Low relative sit-to-stand power is associated with history of falls and fractures, prospective hospitalization, and all-cause mortality in older adults from the Toledo Study for Healthy Aging.

Abstract

BACKGROUND Low relative sit-to-stand (STS) power has emerged as a critical predictor of adverse health outcomes, such as frailty and disability, in older adults. However, its impact on falls, fractures, hospitalizations, and all-cause mortality remains unclear. Therefore, this longitudinal study aimed to investigate the potential associations between low relative STS power and these adverse health outcomes in older adults. METHODS A total of 1876 older adults (aged ≥ 65 years, 56.4% women) were included from the Toledo Study for Healthy Aging. Relative STS power was assessed using the 30-s STS test and the Alcazar equation. Participants were categorized as having low relative STS power based on previously established cut-off points (2.53 W/kg for men and 2.01 W/kg for women). Falls and fractures (hip and all-type) within the previous year were recorded. Hospitalizations and all-cause mortality were obtained during a follow-up of 6.8 ± 3.1 years (mean ± SD; median = 7.8 years; interquartile range: 3.9-10.1 years) and 9.7 ± 3.5 years (median = 10.9 years; interquartile range: 8.2-12.5 years), respectively. Generalized linear mixed models, binary logistic regression, and proportional hazards regression adjusted for age, educational level, and comorbidities were used. RESULTS In men, low relative STS power was significantly associated with an increased likelihood of history of falls (odds ratio (OR) = 1.73, 95% confidence internal (95%CI): 1.08-2.75, p = 0.022) and all-type fractures (OR = 1.86, 95%CI:1.21-2.84, p = 0.004) in the previous year. In women, low relative STS power was associated with a higher probability of hip fractures within the previous year (OR = 3.25, 95%CI: 1.07-9.86, p = 0.038). Low relative STS power predicted hospitalizations in women (hazard ratio (HR) = 1.29, 95%CI: 1.06-1.58, p = 0.012) and longer hospital stays in both men (p = 0.020) and women (p = 0.033). Low relative STS power significantly increased all-cause mortality in both men (HR = 1.57, 95%CI: 1.26-1.97, p < 0.001) and women (HR = 2.04, 95%CI: 1.51-2.74, p < 0.001). CONCLUSION Low relative STS power was associated with history of hip fractures in women, whereas in men it was associated with history of falls and all-type fractures. Low relative STS power predicted hospitalizations in women but not in men. In both men and women, low relative STS power was associated with longer hospital stays and increased risk of all-cause mortality.