Upper extremity weakness: A novel risk factor for non-cardiovascular mortality among community-dwelling older adults

Abstract

Aging-associated upper extremity weakness has been shown to be associated with adverse health outcomes in older adults, but less is known about the association between impaired upper extremity function and cause-specific mortalities. Among the 5512 prospective community-based longitudinal Cardiovascular Health Study participants, 1438 had difficulty with one of the three upper extremity functions of lifting, reaching, or gripping. We assembled a propensity score-matched cohort in which 1126 pairs of participants with and without difficulty with upper extremity function, balanced on 62 baseline characteristics including geriatric and functional variables such as physical and cognitive function. Hazard ratios (HRs) and 95% confidence intervals (CIs) for all-cause and cause-specific mortalities associated with upper extremity weakness were estimated in the matched cohort. Matched participants had a mean age of 73.1 years, 72.5% were women, and 17.0% African American. During 23 years of follow-up, all-cause mortality occurred in 83.7% (942/1126) and 81.2% (914/1126) of participants with and without upper extremity weakness, respectively (HR, 1.11; 95% CI, 1.01-1.22; p=0.023). Upper extremity weakness was associated with a higher risk of non-cardiovascular mortality, occurring in 595 (52.8%) and 553 (49.1%) of participants, respectively (HR, 1.17; 95% CI, 1.04-1.31; p=0.010), but had no association with cardiovascular mortality (30.8% vs 32.1% in those with and without upper extremity weakness, respectively; HR, 1.03; 95% CI, 0.89-1.19; p=0.70). Among community-dwelling older adults, upper extremity weakness had a weak, albeit independent, significant association with all-cause mortality, which was primarily driven by a higher risk of non-cardiovascular mortality. Future studies need to replicate these findings and understand the underlying reasons for the observed associations.