Are asthma-like symptoms in elite athletes associated with classical features of asthma?

Abstract

Background: Asthma is frequent in elite athletes and clinical studies in athletes have found increased airway inflammation.

Objective: To investigate asthma-like symptoms, airway inflammation, airway reactivity (AR) to mannitol and use of asthma medication in Danish elite athletes.

Methods: The study group consisted of 54 elite athletes (19 with physician-diagnosed asthma), 22 non-athletes with physician-diagnosed asthma (steroid naïve for 4 weeks before the examination), and 35 non-athletes without asthma; all aged 18-35 years. Examinations (one day): questionnaires, exhaled nitric oxide (eNO), spirometry, skin prick test, AR to mannitol and blood samples. Induced sputum was done in subjects with asthma.

Results: We found no difference in values for eNO, AR and atopy between 42 elite athletes with and 12 without asthma-like symptoms (NS). Elite athletes with physician-diagnosed asthma had less AR (Response Dose Ratio 0.02 (0.004) vs. 0.08 (0.018) p < 0.01) and fewer sputum eosinophils (0.8% (0-4.8) vs. 6.0% (0-18.5), p < 0.01) than non-athletes with physician-diagnosed asthma. Use of asthma medication was similar in the two groups (NS). Forty-two elite athletes had asthma-like symptoms but only 12 had evidence of current asthma. Elite athletes without asthma had asthma-like symptoms more frequently than non-athletes without asthma (68.6% vs. 25.7%, p < 0.001).

Conclusion: Asthma-like symptoms in elite athletes are not necessarily associated with classic features of asthma and alone should not give a diagnosis of asthma. More studies are needed to further investigate if and how the asthma phenotype of elite athletes differs from that of classical asthma.