Pepsin levels and oxidative stress markers in exhaled breath condensate of patients with gastroesophageal reflux disease.

ABSTRACT

AIM: To evaluate the pepsin and oxidative stress markers in exhaled breath condensate (EBC) in patients with gastroesophageal reflux disease (GERD). PATIENTS AND METHOD: 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)]. CONCLUSION: Decreased levels of NOX in patients with GER disease suggest increased oxidative stress in airways of these patients.