Subjects
Fifty-one men and women with moderate to very severe
COPD, according to the Global Initiative for Chronic Obstructive
Lung Disease criteria,16 able to perform treadmill
exercise tests, and free from other substantial disease potentially
contributing to exercise limitation were recruited
from the pulmonary clinic at a tertiary-care university hospital.
All patients of this convenience sample were clinically
stable (during the 8 week period prior to the study)
and receiving appropriate standard therapy with long-acting
bronchodilators. Those with FEV1 50% of predicted
were receiving inhaled steroids plus long-acting bronchodilators.16
Exclusion criteria included: cardiovascular system
contraindications for exercise, long-term oxygen therapy
or arterial oxygen saturation 85% at rest, use of oral
corticosteroids or antihistamines, and changes in chronic
inhaled therapy. Incapacity to complete the exercise test
protocol was also considered an exclusion criterion. The
study was approved by the ethics committee of the Clinical
Hospital of Porto Alegre, project approval number
05– 449, and all subjects gave written informed consent