Exhaled breath condensate pH is increased after moderate exercise.
Exhaled breath condensate (EBC) of patients with inflammatory diseases has a decreased pH. This could make EBC-pH an interesting tool for studying work-related inflammatory processes, provided that normal work activities would not interfere with the results. We consequently tested whether EBC-pH was influenced by moderate exercise. Fifteen healthy nonsmoking subjects exercised for 30 min on a treadmill by walking at 60% of predicted maximal heart rate. Four EBC samples were obtained: one to learn the technique, one before exercise, one immediately after exercise, and one 60 min later. EBC-pH was significantly increased after exercise compared to before (mean of 8.27 vs. 8.20, p = 0.001). It remained significantly increased after 60 min (8.25, p = 0.02). The increase was strongest for the subjects with lowest pH. All pH measures were significantly correlated with each other. Light physical activity increases EBC-pH. The persistence of this increase after the end of the exercise poses a serious challenge if one wants to use this technique for health surveys or for diagnostic purposes. It could prevent the observation of a lowered EBC-pH that results from an inflammatory response.
Riediker
Michael
M
Institute for Occupational Health Sciences, Lausanne, Switzerland. michael.riediker@alumni.ethz.ch
Danuser
Brigitta
B
D000293:Adolescent; D000328:Adult; D000336:Aerosols; D001944:Breath Tests; D015444:Exercise / Q000502:physiology*; D005080:Exercise Test; D045853:Exhalation / Q000502:physiology*; D005260:Female; D005500:Follow-Up Studies; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008297:Male; D015203:Reproducibility of Results; D016138:Walking / Q000502:physiology
D000336:Aerosols