Pulmonary function analysis of Japanese athletes: possibly even more asthmatics in the field.

Background: The prevalence of bronchial asthma (BA) in youth is increasing in Japan, but very few athletes are reported to be affected with BA. The aim of this study is to analyze pulmonary function test (PFT) in athletes from the aspect of BA retrospectively.

Methods: Medical history questionnaires of 2111 athletes (male: 1549, female: 562) were reviewed. All athletes participated in the institute's athletic test for the first time, from April 2003 through March 2006. Athletes were categorized into three groups; current-BA confirmed and treated by the physician, possible-BA according to the allergic history and/or BA symptoms, and non-BA that is neither of the above two groups. The PFT data were then analyzed.

Results: There were 24 current-BA (1.1%), 137 possible-BA (6.5%), and 183 cases with a past history of BA (PH; 8.7%). Percent of predicted forced expiratory volume in 1 second (%FEV1) and of predicted peak expiratory flow rate (%PEF) in current-BA (86.2+/-17.7% and 81.6+/-19.1%, respectively) and possible-BA (84.7+/-14.6% and 81.2+/-17.3%, respectively) were significantly lower than those in non-BA (93.9+/-13.7% and 93.8+/-19.8%, respectively), without any significant difference between current-BA and possible-BA. Athletes with PH show impaired obstructive indices; even in non-BA with PH showed lower %FEV1 (91.3+/-13.9%, p<0.05) and %PEF (86.8+/-17.8%, p<0.001) than non-BA without PH (94.0+/-13.7% and 94.2+/-19.9%, respectively).

Conclusions: The incidence of BA in Japanese athletes may be higher than currently recognized. More intervention is encouraged for the diagnosis of BA, to avoid any fatal asthma during sports by initiating preventive therapy.