title: Added value with extended NO analysis in atopy and asthma.
abstract: BACKGROUND
  Assessments of the usefulness of exhaled nitric oxide (NO) in the treatment of asthma have given conflicting results. It is not always obvious if atopic status has been tested in these evaluations.
  
  
  OBJECTIVE
  The aim of the study is to use extended NO analysis to characterize subjects from a random sample populations with focus on rhinitis and asthma.
  
  
  METHODS
  Data were extracted from the European Community Respiratory Health Survey II. A subgroup from the Uppsala site that had had their NO measured at multiple flow rates was included (n = 284). The nonlinear model for NO parameters was used. Atopy was defined as having a titre against at least one of the tested allergens ≥0·35 kU l(-1) . Bronchial responsiveness was assessed by methacholine challenge.
  
  
  RESULTS
  Subjects with non-atopic rhinitis or non-atopic asthma could not be separated from healthy subjects regarding NO parameters. There was a gradual increase with atopy in airway diffusion rate (D(aw) NO); healthy subject 8·0 (7·3, 8·8), healthy atopic 8·8 (6·7, 11·5), atopic rhinitis 10·6 (9·0, 12·4) and atopic asthma 11·2 (9·9, 28·3) ml s(-1) [geometrical mean (CI(95%) )]. There was a correlation between bronchial responsiveness and D(aw) NO in atopic rhinitis (r = -0·41, P<0·01), and bronchial responsiveness and airway wall content of NO (C(aw) NO) in atopic asthma (r = -0·56, P<0·001).
  
  
  CONCLUSIONS
  It is of importance to characterize atopic status when evaluating the association between NO and asthma. Our results indicate that the use of extended NO analysis, with particular attention to D(aw) NO and C(aw) NO, may be useful in monitoring treatment for rhinitis and asthma.
authors.affiliation: Centre for Research and Development, Uppsala University/County Council of Gävleborg, Sweden. marieann.hogman@lg.se
authors.forename: Marieann
authors.initials: M
authors.lastname: Högman
authors.forename: Andrei
authors.initials: A
authors.lastname: Malinovschi
authors.forename: Dan
authors.initials: D
authors.lastname: Norbäck
authors.forename: Christer
authors.initials: C
authors.lastname: Janson
mesh_terms: D000328:Adult; D001249:Asthma / Q000175:diagnosis* / Q000628:therapy*; D001944:Breath Tests / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009569:Nitric Oxide / Q000032:analysis*; D011379:Prognosis; D015203:Reproducibility of Results; D012220:Rhinitis / Q000175:diagnosis* / Q000628:therapy*; D012680:Sensitivity and Specificity; D016896:Treatment Outcome
chemical_list: D009569:Nitric Oxide