Abstract
Background: Several studies support the role of cysteinyl leukotrienes (Cys-LTs) in exercise-induced bronchoconstriction (EIB), however the concentration of these mediators during the development of EIB has not been investigated yet.
Aim: To study the effect of exercise on airway concentration of Cy-LTs in asthmatic patients by measuring Cy-LT in exhaled breath condensate (EBC).
Methods: Seventeen asthmatic patients with previous history of EIB and six healthy subjects participated in the study. Lung function was measured and EBC was collected at rest (baseline), immediately and ten minutes after exercise challenge on treadmill. Exhaled NO (FENO) was also determined at baseline. To compare the exercise-induced changes in FEV1 and Cys-LT between groups, repeated-measures ANOVA was used. Pearson correlation was applied to assess the relationship between variables. Cys-LT levels are expressed as median (range).
Results: Baseline Cys-LT level was higher in asthmatic than in healthy subjects (168 pg/ml (112-223) vs. 77 pg/ml (36-119), p=0.03). Exhaled breath condensate Cys-LT concentration increased in all asthmatic patients post-exercise (n=17, p=0.03), with the increase significantly greater in patients developing exercise-induced bronchospasm (n=7, p=0.03), while no change was observed in healthy controls (p=0.59). There was a strong correlation between baseline FENO and the maximal increase in Cys-LT concentration in the asthmatic group (p=0.01, r=-0.57). A significant relationship was observed between the increase in EBC Cys-LT and the exercise-induced fall in FEV1.
Conclusion: Our study supports the concept that the release of Cys-LTs is involved in the development of EIB.
- © 2011 ERS