Nav: Home

COPD exacerbations lead to lung function decline, particularly among those with mild COPD

September 08, 2016

Acute exacerbations of chronic obstructive pulmonary disease, or COPD, are associated with significant long-term lung function loss, according to research published online, ahead of print in the American Thoracic Society's American Journal of Respiratory and Critical Care Medicine.

In "Acute Exacerbations and Lung Function Loss in Smokers with and without COPD," the researchers reported that the greatest lung function loss occurred among those with mild COPD, and following severe exacerbations.

"Very early on in this disease -- at a time when outside a study like ours the majority of people would not have been diagnosed with COPD -- patients appear to be losing lung function," said lead author Mark T. Dransfield, MD, medical director of the University of Alabama at Birmingham Lung Center. "The whole medical community is focused on the latter stages of COPD, when, like diabetes and heart disease and other chronic diseases, we should probably be focused on preventing morbidity much earlier."

The study also looked at smokers without airway obstruction to determine whether acute respiratory events were associated with a decline in lung function. To the researchers' surprise, it was not.

Participants in the study are part of COPDGene, a multicenter, longitudinal observational cohort study of the disease's underlying genetic factors. COPDGene enrolled more than 10,000 white and African-American current and former smokers, with and without COPD.

In the current study, the researchers analyzed data from the first 2,000 COPDGene participants who returned for a follow-up visit five years after joining the study. Participants were grouped by COPD severity based on Global Initiative for Chronic Obstructive Lung Disease, or GOLD, guidelines. The study also identified participants with Preserved Ratio Impaired Spirometry (PRISm). These patients do not meet the GOLD criteria for COPD, but have reduced FEV1 (<80% of expected) but a normal FEV1/FVC ratio (>0.70%). FEV1 is defined as the amount of air a person can forcibly exhale in one second while FVC is the total amount of air a person can exhale after taking the deepest breath possible. Exacerbations as well as acute respiratory events in those participants without COPD were defined as requiring either antibiotics or systemic steroids. Severe exacerbations were defined as requiring hospitalization.

The study found:
  • Across all groups, including those without COPD and those with PRISm, exacerbations and severe exacerbations were common, with 36.7% reporting events during the past five years.

  • Among those with COPD overall, exacerbations were associated with FEV1 decline in excess of that predicted by aging and other time-dependent factors.

  • Those with mild COPD (GOLD 1) experienced the greatest FEV1 decline. Each exacerbation was associated with an additional 23 mL/year decline. Each severe exacerbation was associated in this group with an additional 87 mL/year decline.

  • Those with moderate (GOLD 2) or severe (GOLD 3) COPD experienced statistically significant but smaller declines in FEV1 with each exacerbation than those with mild COPD.

  • Smokers without COPD with an acute respiratory event and those with PRISm with an exacerbation of any severity did not experience FEV1. A similar result was observed among those with very severe COPD (GOLD 4), which authors said likely reflects survivor bias.

  • Current and intermittent smokers experienced a steeper FEV1 decline than former smokers, 9 mL vs. 2 mL.
Because those with mild COPD appear to have the greatest loss of lung function following an exacerbation, the authors wrote, preventing exacerbations in this group "could reduce the risk of developing severe COPD." Dr. Dransfield said that the medicines used to prevent exacerbations have rarely, if ever, been studied in those with mild COPD, suggesting that a randomized trial of this group may be warranted.

Dr. Dransfield cautioned that the take-home message of the study is not that the lung function loss associated with exacerbations in those with severe COPD is unimportant. Though smaller, these losses have important detrimental effects on patient health.

The authors also believe there is a need for further studies of smokers without COPD and those with PRISm. In the current study, both groups experienced significant respiratory symptoms and impairment but did not lose lung function as a result of an acute respiratory event or exacerbation. The researchers, who could only speculate why that might be the case, wrote that further research in this area may shed light on the heterogeneity of COPD, leading to better treatments of its distinct features in patients.

As with all observational studies, the authors noted their study cannot determine causality or directionality between exacerbations and lung function loss. It is possible, Dr. Dransfield said, that lung function loss leads to exacerbations.
-end-
Share via Twitter

People with mild #COPD at most risk of lung function loss due to COPD exacerbations: new #COPDGene study.

