A population-based study of smoking, serum cotinine and exhaled nitric oxide among asthmatics and a healthy population in the USA

摘要

Background: Fractional concentration of exhaled nitric oxide (FeNO) is recommended by the American Thoracic Society (ATS) as a noninvasive biomarker of airway inflammation. In addition to inflammation, many factors may be associated with FeNO, particularly tobacco exposure; however, only age has been included as an influential factor for children below 12 years. Numerous studies have demonstrated negative associations between tobacco exposure and FeNO levels with self-reported data, but few with an objective assessment of smoking.