Proton pump inhibitor improves breath marker in moderate asthma with gastroesophageal reflux disease.

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.