Mediating effects of physical activity and vitamin D on the association between cognition and dysmobility syndrome in Korean older women.

Background: This study aimed to examine the associations between cognitive function, physical activity, and vitamin D with dysmobility syndrome (DMS), and to assess the mediation effects of physical activity and vitamin D. Methods: This cross-sectional study included 181 community-dwelling older women. Cognitive function was assessed using the Korean version of the Mini-Mental State Examination. Physical activity was measured using the International Physical Activity Questionnaire and categorized as active or inactive. Serum vitamin D was analyzed and classified as either '≥20 ng/mL' or '<20 ng/mL'. DMS was defined as meeting at least three of six clinical criteria, including low muscle mass, high body fat, osteoporosis, slow gait speed, low hand-grip strength and history of fall. Results: Mediation analysis revealed mediation effects for both physical activity (Indirect effect = -0.0091) and vitamin D (Indirect effect = -0.0066) on the relationship between cognitive function and DMS through independent paths. Additionally, the sequential path of physical activity → vitamin D showed partial mediation (Indirect effect = -0.0013). Conclusions: This study suggested that regular physical activity and adequate vitamin D levels can contribute to the prevention and management of cognitive impairment-related DMS in older Korean women.