24-hour Blood Pressure Variability and Falls Among Older Adults with Hypertension Taking Antihypertensive Medication: Results from the AMBROSIA Study

BACKGROUND: Higher short-term blood pressure (BP) variability (BPV) can reflect impaired autonomic regulation of BP in response to postural change and physical activity, which could precipitate falls through transient cerebral hypoperfusion and loss of postural stability. We hypothesized that higher short-term BPV assessed by ambulatory BP monitoring (ABPM) would be associated with an increased risk of falls. METHODS: This prospective study examined the association between BPV assessed by ABPM and fall risk among community-dwelling adults aged ≥65 years with hypertension who were taking antihypertensive medication. Participants completed 24-hour ABPM; subsequently, they completed 12 monthly falls calendars. Systolic BPV was quantified as the standard deviation (SD) of 24-hour systolic BP (SBP) (SD24h-SBP), calculated from the weighted average of awake and asleep SD values. Cox proportional hazards models estimated hazard ratios (HRs) for time to first fall, comparing quartile 4 (Q4) with quartiles 1-3 (Q1-Q3) of SD24h-SBP. RESULTS: Among 608 participants (mean±SD age 74.6±6.2 years; 56.9% female), 238 (39.1%) reported a fall during the 12-month follow-up period. Falls occurred in 172/457 (37.6%) and 66/151 (43.4%) participants in Q1-Q3 and Q4 of SD24h-SBP, respectively. Participants in Q4 of SD24h-SBP did not have a higher fall risk than Q1-Q3 (adjusted HR [95% CI] 1.17 [0.86-1.58]). In analyses using the SDs of awake and asleep SBP, Q4 was not associated with fall risk compared with Q1-Q3. CONCLUSION: Twenty-four hour and awake BPV assessed by ABPM was not associated with fall risk among older adults taking antihypertensive medication.