Associations of blood pressure with risk of injurious falls in old age vary by functional status: A cohort study

Abstract

Objectives: We aimed to examine to what extent blood pressure (BP) components are associated with injurious falls in older adults, and whether the possible associations differ by functional status (indicated by physical and cognitive impairment at baseline).

Methods: This prospective cohort study included 3055 community-living participants of the Swedish National study on Aging and Care in Kungsholmen (aged ≥60 years). At baseline (2001-2004), we measured systolic BP (SBP) and diastolic BP (DBP), mean arterial pressure, pulse pressure (PP), and orthostatic hypotension. Physical function was assessed using tests of balance, chair stands, and walking speed. Cognitive function was assessed with the Mini-Mental State Examination. Injurious falls leading to inpatient or outpatient care during 3 and 10 years of follow-up were identified via patient registers. Data were analyzed using flexible parametric survival models adjusted for potential confounders.

Results: During the 10-year follow-up period in people without functional impairment, the multi-adjusted hazard ratios (HR) of injurious falls were 1.77 (95% CI 1.02-3.07) for having SBP <130 mmHg, 1.73 (95% CI 1.05-2.83) for having SBP ≥160 mmHg (vs. 130-139), and 1.46 (1.05-2.02) for having higher tertile of PP (vs. lower tertile). During the 3-year follow-up period in people with functional impairment, the multi-adjusted HR of injurious falls was 1.91 (95% CI 1.17-3.13) for having SBP <130 mmHg (vs. 130-139) and 0.74 (0.59-0.94) for having higher tertile of PP (vs. lower tertile). There was no significant association between BP components and injurious falls either in people without functional impairment during the 3-year follow-up period, or in people with functional impairment during the 10-year follow-up period.

Conclusions: This large-scale Swedish study provides evidence that the associations between some specific components of BP and risk of injurious falls in older adults vary by functional status. This supports the view that a personalized approach to blood pressure management depending on functional status among older adults might be warranted in clinical settings.

Keywords: Aging; Blood pressure; Falls; Injury; Swedish National study on Aging and Care in Kungsholmen (SNAC-K).