Research Paper Volume 16, Issue 17 pp 12138—12167
Poor sleep quality, dementia status and their association with all-cause mortality among older US adults
- 1 Laboratory of Epidemiology and Population Sciences, National Institute on Aging, Intramural Research Program, NIA/NIH/IRP, Baltimore, MD 21224, USA
- 2 Department of Psychology, Clemson University, Clemson, SC 29634, USA
- 3 Department of Veterans Affairs, VA National Center on Homelessness Among Veterans, Washington, DC 20420, USA
- 4 Department of Management, Policy, and Community Health, School of Public Health, University of Texas Health Science Center at Houston, Houston, TX 77030, USA
Received: January 23, 2024 Accepted: August 20, 2024 Published: September 4, 2024
https://doi.org/10.18632/aging.206102How to Cite
Copyright: © 2024 Beydoun et al. This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Abstract
Background: Evidence points to associations between sleep quality, dementia, and mortality. We examined whether poor sleep quality mediated or moderated the association between dementia and mortality risk among older US adults and vice versa, and whether these associations differed by sex and by race.
Methods: The study investigated bi-directional associations between sleep quality, dementia and mortality in older US adults using data from the Health and Retirement Study (N = 6,991, mean age = 78.1y, follow-up: 2006–2020, number of deaths = 4,938). It tested interactions and mediating effects, using Cox proportional hazards models and four-way decomposition models.
Results: Poor sleep quality was associated with increased mortality risk, particularly among male and White older adults. However, the association was reversed in the fully adjusted model, with a 7% decrease in risk per tertile. Probable dementia was associated with a two-fold increase in mortality risk, with a stronger association found among White adults. The association was markedly attenuated in the fully adjusted models. Sleep quality-stratified models showed a stronger positive association between dementia and mortality among individuals with better sleep quality. Both mediation and interaction were involved in explaining the total effects under study, though statistically significant total effects were mainly composed of controlled direct effects.
Conclusions: Poor sleep quality is directly related to mortality risk before lifestyle and health-related factors are adjusted. Dementia is linked to mortality risk, especially in individuals with better sleep quality, males, and White older adults. Future research should explore the underlying mechanisms.
Abbreviations
AD: Alzheimer’s Disease; ADAMS: Aging, Demographics, and Memory Study; CES-D: Center for Epidemiologic Studies Depression Scale; CDE: Controlled Direct Effect; EFTF: Enhanced Face-to-Face; INTREF: Interaction Referent; INTMED: Mediated Interaction; HRS: Health Retirement Study; LASSO: Least Absolute Shrinkage and Selection Operator; OLS: Ordinary Least Squares; PH: Proportional Hazards; PIE: Pure Indirect Effect; Pr: Probability; PSU: Primary Sampling Unit; SE: Standard Errors; svy: Survey commands in Stata; TE: Total Effect.