Airway inflammation in nonasthmatic amateur runners

Elite athletes show a high prevalence of symptoms and signs of asthma, but no study has assessed the acute effects of endurance exercise on airway cel ls in nonasthmatic athletes. We measured exhaled nitric oxide (NO) and coll ected samples of induced sputum after 3% NaCl aerosol administration for 20 min in nonasthmatic middle-aged amateur runners after the Fourth Palermo I nternational Marathon and 6-9 wk later (habitual training period) at baseli ne. After the marathon, exhaled NO (n = 9 subjects) was higher [27 +/- 9 pa rts/billion (ppb)] than at baseline (12 +/- 4 ppb; P < 0.0005). Polymorphon uclear neutrophil (PMN) counts in induced sputum were much higher in runner s (91.2 +/- 3.6% of total cells postmarathon and 78.7 +/- 9.1% at baseline) than in sedentary control subjects (9.9 +/- 5.9%; P < 0.001). Expression o f L-selectin and CD11b/CD18 in sputum PMNs was lower after the race than at baseline and inversely related to the amount of exhaled NO (r = -0.66 and -0.69, respectively; P < 0.05). Our data indicate that sputum PMNs are incr eased in nonasthmatic runners both after a marathon and at baseline and sug gest that NO may modulate exercise-associated inflammatory airway changes.