SLEEP DURATION AND CARDIOVASCULAR OUTCOMES: A META-ANALYSIS OF 474,000 PEOPLE WITH 16,500 EVENTS: 3B.03

Abstract

Background: Both short and long duration of habitual sleep are associated with adverse health outcomes. Objective: To assess the population longitudinal evidence of a relationship between duration of sleep and morbidity and mortality from coronary heart disease (CHD), stroke and total cardiovascular disease (CVD), and to obtain estimates of risk. Methods and Results: We performed a systematic search of publications using MEDLINE (1966–2009), EMBASE (from 1980), the Cochrane Library and manual searches without language restrictions. Studies were included if they were prospective, follow up >3 years, had duration of sleep at baseline and cases of fatal and non-fatal CHD, stroke or total CVD assessed prospectively. Relative risks (RR) and 95% C.I. were extracted and pooled using a random effect model. Sensitivity analysis was performed, heterogeneity and publication bias were also assessed. Overall, 15 studies provided 24 independent cohort samples, including 474,866 male and female participants (follow-up range 6.9 to 25 years), and 16,502 fatal and non-fatal events (3,753 for CHD, 3,163 for stroke and 9,586 for total CVD). Sleep duration was assessed by questionnaire, death through certification and non-fatal events event registers. In the pooled analyses, short duration of sleep was associated with a greater risk of developing or dying of CHD (RR: 1.48; 95% CI 1.22 to 1.80; p < 0.0001), stroke (1.15; 1.00 to 1.31; p = 0.047), but not total CVD (1.06; 0.98 to 1.16; p = 0.15) with no evidence of publication bias (p = 0.95, p = 0.30 and p = 0.97, respectively). Long duration of sleep was also associated with a greater risk of CHD (1.38; 1.15 to 1.66; p = 0.0005), stroke (1.65; 1.45 to 1.87; p < 0.0001) and total CVD (1.44; 1.24 to 1.68; p < 0.0001) with no evidence of publication bias (p = 0.92, p = 0.96 and p = 0.82, respectively). Gender, duration of follow-up and geographical location did not explain the heterogeneity between studies. Conclusion: Both short and long duration of sleep are significant predictors of cardiovascular outcomes in prospective population studies.