title: Changes in exhaled nitric oxide measured by two offline methods predict improvements in bronchial hyperresponsiveness after inhaled steroid therapy in Japanese adults with asthma.
abstract: BACKGROUND
  The fraction of exhaled nitric oxide (FeNO) is a useful marker of eosinophilic airway inflammation in asthmatics. No studies have examined the relationship between the change in FeNO levels measured offline and changes in bronchial hyperresponsiveness (BHR) in asthmatic patients treated with inhaled corticosteroids (ICS). The objective of this study was to investigate the relationship between the change in FeNO levels measured offline and the change in BHR to acetylcholine in asthmatic patients taking ICS.
  
  
  METHODS
  The study population comprised 41 ICS-treated asthmatics from our outpatient clinic. We measured FeNO levels by two methods -with a Sievers kit ("FeNOs") and with a kit from the Center for Environmental Information Science, Japan ("FeNOc") at baseline and after 1 year of regular treatment. We also used spirometry to test BHR to acetylcholine (PC(20Ach)).
  
  
  RESULTS
  The mean of duration of observation was 406 days. There were significant relationships between DeltalogPC(20Ach) and logPC(20Ach) (r = -0.877, P < 0.001), FeNOs (r = 0.465, P = 0.002), and FeNOc (r = 0.524, P = 0.004) at baseline, but not with age, the dose of ICS, FEV(1), or %FEV(1). Moreover, there was a significant relationship between DeltalogPC(20Ach) and DeltaFeNOs (r = -0.386, P = 0.013) and DeltaFeNOc (r = -0.473, P = 0.004), but not with DeltaFEV(1).
  
  
  CONCLUSIONS
  Changes in FeNOs and FeNOc correlated with improvements in BHR to acetylcholine in adult asthmatics after ICS therapy. Our findings suggest that offline monitoring of FeNO will facilitate the management of bronchial asthma in patients treated with ICS.
authors.affiliation: Clinical Research Center for Allergy and Rheumatology, National Hospital Organization, Sagamihara National Hospital, Kanagawa, Japan. t-tuburai@Sagamihara-hosp.gr.jp
authors.forename: Takahiro
authors.initials: T
authors.lastname: Tsuburai
authors.forename: Naomi
authors.initials: N
authors.lastname: Tsurikisawa
authors.forename: Sayaka
authors.initials: S
authors.lastname: Tatsuno
authors.forename: Yuma
authors.initials: Y
authors.lastname: Fukutomi
authors.forename: Hidenori
authors.initials: H
authors.lastname: Tanimoto
authors.forename: Emiko
authors.initials: E
authors.lastname: Ono
authors.forename: Chiyako
authors.initials: C
authors.lastname: Oshikata
authors.forename: Kiyoshi
authors.initials: K
authors.lastname: Sekiya
authors.forename: Mamoru
authors.initials: M
authors.lastname: Otomo
authors.forename: Yuji
authors.initials: Y
authors.lastname: Maeda
authors.forename: Masami
authors.initials: M
authors.lastname: Taniguchi
authors.forename: Kunihiko
authors.initials: K
authors.lastname: Ikehara
authors.forename: Kazuo
authors.initials: K
authors.lastname: Akiyama
mesh_terms: D000280:Administration, Inhalation; D000328:Adult; D015415:Biomarkers / Q000032:analysis*; D016535:Bronchial Hyperreactivity / Q000175:diagnosis* / Q000188:drug therapy; D003948:Diagnostic Techniques, Respiratory System; D018450:Disease Progression; D045853:Exhalation; D005260:Female; D006801:Humans; D007249:Inflammation; D007564:Japan; D008297:Male; D008875:Middle Aged; D009569:Nitric Oxide / Q000032:analysis*; D011379:Prognosis; D012137:Respiratory System / Q000276:immunology*; D013256:Steroids / Q000627:therapeutic use*
chemical_list: D015415:Biomarkers; D013256:Steroids; D009569:Nitric Oxide