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

Am J Physiol Lung Cell Mol Physiol. 2010 Jun;298(6):L857-62. doi: 10.1152/ajplung.00053.2010. Epub 2010 Apr 2.


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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Air Pollutants / analysis
  • Bronchi / pathology*
  • Bronchial Hyperreactivity / pathology
  • Epithelium / pathology
  • Humans
  • Interleukin-8 / metabolism
  • Leukocyte Count
  • Male
  • Neutrophils
  • Physical Endurance
  • Running*
  • Sputum / cytology
  • Uteroglobin / metabolism


  • Air Pollutants
  • Interleukin-8
  • SCGB1A1 protein, human
  • Scgb1a1 protein, mouse
  • Uteroglobin