title: Self-reported sleep duration and coronary heart disease mortality: A large cohort study of 400,000 Taiwanese adults.
abstract: BACKGROUND
  Most previous studies on sleep duration and coronary heart disease (CHD) have been small and have inadequately controlled for cardiovascular risk factors and chronic diseases. Therefore, our aim was to prospectively examine the associations of sleep duration with CHD while accounting for these factors.
  
  
  METHODS
  Prospective cohort study of 392 164 adults at age 20years or older who attended a health check-up program from 1994 to 2011 in Taiwan and who have information on sleep duration, sleep medications and potential confounders. Participants answered the question: "How long do you sleep for?"-there were four response categories: (a) 0-4h; (b) 4-6h; (c) 6-8h and (d) >8h. The participants were then followed for CHD mortality from the Taiwanese cause-of-death register.
  
  
  RESULTS
  When compared to those who slept 6-8h per night, the risk of dying from CHD was increased by 34% (HR 1.34, 95% Confidence Interval [CI] 0.87-2.07) and 35% (HR 1.35, 95% CI 1.11-1.65) in those who slept less than 4h per night and more than 8h per night, respectively. When stratifying by sex and age, we found some evidence for a stronger U-shaped association in females than in males and in older adults than in younger adults (p for interaction=0.01 and 0.13, respectively).
  
  
  CONCLUSIONS
  Adequate sleep duration should be considered an important component of a healthy lifestyle. Further studies are needed to better elucidate the underlying mechanisms.
authors.affiliation: Department of Public Health and General Practice, Norwegian University of Science and Technology, Hakon Jarls gate 11, 7495 Trondheim, Norway.
authors.forename: Linn B
authors.initials: LB
authors.lastname: Strand
authors.affiliation: Institute of Population Health Sciences, National Health Research Institutes, 35 Keyan Road, Zhunan Town, Miaoli County 35053, Taiwan.
authors.forename: Min Kuang
authors.initials: MK
authors.lastname: Tsai
authors.affiliation: School of Social and Community Medicine, University of Bristol, 39 Whatley Road, Bristol BS8 2PS, United Kingdom.
authors.forename: David
authors.initials: D
authors.lastname: Gunnell
authors.affiliation: Department of Public Health and General Practice, Norwegian University of Science and Technology, Hakon Jarls gate 11, 7495 Trondheim, St Olav Hospital, Prinsesse Kristinas gate 3, Norway and Center for Health Care Research, 7030 Trondheim, Norway.
authors.forename: Imre
authors.initials: I
authors.lastname: Janszky
authors.affiliation: China Medical University Hospital, 91 Hsueh-Shih Road, Taichung City 40402, Taiwan; and Institute of Population Health Science, National Health Research Institutes, 35 Keyan Road, Zhunan Town, Miaoli County 35053, Taiwan. Electronic address: cwengood@nhri.org.tw.
authors.forename: Chi Pang
authors.initials: CP
authors.lastname: Wen
authors.affiliation: Institute of Health Behaviors and Community Sciences and Department of Public Health, College of Public Health, National Taiwan University, No.17, Xu-zhou Road, Taipei City 10055, Taiwan. Electronic address: shusenchang@ntu.edu.tw.
authors.forename: Shu-Sen
authors.initials: SS
authors.lastname: Chang
mesh_terms: D000328:Adult; D000368:Aged; D015331:Cohort Studies; D003327:Coronary Disease / Q000175:diagnosis* / Q000401:mortality*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009026:Mortality / Q000639:trends; D011446:Prospective Studies; D057566:Self Report; D012890:Sleep / Q000502:physiology*; D013624:Taiwan / Q000453:epidemiology; D013997:Time Factors
keywords: Cardiovascular disease; Cohort study; Coronary heart disease; Epidemiology; Sleep duration