Asthma-COPD Overlap Examined in New Study

15% of Those with COPD also have Asthma (called Asthma-COPD Overlap)

The asthma-COPD overlap (ACO) is one of the “hot” topics at respiratory meetings.  These individuals have some features of both asthma and COPD.
ACOS = asthma COPD Overlap Syndrome

ACOS = asthma COPD Overlap Syndrome

In the January 2016 issue of the journal CHEST (volume 149; pages 45-52), Dr. Cosio and colleagues studied 831 individuals seen for COPD in Spain. Based on specific characteristics, the authors considered that 15% of those with COPD also had asthma.  Of the group with the asthma-COPD overlap, 82% were male and 67% had mild ot moderate disease based on results of breathing tests. Interestingly, they found that those with asthma-COPD Overlap had a better survival over one year compared with those who only had COPD.
Professor Peter J. Barnes of the Imperial College in London

Professor Peter J. Barnes of the Imperial College in London

Editorial about the study: Dr. Peter Barnes reviewed the differences in types of inflammatory cells in asthma and in COPD.  He commented that the reason to identify ACO is to select the most appropriate therapy. Studies suggest that those with COPD who have a specific type of white blood cell called an eosinophil in sputum or blood will benefit from adding an inhaled corticosteroid medication to the two different types of bronchodilator called beta2-agonists and muscarinic antagonists.  The use of all three types of medications is commonly called “triple therapy.”   My Comments: The following diagram shows the overlap between COPD (chronic bronchitis and emphysema) and asthma.  I was taught about these overlapping conditions during medical school and fellowship training.
Overlapping circles show that some individuals have features of asthma and COPD.

Overlapping circles show that some individuals have features of asthma and COPD.

Most individuals in my practice who have severe or very severe COPD or severe asthma are on “triple therapy” because this is considered optimal for relief of symptoms (breathing difficulty) and for reducing the risk for an exacerbation (worsening of shortness of breath, cough, and yellow or green mucus). From my perspective, the diagnosis of asthma-COPD overlap will be important when new unique and specific treatments become available.

Donald A. Mahler, M.D. is Emeritus Professor of Medicine at Geisel School of Medicine at Dartmouth in Hanover, New Hampshire. He works as a pulmonary physician at Valley Regional Hospital in Claremont, NH, where he is Director of Respiratory Services.