RESPIRATORY SYMPTOMS, BRONCHIAL RESPONSIVENESS, AND CELLULAR CHARACTERISTICS OF INDUCED SPUTUM IN ELITE SWIMMERS

To investigate respiratory symptoms, increased bronchial responsivenes s, and signs of airway inflammation in elite swimmers, we examined 29 swimmers from the Finnish national team and 19 healthy control subject s (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. Induc ed sputum samples were also collected. Fourteen (48%) of the swimmers and three (16%) of the control subjects showed increased bronchial res ponsiveness (P<0.05). The sputum cell differential counts of eosinophi ls (mean 2.7% vs 0.2%) and neutrophils (54.7% vs 29.9%) from swimmers were significantly higher than those from controls (P<0.01). Eosinophi lia (sputum differential eosinophil count of >4%) was observed in six (21%) of the swimmers and in none of the controls (P<0.05). Symptomati c swimmers had significantly more sputum eosinophils than did the symp tom-free. The concentrations of sputum eosinophil peroxidase (EPO) and human neutrophil lipocalin (HNL) were significantly higher in swimmer s than control subjects (P<0.001 and P=0.05). We conclude that elite s wimmers had significantly more often increased bronchial responsivenes s than control subjects. Sputum from swimmers contained a higher perce ntage 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 hyperresponsiv eness and airway inflammation in swimmers.