Researchers assessed more than 2,700 current or former smokers in order to evaluate their respiratory symptoms using the COPD Assessment Test. Although many smokers did not meet the clinical definition of COPD, they nonetheless displayed several key symptoms.
Smokers commonly demonstrate symptoms of chronic obstructive pulmonary disease (COPD), even when they are not diagnosed with the disease, according to findings published in The New England Journal of Medicine.
Researchers from the University of Michigan Health System observed more than 2,700 current or former smokers in order to evaluate their respiratory symptoms using the COPD Assessment Test. The researchers added that many smokers do not meet the definition of COPD — a forced expiratory volume in 1 second (FEV 1) to forced vital capacity (FVC) of less than 0.70 as assessed by spirometry after bronchodilator use – yet still have respiratory problems. The patients underwent FEV 1 examination to test whether current or former smokers with preserved pulmonary function were asymptomatic or displayed COPD symptoms, and to what degree. The patients were tested on their six minute walk distance, lung function and high resolution computer tomographic scan of the chest.
The researchers found that half of the current or former smokers displayed respiratory symptoms, and the rate of respiratory exacerbations among the current or former smokers was significantly higher than in the asymptomatic current or former smokers, as well as the control group of non-smokers in the study.
“Clinically, this is an important group of patients that we as physicians currently have no guidance on how to treat,” lead study author Meilan Han, MD, explained in a Michigan Q&A-style press release. “A significant percentage of these symptomatic smokers with ‘normal’ breathing tests had been given respiratory medications by their doctors to treat their symptoms, but this is a group of individuals that has never really been studied with those medications in clinical trials. Therefore physicians really have no evidence base to guide decision making.”
Plus, regardless of their history of asthma, current or former smokers with respiratory symptoms had greater limitation of activity, lower FEV 1, FVC, inspiratory capacity and greater airway wall thickening without emphysema than the asymptomatic current or former smokers.
“I think we do need a name for this condition so we can define these patients and develop treatments,” Meilan added. “However, it’s still unclear whether these patients have ‘early’ COPD, in that they will ultimately progress to airflow obstruction that we can detect on a breathing test. More information is still needed.”
About two in five symptomatic current or former smokers used bronchodilators (42 percent), while about a quarter of those patients used inhaled corticosteroids (23 percent).
“This study is just the first step in trying to better identify these patients so we can develop targeted treatments,” Meilan concluded.”