Intraindividual reproducibility of postprandial and orthostatic blood pressure changes in older nursing-home patients: Relationship with chronic use of cardiovascular medications

OBJECTIVES: Although postprandial and orthostatic hypotension are commonly observed in nursing home residents, their reproducibility, relationship to each other, and association with chronic use of cardiovascular medications are poorly understood. DESIGN: We examined blood pressure (BP) and heart rate (HR) before and after postural change, and before and after a 419-kcal meal in 22 nursing home residents (mean age 89 +/- 5 (SD) years), each on two occasions, to determine reproducibility of changes. These studies were repeated in 17 residents, with and without previous administration of cardiovascular medications, in random order. SETTING: Hebrew Rehabilitation Center for the Aged, an academic long-term care facility. RESULTS: Systolic BP declined an average (+/- SE) of 16 +/- 4 mm Hg and 12 +/- 4 mm Hg during the first and second meal studies, respectively. Mean intra-class correlation of post prandial systolic BP values during the two studies was 0.88 (95% CI 0.85-0.97). Systolic BP increased significantly during the first posture test to a maximum of 8 +/- 6 mm Hg at 6 minutes. There was no significant difference over time in postural systolic BP between the two tests. Repeated postural studies showed a mean intra-class correlation of 0.72 (95% CI 0.62-0.92) for changes in systolic BP. Cardiovascular medications had no additional effect on mean postprandial or orthostatic BP and HR changes. During the first studies, 10 subjects had postprandial hypotension, and three subjects had orthostatic hypotension, but only two of 22 subjects had both. CONCLUSIONS: Patterns of systolic BP response to meals or postural change are reproducible. BP responses to meals and postural change seem to be unaffected by potentially hypotensive medications in chronic users. Postprandial hypotension is distinct from orthostatic hypotension, occurring more commonly than orthostatic hypotension and infrequently together in the same patients.