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.
Acknowledgements
The study was supported by local funds without external financial support.
Disclosure statement
No potential conflict of interest was reported by the authors.