Falls and Orthostatic Hypotension in Older Adults: Re-examining Limits.

Background: Orthostatic hypotension (OH) is defined using substantial thresholds of blood pressure (BP) drops with standing, which may be insufficient for identifying falls risk.

Objective: To assess associations between falls risk and (1) consensus-defined OH (cOH), (2) standing BP levels, (3) BP changes with standing, (4) combined standing BP levels and BP changes with standing.

Design: Observational study of normative aging.

Setting: Baltimore Longitudinal Study of Aging.

Participants: Participants ≥65 years with first visits evaluating OH and self-reported falls (2004-2010).

Measurements: BP was measured supine and 3 minutes after standing. A drop in systolic BP (SBP) ≥20mmHg or a drop in diastolic BP (DBP) ≥10mmHg upon standing defined cOH. Participants self-reported the number of falls experienced in the previous 12 months.

Results: Among 400 participants (45% women; 30% black; mean age 74.8 years), 113 (28%) reported ≥1 fall; 19 (4.8%) had cOH. In adjusted models, cOH (OR=2.77, 95% CI: 1.00-7.71 p=0.051) and continuous SBP-drops per 5mmHg (OR=1.21, 1.00-1.47 p=0.046) were associated with having any fall and multiple falls (cOH: OR=3.94, 1.04-14.96 p=0.044; SBP 5mmHg drops: OR=1.34, 1.00-2.15 p=0.020). Attained SBP with standing was not associated with falls either alone (OR=1.01, 0.99-1.02 p=0.369) or in combination with SBP-drops (interaction OR=1.03, 0.96-1.09 p=0.414).

Limitations: Cross-sectional design, prohibiting conclusions about causal relationships.

Conclusions: Findings suggest that postural SBP-drops that are much lower than current OH definition thresholds indicate increased falls risk in older adults, regardless of absolute SBP level. This has implications for standard clinical falls risk assessment and communication of falls risk to patients.