Are known biomarkers for asthma present in early infancy

Background Exhaled nitric oxide (FENO) is a biomarker for eosinophilic airway inflammation [1]. Elevated FENO has been proposed as a marker for diagnosing asthma and predicting asthma exacerbations [2]. We wished to examine the association between known asthma risk factors and FENO. A sub cohort of children (n=222) participating in the Canadian Healthy Infant Longitudinal Development (CHILD) study underwent infant pulmonary function tests (IPFTs) during the first year of life.