Fractional exhaled nitric oxide is correlated with pulmonary function in patients with stable chronic obstructive pulmonary disease

This study examined the correlation between FeNO levels and pulmonary function in 50 male patients with stable COPD (age 45–83 years), as compared with 50 healthy, non-smoking males (44–77 years). Pulmonary function testing during the study (FEV1, FVC, MEF, PEF) was undertaken using a Vitalograph Pneumotrac spirometer.