Exhaled pentane and nitric oxide levels in patients with obstructive sleep apnea.

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).
Conclusion: 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.