About the American Journal of Respiratory and Critical Care Medicine (AJRCCM)

The AJRCCM is a peer-reviewed journal published by the American Thoracic Society. The Journal takes pride in publishing the most innovative science and the highest quality reviews, practice guidelines and statements in pulmonary, critical care and sleep medicine. With an impact factor of 12.996, it is the highest ranked journal in pulmonology. Editor: Jadwiga Wedzicha, MD, professor of respiratory medicine at the National Heart and Lung Institute (Royal Brompton Campus), Imperial College London, UK.

About the American Thoracic Society

Founded in 1905, the American Thoracic Society is the world's leading medical association dedicated to advancing pulmonary, critical care and sleep medicine. The Society's 15,000 members prevent and fight respiratory disease around the globe through research, education, patient care and advocacy. The ATS publishes three journals, the American Journal of Respiratory and Critical Care Medicine, the American Journal of Respiratory Cell and Molecular Biology and the Annals of the American Thoracic Society

The ATS will hold its 2017 International Conference, May 19-24, in Washington, DC, where world-renowned experts will share the latest scientific research and clinical advances in pulmonary, critical care and sleep medicine.

American Thoracic Society

Related Copd Articles:

Treatment seeks to address exacerbations of COPD
A new study finds that delivery of oxygen via high-flow nasal tubes may help patients who experience exacerbations of chronic obstructive pulmonary disease (COPD).
Study reveals surprises concerning COPD and smoking
A new study challenges the widely accepted but oversimplified description of airway inflammation in smokers and patients with chronic obstructive pulmonary disease (COPD).
New guidelines for treatment and management of COPD exacerbations
A multi-disciplinary ERS/ATS task force of chronic obstructive pulmonary disease (COPD) experts has published comprehensive new guidelines on the treatment of COPD exacerbations.
New genetic markers for COPD discovered
In a new Research Letter published in Nature Genetics on Feb.
COPD -- what causes the lungs to lose their ability to heal?
In chronic obstructive pulmonary disease (COPD), the patients' lungs lose their ability to repair damages on their own.
New technology detects COPD in minutes
Pioneering research by Professor Paul Lewis of Swansea University's Medical School into one of the most common lung diseases in the UK, Chronic Obstructive Pulmonary Disease, has led to the development of a new technology that can quickly and easily diagnose and monitor the condition.
COPD exacerbations lead to lung function decline, particularly among those with mild COPD
Acute exacerbations of chronic obstructive pulmonary disease, or COPD, are associated with significant long-term lung function loss, according to research published online, ahead of print in the American Thoracic Society's American Journal of Respiratory and Critical Care Medicine.
Depression decreases adherence to COPD maintenance medications
A recent study in the Annals of the American Thoracic Society found that in a nationally representative sample of Medicare beneficiaries who were newly diagnosed with COPD, adherence to maintenance medications decreased with new episodes of depression.
Care for COPD: Could more be done?
Meilan Han, M.D., an associate professor of internal medicine at the University of Michigan and the medical director of the U-M Women's Respiratory Health Program, is the lead author on a new report that set out to provide a comprehensive view of COPD care in the US.
COPD symptoms common among smokers, even when undiagnosed
A new study in the New England Journal of Medicine finds that smokers, who wouldn't typically be diagnosed with chronic obstructive pulmonary disease, or COPD, are still showing symptoms consistent with the diagnosis.

Related Copd Reading:

Best Science Podcasts 2019

We have hand picked the best science podcasts for 2019. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Don't Fear Math
Why do many of us hate, even fear math? Why are we convinced we're bad at it? This hour, TED speakers explore the myths we tell ourselves and how changing our approach can unlock the beauty of math. Guests include budgeting specialist Phylecia Jones, mathematician and educator Dan Finkel, math teacher Eddie Woo, educator Masha Gershman, and radio personality and eternal math nerd Adam Spencer.
Now Playing: Science for the People

#517 Life in Plastic, Not Fantastic
Our modern lives run on plastic. It's in the computers and phones we use. It's in our clothing, it wraps our food. It surrounds us every day, and when we throw it out, it's devastating for the environment. This week we air a live show we recorded at the 2019 Advancement of Science meeting in Washington, D.C., where Bethany Brookshire sat down with three plastics researchers - Christina Simkanin, Chelsea Rochman, and Jennifer Provencher - and a live audience to discuss plastics in our oceans. Where they are, where they are going, and what they carry with them. Related links:...