Increased exhaled breath condensate 8-isoprostane after a swimming session in competitive swimmers

Abstract

Objectives: This study aimed to evaluate the levels of 8-isoprostane (8-IsoP) in the airways of competitive swimmers at baseline and after a swimming session according to their airway responsiveness. Methods: Twenty-three swimmers and six lifeguards had a baseline spirometry and bronchoprovocative challenges. During a second visit, swimmers performed a usual swimming session while lifeguards stayed in the same pool environment for the same time period. Forced expiratory volume in one second (FEV₁) was measured before and 5 min after the end of the session. Exhaled breath condensate (EBC) was sampled before and 10 min after the session and EBC 8-IsoP levels were analysed by enzyme immunoassay. Change in EBC 8-IsoP from baseline to post-swimming session was calculated. Results: We observed no relationships between airway hyper-responsiveness and 8-IsoP values before or after swimming in swimmers. The levels of 8-IsoP were significantly higher after the training session (mean value 2.9, s = 0.5 pg mL⁻¹) than at baseline (mean value 1.9, s = 0.4 pg mL⁻¹) in swimmers only (p = .012). EBC 8-IsoP levels after the swimming session significantly correlated with the percent change in FEV₁ after swimming. Conclusions: EBC 8-IsoP levels were increased after training in swimmers but not in lifeguards, suggesting that exercise-induced hyperpnoea in a chlorinated pool environment increases airways oxidative stress.

Keywords:

• Oxidative stress
• swimming
• bronchodilation
• bronchoconstriction

Acknowledgements

The study was supported by local funds without external financial support.

Disclosure statement

No potential conflict of interest was reported by the authors.