Longitudinal changes in the blood pressure responses to, and gastric emptying of, an oral glucose load in healthy older subjects.

The rate of gastric emptying is a major determinant of the hypotensive response to a meal. Cross-sectional studies suggest that healthy aging is associated with a modest slowing of gastric emptying. We aimed to determine longitudinal changes in the blood pressure (BP) response to, and gastric emptying of, glucose in healthy older people. Thirty-three participants (77.0 +/- 0.7 years) had baseline and follow-up measurements after 5.8 +/- 0.1 years. Participants consumed a 300-mL drink containing 75 g glucose and 150 mg C-13-acetate. BP and heart rate (HR) were measured at 5-minute intervals for 120 minutes after the drink. Exhaled breath was collected to calculate the gastric 50% emptying time. The prevalence of postprandial hypotension (PPH) doubled from 9.1% to 18.2%. Gastric emptying was slower at follow-up (p = .04). The fall in systolic BP (SBP) was related directly to the rate of gastric emptying at both the initial study (r = .54, p = .005) and at follow-up (r = .41, p = .04). The change in the maximum fall in SBP was related to the increase in baseline SBP (r = -.63, p < .001). In conclusion, in healthy older people over a period of similar to 5.8 years, there was an increased prevalence of PPH and a modest slowing of gastric emptying. The latter was related directly to a greater hypotensive response.