Determinants of fractional exhaled nitric oxide in healthy men and women from the European Community Respiratory Health Survey III.

Introduction: The fractional exhaled nitric oxide (F NO) is a marker for type 2 inflammation used in diagnostics and management of asthma. In order to use F NO as a reliable biomarker, it is important to investigate factors that influence F NO in healthy individuals. Men have higher levels of F NO than women, but it is unclear whether determinants of F NO differ by sex.