title: The role of inhaled and/or nasal corticosteroids on the bronchodilator response.
abstract: OBJECTIVE
  To compare the profiles of the bronchodilator response (BDR) among children with asthma and/or allergic rhinitis (AR) and to determine whether BDR in these children is reduced by treatment with inhaled and/or nasal corticosteroid.
  
  
  METHODS
  Sixty-eight children with asthma (mean age, 10.9 years), 45 children with comorbid asthma and AR (mean age, 10.5 years), and 44 children with AR alone (mean age, 10.2 years) were investigated. After a 2-week baseline period, all children were treated with inhaled fluticasone propionate (either 100 or 250 µg b.i.d., tailored to asthma severity) or nasal fluticasone propionate (one spray b.i.d. in each nostril) or both, according to the condition. Before and 2 weeks after starting treatment, all children were evaluated with spirometry and bronchodilator testing. BDR was calculated as a percent change from the forced expiratory volume in 1 second (FEV(1)) at baseline.
  
  
  RESULTS
  The mean BDR was 10.3% [95% confidence interval (CI) 8.3-12.4%] in children with asthma, 9.0% (95% CI 7.3-10.9%) in subjects with asthma and AR, and 5.0% (95% CI 4.1-5.9%) in children with AR alone (P<0.001). After treatment, the mean BDR was reduced to 5.2% (95% CI 4.2-6.3%) (P<0.001) in children with asthma and to 4.5% (95% CI 3.5-5.5%) (P<0.001) in children with asthma and AR. However, children with rhinitis showed no significant change in BDR after treatment, with the mean value being 4.7% (95% CI 3.7-5.8%) (P=0.597).
  
  
  CONCLUSIONS
  The findings of this study imply that an elevated BDR in children with AR cannot be attributed to nasal inflammation alone and highlights the close relationship between the upper and lower airways.
authors.affiliation: Department of Pediatrics, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Ju Kyung
authors.initials: JK
authors.lastname: Lee
authors.forename: Dong In
authors.initials: DI
authors.lastname: Suh
authors.forename: Young Yull
authors.initials: YY
authors.lastname: Koh