Association between sleep apnoea and risk of cognitive impairment and Alzheimer's disease: a meta-analysis of cohort-based studies.
Level 3 - non-randomized controlled study
Systematic review and meta-analysis of observational cohort studies
PubMed 37857768 · doi:10.1007/s11325-023-02934-w
What was done
A systematic review and meta-analysis of retrospective and prospective cohort studies published from 2000 onwards (searched in PubMed, EMBASE, and Scopus). Authors evaluated the association between sleep-disordered breathing (SDB) or obstructive sleep apnoea (OSA) and the risk of cognitive impairment, all-cause dementia, or Alzheimer's disease using a random-effects model to calculate pooled hazard ratios (HR) with 95% confidence intervals.
What was found
Fifteen cohort studies were included. SDB/OSA diagnosis was based on at-home polysomnography in 6 studies, self-report/questionnaires in 5 studies, and ICD codes in the remaining studies. Overall, SDB/OSA was associated with a higher risk of cognitive impairment or all-cause dementia (HR 1.52, 95% CI: 1.32 to 1.74). In the subgroup of studies using polysomnography, the association was attenuated (HR 1.32, 95% CI: 1.00 to 1.74). Specific numerical results for Alzheimer's disease were not reported in the abstract.
Why it matters
The findings link sleep-disordered breathing to elevated dementia risk, but highlight that subjective or administrative diagnostic methods may overestimate risk compared to objective polysomnography.
Limits
The total number of individual participants is not reported in the abstract. More than half of the included studies relied on self-reports or administrative diagnostic codes rather than objective sleep studies. As a meta-analysis of observational cohorts, residual confounding cannot be excluded and causality cannot be established.
Cited by
- supports Research from the Queensland Brain Institute at the University of Queensland found that individuals with untreated sleep apnea have a 45% higher risk of developing Alzheimer's disease.