Background: Gastroesophageal reflux disease (GERD) influences the symptoms of asthma with acid and oxidative stress.
Objectives: The purpose of this study was to determine the usefulness of measurement of the acid stress marker pH and the oxidative stress marker 8-isoprostane by exhaled breath condensate in proton pump inhibitor (PPI) therapy effect on moderate asthma patients with GERD.
Methods: The pH and the concentration of 8-isoprostane were measured in the exhaled breath condensate of patients with moderate asthma (n = 36) and healthy subjects (n = 26). Two months of PPI therapy (lansoprazole at 30 mg/day) were done in the asthma patients with (n = 13) or without (n = 13) GERD according to a questionnaire for the diagnosis of reflux disease, and exhaled markers were measured.
Results: The pH was lower (7.3 +/- 0.3) and the 8-isoprostane level was higher (27.7 +/- 2.3) in the asthma patients than in the healthy control subjects (pH 7.5 +/- 0.2 and 8-isoprostane 6.6 +/- 1.2). Two months of PPI therapy improved the pH (from 7.2 +/- 0.1 to 7.3 +/- 0.1) and the 8-isoprostane concentration (from 32.7 +/- 3.4 to 19.2 +/- 3.4) in the asthma patients with GERD, along with improvement of GERD symptoms. However, these markers did not change in the asthma patients without GERD.
Conclusions: Measurement of the pH and 8-isoprostane level of exhaled breath condensate may be useful to evaluate the influence of GERD on asthma, as well as to determine the timing of intermittent PPI therapy.
Copyright 2007 S. Karger AG, Basel.