Handgrip strength and 4-meter walk performance as practical functional measures of sarcopenia and physiologic reserve in acute hospital care: a prospective cohort study

Abstract Background Functional reserve is difficult to characterize during routine acute hospital care. Sarcopenia is associated with frailty, disability, and mortality, but rapid functional assessment remains underused in hospitalized older adults. We evaluated handgrip strength and 4-meter walk test (4MWT) performance as pragmatic measures of probable sarcopenia and physiologic reserve during acute illness. Methods We conducted a prospective cohort study of 279 hospitalized adults aged 65–95 years at a tertiary medical center. Handgrip strength was measured using dynamometry; values < 27 kg in men and < 16 kg in women were classified as probable sarcopenia according to EWGSOP2. Among 169 participants who completed the 4MWT without an assistive device, associations between probable sarcopenia, walk time, age, and sex were evaluated using linear regression. Selection into the 4MWT subgroup was examined using inverse-probability weighting (IPW). Results Participants with probable sarcopenia were underrepresented in the 4MWT subgroup. In the 169 participants with eligible 4MWT measurements, probable sarcopenia was independently associated with a 1.59-second longer walk time after adjustment for age and sex (95% CI 0.55–2.63; P = 0.003). The IPW estimate was similar (β = 1.62 s, 95% CI 0.49–2.75; P = 0.005). In an exploratory overlapping age-window analysis, concordance was greatest in the 73–84-year interval (AUC = 0.69, bootstrap 95% CI 0.58–0.80). Conclusions Handgrip strength is a rapid bedside-feasible measure, whereas the 4MWT is a complementary ward-based assessment for sufficiently mobile and clinically stable hospitalized older adults. These state-dependent measures characterize functional performance and physiologic reserve during acute illness; longitudinal studies are required to determine their relationship to baseline function, recovery, and healthspan outcomes.