Exhaled nitric oxide and the risk of wheezing in infancy: The Generation R study

Abstract

We assessed whether exhaled nitric oxide fraction (FeNO), a marker of eosinophilic airway inflammation, at 6 months was associated with the risk of wheezing during the first 2 yrs of life. In the Generation R birth cohort, pre- and post-natal risk factors for respiratory morbidity and respiratory symptoms were assessed by questionnaires at 6 and 24 months. In 428 infants, off-line mixed oral/nasal FeNO was successfullymeasured during tidal breathing at 6 months. Complete data on FeNO and respiratory symptoms within the first 6 months of life were available for 294 infants. FeNO was higher in males, was positively associated with age and was negatively associated with upper and lower respiratory symptoms within the first 6 months. Logistic regression analysis showed that for every ppb increase of FeNO measured at 6 months, infants had a 1.06 (95% confidence interval 1.01-1.11)-fold increased risk of wheezing in the second year of life. High FeNO (>17.5 ppb) showed a limited added value in predicting wheezing in the second year. We conclude that FeNO at 6 months is positively associated with the risk of wheezing, but has limited added value in predicting wheezing in the second year of life in individual children. Copyright©ERS 2012.