By: Jennifer Brown

Sudden worsening of respiratory symptoms, like shortness of breath, wheezing, and coughing, are a hallmark of declining lung function and disease progression in those already diagnosed with chronic obstructive pulmonary disease (COPD.) But these so-called respiratory exacerbations could also serve as an early indicator of COPD, even when patients still have normal lung function test results. These results are documented in a new study led by researchers at University of Iowa Health Care. 

"We are showing for the first time that COPD exacerbations occur before COPD development,” says Spyridon Fortis, MD, PhD, MS, UI clinical professor of internal medicine-pulmonary, critical care and occupational medicine. “This highlights the importance of monitoring these respiratory flare-ups even in those who do not yet have COPD.” 

The current study, which was published recently in the American Journal of Respiratory and Critical Care Medicine, builds on the team’s earlier work that linked sudden worsening of respiratory symptoms to a higher risk of death.  

The new study analyzed data from almost 3,000 participants from the COPDGene database. All the participants were current or former smokers with a smoking history of at least 10 pack-years. However, all the participants had normal lung capacity at the start of the study, as measured by spirometry.  

The researchers tracked how many respiratory exacerbations occurred between the start of the study and a five-year follow-up visit. They found that one or more episodes of respiratory flare up was linked to a significant decline in lung function compared to people who had no exacerbations. In addition, people with at least one severe exacerbation had an almost two-fold increase in the risk of death. 

Overall, the findings show that respiratory exacerbations can occur in individuals without COPD but with a history of smoking, and these worsening respiratory symptoms are linked to a decline in lung function and progression to COPD.  

Fortis notes that doctors should be aware of this relationship and recognize that respiratory exacerbations in patients with a smoking history, even when the patient has normal spirometry, may signal progress toward COPD. 

"The next step in this research will be to focus on accurately identifying at-risk individuals and investigating whether interventions that reduce exacerbations in COPD can also prevent progression to COPD in these high-risk individuals,” Fortis says. 

In addition to Fortis, the team included Patrick Ten Eyck, Linder Wendt, and Alejandro Comellas from UI Health Care, and colleagues from National Jewish Health, Denver, Colorado; University of Alabama at Birmingham; University of Texas at Austin; University of Michigan; University of Colorado; Brigham and Women's Hospital; and Minneapolis VA Health Care System. 

The research was funded in part by grants from the National Heart, Lung, and Blood Institute, part of the National Institutes of Health.