title: Sleep-related disturbances and physical inactivity are independently associated with obesity in adults.
abstract: OBJECTIVE
  To study relationships between obesity, physical inactivity and sleep-related disturbances (obstructive sleep apnea (OSA), sleep duration, sleep disturbances concomitant with daytime tiredness) in adults (> or =30 years).
  
  
  METHODS
  Cross-sectional study with a random population sample.
  
  
  METHODS
  A total of 3377 men (mean age 52.3, s.d. 14.8, years) and 4264 women (56.4, s.d. 17.2, years).
  
  
  METHODS
  Dependent variables, measured: Waist circumference (WC) and body mass index (BMI). Independent variables, from a detailed interview/questionnaire: probable OSA, other sleep-related disturbances, sleep duration, type and frequency of leisure physical activity. Age, mental health, smoking and education were included in analyses as potential confounders.
  
  
  RESULTS
  In men, OSA and physical inactivity increased likelihood for abdominal obesity (WC > or =102 cm). Physical inactivity also increased, but long (> or =9 h/day) sleep decreased likelihood for abdominal overweight (WC: 94-101 cm) in men. In women, abdominal obesity (WC > or =88 cm) was associated positively with OSA, moderate sleep-related disturbances, and physical inactivity. Education modulated the influence of age on abdominal obesity in both genders. Using BMI as the dependent variable did not change the general information obtained by the model. In addition, abdominal obesity was found to be an independent risk factor also in multivariable models predicting categories of a combined sleep duration and sleep disturbances.
  
  
  CONCLUSIONS
  Sleep duration and sleep-related disturbances are associated with obesity, even after controlling for OSA and physical inactivity. The results support the hypothesis of vicious circle between sleep and obesity.
authors.affiliation: The UKK Institute for Health Promotion Research, Tampere, Finland. mikael.fogelholm@uta.fi
authors.forename: M
authors.initials: M
authors.lastname: Fogelholm
authors.forename: E
authors.initials: E
authors.lastname: Kronholm
authors.forename: K
authors.initials: K
authors.lastname: Kukkonen-Harjula
authors.forename: T
authors.initials: T
authors.lastname: Partonen
authors.forename: M
authors.initials: M
authors.lastname: Partinen
authors.forename: M
authors.initials: M
authors.lastname: Härmä
mesh_terms: D000328:Adult; D000368:Aged; D000886:Anthropometry; D015992:Body Mass Index; D003430:Cross-Sectional Studies; D020920:Dyssomnias / Q000150:complications* / Q000453:epidemiology; D004522:Educational Status; D005260:Female; D005387:Finland / Q000453:epidemiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009043:Motor Activity; D009765:Obesity / Q000453:epidemiology / Q000209:etiology*; D012307:Risk Factors; D020181:Sleep Apnea, Obstructive / Q000150:complications / Q000453:epidemiology; D012907:Smoking