Association of Sleep-Disordered Breathing With Cognitive Function and Risk of Cognitive Impairment: A Systematic Review and Meta-analysis

JAMA Neurol. 2017 Oct 1;74(10):1237-1245. doi: 10.1001/jamaneurol.2017.2180.


Importance: Growing evidence suggests an association between sleep-disordered breathing (SDB) and cognitive decline in elderly persons. However, results from population-based studies have been conflicting, possibly owing to different methods to assess SDB or cognitive domains, making it difficult to draw conclusions on this association.

Objective: To provide a quantitative synthesis of population-based studies on the relationship between SDB and risk of cognitive impairment.

Data sources: PubMed, EMBASE, and PsychINFO were systematically searched to identify peer-reviewed articles published in English before January 2017 that reported on the association between SDB and cognitive function.

Study selection: We included cross-sectional and prospective studies with at least 200 participants with a mean participant age of 40 years or older.

Data extraction and synthesis: Data were extracted independently by 2 investigators. We extracted and pooled adjusted risk ratios from prospective studies and standard mean differences from cross-sectional studies, using random-effect models. This meta-analysis followed the PRISMA guidelines and also adhered to the MOOSE guidelines.

Main outcomes and measures: Cognitive outcomes were based on standard tests or diagnosis of cognitive impairment. Sleep-disordered breathing was ascertained by apnea-hypopnea index or clinical diagnosis.

Results: We included 14 studies, 6 of which were prospective, covering a total of 4 288 419 men and women. Pooled analysis of the 6 prospective studies indicated that those with SDB were 26% (risk ratio, 1.26; 95% CI, 1.05-1.50) more likely to develop cognitive impairment, with no evidence of publication bias but significant heterogeneity between studies. After removing 1 study that introduced significant heterogeneity, the pooled risk ratio was 1.35 (95% CI, 1.11-1.65). Pooled analysis of the 7 cross-sectional studies suggested that those with SDB had slightly worse executive function (standard mean difference, -0.05; 95% CI, -0.09 to 0.00), with no evidence of heterogeneity or publication bias. Sleep-disordered breathing was not associated with global cognition or memory.

Conclusions and relevance: Sleep-disordered breathing is associated with an increased risk of cognitive impairment and a small worsening in executive function. Further studies are required to determine the mechanisms linking these common conditions and whether treatment of SDB might reduce risk of cognitive impairment.

Publication types

  • Meta-Analysis
  • Review
  • Research Support, N.I.H., Extramural
  • Systematic Review

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Cognitive Dysfunction / complications*
  • Cross-Sectional Studies
  • Databases, Bibliographic / statistics & numerical data
  • Female
  • Humans
  • Male
  • Middle Aged
  • Polysomnography
  • Prospective Studies
  • Risk Factors
  • Sleep Apnea Syndromes / complications*