# Coupling of within-person changes in sleep quality and subjective cognition in community-dwelling adults

## TL;DR

This study explores how changes in sleep quality relate to changes in perceived cognitive abilities in older adults over time.

## Contribution

The study introduces a novel longitudinal analysis of the dynamic relationship between sleep quality and subjective cognitive decline.

## Key findings

- Changes in sleep quality were positively linked to changes in subjective cognition over time.
- This association remained significant after accounting for baseline sleep quality and sociodemographic factors.
- Monitoring sleep quality could help detect early signs of cognitive decline in older adults.

## Abstract

Subjective cognitive decline (SCD) is an early indicator of cognitive impairment and dementia risk. Sleep quality, essential for cognitive health, often deteriorates with age. Intraindividual changes in sleep quality may be linked to concurrent changes in subjective cognition; this dynamic ‘coupling effect’ could inform strategies for prevention before objective impairments emerge but remains unexamined longitudinally. We investigated this interplay in older adults over multiple years.

Utilizing the ‘nlme’ R package, we analyzed nine waves of sleep quality and subjective cognition data from the Transitions in Health and Relationships study (n = 131, ages 59–94 at baseline, 63% female) in hierarchical multilevel models, with random intercepts and slopes.

Multilevel models indicated changes in sleep quality were positively associated with concurrent changes in subjective cognition, independent of baseline sleep quality, and sociodemographic covariates.

Findings highlight the importance of monitoring within-person sleep quality changes as a potential indicator of SCD in older adults. Further studies may help identify pathways to support cognitive health in aging populations.