title: Associations between poor sleep quality and different measures of obesity.
abstract: OBJECTIVE
  Poor sleep may be a risk factor for obesity. Previous studies have mainly investigated the effects of sleep duration on body mass index, but research considering overall sleep quality and other anthropometric measures is scarce. The aim of this study was to examine the association between sleep quality and different measures of obesity (general obesity, abdominal obesity, body composition) in a population-based sample of adults.
  
  
  METHODS
  The study included 753 participants aged 35-65 years from the BiDirect Study, conducted in Münster, Germany. Participants completed the Pittsburgh Sleep Quality Index (PSQI) on sleep characteristics. Weight, height, and waist circumference were measured by trained study nurses. Body composition (fat mass and fat-free mass) was assessed using bioelectrical impedance analysis. The cross-sectional relationship between sleep quality and measures of obesity was investigated using logistic regression analysis.
  
  
  RESULTS
  Among the participants, 65.3% reported good (PSQI ≤ 5) and 34.7% poor (PSQI > 5) sleep quality. We observed a significant association of poorer sleep quality assessed by the continuous PSQI score with general obesity and high body fat (for both, odds ratio = 1.07, 95% confidence interval = 1.01-1.13), adjusted for socio-demographic and lifestyle factors. Further adjustment for depressive symptoms and somatic comorbidities attenuated the relationship. The observed association was mainly driven by the PSQI components sleep latency, sleep disturbances, and daytime dysfunction.
  
  
  CONCLUSIONS
  The present study suggests that poor sleep quality may predict obesity and high body fat mass among adults. However, a causal relationship still has to be confirmed by prospective studies with objective measurements of sleep and obesity.
authors.affiliation: Institute of Epidemiology and Social Medicine, University of Münster, Münster, Germany. Electronic address: corinna.rahe@uni-muenster.de.
authors.forename: Corinna
authors.initials: C
authors.lastname: Rahe
authors.affiliation: Institute of Epidemiology and Social Medicine, University of Münster, Münster, Germany.
authors.forename: Maria Eszter
authors.initials: ME
authors.lastname: Czira
authors.affiliation: Institute of Epidemiology and Social Medicine, University of Münster, Münster, Germany.
authors.forename: Henning
authors.initials: H
authors.lastname: Teismann
authors.affiliation: Institute of Epidemiology and Social Medicine, University of Münster, Münster, Germany.
authors.forename: Klaus
authors.initials: K
authors.lastname: Berger
mesh_terms: D000273:Adipose Tissue / Q000502:physiology; D000328:Adult; D000368:Aged; D001823:Body Composition / Q000502:physiology; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000209:etiology*; D012893:Sleep Wake Disorders / Q000150:complications*
keywords: Body composition; Body mass index; Obesity; Pittsburgh sleep quality index; Sleep quality; Waist circumference