Multi-trajectories of activity participation and risk of mild cognitive impairment in China: A national longitudinal cohort study.

BackgroundEngagement in physical, social, and intellectual activities is associated with cognitive health in later life, but how their long-term combinations relate to mild cognitive impairment (MCI), a key preclinical stage of Alzheimer's disease, remains unclear.ObjectiveTo identify multi-activity trajectories and examine their associations with MCI.MethodsData were from the China Health and Retirement Longitudinal Study (CHARLS), a nationally representative biennial survey collecting demographic, socioeconomic, health, cognitive, and activity-related information. We included 1884 participants aged ≥60 years in 2020. Group-based multi-trajectory modeling identified physical, social, and intellectual activity patterns using the 2011, 2013, 2015, and 2018 waves. Multivariable logistic regression examined associations with MCI in 2020, with subgroup analyses by sex, baseline age, education, and residence.ResultsFour distinct trajectory groups were identified: Moderate PA-low SI (social and intellectual activity), High PA-low SI, Moderate PA-higher SI, and High PA-moderate SI. The Moderate PA-higher SI group had the lowest MCI prevalence (9.47%) and served as the reference. In the fully adjusted model, MCI odds were highest in the High PA-low SI group (OR = 2.05, 95% CI: 1.34-3.15), followed by the Moderate PA-low SI group (OR = 1.57, 95% CI: 1.08-2.30). The High PA-moderate SI group was not significantly associated with MCI (OR = 1.38, 95% CI: 0.72-2.58).ConclusionsModerate physical activity combined with higher social and intellectual engagement was associated with more favorable cognitive outcomes, supporting integrated, pattern-based lifestyle strategies for early prevention of MCI and Alzheimer's disease.