Objective:

To systematically evaluate the relationship between sleep duration and the risk of ischemic and hemorrhagic stroke and to determine whether the association follows a U-shaped pattern across diverse populations.

Background:

Stroke is a major global cause of morbidity and mortality. Increasing evidence suggests that both short and long sleep durations influence cerebrovascular risk through vascular, inflammatory, and metabolic pathways. However, heterogeneity across studies has limited the establishment of clear thresholds for optimal sleep duration in stroke prevention.

Design/Methods:

A systematic review was conducted in accordance with PRISMA guidelines. PubMed, Scopus, and Web of Science were searched for studies published through October 2025 using the terms “sleep duration,” “stroke risk,” “ischemic stroke,” and “hemorrhagic stroke.” Eligible studies included adult participants (≥18 years) and reported quantitative data on stroke incidence by sleep duration categories. Observational designs (cohort, case-control, cross-sectional) were included. Extracted variables included sample size, sleep duration categories (<6 h, 7–8 h, ≥9 h), stroke subtype, and effect estimates.

Results:

Twenty-five studies met inclusion criteria, encompassing more than 2 million participants across multiple geographic regions. A consistent U-shaped association was observed between sleep duration and stroke risk. Short sleep (<6 h) was linked to higher ischemic and total stroke risk (adjusted risk ratios 1.25–1.68), likely mediated by hypertension, metabolic dysregulation, and inflammation. Long sleep (≥9 h) was more strongly associated with hemorrhagic stroke (risk ratios 1.30–1.72) and may represent underlying comorbid conditions. Sex and age stratified analyses revealed stronger effects in older adults and women

Conclusions:

Both short and long sleep durations are associated with elevated stroke risk, supporting a U-shaped dose response relationship. These findings highlight sleep as a modifiable determinant in CVA prevention. Integrating sleep evaluation into cardiovascular risk screening could improve early detection and primary prevention of stroke. Future longitudinal and mechanistic studies should explore this relationship.