Changes in airway inflammation and remodelling in swimmers after quitting sport competition

Abstract

Intense swimming training in chlorinated pools affects the structure of the airways in elite swimmers. 1 Regardless of the magnitude of airway responsiveness, airway inflammation and remodelling are similar to those of non-athletes with mild asthma. Airway structural changes in swimmers are mainly characterized by increased mast cell and eosinophil numbers, collagen deposition and sub-epithelial basement membrane thickness. 1 A partial reversibility of airway hyperresponsiveness (AHR) has been reported in competitive swimmers after a rest or retirement period. 2,3 This study aimed at comparing inflammation and remodelling in competitive swimmers' airways before and 2 years after retirement from competitive sport.The study protocol was approved by the Institutional Ethics committee (CER20159) and registered at www.clinicaltrials.gov (NCT00686452). Twenty-one elite swimmers who signed a written informed consent and had bronchial biopsies during their training career were solicited about 2 years after retirement from sport competition and six of them accepted a second bronchoscopy (for subjects' selection details see Figure S1).Bronchial biopsies obtained when they were competitive swimmers (PRE) and 2 years after retirement (POST) (23 ± 3 months) were then analysed. 1 The subjects had an exhaled nitric oxide (FeNO) measurement, allergy skin prick tests, blood sampling for immunoglobulin E (IgE) measurement, methacholine inhalation T A B L E 1 Swimmers' individual data Swimmers Sex FEV 1 (% pred.) FVC (% pred.) PC 20 (mg/mL) EVH (% fall in FEV 1 ) FeNO (ppb) Exerciseinduced symptoms (yes:no) Atopy (yes: no) PRE POST % change PRE POST % change PRE POST PRE POST PRE POST PRE POST PRE/POST

Software development to optimize the minimal detectable difference in human airway images captured using optical coherence tomography

“…In biopsies taken from six swimmers before and 2 years after retirement, collagen III expression was higher in retirement than during swim training and tenascin expression was unchanged after retirement. In the same study, lymphocytes and neutrophils were significantly reduced in all swimmers after retirement suggesting reversibility of bronchial inflammation that was present during a swim career (Bougault et al, 2018). The application of OCT imaging used in conjunction with our semi‐automated software can be used to address whether airway remodelling in elite athletes is reversible.…”

“…Similarly, biopsy data from the segmental, subsegmental, and lobar airways have shown increased tenascin deposition and submucosal type I and type III collagen expression in elite swimmers compared to controls (Bougault et al, 2012). Whether or not the remodelling of airways in athletes is reversible upon cessation of competitive training is unclear (Bougault et al, 2018; Vergès et al, 2004). Evidence of deviations from normal healthy structure cannot be provided with certainty without quantitative analysis of airway structural components (Fehrenbach et al, 2017).…”

Health effects of exposure to chlorination by‐products in swimming pools

“…Discontinuation of a swimming career decreases eosinophilic and neutrophilic inflammation and reduces BHR, although these findings should be interpreted with caution given the small sample sizes. 71,72 These inflammatory changes did not seem, however, to correlate with BHR. A study carried out in a mixed population of competitive athletes including mostly non-asthmatic swimmers and speed skaters indicated that the baseline pattern of pro-inflammatory cytokine TNFα and antiinflammatory IL-1ra concentrations in the lower airways appears to be similar in top level athletes and asthmatic patients, but different in healthy controls.…”

“…Inflammatory and remodeling changes reported in bronchial biopsies of competitive swimmers were similar to non‐exercising mild asthmatics and were present also during off‐training period. Discontinuation of a swimming career decreases eosinophilic and neutrophilic inflammation and reduces BHR, although these findings should be interpreted with caution given the small sample sizes 71,72 . These inflammatory changes did not seem, however, to correlate with BHR.…”

Health effects of exposure to chlorination by-products in swimming pools: Position Paper

“…Inflammatory and remodeling changes reported in bronchial biopsies of competitive swimmers were similar to non-exercising mild asthmatics and were present also during off-training period. Discontinuation of a swimming career decreases eosinophilic and neutrophilic inflammation and reduces BHR, although these findings should be interpreted with caution given the small sample sizes 40,41 . These inflammatory changes did not seem, however, to correlate with BHR.…”