Role of Endorphins in the Perception of Dyspnea in Patients With Chronic Obstructive Pulmonary Disease

Role of Endorphins in the Perception of Dyspnea in Patients With Chronic Obstructive Pulmonary Disease

Endorphins are naturally occurring narcotic substances that are released when individuals perform exercise. The hypothesis of the study is that endorphins reduce the severity of breathlessness during exercise in patients with chronic obstructive pulmonary disease (COPD). The initial five visits include familiarization and validation of a computerized system for patients to report dyspnea and leg discomfort continuously during exercise testing.

At Visits 6 and 7 blood is drawn to measure serum endorphin levels pre-exercise, end exercise, and 30 minutes after exercise. Normal saline or naloxone is given intravenously 5 minutes prior to exercise in a double-blinded design. The primary outcome is the slope of oxygen consumption - dyspnea.

Inclusion Criteria:

• Diagnosis of COPD
• Ability to exercise
• Ability to computer mouse to provide ratings
• > 10 pack-years smoking
• Baseline dyspnea index < 9

Exclusion Criteria:

• Clinically significant comorbidities