Self-Reported Sleep Duration and Quality and Cardiovascular Disease and Mortality: A Dose-Response Meta-Analysis.
Level 3 - non-randomized controlled study
Systematic review and meta-analysis of prospective cohort studies
PubMed 30371228 · doi:10.1161/JAHA.118.008552
What was done
Authors conducted a systematic review, linear and nonlinear dose-response meta-analysis, and spline analysis of prospective cohort studies identified via MEDLINE and EMBASE. They evaluated associations between self-reported sleep duration and quality with cardiovascular outcomes and mortality using DerSimonian-Laird random-effects models with inverse variance weighting. The analysis included 74 studies comprising 3,340,684 participants and 242,240 deaths.
What was found
Linear dose-response modeling in 30 studies with over 1,000,000 participants showed that self-reported sleep duration over 8 hours was associated with increased all-cause mortality: risk ratio 1.14 (95% CI, 1.05-1.25) for 9 hours, 1.30 (95% CI, 1.19-1.42) for 10 hours, and 1.47 (95% CI, 1.33-1.64) for 11 hours. Self-reported sleep under 7 hours was not significantly associated with all-cause mortality, though similar patterns were reported for stroke and cardiovascular disease mortality. Subjective poor sleep quality was associated with coronary heart disease (risk ratio 1.44, 95% CI, 1.09-1.90), with no significant difference observed for mortality and other outcomes.
Why it matters
This large-scale synthesis indicates that extended sleep duration beyond recommended thresholds carries a graded association with increased mortality, while subjective sleep quality relates specifically to coronary heart disease risk.
Limits
Sleep duration and quality were entirely self-reported rather than objectively measured through polysomnography or actigraphy. Because all included data are observational, residual confounding and reverse causality from underlying chronic illness cannot be ruled out. Numerical estimates and confidence intervals for stroke and cardiovascular mortality were not reported in the abstract.
Cited by
- supports Sleeping fewer than 7 hours per night or more than 10 hours per night is associated with increased all-cause mortality compared to sleeping 7 to 9 hours.