title: The associations between overweight, weight change and health related quality of life: Longitudinal data from the Stockholm Public Health Cohort 2002-2010.
abstract: OBJECTIVE
  Cross-sectional studies have shown that people with obesity and overweight report lower health related quality of life (HRQoL). With a lack of longitudinal studies, this study aims to assess the association between eight-year weight change and HRQoL measured by the EQ-5D instrument and to investigate whether the association differs with regard to baseline body mass index (BMI).
  
  
  METHODS
  A population-based survey was conducted among a random sample of 31,182 individuals from Stockholm County aged 18-84years in 2002 and reassessed in 2010 and supplemented by record linkage with regional and national registers. Multivariate Poisson regression and linear regression were conducted with adjustments for socio-demographic and health-related variables and baseline BMI category as effect modifier for the association between weight change and HRQoL.
  
  
  RESULTS
  Individuals with overweight and obesity respectively have 0.014 and 0.039 lower EQ-5D indexes compared to those being normal weight. Over the eight-year follow-up, 17.6% gained moderately (≥5% body weight) and 13.9% gained heavily (≥10% body weight) in weight. In the fully adjusted analysis, heavy weight gain was associated with a significantly lower overall EQ-5D index and an increased risk of reporting impairment in all but one EQ-5D dimensions irrespective of baseline BMI category. Weight reduction had no significant preventive effect.
  
  
  CONCLUSIONS
  Next to obesity status itself, weight gain leads to impairment in HRQoL irrespective of BMI category at baseline while eight year weight loss seems not to have the reversed effect on HRQoL, emphasizing the importance of primary prevention of weight gain.
authors.affiliation: Child and Adolescent Public Health Epidemiology, Department of Public Health Sciences, Karolinska Institutet, Stockholm, Sweden. Electronic address: nora.doering@ki.se.
authors.forename: N
authors.initials: N
authors.lastname: Döring
authors.affiliation: Child and Adolescent Public Health Epidemiology, Department of Public Health Sciences, Karolinska Institutet, Stockholm, Sweden.
authors.forename: J
authors.initials: J
authors.lastname: de Munter
authors.affiliation: Child and Adolescent Public Health Epidemiology, Department of Public Health Sciences, Karolinska Institutet, Stockholm, Sweden; Centre for Epidemiology and Community Medicine, Stockholm County Council, Health Care Services, Stockholm, Sweden.
authors.forename: F
authors.initials: F
authors.lastname: Rasmussen
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015992:Body Mass Index; D003430:Cross-Sectional Studies; D005260:Female; D006304:Health Status; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D050177:Overweight; D016012:Poisson Distribution; D011788:Quality of Life; D013548:Sweden; D015430:Weight Gain; D055815:Young Adult
keywords: Body mass index; EQ-5D; Obesity; Weight gain