Exercise-induced bronchoconstriction in adolescent recreational athletes: Potential screening strategies.

BACKGROUND: Intense physical exercise in athletes increases the risk to develop exercise-induced bronchocontriction (EIB). We aimed to study EIB prevalence and explore methods for effective EIB screening. METHODS: Three hundred twenty-seven adolescent athletes (12-18 years) performing at least 12 h of sports a week were included. The evaluation consisted of spirometry, eucapnic voluntary hyperpnoea test (EVH) to evaluate for EIB, FeNO, skin prick testing, blood sampling (serum markers of epithelial damage and mast cell activation), and questionnaires (AQUA©, ACT, ACQ, and exposure and symptom-related questions). RESULTS: Of all athletes, 22% tested positive for EIB (n = 72), 14% reported a previous asthma diagnosis and 40% were atopic. Eighty percent of EIB+ athletes did not use any inhalation therapy. EIB+ athletes were significantly younger, had decreased FEV1/FVC (%), and increased post-EVH-reversibility (%) post-salbutamol compared with EIB- athletes. Furthermore, EIB was significantly associated with previous asthma diagnosis and atopy. The best predictors for a positive EVH test were AQUA© score ≥ 6 (sensitivity of 78%, p = .0171) and wheezing during exercise (specificity of 82%, p = .0002). FeNO negatively and significantly correlated with maximal fall in FEV1 post-EVH test in atopic athletes (r = -.2735, p = .0056). Maximal fall in FEV1 was also associated with prior PM10 exposure (p = .036). Serum markers of epithelial damage were significantly associated with training type, training intensity, EIB severity, and prior air pollution exposure. CONCLUSION: Our findings support the effectiveness of a systematic respiratory screening approach, including baseline questionnaires, lung function tests, and FeNO measurement, to improve EIB detection in adolescent athletes in whom respiratory response to EVH testing is associated with prior exposure to air pollution.

Activation of epithelial and inflammatory pathways in adolescent elite athletes exposed to intense exercise and air pollution.

RATIONALE: Participation in high-intensity exercise in early life might act as stressor to the airway barrier. OBJECTIVES: To investigate the effect of intense exercise and associated exposure to air pollution on the airway barrier in adolescent elite athletes compared with healthy controls and to study exercise-induced bronchoconstriction (EIB) in this population. METHODS: Early-career elite athletes attending 'Flemish-Elite-Sports-Schools' (12-18 years) of 4 different sport disciplines (n=90) and control subjects (n=25) were recruited. Presence of EIB was tested by the eucapnic voluntary hyperventilation (EVH) test. Markers at mRNA and protein level; RNA-sequencing; carbon load in airway macrophages were studied on induced sputum samples. RESULTS: 444 genes were differentially expressed in sputum from athletes compared with controls, which were related to inflammation and epithelial cell damage and sputum samples of athletes contained significantly more carbon loaded airway macrophages compared with controls (24%, 95% CI 20% to 36%, p<0.0004). Athletes had significantly higher substance P (13.3 pg/mL, 95% CI 2.0 to 19.2) and calprotectin (1237 ng/mL, 95% CI 531 to 2490) levels as well as IL-6, IL-8 and TNF-α mRNA levels compared with controls (p<0.05). The incidence of EIB in athletes was 9%. The maximal fall in forced expiratory volume in 1 s (%) after EVH test in athletes was significantly associated with prior PM10 and PM2.5 exposure. CONCLUSION: Early-career elite athletes showed increased markers of air pollution exposure, epithelial damage and airway inflammation compared with controls. Acute exposure to increased air pollution PM10 levels was linked to increased airway hyper-reactivity. TRIAL REGISTRATION NUMBER: NCT03587675.