Association between Excessive Daytime Sleepiness and Risk of Cardiovascular Disease and All-Cause Mortality: A Systematic Review and Meta-Analysis of Longitudinal Cohort Studies

Objective Excessive daytime sleepiness (EDS) is a prevalent phenomenon in adults, and although cohort studies have reported an association between EDS and adverse health outcomes, the results are inconclusive. This meta-analysis summarizes the evidence from longitudinal cohort studies on the relationship between EDS and the risk of cardiovascular disease (CVD) or all-cause mortality. Design A meta-analysis of prospective cohort studies was conducted. Setting and Participants We searched for relevant longitudinal cohort studies published through September 2019 using Web of Science, PubMed, Medline, and SciELO. Measures The relative risk (RR) of EDS was pooled in random-effects or fixed-effects meta-analyses. Subgroup, sensitivity, and meta-regression analyses were performed to identify heterogeneous sources. Publication bias was assessed using the Begg and Egger tests. Results Seventeen studies (153,909 participants) were included. The mean follow-up was 5.4 (range, 2–13.8) years. The pooled relative risks of EDS were 1.28 [95% confidence interval (CI) 1.09–1.50] for total CVD events, 1.28 (95% CI 1.12–1.46) for coronary heart disease (CHD), 1.52 (95% CI 1.10–2.12) for stroke, 1.47 (95% CI 1.09–1.98) for CVD mortality, and 1.23 (95% CI 1.13–1.33) for all-cause mortality. Subgroup analyses by mean age, region, follow-up time, EDS assessment method, and year of publication yielded similar results. Conclusions and Implications EDS is a modest but statistically significant predictor for CVD events, coronary heart disease, stroke, and CVD and all-cause mortality. However, its prognostic value warrants further investigation to identify those at highest risk of mortality and in need of intervention to improve outcomes.