COPD (chronic obstructive pulmonary disease), which occurs almost exclusively in smokers and ex-smokers, is the third leading cause of death in the United States, behind heart disease and cancer.

Although fewer adults are smoking now than in the past, the incidence of COPD is continuing to rise because of the often decades-long lag time between when people start smoking and when they contract the disease.

Neil MacIntyre, MD, professor of medicine (Pulmonary, Allergy and Critical Care Medicine) worked on one of the first studies showing the benefits for COPD patients of pulmonary rehabilitation — cardiovascular exercise combined with tools to address anxiety and depression. That study took place about 20 years ago at Duke, and today pulmonary rehab is standard of care for COPD patients all around the country.

Since then MacIntyre has continued doing research into COPD. He wants to know why some smokers develop COPD and some don’t. “Clearly you have to be a smoker to get COPD, but not all smokers get it,” he says.

In an attempt to answer that question, he’s working on a large NIH-funded project called COPDGene that is collecting genetic material and other data from 10,000 smokers — some with COPD and some without. The study is designed to illuminate the role of genetics and to differentiate among different types of COPD. “Once we understand what the determinants are, medicines can be more focused to a specific population,” MacIntyre says.

COPDGene is being carried out in 21 centers across the United States; MacIntyre is the principal investigator at the Duke site. (See )

MacIntyre is also the Duke principal investigator on another multicenter NIH-funded project.  This one is investigating the effects of supplemental oxygen for COPD patients whose blood oxygen level is lower than normal, but not low enough to qualify for supplemental oxygen under current guidelines. “We’re seeing if giving those patients supplemental oxygen will improve outcome and function, and reduce hospitalization and mortality,” he says.

For a subset of COPD patients, a surgical procedure called lung volume reduction surgery (LVRS) may provide benefit, and Duke is one of only a few hospitals in North Carolina recognized by Medicare for the procedure. In LVRS, a small portion of diseased lung is removed, allowing healthy lung to expand into that area.