Pulmonary and cardiovascular responses to repeated ozone exposure during exercise in adults with exercise‐induced bronchoconstriction
Patric Emerson Oliveira Gonçalves, Bennett Stothers, Andy Hung, André Casanova Silveira, Owen Drake Harris, Tessa van de Kerkhof, Nadine Borduas‐Dedekind, Andrew William Sheel, Michael Stephen KoehleAbstract
We tested the hypothesis that exercising while breathing real‐world ozone (O 3 ) concentrations impairs pulmonary and cardiovascular function in individuals with exercise‐induced bronchoconstriction (EIB) and that repeated exposures induce acclimation. Participants completed consecutive 30‐min cycling sessions breathing room air (RA) and 170 ppb O 3 . A mixed‐effects model and ANOVA were used. Sixteen individuals (50% male) with mild–moderate EIB completed the study. O 3 exposure produced pulmonary impairment on Day 2 in forced expiratory volume in 1 s (Estimate = −5.1, 95% CI: −8.5 to −1.7, p = 0.003), forced vital capacity (Estimate = −4.0, 95% CI: −7.1 to −0.9, p = 0.008), and forced expiratory flow in the midportion of vital capacity (Estimate = −6.7, 95% CI: −12.7 to −0.7, p = 0.008). Minute ventilation was lower on Days 3 and 4 in O 3 , p = 0.007 and p = 0.001. Diastolic blood pressure was lowest on Day 2 under O 3 , 58 mmHg (95% CI: 52, 64) versus RA, 63 mmHg (95% CI: 58, 69), and a significant overall lower HR in O 3 was found across all visits, p = 0.032. These findings demonstrate a significant difference in pulmonary and cardiovascular responses to O 3 compared to RA, but no statistical evidence of acclimation.