Mediating Role of Physical Capabilities in the Association Between Perceived Physical Fatigability and Cognitive...

To investigate perceived physical fatigability (PPF) as a novel predictor of cognitive frailty (CF) and elucidate mediating roles of physical capability markers in community-dwelling older adults.

Cross-sectional analysis from the first wave of an ongoing longitudinal cohort.

A total of 837 Beijing residents aged ≥60 (49.5% female; mean age 83.1 ± 7.1 years), excluding dementia/severe cognitive impairment.

PPF was measured using the Pittsburgh Fatigability Scale (PFS) and CF was defined as the co-occurrence of pre-frailty, frailty, and mild cognitive impairment (MCI). Frailty was assessed with the FRAIL scale and the Frailty Index (FI). Multivariate logistic regression models evaluated the association between physical fatigability and CF. Mediation analysis explored the roles of gait speed (GS), handgrip strength (HGS), and instrumental activities of daily living (IADL) disability.

CF prevalence was higher when defined by the FI than the FRAIL scale, in groups with both mild and severe physical fatigability. Higher PFS scores were associated with increased CF risk, with odds ratios (ORs) decreasing after covariate adjustment (FRAIL: ORs 2.63 to 1.90; FI: ORs 2.31 to 1.71). Mediation analysis revealed that GS, HGS, and IADL disability accounted for 36.7%, 14.7%, and 22.7% of the association between physical fatigability and CF using the FRAIL scale, and 33.5%, 24.2%, and 22.6% using the FI.

Severe physical fatigability is linked to higher CF risk. Interventions targeting GS, HGS, and IADL disability could delay or mitigate CF, enhancing independence and well-being in older adults.