Intraindividual variability in orthostatic blood pressure changes among older adults: The influence of meals

OBJECTIVES: To examine the influence of time of day and of meals on postura l blood pressure (BP) changes in older adults. DESIGN: Prevalence study of BP changes in response; to orthostasis. SETTING: A geriatric short-stay department PARTICIPANTS: A total of 126 inpatients (91 women and 35 men; mean age: 81. 4 +/- 7.9, range 61-95 years) were included in the study. MEASUREMENTS: Two sets of BP and heart rate measurements were obtained for each subject by one examiner using a standard mercury manometer: (1) in mid -morning (between 10:00 and 10:30 a.m.) and (2) within 30 to 60 minutes aft er lunch (between 1:00 and 1:30 p.m.), Orthostatic hypotension (OH) was def ined as a systolic blood pressure (SBP) decline greater than or equal to 20 mm Hg within 3 minutes after standing. RESULTS: Sixty-one participants (48%) experienced significant orthostatic B P decline on at. least one reading. Among them, 46 (37%) had OH in the mid- morning, and 32 (25%) had OH after lunch (P = .05). Only 17 (13%) had OH on both readings (persistent OH). Forty-four patients (35%) had variable OH. Patients with persistent OH were more likely to exhibit symptoms of dizzine ss and had a lower body mass index and a higher mean basal supine SEP. Ther e was a positive correlation between basal supine SEP and postural SEP decl ine. CONCLUSIONS: Because of the variability of postural BP changes, the diagnos is of OH should not be based on a single orthostatic BP measurement but req uires repeated testing, at best under circumstances similar to those in whi ch the symptoms occurred. The postprandial period is not particularly favor able to OH, suggesting that the ingestion of a meal does not worsen orthost atic BP changes in most aged patients.