Abstract
Background: Exercise-induced bronchoconstriction (EIB) in asthmatics depends on the presence of allergic inflammation. This study was performed to assess the possible association of EIB with low-grade systemic inflammation, whose presence was revealed in asthmatic patients. Methods: The study was conducted in a group of 24 asthmatics (14 with EIB, 10 without EIB) and 8 healthy volunteers. Changes in serum and exhaled breath condensate (EBC) high-sensitivity C-reactive protein (hs-CRP) levels induced by intensive exercise were determined. Moreover, the possible correlation of these measurements with the results of other tests used in the diagnosis of asthma as well as laboratory tests commonly associated with asthma were investigated. Results: In asthmatic patients with EIB, a statistically significant increase in hs-CRP levels both in serum and EBC after an exercise test was observed. Twenty-four hours after the exercise test in the group of asthmatics with EIB, a statistically significant increase in exhaled nitric oxide (FENO), serum eosinophil cationic protein (ECP) concentrations and bronchial hyperreactivity to histamine was revealed. A statistically significant correlation between the maximum increase in hs-CRP levels both in serum and EBC after exercise and either baseline FENO and an increase in serum ECP or FENO 24 h after exercise in the group of asthmatics with EIB was revealed. Conclusions: We show that, as a result of intensive exercise leading to bronchoconstriction, an increase in serum and EBC hs-CRP occurs. Our observations could suggest that in asthmatic patients, as a consequence of exercise-induced bronchoconstriction, an intensification of low-grade systemic inflammation can be observed.