Jan. 16 (UPI) -- Researchers found in study published Tuesday that genetic variations in lungs can help identify people at risk for chronic obstructive pulmonary disease, or COPD, which is often caused by cigarette smoke and pollution.
The study -- funded by the National Heart, Lung and Blood Institute, which is part of the National Institutes of Health -- identified people with low, but stable, lung function early in life who developed COPD.
For the study, published today in the Proceedings of the National Academy of Sciences, the scientists were attempting to learn why not all smokers develop COPD, but many non-smokers do.
"This work raises many interesting questions for researchers. Understanding precisely why these genes influence the development of COPD may lead to entirely new and more effective ways of preventing or treating this disease," Dr. James Kiley, director of the NHLBI Division of Lung Diseases, said in a press release. "This novel study suggests that a CT scan, which is widely available, can be used to measure airway structure and predict who is at higher risk for smoke-induced lung injury."'
An estimated 15 million people have been diagnosed with COPD, a progressive disease that makes it hard to breathe, according to the Centers for Disease Control and Prevention. Chronic respiratory diseases are the third-leading cause of death in the United States -- 155,931 in 2016 -- behind heart disease and cancer, the CDC reported.
Researchers had believed that COPD developed later in life because of prolonged exposure to cigarette smoke or air pollution. But in recent studies older adults with COPD had low lung function early in life and the decline was associated with aging.
"In the current study, we found that central airway branches of the lungs, which are believed to form early in life, do not follow the textbook pattern in one quarter of the adult population and these non-textbook variations in airway branches are associated with higher COPD prevalence among older adults," said Dr. Benjamin M. Smith, an assistant professor at Columbia University Medical Center. "Interestingly, one of the airway branch variants was associated with COPD among smokers and non-smokers. The other was associated with COPD, but only among smokers."
Researchers say future studies will address whether family history plays a factor. The study identified a common airway branch variation that occurs within families and is associated with COPD among non-smokers. His research team is looking into whether there is a genetic basis for this variant.
"If proven," Smith said, "this would represent a novel mechanism of COPD among non-smokers."