Association between fraction of exhaled XXXX , bronchodilator response and inhaled corticosteroid type.

@entity1 @entity32 @entity10924 @entity2023 @entity565 @entity3810 @entity5023
BACKGROUND: Fraction of exhaled @entity3810 (FeNO) is a known marker of airway @entity32 and a topic of recent investigation for @entity565 control in @entity1 . OBJECTIVE: To investigate the relationship among FeNO and bronchodilator response measured by spirometry and types of inhaled corticosteroids (ICS). METHODS: A one-year review of @entity1 tested with spirometry and FeNO in a regional pediatric @entity565 centre was conducted. RESULTS: A total of 183 @entity1 were included (mean [   SD] age 12.8  2.8 years). @entity5023 was used most commonly (n=66 [36.1%]), followed by @entity10924 (n=50 [27.3%]). Most @entity1 (n=73 [39.9%]) had moderate persistent @entity565 . Increased FeNO was associated with percent change in forced expiratory volume in 1 s (FEV1) after bronchodilator adjusted for @entity2023 , parental smoking and ICS type (B=0.08 [95% CI 0.04 to 0.12]; P<0.001). Similarly, FeNO was associated with percent change in forced expiratory flow at 25% to 75% of the pulmonary volume (FEF25-75) after bronchodilator adjusted for parental smoking and ICS type (B=0.13 [95% CI 0.01 to 0.24]; P=0.03). FeNO accounted for only 16% and 9% of the variability in FEV1 and FEF25-75, respectively. Mean-adjusted FeNO was lowest in @entity5023 users compared with no ICS (mean difference 18.6 parts per billion [ppb] [95% CI 1.0 to 36.2]) and there was no difference in adjusted FeNO level between @entity10924 and no ICS (5.9 ppb [95% CI -9.0 to 20.8]). CONCLUSION: FeNO levels correlated with bronchodilator response in a regional pediatric @entity565 centre. However, FeNO accounted for only 16% and 9% of the variability in FEV1 and FEF25-75, respectively. Mean adjusted FeNO varied according to ICS type, suggesting a difference in relative efficacy between ICS beyond their dose equivalents.
