Mediating pathways of physical capabilities: linking perceived physical fatigability to motoric cognitive risk syndrome in community older adults

Motoric Cognitive Risk Syndrome (MCR), a critical pre-dementia marker, synergistically predicts dementia and physical disability. While perceived physical fatigability (PPF) is prevalent in aging populations, its association with MCR and the mediating role of physical capabilities (balance ability, handgrip strength, IADL limitation) remain unexplored. This study pioneers a mechanistic investigation into how PPF contributes to MCR through declining physical function. In a community-based cohort of 1,657 urban older adults (mean age = 82.5 ± 8.35 years), PPF was quantified using the validated Pittsburgh Fatigability Scale (PFS). MCR was diagnosed via standardized criteria. Multivariable logistic regression and Karlson-Holm-Breen mediation analysis dissected the PPF-MCR relationship, controlling for demographics, comorbidities, and lifestyle factors. Severe PPF (PFS ≥ 15) was associated with MCR risk (adjusted OR = 1.38, 95%CI:1.16–1.64). Mediation analysis revealed balance ability as the predominant pathway, explaining 33.33% of PPF’s effect on MCR (PM = 33.33%, p < 0.001), surpassing the non-significant mediation effects of handgrip strength (PM = 7.95%) and IADL limitation (PM = 0.7%). This first-in-field study identifies PPF as a modifiable MCR risk factor, with decline in balance ability being the central mediator. Targeted interventions, such as balance training, could disrupt the PPF-MCR cascade by addressing this key pathway, offering novel strategies for dementia prevention in aging populations.