Fractional exhaled nitric oxide correlates with FEV1 in bronchial reversibility test in children with asthma

Introduction. There are many studies about FeNO measurement as the marker of inflammation in airways, however clinical significance of this parameter is still not proven. Aim. The objective of this study was to determine correlation between FeNO and changes in FEV1 in bronchial reversibility test and clinical symptoms/quality of life recorded in questionnaire (PAQLQ according to Juniper) in children. Material and methods. 101 children, aged 7-18 yrs, with asthma, treated at least 6 months prior to first visit, participated in the study. The children underwent spirometry with bronchial reversibility test, FeNO measurement and recorded symptoms in PAQLQ questionnaire. Results. The results showed significant correlation between Delta FEV1% in bronchial reversibility test and FeNO. This correlation was stronger in patients with AR. ROC curves revealed correlation between FeNO and the significant increase of FEV1 (>12%). The significant increase of FEV1 determined higher measurements of FeNO, especially in children with AR. There was no significant correlation stated between PAQLQ(S) and Delta FEV1% and FeNO. There was negative correlation between.FEV1% and activity domain in questionnaire (R=-0,271; P=0,006) - higher changes in FEV1% correlated with lower physical activity. Conclusions. FeNO measurement can be very helpful in monitoring asthma in children, however it should be considered always with clinical symptoms, asthma phenotype and concomitant disorders, e.g. allergic rhinitis.