Exhaled nitric oxide and exercise-induced bronchospasm assessed by FEV1, FEF25-75% in childhood asthma

J Asthma. Jul-Aug 2007;44(6):475-8. doi: 10.1080/02770900701424090.

Abstract

The relationship between exhaled nitric oxide (eNO) and bronchial hyperresponsiveness (BHR) should be clarified. The aim of this study was to determine the relationship between eNO and exercise-induced bronchospasm (EIB) by estimation of the each lung parameter in asthmatic children who performed a bicycle ergometer exercise test. Twenty children with asthma were recruited. eNO concentration was examined by the recommended online method. To evaluate BHR, an exercise stress test was performed on a bicycle ergometer. The mean baseline eNO value was significantly correlated with the mean maximum % fall in forced expiratory volume in 1 second (FEV1), forced expiratory flow between 25% and 75% (FEF25-75%) after exercise (r=0.53, r=0.65, respectively). eNO in the EIB-positive group was significantly higher than that in the EIB-negative group by assessing FEV1, FEF25-75% (p<0.005, p=0.005). We demonstrated that the most important lung parameter assessed the occurrence of EIB by a bicycle ergometer exercise test was not only FEV1 but FEF25-75%, which significantly correlated with eNO. This suggests that not only FEV1 but FEF25-75% can be used to evaluate the correlations between BHR (EIB) and airway inflammation (eNO) in asthmatic children. A low eNO is useful for a negative predictor for EIB.

MeSH terms

  • Asthma / metabolism
  • Asthma / physiopathology
  • Asthma, Exercise-Induced / diagnosis
  • Asthma, Exercise-Induced / metabolism
  • Asthma, Exercise-Induced / physiopathology*
  • Breath Tests
  • Child
  • Exercise Test
  • Female
  • Forced Expiratory Volume / physiology*
  • Humans
  • Male
  • Maximal Midexpiratory Flow Rate / physiology*
  • Nitric Oxide / metabolism*
  • Predictive Value of Tests
  • Spirometry

Substances

  • Nitric Oxide