New research is uncovering evidence that ethnicity may influence the development of chronic obstructive pulmonary disease (COPD) and asthma.
One recent study, for example, found that among patients with advanced COPD, the African-Americans had equally severe disease as did the white Americans, even though they were younger, had started smoking later in life, and had smoked less. This finding is at odds with the prevailing view that COPD tends to be more severe in whites. “Our data may reflect a genuine biological difference in the effect of smoking on African-Americans and whites, or they could be artifactual,” acknowledged lead author Wissam M. Chatila, MD.
“More research will be needed to confirm our findings,” said Dr. Chatila, an Associate Professor of Pulmonary and Critical Care Medicine at Temple University in Philadelphia. In an interview, Dr. Chatila said that he is certain his study pertains to COPD and that it is highly unlikely that undetected asthma could have influenced the results. “We retrospectively identified patients who were evaluated for lung volume reduction or lung transplantation—procedures used to treat COPD but never asthma,” he explained.
Also, in his study, COPD had been diagnosed and staged according to the GOLD (Global Initiative for Chronic Obstructive Lung Disease) criteria. Thus, the 80 African-American and 80 white patients all had key traits of severe COPD, including a smoking history of 15 or more pack-years and an FEV1 below 50% of predicted without significant bronchodilator response.
At presentation, the two groups had similarly poor lung function and performed equally on cardiopulmonary exercise tests. On average, however, the African-American patients were four years younger than the white patients (58 vs. 62), had a shorter smoking history (44 vs. 66 pack-years), and had begun smoking at a later age (18 vs. 16). A gender analysis yielded similar findings. The women were younger than the men, had smoked less, and had started smoking later in life.
It is Dr. Chatila’s hope that his study will help to make African-Americans more aware of their risk for severe obstructive lung disease and to change physicians’ perception that COPD is a disease of whites. “We also hope to develop a smoking intervention targeted specifically to African-Americans because they have been less successful in their attempts to quit smoking compared to whites,” he added.