title: Prevalence of short sleep duration and its association with obesity among adolescents 15- to 19-year olds: A cross-sectional study from three major cities in Saudi Arabia.
abstract: BACKGROUND
  Adequate sleep has been considered important for the adolescent's health and well being. On the other hand, self-imposed sleep curtailment is now recognized as a potentially important and novel risk factor for obesity. The present study aimed to assess the prevalence of short sleep duration and its association with obesity among Saudi adolescents.
  
  
  METHODS
  This is a school-based cross-sectional study with self-reported sleep questionnaires. It was conducted during the years 2009/2010 in three cities in Saudi Arabia; Al-Khobar, Jeddah, and Riyadh. Participants were 2868 secondary-school males (1379) and females (1389) aged 15 to 19 years, randomly selected using a multistage stratified sampling technique. Measurements included weight, height, waist circumference, BMI, and sleeping duration. Logistic regression analysis while adjusted for age, gender, and location was used to examine the associations between sleep duration and obesity measures.
  
  
  RESULTS
  The mean (SD) of sleep duration was 7.2 (1.6) hours/day with no significant differences between males and females. About 31% of the participants obtain less than 7 hours of sleep per day, while approximately 50% of the sample gets less than 8 hours of daily sleep. Two-way ANCOVA results while controlling for the effect of age revealed a significant gender by school-type interaction (P<0.001). In addition, adequate sleep duration increased the odds of having normal weight (adjusted odds ratios = 1.28, 95% CI = 1.08-1.50, P = 0.003).
  
  
  CONCLUSIONS
  The present study observed a high prevalence of short sleep duration among Saudi adolescents 15- to 19-year olds and that short sleep duration was significantly associated with increased risk of overweight and obesity. Future interventions should investigate whether adopting a healthy lifestyle by adolescents with short sleep duration would improve their sleeping habits or not.
authors.affiliation: Pediatric Exercise Physiology Laboratory, College of Education, Riyadh, Saudi Arabia.
authors.forename: Hazzaa M
authors.initials: HM
authors.lastname: Al-Hazzaa
authors.forename: Abdulrahman O
authors.initials: AO
authors.lastname: Musaiger
authors.forename: Nada A
authors.initials: NA
authors.lastname: Abahussain
authors.forename: Hana I
authors.initials: HI
authors.lastname: Al-Sobayel
authors.forename: Dina M
authors.initials: DM
authors.lastname: Qahwaji