Physical Activity Mediates the Relationship Between Sarcopenia and Cognitive Function Among Older Adults in Nursing Homes

Purpose: Sarcopenia and physical activity are significant factors influencing cognitive function. However, few studies have examined their underlying mechanisms between the three conditions. The aim of the study is to examine the mediating role of physical activity in the relationship between sarcopenia and cognitive function in elderly nursing home residents.Materials and Methods: A total of 420 older adults aged 60 years and above in nursing homes participated in this study. Sarcopenia was defined following the Asian Sarcopenia Working Group (AWGS) 2019 criteria. Cognitive function was assessed by the MiniMental State Examination (MMSE). Multiple linear regression analysis was employed to explore the relationships between sarcopenia, cognitive function and physical activity. Mediation analyses were performed to examine whether physical activity moderates the relationship between sarcopenia and cognitive function, with the use of PROCESS macro version 4.0.Results: A total of 386 older adults were included in the analysis (mean age 80.30 years), 175 (45.3%) were assessed as cognitive impairment, and sarcopenia was more common in those with cognitive impairment (p < 0.01). The linear regression analysis indicated that there were significant associations between sarcopenia and physical activity (0 = -0.285, p = 0.012), physical activity and cognitive function (0 = 0.218, p < 0.001), and sarcopenia and cognitive function (0 = -0.245, p = 0.021). Mediating effects of physical activity on the association between sarcopenia and cognitive function were observed in participants, with 20.2% of partial mediating effect. Conclusion: The results of the study suggest physical activity may partially buffer the adverse effects of sarcopenia on cognitive impairment among the older adults in nursing homes. Accordingly, engagement in physical activity can help to preserve cognitive function among those with sarcopenia.