glucose in healthy older individuals. We sought to determine the effects of exogenous GLP-1 on BP, GE, superior mesenteric artery (SMA) flow and glycaemic response to oral ingestion of glucose in healthy older individuals and patients with type 2 diabetes. Methods Fourteen older volunteers (six men, eight women; age 72.1±1.1 years) and ten patients with type 2 diabetes (six men, four women; age 68.7±3.4 years; HbA 1c 6.6±0.2% [48.5± 2.0 mmol/mol]; nine with blood glucose managed with metformin, two with a sulfonylurea and one with a dipeptidyl-peptidase 4 inhibitor) received an i.v. infusion of GLP-1 (0.9 pmol kg â1 min â1 ) or saline (154 mmol/l NaCl) for 150 min (t=â30 min to t= 120 min) in randomised order. At t=0 min, volunteers consumed a radiolabelled 75 g glucose drink. BP was assessed with an automated device, GE by scintigraphy and SMA flow by ultrasonography. Blood glucose and serum insulin were measured. Results GLP-1 attenuated the fall in diastolic BP after the glucose drink in older individuals (p<0.05) and attenuated the fall in systolic and diastolic BP in patients with type 2 diabetes (p<0.05). GE was faster in patients with type 2 diabetes than in healthy individuals (p<0.05). In both groups, individuals had slower GE (p<0.001), decreased SMA flow (p<0.05) and a lower degree of glycaemia (p<0.001) when receiving GLP-1. Conclusions/interpretation Intravenous GLP-1 attenuates the hypotensive response to orally administered glucose and decreases SMA flow, probably by slowing GE. GLP-1 and 'short-acting' GLP-1 agonists may be useful in the management of postprandial hypotension.