title: Sleep apnea is associated with bronchial inflammation and continuous positive airway pressure-induced airway hyperresponsiveness.
abstract: BACKGROUND
  Obstructive sleep apnea syndrome (OSA) is associated with systemic and upper airway inflammation. Pharyngeal inflammation has a potential role in upper airway collapse, whereas systemic inflammation relates to cardiovascular morbidity. However, the presence of an inflammatory involvement of lower airway has been poorly investigated.
  
  
  OBJECTIVE
  The aim of the study was to demonstrate an inflammatory process at the bronchial level in patients with OSA and to analyze effects of continuous positive airway pressure (CPAP) application and humidification on bronchial mucosa.
  
  
  METHODS
  The study was conducted by using sequential induced sputum for cell analysis and IL-8 production, nitric oxide exhalation measurement, and methacholine challenge before and after CPAP.
  
  
  RESULTS
  Bronchial neutrophilia and a high IL-8 concentration were observed in untreated OSA compared with controls (75% +/- 20% vs 43% +/- 12%, P < .05; and 25.02 +/- 9.43 ng/mL vs 8.6 +/- 3.7 ng/mL, P < .001, respectively). IL-8 in sputum supernatant was correlated to apnea hypopnea index (P < .01; r = 0.81). After 1 month of CPAP, this inflammatory pattern remained unchanged, and an increase in airway hyperresponsiveness (AHR) was observed (P < .001).
  
  
  CONCLUSIONS
  Obstructive sleep apnea syndrome is associated with bronchial inflammation. Our data demonstrate CPAP effect on the development of AHR, possibly facilitated by the pre-existing inflammation. Both issues should be evaluated during long-term CPAP use.
  
  
  CONCLUSIONS
  Results showing a spontaneous bronchial inflammation in OSA and the development of a CPAP-related AHR require a long-term follow-up to evaluate consequences on chronic bronchial obstruction.
authors.affiliation: Sleep Laboratory, Exploration Fonctionnelle Cardio-Respiratoire, University Hospital Grenoble, Grenoble Cedex, France.
authors.forename: Gilles
authors.initials: G
authors.lastname: Devouassoux
authors.forename: Patrick
authors.initials: P
authors.lastname: Lévy
authors.forename: Eliane
authors.initials: E
authors.lastname: Rossini
authors.forename: Isabelle
authors.initials: I
authors.lastname: Pin
authors.forename: Michèle
authors.initials: M
authors.lastname: Fior-Gozlan
authors.forename: Mireille
authors.initials: M
authors.lastname: Henry
authors.forename: Daniel
authors.initials: D
authors.lastname: Seigneurin
authors.forename: Jean-Louis
authors.initials: JL
authors.lastname: Pépin
mesh_terms: D000328:Adult; D001980:Bronchi / Q000187:drug effects; D016535:Bronchial Hyperreactivity / Q000175:diagnosis / Q000209:etiology*; D001991:Bronchitis / Q000175:diagnosis / Q000209:etiology* / Q000276:immunology; D016085:Bronchoconstrictor Agents / Q000494:pharmacology; D045422:Continuous Positive Airway Pressure / Q000009:adverse effects*; D045853:Exhalation; D005260:Female; D006801:Humans; D016209:Interleukin-8 / Q000032:analysis; D008297:Male; D016210:Methacholine Chloride / Q000494:pharmacology; D008875:Middle Aged; D009504:Neutrophils / Q000276:immunology; D009569:Nitric Oxide / Q000378:metabolism; D020545:Respiratory Mucosa / Q000187:drug effects; D020181:Sleep Apnea, Obstructive / Q000150:complications* / Q000628:therapy; D013183:Sputum / Q000737:chemistry / Q000166:cytology / Q000276:immunology
chemical_list: D016085:Bronchoconstrictor Agents; D016209:Interleukin-8; D016210:Methacholine Chloride; D009569:Nitric Oxide