Satia I; Priel E; Al-Khazraji BK; Jones G; Freitag A; O’Byrne PM; Killian KJ;

The European respiratory journal [Eur Respir J] 2021 Aug 26; Vol. 58 (2).
Date of Electronic Publication: 2021 Aug 26 (Print Publication: 2021).

Exercise-induced bronchoconstriction (EIBc) is a recognised response to exercise in asthmatic subjects 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 (FEV ₁ ) and airflow limitation (FEV ₁ /forced vital capacity (FVC) <0.7) on the prevalence of EIBc and EIBd.This was a retrospective study based on incremental cardiopulmonary exercise testing on cycle ergometry to symptom limitation performed between 1988 and 2012. FEV ₁ was measured before and 10 min after exercise. EIBc was defined as a percentage fall in FEV ₁ post-exercise below the 5th percentile, while EIBd was defined as a percentage increase in FEV ₁ above the 95th percentile.35 258 subjects aged 6-95 years were included in the study (mean age 53 years, 60% male) and 10.3% had airflow limitation (FEV ₁ /FVC <0.7). The lowest 5% of subjects demonstrated a ≥7.6% fall in FEV ₁ post-exercise (EIBc), while the highest 5% demonstrated a >11% increase in FEV ₁ post-exercise (EIBd). The probability of both EIBc and EIBd increased with age and was highest in females across all ages (OR 1.76, 95% CI 1.60-1.94; p<0.0001). The probability of EIBc increased as FEV ₁ % pred declined (<40%: OR 4.38, 95% CI 3.04-6.31; p<0.0001), with a >2-fold increased likelihood in females (OR 2.31, 95% CI 1.71-3.11; p<0.0001), with a trend with airflow limitation (p=0.06). The probability of EIBd increased as FEV ₁ % pred declined, in the presence of airflow limitation (OR 1.55, 95% CI 1.24-1.95; p=0.0001), but sex had no effect.EIBc and EIBd can be demonstrated at the population level, and are influenced by age, sex, FEV ₁ % pred and airflow limitation.