Association of exhaled nitric oxide with asthma and atopy among children living in Santiago, Chile

Background: Chronic airway inflammation is a central process in asthma. Measurement of exhaled nitric oxide (eNO) is a non-invasive biomarker of eosinophilic airway inflammation. Aim: To measure eNO levels in a population of asthmatic and non-asthmatic children and to evaluate their relationship with asthma and atopy. Material and Methods: We studied 143 asthmatic and non-asthmatic children aged 6 to 14 years attended a hospital and primary health service. Participants were tested for allergies and followed during the winter months of 2010 and 2011. They were visited regularly at their homes and eNO levels were measured on each visit using a handheld equipment. Mean eNO distribution were compared by the presence of asthma or atopy using t-test and regression models. Results: No significant differences for mean eNO levels were detected, according to presence of asthma or atopy, by any of the statistical methods used. Regression models showed significant effects for age but not for sex. Conclusions: There were no differences in eNO levels in the studied children by the presence of asthma or atopy.