title: Relationship of pulmonary function response to ozone exposure and capsaicin cough sensitivity.
abstract: BACKGROUND
  Challenge studies in humans have shown considerable interindividual variability in pulmonary impairment across ozone exposure.
  
  
  OBJECTIVE
  Since previous results suggested effect modulation by neural mechanism, we investigated sensory C-fiber reactivity in relationship to ozone-triggered response pattern.
  
  
  METHODS
  Cough reflex thresholds reflecting C-fiber sensitivity were evaluated by capsaicin single breath dose-response method. Capsaicin concentrations triggering, respectively, two and five or more coughs (C2, C5) were recorded. Sixteen healthy subjects were randomly exposed in an intermittent exercise protocol to ozone concentrations of 240 and 40 ppb (sham exposure). Ozone responsiveness was defined by a decrease in forced expiratory volume in 1 s (FEV(1)) of more than 5%.
  
  
  RESULTS
  Based on a dichotomous classification, subjects with enhanced reactivity to ozone had lower cough thresholds than non-responders (C2, p = 0.035; C5, p = 0.086). Over all, we could demonstrate relationships between capsaicin sensitivity and ozone-triggered changes in FEV(1), peak expiratory flow and maximal expiratory flow at 50% vital capacity but not in specific airway resistance.
  
  
  CONCLUSIONS
  Our results suggest that capsaicin challenge tests might be useful to characterize subjects with enhanced pulmonary function response towards inhalant irritants.
authors.affiliation: Institute for Prevention and Occupational Medicine of the German Social Accident Insurance, Institute of the Ruhr-Universität Bochum (IPA), Bochum, Germany. hoffmeyer@ipa-dguv.de
authors.forename: Frank
authors.initials: F
authors.lastname: Hoffmeyer
authors.forename: Kirsten
authors.initials: K
authors.lastname: Sucker
authors.forename: Christian
authors.initials: C
authors.lastname: Monsé
authors.forename: Hans
authors.initials: H
authors.lastname: Berresheim
authors.forename: Nina
authors.initials: N
authors.lastname: Rosenkranz
authors.forename: Birger
authors.initials: B
authors.lastname: Jettkant
authors.forename: Alexandra
authors.initials: A
authors.lastname: Beine
authors.forename: Thomas
authors.initials: T
authors.lastname: Brüning
authors.forename: Jürgen
authors.initials: J
authors.lastname: Bünger
mesh_terms: D000328:Adult; D000393:Air Pollutants / Q000633:toxicity; D000818:Animals; D002211:Capsaicin / Q000633:toxicity*; D003371:Cough / Q000139:chemically induced*; D005260:Female; D006801:Humans; D008297:Male; D010126:Ozone / Q000633:toxicity*; D055815:Young Adult
chemical_list: D000393:Air Pollutants; D010126:Ozone; D002211:Capsaicin