Effect of adjunct fluticasone propionate on airway physiology during rest and exercise in COPD.
RATIONALE
Combination therapy with corticosteroid and long-acting β(2)-agonists (LABA) in a single inhaler is associated with superior effects on airway function and exercise performance in COPD compared with LABA monotherapy. The physiological effects of adding inhaled corticosteroid monotherapy to maintenance bronchodilator therapy (long-acting anticholinergics and LABA singly or in combination) in COPD are unknown.


METHODS
This was a randomized, double-blind, placebo-controlled, crossover study (NCT00387036) to compare the effects of inhaled fluticasone propionate 500 μg (FP500) twice-daily and placebo (PLA) on airway function during rest and exercise, measured during constant work rate cycle exercise at 75% of maximum incremental cycle work rate, in 17 patients with COPD (FEV(1) ≤ 70% predicted).


RESULTS
After treatment with FP500 compared to PLA, there were significant increases in post-dose measurements of FEV(1) (+115 mL, P = 0.006) and the FEV(1)/FVC ratio (+2.5%, P = 0.017), along with decreases in plethysmographic residual volume (-0.32L; P = 0.031), functional residual capacity (-0.30L, P = 0.033), and total lung capacity (-0.30L, P = 0.027) but no changes in vital capacity or inspiratory capacity (IC). Post-treatment comparisons demonstrated a significant improvement in endurance time by 188 ± 362 s with FP500 (P = 0.047) with no concomitant increase in dyspnea intensity. End-inspiratory and end-expiratory lung volumes were reduced at rest and throughout exercise with FP500 compared with PLA (P < 0.05).


CONCLUSION
Inhaled FP500 monotherapy was associated with consistent and clinically important improvements in FEV(1), static lung volumes, dynamic operating lung volumes, and exercise endurance when added to established maintenance long-acting bronchodilator therapy in patients with moderate to severe COPD.