Screening Evaluation for Studies of Chronic Obstructive Pulmonary Disease (COPD)

This research is being done to study mechanisms of progression of COPD and to develop treatments for it. The investigators are doing the present study to identify people age 40 and older with mild to moderate COPD who will qualify for such studies to include in a database. The study will include establishing a screening evaluation or characterization of the following two studies: * Emphysema Progression in COPD- Losartan's Effects on Airway Parameters - NA\_00009980 * Sleep-Related Physiology and Inflammation in Chronic Obstructive Pulmonary Disease - NA\_00001771