Objectively measured sleep characteristics and incidence of ischemic stroke: The sleep heart health study

Objective: Sleep disorders are associated with the prevalence of stroke. However, there is limited evidence regarding the association between objectively measured sleep characteristics and ischemic stroke. Methods: Ischemic stroke was assessed during the mean follow-up period of 11 years in the Sleep Heart Health Study. Sleep parameters such as wake after sleep onset (WASO) and sleep efficiency (SE) were objectively measured based on in-home polysomnography records. Multivariable Cox regression analysis was utilized to examine the relationship between objective sleep characteristics and ischemic stroke incidence. Results: This study involved 4204 participants (1978 males and 2226 females, 63.8±11.1 years). The incidence of ischemic stroke increased in individuals with long WASO, poor SE, and short sleep duration. Multivariable Cox regression analysis showed that WASO within the fourth quartile (hazard ratio [HR] 3.771, 95% confidence interval [CI] 1.805–7.877, P<0.001), third quartile (HR 3.009, 95% CI 1.433–6.317, P=0.004), and second quartile (HR 3.108, 95% CI 1.470–6.568, P=0.003) had a higher incidence of ischemic stroke than WASO within the first quartile. Poor SE (<80.0%) was also found to be a predictor for ischemic stroke (HR 2.220, 95% CI 1.244–3.960, P=0.007). Additionally, a short sleep duration (<6 h) was associated with an increased risk of ischemic stroke (HR 1.725, 95% CI 1.026–2.899, P=0.040). Conclusion: Our results revealed a relationship between WASO, SE, and sleep duration and ischemic stroke. Therefore, these sleep characteristics may be adequate predictors for the incidence of ischemic stroke.