title: Adiposity, fractional exhaled nitric oxide, and asthma in U.S. children.
abstract: BACKGROUND
  Whether allergic airway inflammation mediates the association between overweight or obesity and childhood asthma is unknown.
  
  
  OBJECTIVE
  To examine adiposity, asthma, and fractional exhaled nitric oxide (FeNO) in U.S. children.
  
  
  METHODS
  Cross-sectional study of indicators of adiposity or obesity, FeNO (a biomarker of eosinophilic airway inflammation), and asthma in 2,681 children aged 6-17 years in the 2007-2010 National Health and Nutrition Examination Survey. Adiposity measures included body mass index (BMI), percent body fat (PBF), and waist circumference (WC).
  
  
  RESULTS
  BMI, PBF, and WC were associated with asthma among children with low FeNO (odds ratio, 1.54-1.68; P < 0.01), but not among children with increased FeNO. Among children without asthma, BMI, PBF, and WC were associated with higher FEV1 and FVC, and lower FEV1/FVC. Among children with asthma and a high FeNO, all adiposity indicators were associated with decreased FEV1/FVC (β = -1.5% to -1.7% per z score) but not with FEV1 or FVC. Higher BMI or PBF was associated with worse asthma severity or control in children with asthma and increased FeNO, but not in children with asthma and low FeNO. Similar results were obtained in a secondary multivariate analysis of overweight or obesity (defined as BMI ≥85th percentile) and asthma or indicators of asthma severity or control, stratified by FeNO level.
  
  
  CONCLUSIONS
  Adiposity indicators are associated with asthma in children with low FeNO. Among children with asthma, adiposity indicators are associated with worse asthma severity or control in those with high FeNO.
authors.affiliation: Division of Pediatric Pulmonary Medicine, Allergy, and Immunology, Children's Hospital of Pittsburgh of UPMC, University of Pittsburgh, Pittsburgh, Pennsylvania.
authors.forename: Yueh-Ying
authors.initials: YY
authors.lastname: Han
authors.forename: Erick
authors.initials: E
authors.lastname: Forno
authors.forename: Juan C
authors.initials: JC
authors.lastname: Celedón
mesh_terms: D050154:Adiposity / Q000502:physiology*; D000293:Adolescent; D000402:Airway Obstruction / Q000276:immunology*; D001249:Asthma / Q000453:epidemiology / Q000276:immunology / Q000503:physiopathology*; D015415:Biomarkers / Q000032:analysis; D015992:Body Mass Index; D001944:Breath Tests; D002648:Child; D015897:Comorbidity; D003430:Cross-Sectional Studies; D005260:Female; D005541:Forced Expiratory Volume / Q000502:physiology; D006801:Humans; D008297:Male; D009569:Nitric Oxide / Q000032:analysis*; D009749:Nutrition Surveys; D009765:Obesity / Q000453:epidemiology / Q000276:immunology / Q000503:physiopathology*; D014481:United States / Q000453:epidemiology; D055105:Waist Circumference / Q000502:physiology
chemical_list: D015415:Biomarkers; D009569:Nitric Oxide
keywords: NHANES; adiposity; airway inflammation; asthma; obesity