Association between Fraction of Exhaled Nitric Oxide and Spirometry Data and Clinical Control of Asthma in Children and Adolescents

OBJECTIVE To evaluate the association between fraction of exhaled nitric oxide (FeNO) values and forced expiratory volume in the first second (FEV1) and the level of asthma control, as proposed by the Global Initiative for Asthma (GINA), in asthmatic children and adolescents attended at the National Institute of Women, Children and Adolescents Health Fernandes Figueira of Fundação Oswaldo Cruz (IFF/FIOCRUZ). METHODS This was a cross-sectional study, with a review of medical records of 90 asthmatics between 7 and 17 years old, who were followed up at the IFF/FIOCRUZ Asthma Outpatient Clinic and were referred to perform respiratory function tests (RFT)between March 2013 and September 2014. After classification according to GINA, patients performed complete spirometry and FeNO measurement. Subsequently, they were separated into two groups: regular and non-regular inhaled corticosteroid (ICS) use, regardless of the ventilatory pattern in spirometry. RESULTS The association between FEV1 values and the degree of asthma control according to GINA (p=0.001) was observed in all patients, regardless of ICS use, but there was no association between FEV1 and levels of FeNO. CONCLUSIONS The correlation observed between GINA and FEV1 reinforces the importance of spirometry in the clinical follow-up of these patients. Although no association was found between the value of FeNO and the degree of asthma control and FEV1, FeNO may be an early method to detect airway inflammation, even before the symptoms and spirometric changes.