Relationship of sleep duration with the risk of stroke incidence and stroke mortality: an updated systematic review and dose–response meta-analysis of prospective cohort studies

The relationship between inappropriate sleep duration with stroke incidence and mortality remains controversial. We carried out dose–response meta-analysis to quantify their dose–response relationships. We systematically searched and extracted data from prospective cohort studies regarding sleep duration and stroke published on PubMed, EMBASE, Cochrane Library, CNKI, and Wangfang Data until October 20, 2020. We used Stata version 15.0 for meta-analysis and dose–response meta-analysis. A total of 20 articles including 27 reports were included. There had fifteen and 12 reports concerning sleep duration and stroke incidence and stroke mortality respectively. Meta-analysis showed that short sleep was linked to an increased risk of stroke incidence and stroke mortality (RR: 1.33, 95% CI: 1.19–1.49 and RR: 1.37, 95% CI: 1.16–1.62 respectively). Long sleep was also associated with an increased risk of stroke incidence and stroke-related death (RR: 1.71, 95% CI: 1.50–1.95 and RR: 2.41, 95% CI: 1.87–3.09, respectively). Dose–response meta-analysis demonstrated that U-shaped relationship was observed between sleep duration and risk of all outcomes. Sleep duration presented a nonlinear relationship with stroke incidence, stroke mortality, ischemic stroke, female stroke and male stroke. Prolonged sleep was associated with an increased risk of hemorrhagic stroke and male stroke. Our findings indicate that both short and long sleep duration was linked to a higher risk of stroke incidence and stroke mortality. Extended sleep duration was more associated with adverse outcomes compared with short sleep duration. Inappropriate sleep duration correlated more with ischemic stroke and an increased risk of stroke in females.