Longitudinal associations of sleep duration and sleep quality with coronary heart disease risk among adult population: classical meta-analysis and Bayesian network meta-analysis

To examine the longitudinal associations of sleep duration and sleep quality with coronary heart disease (CHD) risk among individuals aged >= 20 years. A systematic review and meta-analysis of observational cohort studies were performed to evaluate the association between sleep quality and duration, and the risk of CHD. We searched three databases including PUBMED, the Cochrane Library and EMBASE, selected relevant studies and used the classical and Net-work models to establish the hazard ratio (HRs) of the results. Data extracted from 11 studies including 769,452 participants and 14,769 patients with CHD events were reviewed. In the classical meta-analysis, night sleep duration of < 7 h and/or > 8 h showed an increased risk of CHD (HR = 1.13, and 1.13, respectively) compared with reference sleep (7-8 h). However, the net-work model stratified sleep quality into good and poor subgroups, and there was no change in CHD risk in each subgroup despite different sleep hours. Furthermore, individuals with poor-quality sleep were at a greater risk of CHD than those with good-quality sleep (HR = 1.4, 1.3, and 1.4 for < 7, 7-8, and > 8 h, respectively). Moreover, individuals with reference time sleep but that of poor quality were associated with an increased risk of CHD compared with good sleepers having short/long sleep duration (HR = 1.3 and 1.2, respectively). Poor-quality sleep was associated with great morbidity and mortality of CHD, independent of sleep duration. Sleep quality rather than sleep duration might be crucial for increased CHD risk, suggesting the potential importance of poor-quality sleep as a possible CHD risk factor.