Table 1.

Current knowledge on the association between long sleep and CVD.

Reference	Study design	Participant details	Measures	Results
Cappuccio et al. 2011 [2]	Meta-analysis of 15 prospective studies; follow-up >3 y; incident cases of coronary heart disease (CHD), stroke, or CVD	474,684 male and female participants with 4169 CHD events and 8420 CVD events in a follow-up of 6.9-25 y	Self-reported sleep duration and incident cases thru certification and event registers, risk ratios (RRs) for incident cases	Long sleep (>8-9 h) associated with greater risk of CHD (RR 1.38), stroke (1.65), and total CVD (1.41)
Jike et al. 2017 [25]	Meta-analysis of 137 prospecive studies; incidence of diabetes mellitus, hypertension, CVD, stroke, CHD, obesity, depression, and dyslipidemia.	5,134,036 participants	Self-reported sleep duration and incident health conditions at follow-up, risk ratios (RRs) for mortality and incident health conditions	Long sleep (>9 h or >10 h) associated with mortality (RR, 1.39), diabetes mellitus (1.26), CVD (1.25), stroke (1.46), CHD (1.24), and obesity (1.08)
Daghlas et al. 2019 [26]	Prospective observational analysis using Mendelian randomization to assess causality	461,347 UK Biobank participants free of CVD	Self-reported sleep duration and estimated multivariable adjusted hazard ratios (HR) for myocardial infarction (MI)I; examined joint effects with sleep disturbance traits and a coronary disease genetic risk score	Long sleepers (>9 h) had a 34% higher risk of incident MI, healthy sleep durations (6-9 h) mitigated MI risk even with high genetic predispositions
Zhao et al. 2019 [41]	Cross-sectional study using a sleep factor questionnaire (SFQ) and the prevalence of hypertension	1518 participants recruited from health examination population at primary care setting of Jiujiang University Hospital	SFQ to assess wide range of sleep characteristics and their association with the prevalence of hypertension	Compared to sleep durations of 7-8 h, sleep durations of 8-9 h resulted in greater odds for hypertension OR=1.60 and sleep durations >9 h had an OR= 2.39