title: Sleep duration is significantly associated with carotid artery atherosclerosis incidence in a Japanese population.
abstract: BACKGROUND
  Previous studies have indicated that sleep duration is associated with total mortality in a U-shaped fashion. The purpose of the current study was to examine the relationship between self-reported sleep duration and carotid artery atherosclerosis in a Japanese population.
  
  
  METHODS
  In 2009-2010, a total of 2498 participants (1195 men, 1303 women; age range, 23-92 years) were recruited from members of a Japanese community receiving annual health check-up at a local health center who agreed to participate in the study. Exclusion criteria were as follows: age <40 or ≥85 years; and more than one missing value from either laboratory data or questionnaire responses. A total of 2214 participants were entered into the study. Carotid artery arteriosclerosis was evaluated ultrasonographically and quantified as intima-medial thickness (IMT). The presence of carotid artery atherosclerosis was defined as IMT≥1.2 mm. Sleep durations were compared with IMT measurements after controlling for confounding factors such as age, sex, lipid profile, fasting plasma glucose, hemoglobin A1c, blood pressure, alcohol intake, and smoking habit.
  
  
  RESULTS
  Sleep duration ≥7 h correlated significantly with the incidence of IMT≥1.2 m when compared with a sleep duration of 6 h (multivariate-adjusted odds ratio, 1.263; 95% confidence interval, 1.031-1.546, P=0.024). Shorter sleep duration ≤5 h did not correlate significantly with the risk compared with a sleep duration of 6 h.
  
  
  CONCLUSIONS
  Long sleep duration (≥7 h) correlated significantly with the incidence of carotid artery atherosclerosis compared with a sleep duration of 6 h, but shorter sleep duration did not.
authors.affiliation: Division of Preventive Medicine, Graduate School of Medical and Dental Sciences, Niigata University, 1-757 Asahimachi, Chuo-ku, Niigata City 951-8510, Japan.
authors.forename: Tsueko
authors.initials: T
authors.lastname: Abe
authors.forename: Toshinari
authors.initials: T
authors.lastname: Aoki
authors.forename: Syogo
authors.initials: S
authors.lastname: Yata
authors.forename: Masahiko
authors.initials: M
authors.lastname: Okada
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D044466:Asian People / Q000706:statistics & numerical data*; D002340:Carotid Artery Diseases / Q000000981:diagnostic imaging / Q000208:ethnology* / Q000503:physiopathology*; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D015994:Incidence; D007564:Japan / Q000453:epidemiology; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D018570:Risk Assessment; D012307:Risk Factors; D012890:Sleep; D011795:Surveys and Questionnaires; D013997:Time Factors; D014463:Ultrasonography; D055815:Young Adult