Psychosocial Pathways Between Physical Activity and Mild Cognitive Impairment in Community-Dwelling Older Adults: Mediation and Moderation Analyses.

ObjectiveTo examine whether physical activity (PA) relates to mild cognitive impairment (MCI) both directly and indirectly through depressive symptoms and social isolation, and whether social isolation moderates this association.MethodsThis cross-sectional analysis used data from the 2011-2014 National Health and Nutrition Examination Survey (n = 2,933; ≥60 years). Self-reported PA, depressive symptoms, and social isolation were assessed. MCI was defined as a composite cognitive score greater than one standard deviation below the sample mean.ResultsWeighted path analysis showed that higher PA levels were inversely associated with MCI. Depressive symptoms and social isolation mediated this association. Social isolation moderated the PA-MCI relationship, with the inverse association being most pronounced among individuals with higher isolation levels.ConclusionsPA is associated with MCI in older adults through psychosocial pathways, and social isolation shapes this relationship. Promoting PA may be particularly relevant for those experiencing social isolation.