Effects of Inhaled Corticosteroids in Chronic Obstructive Pulmonary Disease (COPD)
Status:
Completed
Trial end date:
2005-11-01
Target enrollment:
Participant gender:
Summary
Human and animal studies have shown that inhaled corticosteroids (ICS) decrease airway blood
flow . This effect is immediate (within 30 minutes), transient (lasting 90 minutes), and in
animal studies independent of gene expression. In COPD patients, decrease in bronchial blood
flow may also decrease mucosal edema, airway resistance and improve small airway function. If
such an effect exists, then we should be able to measure improvements in airway conductance
and reduce lung hyperinflation, which would have salutary effects on dyspnea and exercise
endurance.
To our knowledge, no study has examined the immediate effect of ICS on small airway function
in COPD. The purpose of this study is to examine the effects of nebulized Pulmicort on small
airway function (spirometry, plethysmographic lung volumes, airways resistance, closing
volume, partial flow-volume loop analysis) and exercise endurance in patients with moderate
to severe COPD.
HYPOTHESIS
1. Nebulized ICS will immediately improve airway function compared with placebo (nebulized
saline).
2. Enhanced lung emptying and reduced operating lung volumes during rest and exercise
following ICS therapy will translate acutely into clinically important reductions in
exertional dyspnea and improvements in exercise endurance.