A Prospective Study Measuring Exhaled Nitric Oxide in Exercise-Induced Asthma

Study Summary

Exercise induced bronchospasm (EIB), also known as exercise induced asthma (EIA) is a transient obstruction to airflow triggered by exertion. It is now a well known identity, center of discussion in recent years, particularly in the athletes' world. It is more common in asthmatic individuals (regardless of severity of disease), but it is also seen in otherwise healthy subjects, leading to the general consensus that the pathophysiology is different than asthma. The concentration of exhaled nitric oxide (FeNO) in various airway \& respiratory disorders, particularly asthma, has been deeply studied. Its use for noninvasive monitoring of asthma control (reflecting airway eosinophilic inflammation) is being closely examined and put into clinical practice. FeNO is significantly elevated in asthma. Elevated FeNO levels have also been noted in patients hospitalized with a COPD exacerbation, acidosis, rhinitis, bronchiectasis, active pulmonary sarcoidosis, active fibrosing alveolitis, and acute lung allograft rejection. Decreased FeNO levels have been seen in patients with primary ciliary dyskinesia, cystic fibrosis, PiZZ phenotype-related alpha-1 antitrypsin deficiency, and pulmonary hypertension Two studies have addressed the variations on FeNO after EIB and they had contradictory results. Scollo et al. found no change in FeNO in either healthy or asthmatic children after a 6-min of vigorous exertion in an exercise laboratory when they studied 24 asthmatic and 18 control children. Terada et al. reported, for 39 subjects, a decrease in FeNO in subjects with EIB and an increase in healthy controls. It is well accepted that the pathophysiology of exercise induced bronchospasm it is not similar to that of asthma. Certainly the inflammation in the airway does not appear to be eosinophilic. Understanding the disease mechanism is a key factor to adequately manage it. This will be a prospective study measuring online exhaled nitric oxide involving children 8 to 21 years old.