title: Oxidative stress and inflammatory markers in the exhaled breath condensate of children with OSA.
abstract: BACKGROUND
  Obstructive sleep apnea (OSA) in children has been associated with systemic inflammation and oxidative stress. Limited evidence indicates that pediatric OSA is associated with oxidative stress and inflammation in the airway.
  
  
  OBJECTIVE
  The objective of this study is to assess the hypothesis that levels of oxidative stress and inflammatory markers in the exhaled breath condensate (EBC) of children with OSA are higher than those of control subjects.
  
  
  METHODS
  Participants were children with OSA and control subjects who underwent overnight polysomnography. Morning levels of hydrogen peroxide (H(2)O(2)) and sum of nitrite and nitrate (NO(x)) in EBC of participants were measured.
  
  
  RESULTS
  Twelve subjects with moderate-to-severe OSA (mean age ± standard deviation: 6.3 ± 1.7 years; apnea-hypopnea index--AHI, 13.6 ± 10.1 episodes/h), 22 subjects with mild OSA (6.7 ± 2.1 years; AHI, 2.8 ± 1 episodes/h) and 16 control participants (7.7 ± 2.4 years; AHI, 0.6 ± 0.3 episodes/h) were recruited. Children with moderate-to severe OSA had higher log-transformed H(2)O(2) concentrations in EBC compared to subjects with mild OSA, or to control participants: 0.4 ± 1.1 versus -0.9 ± 1.3 (p = 0.015), or versus -1.2 ± 1.2 (p = 0.003), respectively. AHI and % sleep time with oxygen saturation of hemoglobin <95% were significant predictors of log-transformed H(2)O(2) after adjustment by age and body mass index z score (p < 0.05). No significant differences were demonstrated between the three study groups in terms of EBC NO(x) levels.
  
  
  CONCLUSIONS
  Children with moderate-to-severe OSA have increased H(2)O(2) levels in morning EBC, an indirect index of altered redox status in the respiratory tract.
authors.affiliation: Sleep Disorders Laboratory, University of Thessaly School of Medicine and Larissa University Hospital, Larissa, Greece.
authors.forename: Georgia
authors.initials: G
authors.lastname: Malakasioti
authors.forename: Emmanouel
authors.initials: E
authors.lastname: Alexopoulos
authors.forename: Christina
authors.initials: C
authors.lastname: Befani
authors.forename: Kalliopi
authors.initials: K
authors.lastname: Tanou
authors.forename: Vasiliki
authors.initials: V
authors.lastname: Varlami
authors.forename: Dimitrios
authors.initials: D
authors.lastname: Ziogas
authors.forename: Panayiotis
authors.initials: P
authors.lastname: Liakos
authors.forename: Konstantinos
authors.initials: K
authors.lastname: Gourgoulianis
authors.forename: Athanasios G
authors.initials: AG
authors.lastname: Kaditis
mesh_terms: D000293:Adolescent; D001944:Breath Tests; D002648:Child; D005260:Female; D006801:Humans; D006861:Hydrogen Peroxide / Q000032:analysis; D018836:Inflammation Mediators / Q000032:analysis*; D008297:Male; D018384:Oxidative Stress / Q000502:physiology*; D011237:Predictive Value of Tests; D012016:Reference Values; D012137:Respiratory System / Q000503:physiopathology; D020181:Sleep Apnea, Obstructive / Q000175:diagnosis* / Q000503:physiopathology*
chemical_list: D018836:Inflammation Mediators; D006861:Hydrogen Peroxide