Abstract
INTRODUCTION: Sleep disorders are common in older adults and have been increasingly linked to cognitive dysfunction in Alzheimer's disease (AD); however, their associations with functional outcomes and underlying pathways remain insufficiently characterized. METHODS: We performed a cross-sectional analysis of 10,823 participants from the National Alzheimer's Coordinating Center database, examining associations between sleep disorders and instrumental activities of daily living (IADL) using regression, structural equation modeling (SEM), and mediation analyses. RESULTS: Sleep disorders were significantly associated with greater cognitive impairment and poorer IADL performance among individuals with AD. Mediation analysis indicated that cognitive impairment accounted for ≈62% of the association between sleep disorders and IADL difficulties, suggesting a substantial indirect association through cognitive function. DISCUSSION: Sleep disorders are strongly associated with cognitive impairment and functional limitations in AD. These findings highlight the potential clinical value of screening and managing sleep problems as part of comprehensive care strategies.