The Association Between Age- and Sex-Related Differences in Muscle Strength and Physical Performance in Chinese Older Adults: A 5-Year Prospective Cohort Study

This longitudinal study investigated age-related changes in handgrip strength (HGS), physical performance (Timed 'Up and Go' [TUG] test), and their associations with anthropometric indices (height, weight, BMI) and quality of life (EQ-5D) in older Chinese adults. Data from 125 participants (75 women, 50 men; baseline age 67.6 ± 5.0 and 69.0 ± 5.4 years, respectively) enrolled in the China Action on Spine and Hip Status (CASH) study were analyzed over a five-year period. Adjusted linear regression models assessed percentage changes in HGS and TUG relative to anthropometric and EQ-5D changes, stratified by sex.Women aged ≥ 70 years (n = 26) exhibited significant declines in HGS (− 1.5 ± 21.0%, p < 0.05) and worsening TUG times (+ 33.8 ± 27.2%, p < 0.05) and EQ-5D scores (+ 50.7 ± 27.7%, p < 0.05) compared to those < 70 years (n = 49). In contrast, men showed no significant differences in HGS, TUG, BMI, or EQ-5D between age groups (≥ 70: n = 18; <70: n = 32). No associations were found between HGS changes and anthropometric/EQ-5D variables in either sex (p > 0.05). However, TUG changes in women correlated positively with weight (β = 1.1, 95% CI: 0.1–2.0) and BMI (β = 1.1, 95% CI: 0.1–1.9) (both p < 0.05), indicating that increased weight/BMI predicted slower TUG performance. No such associations were observed in men (p > 0.05).These findings highlight sex-specific trajectories of aging: women over 70 experience pronounced declines in muscle strength and physical performance linked to weight gain, whereas men exhibit relative stability across measures. The results underscore the vulnerability of older women to sarcopenia-related functional decline and suggest that weight management may mitigate physical performance deterioration in this demographic. Future interventions should prioritize sex-tailored strategies to preserve mobility and muscle function in aging populations.