Effects of Exercise on the Airways

In the last ten years, the effects of exercise on bronchial epithelial cells and inflammatory cells in the airways have been studied in detail, and such new information has been combined with previous knowledge on bronchial reactivity and asthma evoked by exercise in asthmatic patients and athletes. The resulting picture is very complex, and the potential clinical consequences are often contradictory, suggesting the opportunity to define different phenotypes of exercise-associated airway changes (Lee & Anderson, 1985; Haahtela et al., 2008; Moreira et al., 2011a). Studies in asthmatic athletes in the 90\u2019 had began to explore the possibility that airway inflammation might be involved in exercise-associated respiratory symptoms. However, studies in non-asthmatic athletes also found increased number of inflammatory cells not only at rest, but also after strenuous endurance exercise (Bonsignore et al., 2001). It was therefore hypothesized that endurance exercise may physiologically cause influx of inflammatory cells into the airways, associated with low or absent inflammatory activation (Bonsignore et al., 2003a). Subsequent studies in athletes and animal models have extended these finding, but the mechanisms of inflammatory cell recruitment into the airways and the tight control of inflammatory activation physiologically associated with exercise remain poorly understood. Exercise is a known cause of bronchoconstriction in asthmatic patients (Cabral et al., 1999) and athletes (Parsons & Mastronarde, 2005). A large number of asthmatic elite athletes participate to international top-level competitions, and guidelines regarding management of asthmatic athletes (Fitch et al., 2008) and rules on the use of anti-asthmatic drugs have been issued (World Anti-Doping Agency, WADA, Oct. 18 2010 report). However, exercise is a powerful physiologic stimulus for bronchodilatation, and some reports underlined that exercise training may actually downmodulate bronchial reactivity in normal subjects (Scichilone et al., 2005, 2010), asthmatic children (Bonsignore et al., 2008) and animal models of asthma (Hewitt et al., 2010). This chapter will summarize the changes induced by acute exercise and training in bronchial reactivity and airway cells in both humans and animal models. It will also discuss the changing paradigm regarding the impact of physical activity in patients with bronchial asthma, and the new perspectives of exercise-based rehabilitation in patients with respiratory diseases such as chronic obstructive pulmonary disease (COPD)

Bronchial epithelial damage after a half-marathon in nonasthmatic amateur runners

Am J Physiol Lung Cell Mol Physiol. 2010 Jun;298(6):L857-62. Epub 2010 Apr 2. Bronchial epithelial damage after a half-marathon in nonasthmatic amateur runners. Chimenti L, Morici G, Paternò A, Santagata R, Bonanno A, Profita M, Riccobono L, Bellia V, Bonsignore MR. SourceDept. Biomedico Di Medicina Interna & Specialistica, Section of Pneumology, Univ. of Palermo, Via Trabucco 180, 90146 Palermo, Italy. [email protected] Abstract High neutrophil counts in induced sputum have been found in nonasthmatic amateur runners at rest and after a marathon, but the pathogenesis of airway neutrophilia in athletes is still poorly understood. Bronchial epithelial damage may occur during intense exercise, as suggested by investigations conducted in endurance-trained mice and competitive human athletes studied under resting conditions. To gain further information on airway changes acutely induced by exercise, airway cell composition, apoptosis, IL-8 concentration in induced sputum, and serum CC-16 level were measured in 15 male amateur runners at rest (baseline) and shortly after a half-marathon. Different from results obtained after a marathon, neutrophil absolute counts were unchanged, whereas bronchial epithelial cell absolute counts and their apoptosis increased significantly (P < 0.01). IL-8 in induced sputum supernatants almost doubled postrace compared with baseline (P < 0.01) and correlated positively with bronchial epithelial cell absolute counts (R(2) = 0.373, P < 0.01). Serum CC-16 significantly increased after all races (P < 0.01). These data show mild bronchial epithelial cell injury acutely induced by intense endurance exercise in humans, extending to large airways the data obtained in peripheral airways of endurance-trained mice. Therefore, neutrophil influx into the airways of athletes may be secondary to bronchial epithelial damage associated with intense exercise. PMID:20363849[PubMed - indexed for MEDLINE