Sleep duration and health outcomes: an umbrella review

Purpose To collect existing evidence on the relationship between sleep duration and health outcomes. Methods A thorough search was conducted in PubMed, Web of Science, Embase, and the Cochrane Database of Systematic Reviews from inception to January, 2021. Meta-analyses of observational and interventional studies were eligible if they examined the associations between sleep duration and human health. Results In total, this umbrella review identified 69 meta-analyses with 11 outcomes for cancers and 30 outcomes for non-cancer conditions. Inappropriate sleep durations may significantly elevate the risk for cardiovascular disease (CVD), cognitive decline, coronary heart disease (CHD), depression, falls, frailty, lung cancer, metabolic syndrome (MS), and stroke. Dose-response analysis revealed that a 1-h reduction per 24 hours is associated with an increased risk by 3-11% of all-cause mortality, CHD, osteoporosis, stroke, and T2DM among short sleepers. Conversely, a 1-h increment in long sleepers is associated with a 7-17% higher risk of stroke mortality, CHD, stroke, and T2DM in adults. Conclusion Inappropriate sleep duration is a risk factor for developing non-cancer conditions. Decreasing and increasing sleep hours towards extreme sleep durations are associated with poor health outcomes.

Automated summary

There is a close relationship between sleep duration and health outcomes, with inappropriate sleep duration significantly increasing the risk of cardiovascular disease, cognitive decline, depression, and other non-cancer conditions. A reduction of 1 hour per day for short sleepers is associated with an increased risk of mortality, coronary heart disease, stroke, and type 2 diabetes by 3-11%, while an increase of 1 hour for long sleepers is associated with a 7-17% higher risk of stroke mortality, coronary heart disease, stroke, and type 2 diabetes.