title: Sleep duration and risk of stroke events and stroke mortality: A systematic review and meta-analysis of prospective cohort studies.
abstract: BACKGROUND
  Numerous studies have suggested the relationship between sleep duration and risks of stroke mortality and morbidity, however, the effect estimates varied substantially across studies and it remains unknown how many hours of habitual sleep are associated with the lowest risk of stroke outcomes. Therefore, we performed a dose-response meta-analysis of prospective cohort studies to evaluate the relation of sleep duration with risk of total mortality and stroke events.
  
  
  METHODS
  PubMed and Embase databases were searched through January 2016, and multivariate-adjusted relative risks were pooled by using fixed-effects models. Semiparametric and dose-response methods were used to assess the relationship of sleep duration and risk of stroke and stroke mortality.
  
  
  RESULTS
  Eleven articles with 16 independent reports were included in our meta-analysis. An approximate J-shaped relationship was detected between sleep duration and risk of stroke and stroke mortality. No evidence of a curve linear relationship was seen between sleep duration and risk of stroke or stroke mortality. Compared with 7-h sleep duration per day, the pooled relative risks for stroke events were 1.07 (95% CI 1.02-1.12) for each 1-h shorter sleep duration among individuals who slept <7h per day and 1.17 (1.14-1.20) for each 1-h increase of sleep duration among individuals with longer sleep duration and the pooled RR for stroke mortality was 1.17 (95% CI 1.13-1.20) per 1-h increase of sleep duration.
  
  
  CONCLUSIONS
  Both short and long duration of sleep are predictors of stroke outcomes, and long sleep duration is significant marker of stroke mortality.
authors: Department of Social Medicine and Health Management, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430030, China.
authors: Wenzhen
authors: W
authors: Li
authors: Department of Occupational & Environmental Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430030, China; Wuhan Hospital for the Prevention and Treatment of Occupational Diseases, Wuhan, Hubei 430030, China.
authors: Dongming
authors: D
authors: Wang
authors: Department of Social Medicine and Health Management, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430030, China.
authors: Shiyi
authors: S
authors: Cao
authors: Department of Social Medicine and Health Management, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430030, China.
authors: Xiaoxv
authors: X
authors: Yin
authors: Department of Social Medicine and Health Management, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430030, China.
authors: Yanhong
authors: Y
authors: Gong
authors: Department of Social Medicine and Health Management, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430030, China.
authors: Yong
authors: Y
authors: Gan
authors: Department of Social Medicine and Health Management, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430030, China.
authors: Yanfeng
authors: Y
authors: Zhou
authors: Department of Social Medicine and Health Management, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430030, China. Electronic address: zuxunlu@yahoo.com.
authors: Zuxun
authors: Z
authors: Lu
mesh_terms: D006801:Humans; D018570:Risk Assessment; D012307:Risk Factors; D012890:Sleep / Q000502:physiology*; D000070263:Sleep Hygiene; D020521:Stroke / Q000209:etiology / Q000401:mortality; D013997:Time Factors
keywords: Sleep duration; Stroke; Systematic review