# Waking up to the truth: Associations between sleep disorders and multidomain functional outcomes in Alzheimer's disease

## TL;DR

The study finds that sleep disorders are linked to cognitive decline and daily living difficulties in Alzheimer's patients, with cognitive impairment acting as a key mediator.

## Contribution

The study identifies cognitive impairment as a major mediator linking sleep disorders to functional decline in Alzheimer's disease.

## Key findings

- Sleep disorders are strongly associated with cognitive impairment and functional limitations in Alzheimer's disease.
- Cognitive impairment mediates approximately 62% of the association between sleep disorders and functional decline.
- Sleep apnea shows the strongest link to cognitive decline, while REM sleep behavior disorder correlates with IADL impairment.

## Abstract

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.

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.

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.

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.

Sleep disorders significantly associated with cognitive impairment in patients with Alzheimer's disease.Cognitive impairment mediates the relationship between sleep disorders and functional decline.Sleep apnea shows strongest association with cognitive decline in AD.Rapid eye movement (REM) sleep behavior disorder significantly correlates with instrumental activities of daily living (IADL) impairment.Treating sleep disorders may preserve cognitive function and daily living abilities.

Sleep disorders significantly associated with cognitive impairment in patients with Alzheimer's disease.

Cognitive impairment mediates the relationship between sleep disorders and functional decline.

Sleep apnea shows strongest association with cognitive decline in AD.

Rapid eye movement (REM) sleep behavior disorder significantly correlates with instrumental activities of daily living (IADL) impairment.

Treating sleep disorders may preserve cognitive function and daily living abilities.