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 successfully measured 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.

Predictive value of exhaled nitric oxide in healthy infants for asthma at school age

“…On a cellular level, maternal tobacco smoke modified NOS activity in the fetal vascular bed in newborns [12]. Consistent with this observation, postnatal FeNO is modified by prenatal tobacco smoke exposure in offspring [16,17], interestingly enough, in an interaction with maternal atopy [16]. In contrast to the pre-and early postnatal situation, infancy and preschool age seems to be critical for further gene-environment interactions through exposures other than smoking and maternal atopy and their impact upon NO metabolism [4,5].…”

NO kidding: exhaled nitric oxide fraction in preschool children

“…The results were in line with earlier studies suggesting an association between FeNO early in life and respiratory symptoms, lung function, airways reactivity and/or asthma later in life [7][8][9][10][11]. The different populations studied, the different techniques used to measure FeNO and the different outcomes assessed may explain conflicting results with other studies [12][13][14]. CHAWES et al [12] showed that elevated FeNO at 1 month of age did precede transient early wheeze, but not persistent wheeze, and was unrelated to atopy.…”

Birth cohorts in asthma and allergic diseases: Report of a NIAID/NHLBI/MeDALL joint workshop

“…While there have been some relationships to wheezing early in life, 79,80 levels may be more related to IgE sensitization than asthma. 81 In addition, the on-line and off-line measurements used in infants may not adequately approximate the standardized technique used in older cooperative subjects, 82,83 …”