title: The joint association of anxiety, depression and obesity with incident asthma in adults: the HUNT study.
abstract: BACKGROUND
  Anxiety or depression symptoms may increase the risk of developing asthma, and their interaction with obesity is not known. We aimed to assess the association of anxiety or depression symptoms and the joint association of these symptoms and obesity with incident asthma.
  
  
  METHODS
  We conducted a prospective cohort study of 23 599 adults who were 19-55 years old and free from asthma at baseline in the Norwegian Nord-Trøndelag Health Study. The Hospital Anxiety and Depression Scale was used to measure anxiety or depression symptoms. Obesity was defined as a body mass index≥30.0 kg/m2. Incident asthma was self-reported new cases of asthma during the 11-year follow-up.
  
  
  RESULTS
  Having anxiety or depression symptoms was associated with incident asthma [odds ratio (OR) 1.39, 95% confidence interval (CI) 1.09-1.78). Obese participants with anxiety or depression symptoms had a substantially higher risk of incident asthma (OR 2.93, 95% CI 2.20-3.91) than any other group (non-obese participants without anxiety or depression symptoms [reference], non-obese participants with anxiety or depression symptoms (OR 1.20, 95% CI 1.00-1.45) and obese participants without anxiety or depression symptoms (OR 1.47, 95% CI 1.19-1.82)]. The relative excess risk for incident asthma due to interaction between anxiety or depression symptoms and obesity was 1.26 (95% CI 0.39-2.12).
  
  
  CONCLUSIONS
  This study suggests that having anxiety or depression symptoms contributes to the development of asthma in adults. The risk of asthma may be further increased by the interaction between anxiety or depression symptoms and obesity.
authors.affiliation: Department of Public Health and General Practice, Faculty of Medicine, Norwegian University of Science and Technology, Trondheim, Norway, Department of Epidemiology and Community Medicine, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada and Department of Emergency Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA.
authors.forename: Ben Michael
authors.initials: BM
authors.lastname: Brumpton
authors.forename: Linda
authors.initials: L
authors.lastname: Leivseth
authors.forename: Pål Richard
authors.initials: PR
authors.lastname: Romundstad
authors.forename: Arnulf
authors.initials: A
authors.lastname: Langhammer
authors.forename: Yue
authors.initials: Y
authors.lastname: Chen
authors.forename: Carlos Arturo
authors.initials: CA
authors.lastname: Camargo
authors.forename: Xiao-Mei
authors.initials: XM
authors.lastname: Mai
mesh_terms: D000328:Adult; D001007:Anxiety / Q000453:epidemiology*; D001249:Asthma / Q000453:epidemiology*; D015992:Body Mass Index; D015331:Cohort Studies; D015897:Comorbidity; D003863:Depression / Q000453:epidemiology*; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009664:Norway / Q000453:epidemiology; D009765:Obesity / Q000453:epidemiology*; D016017:Odds Ratio; D011446:Prospective Studies; D012307:Risk Factors; D055815:Young Adult
keywords: Body mass index; epidemiology; interaction; psychological distress