Short sleep duration is an independent predictor of stroke events in elderly hypertensive patients

Data relating habitual sleep duration to the risk of silent or overt stroke are sparse. We tested the hypothesis that short duration of sleep is associated with increased risk of silent cerebral infarct (SCI) and stroke events in hypertensive patients. We performed ambulatory BP monitoring in 1268 hypertensives (mean age: 70.4 years) and followed them for 50 months. Brain MRI was performed in 932 of these subjects for the assessment of SCI, and these subjects were analyzed in this study. Cox proportional hazard models were used to calculate the hazard ratios (HR) of sleep-duration-associated risk for cardiovascular events while controlling for significant covariates. In multivariable Cox regression analysis, a sleep duration <7.5 h was independently associated with the risk of stroke (HR = 2.21; P = 0.003). The presence of SCI was also associated with stroke events (HR = 2.60; P = 0.005). When the subjects were divided into an SCI(+) group and SCI(-) group, the short sleep duration was a significant predictor for incident stroke only in the SCI(+) group (HR = 2.52; P = 0.001). Shorter sleep duration was an independent risk for future incidence of stroke events in hypertensive patients, especially those with SCIs.