COPD exacerbations accelerate lung decline

American Thoracic Society (ATS)May 17 2016

In patients with chronic obstructive pulmonary disease (COPD), exacerbations accelerated lung function loss, according to a new study presented at the ATS 2016 International Conference. The effect was particularly prominent in those with mild disease.

The investigators embarked on their research because previous studies failed to adequately examine if exacerbations in patients with mild COPD, or similar acute respiratory events in current and former smokers without airflow obstruction, affect lung decline, said Ken M. Kunisaki, MD, MS, of the Minneapolis VA Health Care System in Minneapolis.

Investigators analyzed data from 2,861 patients in the COPDGene 5-year follow-up cohort study. All COPDGene participants were current or former smokers. Spirometry, used to diagnose COPD and assess lung function, was performed at study entry in all subjects and at follow-up in 2,000 subjects. Exacerbations were defined as acute respiratory symptoms that required antibiotics or systemic steroids; severe events were defined by the need for hospitalization. (In those without established COPD, the criteria were used to define acute respiratory events.)

Thirty-seven percent of patients reported at least one exacerbation/acute respiratory event. In patients with COPD, each exacerbation was associated with excess loss of lung function, as measured by FEV1—the amount of air a person can forcefully blow out of their lungs in one second.

The investigators saw the greatest excess loss of FEV1 in those with mild COPD. Acute respiratory events were not associated with additional FEV1 decline in subjects who did not have airflow obstruction.

"Our findings are particularly novel due to our large numbers of persons with mild COPD—a group that has not been well studied in previous investigations," Kunisaki said. The investigators recommend additional trials to test existing and novel therapies in subjects with early or mild COPD, to potentially reduce the risk for progression to more advanced lung disease.