Relationship between fractional exhaled nitric oxide and nasal nitric oxide in airways disease

Reduced nNO in NP patients is due to ostiomeatal complex obstruction. FeNO is sensitive to suppression by inhaled corticosteroids. The AR and HV groups have no such confounders; hence, correlation is most evident. Exclusion of confounders reveals a correlation between upper and lower airway inflammation with noninvasive techniques.