Introduction: Sarcopenia is a chronic condition linked to aging-related neuromuscular decline, often defined by dynapenia, muscle atrophy, and impaired physical function. Although diagnostic criteria are debated, sarcopenia is associated with many adverse outcomes, such as falls. However, findings on its link to falls are inconsistent, possibly due to limited consideration of falls' multifactorial nature. Indeed, intrinsic (e.g., comorbidities) and extrinsic (e.g., home environment) factors both influence fall risk, yet few studies examine their combined effects. Hence, this study examined data from the ilSIRENTE cohort to explore how intrinsic and extrinsic factors moderate the cross-sectional and longitudinal relationship between sarcopenia and falls.

Methods: This prospective cohort study was conducted among octogenarians residing in the mountainous Sirente geographic area of Central Italy. Sarcopenia was defined according to the European Working Group on Sarcopenia. Data on fall history and incident falls were collected over a two-year period. A general linear model was used to assess whether intrinsic factors (i.e., multimorbidity, polypharmacy, cognitive function, vision status, and nutritional status) and extrinsic factors (i.e., social functioning and environmental characteristics) moderated the relationship between sarcopenia (independent variable) and falls (dependent variable).

Results: Results of the general linear model revealed that intrinsic factors, but not extrinsic ones, significantly influenced the associations between sarcopenia and falls. Specifically, multimorbidity and polypharmacy were associated with both fall history and incidence, while cognitive function and nutritional status emerged as significant moderators in the longitudinal analysis.

Conclusion: These findings underscore the importance of addressing specific intrinsic health-related factors in order to more effectively mitigate the risk of falls among older adults with sarcopenia.