The influence of inhaled corticosteroids on exhaled nitric oxide in stable chronic obstructive pulmonary disease

The aim of the study was to evaluate the exhaled nitric oxide (F(ENO)) in clinically stable chronic obstructive pulmonary disease (COPD), its relationship to the severity of the disease, pulmonary function, smoking status, reversibility of airflow limitation, and ICS therapy. The study was conducted in 47 patients with COPD and 40 healthy controls. Flow/volume spirometry and F(ENO) measurement were performed before and after 2 months of ICS therapy. F(ENO) were significantly elevated in current smokers and ex-smoking COPD patients. In both groups of COPD patients inhaled corticosteroids (ICS) therapy caused a significant decrease in F(ENO) without significant changes in FEV1. A positive correlation between initial F(ENO) and postbronchodilator FEV1 (% predicted) was observed in the group of ex-smoking COPD patients, but not in the currently smoking COPD group. In both groups of COPD patients, the initial level of F(ENO) correlated with the reversibility of airway obstruction, the increase in postbronchodilator FEV1 and the decrease in F(ENO) following ICS treatment. F(ENO) increases in patients with stable COPD. ICS therapy decreased elevated F(ENO) levels in these patients without statistically significant changes in lung function. The selection of COPD patients with increased F(ENO) level and partial reversibility of airway obstruction should be helpful in terms of proposed ICS treatment.