Dynapenia associated with declining physical function in CHARLS cohort

Following the 2025 Asian Working Group for Sarcopenia consensus, which repositioned physical performance as a downstream outcome, researchers examined muscle-related phenotypes and subsequent functional change in the China Health and Retirement Longitudinal Study (CHARLS). The prospective analysis included 2,657 adults aged ≥50 years with preserved baseline function, defined as a Short Physical Performance Battery (SPPB) score >9. Participants were classified as normal, low muscle mass, dynapenia, or operationally defined sarcopenia using criteria informed by the consensus framework.

Over four years, investigators identified three SPPB trajectories: high-stable (86.4%), moderate-stable (10.4%), and rapidly declining (3.2%). After adjustment for age, sex, waist circumference, smoking, and hypertension, dynapenia was associated with greater odds of moderate-stable membership (OR 1.76, 95% CI 1.18–2.61) and rapidly declining membership (OR 2.40, 95% CI 1.30–4.42), compared with the normal phenotype and using high-stable as the reference trajectory. Low muscle mass alone and operationally defined sarcopenia were associated with moderate-stable membership; their associations with rapid decline were inconclusive.

The findings support an association between low muscle strength and subsequent functional deterioration in initially well-functioning adults. However, this observational analysis cannot establish causation or superior prognostic value for dynapenia over sarcopenia. Only 3.2% followed the rapidly declining trajectory. The authors reported no external funding or competing interests.