Sleep extension and cardiometabolic health: what it is, possible mechanisms and real-world applications

Short sleep duration is associated with heightened cardiometabolic disease risk and has reached epidemic proportions among children, adolescents and adults. Potential mechanisms underlying this association are complex and multifaceted, including disturbances in circadian timing, food intake and appetitive hormones, brain regions linked to control of hedonic eating, physical activity, an altered microbiome and impaired insulin sensitivity. Sleep extension, or increasing total sleep duration, is an emerging and ecologically relevant intervention with significant potential to advance our understanding of the mechanisms underlying the association between short sleep duration and the risk of cardiometabolic disease. If effective, sleep extension interventions have potential to improve cardiometabolic health across the lifespan. Existing data show that sleep extension is feasible and might have potential cardiometabolic health benefits, although there are limitations that the field must overcome. Notably, most existing studies are short term (2-8 weeks), use different sleep extension strategies, analyse a wide array of cardiometabolic health outcomes in different populations and, frequently, lack adequate statistical power, thus limiting robust scientific conclusions. Overcoming these limitations will require fully powered, randomized studies conducted in people with habitual short sleep duration and existing cardiometabolic risk factors. Additionally, randomized controlled trials comparing different sleep extension strategies are essential to determine the most effective interventions. Ongoing and future research should focus on elucidating the potential cardiometabolic health benefits of sleep extension. Such studies have high potential to generate crucial knowledge with potential to improve health and quality of life for those struggling with short sleep duration.image Abstract figure legend A significant proportion of adults and adolescents regularly sleep less than recommended by the Sleep Research Society and American Academy of Sleep Medicine, which is associated with adverse cardiometabolic risk. One hypothesized strategy to combat such risk is to increase or extend nightly sleep duration. This topical review highlights potential mechanisms linking short sleep duration with adverse cardiometabolic risk and summarizes current evidence on potential cardiometabolic health benefits of sleep extension. Given that many unanswered questions remain, we conclude by outlining future research directions and suggesting best practices to help advance our understanding of sleep extension as an intervention to improve cardiometabolic health. Abbreviation: RCTs, randomized controlled trials. (Created with BioRender.com).image