Exercise Induced Bronchoconstriction and Bronchodilation; investigating the effects of age, sex, airflow limitation and the FEV1.

Exercise induced bronchoconstriction (EIBc) is a recognised response to exercise in asthmatics and athletes but is less well understood in an unselected broad population. Exercise induced bronchodilation (EIBd) has received even less attention. The objective of this study was to Investigate the effects of age, sex, forced expiratory volume in 1 s (FEV1), airflow limitation (FEV1/FVC 7.6% fall in FEV1 post exercise (EIBc), whilst the top 5% a >11% increase (EIBd). The probability of both EIBc and EIBd increased with age and was highest in females across all ages (OR 1.76(1.60-1.94) p 2× increased likelihood in females (OR 2.31(1.71-3.113)p<0.0001), with a trend with AL(p=0.06). The probability of EIBd increased as the FEV1%predicted declined, in the presence of AL (OR 1.55 (1.24-0.95) p=0.0001), but sex had no effect. EIBc and EIBd can be demonstrated at the population level and is influenced by age, sex, FEV1%predicted and airflow limitation.