Systemic and airway oxidative stress in competitive swimmers. (April 2018)

• Record Type: Journal Article
• Authors: Škrgat, Sabina; Marčun, Robert; Kern, Izidor; Šilar, Mira; Šelb, Julij; Fležar, Matjaž; Korošec, Peter
• Is Part Of: Respiratory medicine. Volume 137(2018)
• Page Start: 129
• Page End: 133
• Publication Date: 2018-04
• Subjects: Competitive swimmers -- Training -- Bronchial hyperresponsiveness -- Oxidative stress -- Inflammation; Chest -- Diseases -- Periodicals; Chest -- Diseases -- Great Britain -- Periodicals; Respiratory organs -- Diseases -- Periodicals; Respiratory Tract Diseases -- Periodicals; Appareil respiratoire -- Maladies -- Périodiques; Thorax -- Maladies -- Périodiques; Appareil respiratoire -- Maladies -- Traitement -- Périodiques; Electronic journals; 616.2
• DOI: 10.1016/j.rmed.2018.03.005
• Languages: English
• ISSNs: 0954-6111

Abstract

Abstract: Background: The environment in swimming pools, which contain chlorine, might interact with the airway epithelium, resulting in oxidative stress and/or inflammation during high intensity training periods. Methods: We evaluated pulmonary functional (metacholine challenge test, FEV1 and VC), cellular (eosinophils and neutrophils), inflammatory (FeNo, IL-5, IL-6, IL-8 and TNF-α), oxidative (8-isoprostanes) and angiogenesis factors (VEGF) in induced sputum and peripheral blood of 41 healthy non-asthmatic elite swimmers (median 16 years) during the period of high intensity training before a national championship. The second paired sampling was performed seven months later after training had been stopped for one month. Results: There was a ten-fold increase (median 82–924 pg/ml; P < 0.001) in 8-isoprostanes in induced sputum and five-fold increase (median 82–924 pg/ml; P < 0.001) in sera during training in comparison to the period of rest. However, there was no difference in FEV1 (113 vs 116%), VC (119 vs 118%), FeNo (median 34 vs 38 ppb), eosinophils (2.7 vs 2.9% in sputum; 180 vs 165 cells/μl in blood), neutrophils, different cytokines or VEGF in induced sputum or sera. The only exception was TNF-α, which was moderately increased in sera (median 23 vs 40 pg/ml; P = 0.02) during the peak training period. Almost half (18 of 41) of swimmers showed bronchial hyperresponsiveness during the peak training period (PC20 cutoff was 4 mg/ml). There was no correlation between hyperresponsiveness and the markers of oxidative stress or inflammation. Conclusions: High intensity training in healthy, non-asthmatic competitive swimmers results in marked oxidative stress at the airway and systemic levels, but does not lead to airway inflammation. However, we could not confirm that oxidative stress is associated with bronchial hyperresponsiveness (AHR), which is often observed during the peak exercise training period. Highlights: Competitive swimmers have marked oxidative stress at the airway and systemic levels but without concomitant inflammation. Almost half of healthy non-asthmatic competitive swimmers have bronchial hyperresponsiveness in the peak training season. However, we could not confirm that oxidative stress is associated with bronchial hyperresponsiveness (AHR).