title: Pepsin levels and oxidative stress markers in exhaled breath condensate of patients with gastroesophageal reflux disease.
abstract: OBJECTIVE
  To evaluate the pepsin and oxidative stress markers in exhaled breath condensate (EBC) in patients with gastroesophageal reflux disease (GERD).
  
  
  METHODS
  Patients with a presumptive diagnosis of GERD with recurrent respiratory and gastrointestinal problems aged between 2 and 14 years were included in the study. All patients underwent pH monitoring. Patients with a reflux index (RI) ≥4 were assessed as the reflux group, and those with an RO <4 were assessed as the non-reflux group. Pepsin levels and oxidative stress markers [NO metabolites (NOX) and total sulphydrile (TSH) levels] were measured in the EBC.
  
  
  RESULTS
  There were 24 patients in the reflux group [RI 17.6 (6.6-46.4)] [median, interquartile range] and 23 in the non-reflux group [RI 0.8 (0.5-1.9) (p<0.001). Pepsin levels in the EBC were below the level of detection. The median levels of NOx in the EBC of children with reflux [13.7 μmol/L (7.3-24.5)] were lower in than non-reflux group [21.0 μmol/L (14.0-25.2)] (p=0.034). There was a negative correlation between reflux index and NOX levels in EBC (rs: -0.331, p=0.023). In contrast, there was no difference in TSH levels between the reflux and non-reflux groups [37.4 μmol/L (30.2-44.6) vs 40.1 μmol/L (37.4-44.9), respectively, (p>0.05)].
  
  
  CONCLUSIONS
  Decreased levels of NOX in patients with GER disease suggest increased oxidative stress in airways of these patients.
authors.affiliation: Kırıkkale University, School of Medicine, Department of Pediatric Surgery, 71100, Kırıkkale, Turkey. Electronic address: soyer.tutku@gmail.com.
authors.forename: Tutku
authors.initials: T
authors.lastname: Soyer
authors.forename: Ozge Uysal
authors.initials: OU
authors.lastname: Soyer
authors.forename: Esra
authors.initials: E
authors.lastname: Birben
authors.forename: Uçler
authors.initials: U
authors.lastname: Kısa
authors.forename: Omer
authors.initials: O
authors.lastname: Kalaycı
authors.forename: Murat
authors.initials: M
authors.lastname: Cakmak
mesh_terms: D000293:Adolescent; D001249:Asthma / Q000209:etiology; D015415:Biomarkers; D001944:Breath Tests; D002648:Child; D002675:Child, Preschool; D003371:Cough / Q000209:etiology; D005260:Female; D005745:Gastric Acidity Determination; D005764:Gastroesophageal Reflux / Q000150:complications / Q000378:metabolism*; D006801:Humans; D008171:Lung Diseases / Q000209:etiology; D008297:Male; D009589:Nitrogen Oxides / Q000032:analysis; D018384:Oxidative Stress; D010434:Pepsin A / Q000032:analysis*; D011446:Prospective Studies; D012494:Sampling Studies; D013438:Sulfhydryl Compounds / Q000032:analysis
chemical_list: D015415:Biomarkers; D009589:Nitrogen Oxides; D013438:Sulfhydryl Compounds; D010434:Pepsin A
keywords: Children; Exhaled breath condensate; Gastroesophageal reflux disease; Oxidative stress; Pepsin