title: Exhaled pentane and nitric oxide levels in patients with obstructive sleep apnea.
abstract: BACKGROUND
  Upper airway inflammation is present in patients with obstructive sleep apnea (OSA).
  
  
  OBJECTIVE
  To determine whether exhaled pentane and nitric oxide (NO) levels, two nonspecific markers of inflammation, are increased in patients with OSA.
  
  
  METHODS
  Exhaled nasal and oral pentane and NO levels were determined before and after sleep in 20 patients with OSA (apnea-hypopnea index, 48+/-7; mean+/-SEM) and eight healthy control subjects.
  
  
  RESULTS
  In patients with OSA, exhaled nasal and oral pentane levels after sleep were significantly higher than presleep values (6.1+/-1.2 nM vs 3.4+/-0.4 nM, and 7.0+/-1.3 nM vs 4.2+/-0.4 nM, respectively; p<0.05). Likewise, exhaled nasal and oral NO levels after sleep were significantly higher than presleep values in patients with OSA (39.7+/-3.8 ppb vs 28.4+/-2.9 ppb and 10.9+/-1.5 ppb vs 6.6+/-0.8 ppb, respectively; p<0.05). By contrast, there were no significant differences in exhaled nasal and oral pentane, and nasal NO levels before and after sleep in control subjects. Exhaled oral NO levels were significantly increased after sleep in comparison to presleep values in control subjects (p<0.05).
  
  
  CONCLUSIONS
  Exhaled nasal pentane and NO levels are increased after sleep in patients with moderate-severe OSA. These data suggest that upper airway inflammation is present in these patients after sleep.
authors.affiliation: Department of Medicine, College of Medicine, University of Illinois at Chicago, 60612-7323, USA. COSOlopa@uic.edu
authors.forename: C O
authors.initials: CO
authors.lastname: Olopade
authors.forename: J A
authors.initials: JA
authors.lastname: Christon
authors.forename: M
authors.initials: M
authors.lastname: Zakkar
authors.forename: C
authors.initials: C
authors.lastname: Hua
authors.forename: W I
authors.initials: WI
authors.lastname: Swedler
authors.forename: P A
authors.initials: PA
authors.lastname: Scheff
authors.forename: I
authors.initials: I
authors.lastname: Rubinstein
mesh_terms: D000328:Adult; D000886:Anthropometry; D001944:Breath Tests / Q000379:methods; D001991:Bronchitis / Q000378:metabolism; D005260:Female; D006801:Humans; D008297:Male; D009569:Nitric Oxide / Q000032:analysis*; D010420:Pentanes / Q000032:analysis*; D017286:Polysomnography; D012891:Sleep Apnea Syndromes / Q000378:metabolism*; D018709:Statistics, Nonparametric
chemical_list: D010420:Pentanes; D009569:Nitric Oxide; C033353:pentane