Examining the Genetic Factors That May Cause Chronic Obstructive Pulmonary Disease (COPD)

COPD is a disease in which the lung airways are damaged and partly obstructed, making it difficult to breathe. Millions of people in the United States have COPD, and it is the third leading cause of death in the United States. Symptoms include coughing, excess mucus production, shortness of breath, wheezing, and chest tightness. Emphysema and long-term bronchitis are the two most common manifestations of the disease. The most common risk factor for developing COPD is cigarette smoking; however, only 15% to 20% of smokers develop COPD in their lifetimes. It is not known why some smokers develop COPD and some do not, but certain genetic factors, combined with exposure to cigarette smoke, may increase the likelihood of developing COPD. This study will analyze DNA from current and former cigarette smokers to identify genetic factors and markers that may indicate a predisposition to developing COPD.

This study will enroll African-American and white cigarette smokers and former cigarette smokers both with and without COPD. Participants will attend one study visit during which they will complete questionnaires about lung symptoms, breathing difficulties, medical and family history, and quality of life. They will also undergo blood collection, a physical exam, lung function testing, and a walking test to measure endurance. Participants will undergo a high resolution computed tomography (CT) chest scan and a medical record review. Study researchers will contact participants up to four times a year for 15 years to collect follow-up medical information. Five-year, ten-year, and fifteen-year follow-up visits including a similar study protocol as the baseline visit will be performed on all available subjects.

Inclusion criteria

• At least 10 pack-years of cigarette smoking (although a of nonsmoking controls is also being enrolled)
• Self-designation of non-Hispanic white or African-American

Exclusion criteria

• Other lung diseases (except for asthma in participants with COPD)
• Pregnant
• Cancer (other than skin cancer) in the 5 years prior to study entry
• Received antibiotics for a COPD exacerbation in the 1 month prior to study entry
• First- or second-degree relative of a previously enrolled study participant