title: The relationship of the bronchodilator response phenotype to poor asthma control in children with normal spirometry.
abstract: OBJECTIVE
  To determine the relationship of poor asthma control to bronchodilator response (BDR) phenotypes in children with normal spirometry.
  
  
  METHODS
  Children with asthma were assessed for clinical indexes of poorly controlled asthma. Pre- and post-bronchodilator spirometry were performed, and the percent BDR was determined. Multivariate logistic regression assessed the relationship of the clinical indices to BDR at ≥ 8%, ≥ 10%, and ≥ 12% BDR thresholds.
  
  
  RESULTS
  There were 510 controller naïve children and 169 on controller medication. In the controller naïve population the mean age (± 1 SD) was 9.5 (3.4); 57.1% were male, 85.7% Hispanic. Demographics were similar in both populations. In the adjusted profile, significant clinical relationships were found particularly to positive BDR phenotypes ≥ 10% and ≥ 12% versus negative responses including younger age, (OR 2.0, 2.5; P < .05), atopy (OR 1.9, 2.6; P < .01), nocturnal symptoms in females (OR 3.4, 3.8; P < .01); β₂ agonist use (OR 1.7, 2.8; P < .01); and exercise limitation (OR 2.2, 2.5; P < .01) only in the controller naïve population.
  
  
  CONCLUSIONS
  The BDR phenotype ≥ 10% is significantly related to poor asthma control, providing a potentially useful objective tool in controller naïve children even when the pre-bronchodilator spirometry result is normal.
authors.affiliation: Children's Hospital of Orange County(CHOC), Orange, CA, USA. spg1505@aol.com
authors.forename: Stanley P
authors.initials: SP
authors.lastname: Galant
authors.forename: Tricia
authors.initials: T
authors.lastname: Morphew
authors.forename: Robert L
authors.initials: RL
authors.lastname: Newcomb
authors.forename: Kiem
authors.initials: K
authors.lastname: Hioe
authors.forename: Olga
authors.initials: O
authors.lastname: Guijon
authors.forename: Otto
authors.initials: O
authors.lastname: Liao
mesh_terms: D000293:Adolescent; D000305:Adrenal Cortex Hormones / Q000494:pharmacology; D001249:Asthma / Q000628:therapy*; D001993:Bronchodilator Agents / Q000494:pharmacology*; D002648:Child; D045853:Exhalation; D005260:Female; D005541:Forced Expiratory Volume; D006801:Humans; D008297:Male; D009569:Nitric Oxide / Q000378:metabolism; D016017:Odds Ratio; D015272:Pulmonary Medicine / Q000379:methods; D012044:Regression Analysis; D013147:Spirometry / Q000379:methods*
chemical_list: D000305:Adrenal Cortex Hormones; D001993:Bronchodilator Agents; D009569:Nitric Oxide