COPD exacerbations associated with significant lung function loss

Acute exacerbations are related to significant long-term decline in lung function in patients with chronic obstructive pulmonary disease, particularly among those with a mild form of the disease, according to findings published in American Journal of Respiratory and Critical Care Medicine.

“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 chronic obstructive pulmonary disease (COPD) — patients appear to be losing lung function,” Mark T. Dransfield, MD, lead researcher and medical director of the University of Alabama at Birmingham Lung Center said. “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.”

Dransfield and colleagues recruited participants from the COPDGene study. These patients were the first 2,000 to receive a 5-year follow-up for COPDGene and included those with and without COPD who were current and former smokers.

The researchers used the Global Initiative for Chronic Obstructive Lung Disease guidelines to determine the severity level of COPD. Patients without COPD but with Preserved Ratio Impaired Spirometry (PRISm) were identified. PRISm patients had reduced FEV₁ (< 80% of expected) but a normal FEV₁/FVC ratio (> 0.70%).

In participants without COPD, treatment with antibiotics or systemic steroid was required to be considered an exacerbation or acute respiratory event, whereas hospitalization was required to be considered a severe exacerbation.

Results showed that 36.7% of participants from all groups experienced exacerbations and/or severe exacerbations within the last five years.

Overall, FEV₁ decline in excess of predicted time-dependent factors, such as aging, was linked to exacerbations in patients with COPD.

The greatest decline in FEV₁ occurred in patients with mild COPD. Each exacerbation and severe exacerbation was associated with an additional reduction of 23 mL/year and 87 mL/year, respectively.

Statistically significant declines in FEV₁ with each exacerbation also occurred in patients with moderate or severe COPD; however, the declines were smaller than those with mild COPD.

Decline in FEV₁ did not occur in smokers without COPD who experienced an acute respiratory event nor in PRISm patients who experienced an exacerbation of any level of severity. Current and intermittent smokers experienced a 9 mL decline in FEV₁, while former smokers only experienced a 2 mL decline.

According to Dransfield and colleagues, the findings suggest that preventing exacerbations in patients with mild COPD “could reduce the risk of developing severe COPD.” – by Alaina Tedesco

Disclosure: The researchers report that funding was provided by the National Institutes of Health and the COPD Foundation.

Reference: https://www.sciencedaily.com/releases/2016/09/160908120352.htm