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Spirometry alone may not accurately diagnose COPD in smokers

There are an estimated 35 million adults aged 55 years and older nationwide who are current or former smokers, many of whom may remain undiagnosed when COPD is based solely on spirometry.

“The impact of smoking on the lungs and the individual is substantially underestimated when using lung-function tests alone,” James D. Crapo, MD, professor of medicine at National Jewish Health, said in a press release. “Lung disease is common in smokers whose lung-function tests fall within population norms.”

Elizabeth A. Regan

Crapo and colleagues analyzed data from the Genetic Epidemiology of COPD cross-sectional observational study of 8,872 adults aged 45 to 80 years who had smoked at least a pack of cigarettes a day for 10 years.

The researchers considered approximately half of the participants disease-free based on their lung-function tests.

However, when researchers assessed other criteria such as impairments in physical function, respiratory symptoms and CT scans, 55% of the participants labeled as disease-free had some form of respiratory related impairment.

CT scans found emphysema or airway thickening in 42% of the participants labeled disease-free and 23% had significant shortness of breath compared with 3.7% of never smokers (n = 108).

Elizabeth A. Regan, MD, PhD, assistant professor of medicine at National Jewish Health, in the release, said the researchers hope the results nullify the idea that there is such a thing as a healthy smoker.

“Smokers who have ‘normal’ lung-function tests often have significant respiratory disease,” she said. “Many of those smokers likely have the early stages of COPD. We hope these findings will help debunk the myth of the healthy smoker and highlight the importance of smoking prevention and cessation to prevent lung disease and other long-term effects of smoking.” – by Ryan McDonald

Disclosure: Regan reports no relevant financial disclosures. Please see the full study for a list of all other authors’ relevant financial disclosures.