Assessment of reproducibility of exhaled hydrogen peroxide concentration and the effect of breathing pattern in healthy subjects

Reka Gajdocsi, Andras Bikov, Balazs Antus, Ildiko Horvath, Peter J. Barnes, Sergei A. Kharitonov

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Background: Hydrogen peroxide (H 2O 2) is detectable in exhaled breath condensate (EBC) and has been proposed to be a surrogate marker of oxidative stress in the airways. In this study we tested whether the breathing pattern during EBC collection influences the concentration of exhaled H 2O 2. Methods: EBC was collected during (1) tidal breathing and (2) breathing with increased tidal volume for 10 min from 16 healthy volunteers. On-line H 2O 2 measurement was performed by the EcoCheckTM biosensor system. Repeated measurements were also conducted to assess intrasubject reproducibility. Results: Minute ventilation, tidal volume, expiratory flow rate were all increased significantly when subjects were asked to perform breathing with increased tidal volume. In parallel, EBC volume increased (1413 ± 59 vs. 1959 ± 71 mL, p < 0.001), whereas exhaled H 2O 2 levels decreased significantly (1400 ± 170 vs. 840 ± 130 nmol/L, p < 0.001). H 2O 2 levels did not correlate with any individual breathing parameters (p>0.05). Assessment of intersubject variability of H 2O 2 measurements during the two types of breathing revealed a coefficient of variation of 49 and 54%, respectively. The EBC H 2O 2 measurement was highly reproducible (888 ± 176 vs. 874 ± 156 nmol/L) as tested during normal breathing. Conclusions: These data demonstrate that the concentration of H 2O 2 in EBC depends on the ventilatory pattern during sample collection that has to be taken into consideration in all EBC H 2O 2 assays.

Original languageEnglish
Pages (from-to)271-275
Number of pages5
JournalJournal of Aerosol Medicine and Pulmonary Drug Delivery
Issue number6
Publication statusPublished - dec. 1 2011


ASJC Scopus subject areas

  • Pulmonary and Respiratory Medicine
  • Pharmaceutical Science
  • Pharmacology (medical)

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