Evidence Hub

Sleep disorders increase the risk of dementia, Alzheimer’s disease, and cognitive decline: a meta-analysis

Z. Ungvari, M. Fekete, Andrea Lehoczki, G. Munkácsy, J. Fekete, V. Zábó, G. Purebl, P. Varga et al.

GeroScience, 2025

58 citations

Abstract

Sleep disorders, particularly insomnia and obstructive sleep apnea, are increasingly implicated as significant contributors to cognitive decline, dementia, and neurodegenerative diseases such as Alzheimer’s disease (AD) and vascular cognitive impairment and dementia (VCID). However, the extent and specificity of these associations remain uncertain. This meta-analysis evaluates the impact of common sleep disorders on the risk of developing dementia and cognitive decline. A comprehensive search of the literature was conducted to identify prospective cohort studies assessing sleep disorders and dementia risk. Studies reporting risk estimates for dementia, AD, or cognitive decline associated with obstructive sleep apnea, insomnia, and other sleep disorders (e.g., restless legs syndrome, circadian rhythm sleep disorders, excessive daytime sleepiness) were included. Meta-analyses were performed using a random-effects model to calculate pooled hazard ratios (HRs) and 95% confidence intervals (CIs). Thirty-nine cohort studies were included, with subgroup analyses showing significant associations between all-cause dementia and obstructive sleep apnea (HR 1.33, 95% CI 1.09–1.61), insomnia (HR 1.36, 95% CI 1.19–1.55), and other sleep disorders (HR 1.33, 95% CI 1.24–1.43). Obstructive sleep apnea increased the risk for AD (HR 1.45, 95% CI 1.24–1.69), though its association with vascular dementia did not reach statistical significance (HR 1.35, 95% CI 0.99–1.84). Insomnia was…

How strong is the evidence?

Evidence Hub reads this as a meta-analysis. Its evidence level is 1 of 5 (Highest · pooled evidence). Pooled evidence from several studies sits at the top of the evidence pyramid.

How the five levels of evidence work. The level is assigned automatically from the abstract and can be wrong, so check the paper.

Read the paper

Related studies

Go deeper in Evidence Hub

Evidence Hub adds a study data sheet (design, sample size, evidence level, key numbers), an AI summary and a chat grounded in the paper's text.

Open this study Sign up free