Respiratory symptoms, bronchial responsiveness, and cellular characteristics of induced sputum in elite swimmers

Abstract

To investigate respiratory symptoms, increased bronchial responsiveness, and signs of airway inflammation in elite swimmers, we examined 29 swimmers from the Finnish national team and 19 healthy control subjects (nonasthmatic, symptom‐free). They answered a questionnaire and were interviewed for respiratory symptoms. Lung volumes were measured and bronchial responsiveness assessed by a histamine challenge test. Induced sputum samples were also collected. Fourteen (48%) of the swimmers and three (16%) of the control subjects showed increased bronchial responsiveness (P<0.05). The sputum cell differential counts of eosinophils (mean 2.7% vs 0.2%) and neutrophils (54.7% V5 29.9%) from swimmers were significantly higher than those from controls (P<0.01). Eosinophilia (sputum differential eosinophil count of >4%) was observed in six (21%) of the swimmers and in none of the controls (P<0.05). Symptomatic swimmers had significantly more sputum eosinophils than did the symptom‐free. The concentrations of sputum eosinophil peroxidase (EPO) and human neutrophil lipocalin (HNL) were significantly higher in swimmers than control subjects (P<0.001 and P=0.05). We conclude that elite swimmers had significantly more often increased tjronchial responsiveness than control subjects. Sputum from swimmers contained a higher percentage of eosinophils and neutrophils, and higher concentrations of EPO and HNL than sputum from controls. Long‐term and repeated exposure to chlorine compounds in swimming pools during training and competition may contribute to the increased occurrence of bronchial hyperresponsiveness and airway inflammation in swimmers.

Exercise‐induced asthma, respiratory and allergic disorders in elite athletes: epidemiology, mechanisms and diagnosis: Part I of the report from the Joint Task Force of the European Respiratory Society (ERS) and the European Academy of Allergy and Clinical Immunology (EAACI) in cooperation with GA2LEN

“…In another study, total asthma (current asthma, physician-diagnosed asthma or BHR) was found in 23% of the athletes compared with 4% of the controls, current asthma in 14% compared with 2% among controls and positive skin prick test (SPT) in 48% of the athletes compared with 36% among controls (28). High prevalence of BHR (48%) to histamine was also found among swimmers (29). Maiolo et al (30) reported the prevalence of asthma in 15% and atopy in 18% of 1060 Italian competing summer athletes.…”

“…In young competitive skiers as compared with healthy somewhat older medical students, not particularly physically active, the skiers had lymphoid aggregates in their bronchi and signs of bronchial remodelling (tenascin) as demonstrated by bronchial biopsies in addition to increased responsiveness to cold air (5,64). A mixed type of eosinophilic and neutrophilic inflammation was found in elite swimmers (29,65), ice-hockey players (66) and cross-country skiers (64,67,68). Swimmers with exercise-induced bronchial symptoms had significantly higher sputum eosinophil counts than symptom-free swimmers (29).…”

Exercise-induced asthma: why is it so frequent in Olympic athletes?

“…Studies in athletes are in line with this observation. Helenius et al have reported increased levels of eosinophils and neutrophils, as well as increased concentrations of sputum eosinophil peroxidase and human neutrophil lipocalin in induced sputum from swimmers [13]; Sue-Chu et al reported lymphoid aggregates in endobronchial biopsies from skiers [14], suggesting increased airways inflammation due to training as well as a wearand-tear effect caused by increased ventilation during endurance training [15].…”

Dyspneic athlete

“…Other environmental triggers include chlorine in swimming pools [13,14] chemicals from resurfacing ice hockey rinks [15], and in urban areas from automobile exhaust [16]. EIB may be underestimated as athletes have been shown to be poor perceivers of bronchospasm [17,18] and lack awareness of symptoms [19,20].…”