Abstract
Introduction and goal: Measurement of FeNO aids in the clinical management of asthma. Less is known about its role in epidemiology. The study was implemented to find out if FeNO level is related to respiratory symptoms, also in the absence of airflow obstruction (FVC & FEV1>80%pv, FEV1/FVC>70%), in children, participants in respiratory survey.
Methods: FeNO was measured (NIOX) in 134 children aged 6-9 years (62 girls). In 102 children reliable results of spirometry were obtained (EasyOne – ATS/ERS) and expressed as % of predicted values - %pv. Questionnaire was used to define known diagnosis of asthma (A: n=12), children with symptoms of chest wheeze or attacks of dyspnea (S: n=24) and children without respiratory symptoms (H: n=98).
Results: In three defined groups the mean values of FeNO (ppb) were in A: 22.5±23.6, S: 23.3±21.6, H: 15.6±13.5 (p=0.1), and the occurrence (%) of increased FeNO (>35 ppb) was in A: 25.0, S: 20.8, H: 5.1 (p=0.01). The differences were similar in the subgroups with normal spirometry (n=117) - mean FeNO (ppb) in A: 22.5±23.6, S: 21.2±21.5, H: 14.6±12.4 (p=0.5), increased FeNO (%) in A: 25.0, S: 14.2, H: 4.7 (p=0.03). In that subgroup S and H differed (p>0.05) in FEF50 (100 vs 102 %pv), FEF75 (91 vs 100 %pv) and FEF2575 (95 vs 99 %pv). FeNO levels were not related to chronic cough.
Conclusion: The results suggest inflammatory background of asthmatic symptoms in children without diagnosis of asthma. This finding and spirometric signs of „small airways involvement” suggest that this group may include children with undiagnosed asthma or asthma at its early stage. The measurement of FeNO could aid in population-based screening of childhood asthma.
- Copyright ©ERS 2015