Pulmonary functions in children with inflammatory bowel disease

Objective To investigate fractional exhaled nitric-oxide (FeNO) levels in children with Crohn's disease (CD) and ulcerative colitis (UC) and their correlation to disease activity. Materials and methods Children with CD and UC (aged 8-18 years) and age-matched healthy controls without respiratory symptoms were recruited. Disease activity was assessed using validated scores. All children performed spirometry and FeNO tests and the association between intestinal disease parameters and pulmonary functions was studied. Results Thirty-five children with CD, nine with UC, and 24 healthy controls were enrolled. The mean FeNO level was higher in children with CD compared with the controls. Increased FeNO levels (>23 parts per billion) were more common among CD and UC compared with healthy children (46, 33, and 0%, respectively, P<0.05). Nevertheless, FeNO levels did not correlate with disease activity. There were no significant differences between CD, UC patients, and healthy controls in any of the spirometric variables. Conclusion FeNO level, a marker of airway inflammation, is elevated in children with inflammatory bowel diseases irrespective of their intestinal disease activity. Increased FeNO levels are not associated with respiratory symptoms, suggesting a latent pulmonary involvement in the systemic disease.