Examining the effect of salbutamol use in ozone air pollution by people with asthma and/or exercise induced bronchoconstriction

Introduction: Ground level ozone is a respiratory irritant component of air pollution. Exercise is a key part of a healthy lifestyle; however, when ambient air pollution is high, increased ventilation during exercise increases the inhaled dose of ozone which can be problematic for people with asthma and/or exercise-induced bronchoconstriction (EIB). Salbutamol is a medication taken by people with asthma and EIB before exercise. Rodent studies have indicated that salbutamol may exacerbate ozone-related lung inflammation. Aim: To examine if salbutamol use before exercising in realistic ozone air pollution exacerbates ozone-related airway inflammation in individuals with asthma and/or EIB. Methods: Participants with EIB, confirmed through an EVH test, exercised at 60% of their VO2max for 30 minutes in 4 different conditions: room air + placebo, 170 ppb ozone + placebo, room air + salbutamol, and 170 ppb ozone + salbutamol. Pulmonary function was measured by spirometry. Airway inflammation was measured by FeNO. Blood pressure and symptoms were also measured. Measurements were taken before exercise, immediately after, 30 minutes after, and 1 hour after exercise. Results: Pulmonary function, assessed through spirometry measures, was significantly better in the salbutamol condition as compared to the placebo condition. There was a marginal increase in inflammation in all conditions except the room air + placebo condition. There were no notable differences in symptoms and blood pressure between the conditions. Conclusion: Salbutamol improved pulmonary function in ozone, however did not exacerbate ozone-related increases in airway inflammation, as indicated by FeNO. This is opposing to what has been previously found in rodent studies.