What Is the Relationship Between Orthostatic Blood Pressure and Spatiotemporal Gait in Later Life?

Abstract

BACKGROUND/OBJECTIVES: Little work to date has examined the relationship between gait performance and blood pressure (BP) recovery after standing in later life. The aim of this study is to clarify the association of orthostatic BP with spatiotemporal gait parameters in a large cohort of older people. DESIGN: Cross-sectional study using multilevel linear regres- sion to ascertain the difference in orthostatic BP patterns across tertiles of gait speed, and linear regression to analyze the association of orthostatic hypotension 30 seconds after standing (OH-30) with specific gait characteristics. SETTING: The Irish Longitudinal Study on Ageing. PARTICIPANTS: A total of 4311 community-dwelling adults, aged 50 years or older (mean age = 62.2 years; 54% female), one fifth (n = 791) of whom had OH-30. MEASUREMENTS: Continuous orthostatic BP was measured during active stand. OH-30 was defined as a drop in systolic BP of 20 mm Hg or more or drop in diastolic BP of 10 mm Hg or more at 30 seconds. Spatiotemporal gait was assessed using the GAITRite system, reporting gait speed, step length, step width, and double support time in both single and dual (cognitive task) conditions. RESULTS: OH-30 was associated with slower gait speed (β = −3.01; 95% confidence interval [CI] = −4.46 to −1.56) and shorter step length (β = −.73; 95% CI = −1.29 to −.16) in fully adjusted models during single task walking. Similar findings were observed in dual task conditions, in addition to increased double support phase (β = .45; 95% CI = .02-.88). Multilevel models demonstrated that participants in the slowest tertile for gait speed had a significantly larger drop in systolic BP poststanding compared to those with faster gait speeds in single and dual task conditions. CONCLUSIONS: This study demonstrates that slower recovery of BP after standing is independently associated with poorer gait performance in community-dwelling older adults. Given the adverse outcomes independently associated with OH and gait problems in later life, increasing awareness that they commonly coexist is important, particularly as both are potentially modifiable.