Stable, non-smoking COPD patients not on oral corticosteroids will be randomized in single blinded study to evaluate nitric oxide gas exchange at baseline, and subsequent effects of fluticasone 100mcg/salmeterol 50mcg bid, and fluticasone 250mcg/salmeterol 50mcg bid. Primary end points will include measurements of nitric oxide at varying expiratory flow rates to calculate bronchial, and small airway/alveolar nitric oxide. Secondary end points will evaluate lung function. Exhaled nitric oxide production presumably reflects endogenous inflammation. Normal healthy, non-smoking controls will be used for comparison, with exhaled nitric oxide measured before and after 3 weeks of low dose inhlaed corticosteroids.
