Grant: Project Grant

Chronic Obstructive Pulmonary Disease (COPD) is a respiratory disorder commonly caused by smoking, and is characterized by breathlessness and exercise intolerance. During exercise, COPD patients are less efficient breathers, requiring them to breath more compared to individuals without COPD. This increased breathing increases the feeling of breathlessness and causes patients to stop exercising at lower intensities. Our grant will help determine why these COPD patients have inefficient breathing and get breathless during exercise. We think that these patients have problems exchanging fresh gas (i.e., oxygen) into the blood stream because of poor pulmonary blood vessel function. We will look to improve pulmonary blood vessel function and see if this improves the matching of blood flow and ventilation in the lung. We will then see if improving blood vessel function leads to better exercise capacity in more advanced disease. Finally, we will test whether an oral medication (sildenafil) can improve pulmonary blood vessel function and breathing efficiency. With this research, we will understand more about breathing efficiency, pulmonary vessel function and gas exchange in COPD patients, and find out whether improving pulmonary blood vessel function helps COPD patients breathe. Understanding the reasons behind the feeling of breathlessness may lead to more effective therapy and improved quality of life in COPD patients.