Association of daytime napping with incident stroke in middle‐aged and older adults: a large community‐based study

Abstract

BACKGROUND AND PURPOSE: There are conflicting reports on the association between daytime napping and incident stroke. This study was designed to investigate the relationship between daytime napping and stroke within a community-based cohort. METHODS: The present prospective study was based on the Sleep Heart Health Study. Napping habits were assessed with a self-reported Sleep Habits Questionnaire. Participants with napping habits of different durations and frequencies were followed up until the first stroke occurred or the final censoring date. Cox proportional hazards models were used to estimate the relationship between napping habits and stroke. RESULTS: A total of 4757 participants (2219 men, mean age 63.6 ± 11.1 years) were enrolled in this study. Compared with those taking no naps, multivariate proportional hazards models analysis indicated that individuals taking naps with a duration of >60 min [hazard ratio (HR), 2.460; 95% confidence interval (CI), 1.538-3.934] had a higher risk of stroke. There was also an increased risk of stroke among participants taking naps daily (HR, 1.563; 95% CI, 1.059-2.307) or five to six times/week (HR, 1.548; 95% CI, 1.026-2.335). After combining napping durations and frequencies, regular long naps (HR, 1.903; 95% CI, 1.182-3.065) and regular short naps (HR, 1.451; 95% CI, 1.010-2.084) were independent risk factors for incident stroke. CONCLUSION: Daytime napping with a long duration (>30 min) or a high frequency (≥5 times/week) may increase the risk of stroke.