title: Obesity-associated asthma in children: a distinct entity.
abstract: BACKGROUND
  Obesity-associated asthma has been proposed to be a distinct entity, differing in immune pathogenesis from atopic asthma. Both obesity-mediated inflammation and increase in adiposity are potential mechanistic factors that are poorly defined among children. We hypothesized that pediatric obesity-associated asthma would be characterized by T helper (Th) 1, rather than the Th2 polarization associated with atopic asthma. Moreover, we speculated that Th1 biomarkers and anthropometric measures would correlate with pulmonary function tests (PFTs) in obese asthmatic children.
  
  
  METHODS
  We recruited 120 children, with 30 in each of the four study groups: obese asthmatic children, nonobese asthmatic children, obese nonasthmatic children, and nonobese nonasthmatic children. All children underwent pulmonary function testing. Blood was collected for measurement of serum cytokines. T-cell responses to mitogen, phorbol 12-myristate 13-acetate (PMA), or antigens tetanus toxoid or Dermatophagoides farinae were obtained by flow cytometric analysis of intracellular cytokine staining for interferon-γ (IFN-γ) (Th1) or IL-4 (Th2) within the CD4 population.
  
  
  RESULTS
  Obese asthmatic children had significantly higher Th1 responses to PMA (P < .01) and tetanus toxoid (P < .05) and lower Th2 responses to PMA (P < .05) and D farinae (P < .01) compared with nonobese asthmatic children. Th-cell patterns did not differ between obese asthmatic children and obese nonasthmatic children. Obese asthmatic children had lower FEV(1)/FVC (P < .01) and residual volume/total lung capacity ratios (P < .005) compared with the other study groups, which negatively correlated with serum interferon-inducible protein 10 and IFN-γ levels, respectively. PFTs, however, did not correlate with BMI z score or waist to hip ratio.
  
  
  CONCLUSIONS
  We found that pediatric obesity-associated asthma differed from atopic asthma and was characterized by Th1 polarization. The altered immune environment inversely correlated with PFTs in obese asthmatic children.
authors: Department of Pediatrics, Albert Einstein College of Medicine, Bronx. Electronic address: drastogi@montefiore.org.
authors: Deepa
authors: D
authors: Rastogi
authors: Department of Epidemiology and Population Health, Albert Einstein College of Medicine, Bronx; Department of Medicine, College of Physicians and Surgeons, Columbia University, New York, NY.
authors: Stephen M
authors: SM
authors: Canfield
authors: Department of Pediatrics, Albert Einstein College of Medicine, Bronx.
authors: Andrea
authors: A
authors: Andrade
authors: Department of Epidemiology and Population Health, College of Physicians and Surgeons, Columbia University, New York, NY.
authors: Carmen R
authors: CR
authors: Isasi
authors: Department of Epidemiology and Population Health, College of Physicians and Surgeons, Columbia University, New York, NY.
authors: Charles B
authors: CB
authors: Hall
authors: Department of Pediatrics, Albert Einstein College of Medicine, Bronx.
authors: Arye
authors: A
authors: Rubinstein
authors: Department of Pediatrics, Albert Einstein College of Medicine, Bronx.
authors: Raanan
authors: R
authors: Arens
mesh_terms: D000818:Animals; D001249:Asthma / Q000150:complications* / Q000503:physiopathology; D015992:Body Mass Index; D054357:Chemokine CXCL10 / Q000097:blood; D002648:Child; D016207:Cytokines / Q000097:blood; D040001:Dermatophagoides farinae / Q000276:immunology; D006801:Humans; D007371:Interferon-gamma / Q000097:blood; D008934:Mitogens / Q000494:pharmacology; D009765:Obesity / Q000150:complications* / Q000503:physiopathology; D012129:Respiratory Function Tests; D013745:Tetanus Toxoid / Q000276:immunology; D013755:Tetradecanoylphorbol Acetate / Q000031:analogs & derivatives / Q000494:pharmacology; D018417:Th1 Cells / Q000502:physiology; D018418:Th2 Cells / Q000502:physiology; D049629:Waist-Hip Ratio
chemical_list: D054357:Chemokine CXCL10; D016207:Cytokines; D008934:Mitogens; D013745:Tetanus Toxoid; C016658:phorbolol myristate acetate; D007371:Interferon-gamma; D013755:Tetradecanoylphorbol Acetate