title: Environmental influence on the prevalence and pattern of airway dysfunction in elite athletes.
abstract: Elite swimming and boxing require athletes to achieve relatively high minute ventilation. The combination of a sustained high ventilation and provocative training environment may impact the susceptibility of athletes to exercise-induced bronchoconstriction (EIB). The purpose of this study was to evaluate the prevalence of EIB in elite Great British (GB) boxers and swimmers.
  
  
  
  Boxers (n = 38, mean age: 22.1 ± 3.1 years) and swimmers (n = 44, mean age: 21.1 ± 2.6 years) volunteered for the study. Athletes completed an exercise-induced respiratory symptom questionnaire, baseline assessment of fraction of exhaled nitric oxide (FeNO), maximal spirometry manoeuvres and a eucapnic voluntary hyperpnoea (EVH) challenge. EIB was confirmed if forced expiratory volume in 1 s (FEV1) reduced by ≥10% from baseline at two time points post-EVH challenge.
  
  
  
  The prevalence of EIB was greater in elite swimmers (30 of 44; 68%) than in boxers (3 of 38; 8%) (P < 0.001). Twenty-two out of the 33 (67%) EVH-positive athletes had no prior diagnosis of asthma/EIB. Moreover, 12% (6 of 49) of the EVH-negative athletes had a previous diagnosis of asthma/EIB. We found a correlation between FeNO and FEV1change in lung function post-EVH challenge in swimmers (r = 0.32; P = 0.04) but not in boxers (r = 0.24; P = 0.15).
  
  
  
  The prevalence of EIB was ninefold greater in swimmers when compared with boxers. Athletes who train and compete in provocative environments at sustained high ventilation may have an increased susceptibility to EIB. It is not entirely clear whether increased susceptibility to EIB affects elite sporting performance and long-term airway health in elite athletes.
authors.affiliation: School of Sport and Exercise Sciences (SSES), University of Kent, Chatham Maritime, UK. ikl3@kent.ac.uk.
authors.forename: Irisz Karolina
authors.initials: IK
authors.lastname: Levai
authors.affiliation: Department of Respiratory Medicine, Royal Brompton Hospital, London, UK.
authors.forename: James H
authors.initials: JH
authors.lastname: Hull
authors.affiliation: The Institute of Sport, Exercise and Health, University College London, London, UK.
authors.forename: Mike
authors.initials: M
authors.lastname: Loosemore
authors.affiliation: Pool and Marathon Swimming, British Swimming, Loughborough, UK.
authors.forename: Jon
authors.initials: J
authors.lastname: Greenwell
authors.affiliation: Research Institute for Sport and Exercise Sciences (RISES), Liverpool John Moores University, Liverpool, UK.
authors.forename: Greg
authors.initials: G
authors.lastname: Whyte
authors.affiliation: School of Sport and Exercise Sciences (SSES), University of Kent, Chatham Maritime, UK.
authors.forename: John W
authors.initials: JW
authors.lastname: Dickinson
mesh_terms: D000328:Adult; D001250:Asthma, Exercise-Induced / Q000175:diagnosis / Q000453:epidemiology / Q000503:physiopathology; D056352:Athletes / Q000706:statistics & numerical data; D001914:Boxing / Q000502:physiology / Q000706:statistics & numerical data; D001944:Breath Tests / Q000379:methods; D059026:Diagnostic Self Evaluation; D004777:Environment; D005260:Female; D005541:Forced Expiratory Volume; D006801:Humans; D008297:Male; D009569:Nitric Oxide / Q000032:analysis*; D015995:Prevalence; D012129:Respiratory Function Tests / Q000379:methods; D013550:Swimming / Q000502:physiology / Q000706:statistics & numerical data; D006113:United Kingdom / Q000453:epidemiology
chemical_list: D009569:Nitric Oxide
keywords: asthma; athlete's care; exercise-induced bronchoconstriction; sport; training environment