Long-term Smokers Displayed Symptoms Not Meeting Smoking-related Disease Criteria Shows Study

A recent study conducted in the US found that long-term smokers exhibited symptoms that did not fit existing tobacco-related disease criteria. The study recruited 1379 individuals aged 40 to 80 years old.

Among these participants, half consistently experienced respiratory symptoms such as shortness of breath, daily cough and phlegm, and a decreased ability to exercise. Interestingly, they performed well on breathing tests commonly used to diagnose chronic obstructive pulmonary disease (COPD), according to researchers from the University of California-San Francisco (UCSF).

COPD, which is typically associated with long-term tobacco exposure, is evaluated through spirometry, a test that measures lung function by assessing how quickly and effectively a person fills and empties their lungs during maximum effort.

William McKleroy, the first author of the study published in the Journal of the American Medical Association (JAMA), stated that individuals with significant tobacco exposure exhibited symptoms similar to those with COPD but could not be diagnosed with the disease due to normal spirometry results.

The normal spirometry results explained why these individuals were unable to receive a COPD diagnosis.

The participants were followed-up for a period of 3-4 years after the initial 5-year study, with some individuals being followed for 5 to 10 years. During these follow-up visits, spirometry tests, 6-minute walk distance testing, assessment of respiratory symptoms, and CT scans of the lungs were performed.

A subset of participants were diagnosed with COPD based on spirometry results, while others had “preserved spirometry,” meaning they did not have COPD.

The study revealed that participants with tobacco exposure and preserved spirometry (TEPS) at the beginning of the study continued to experience pulmonary symptoms for more than five years. These individuals also had high rates of respiratory exacerbations and experienced shortness of breath, which limited their ability to be physically active throughout the study.

Moreover, symptomatic TEPS participants did not show an increased incidence of COPD compared to asymptomatic TEPS participants. They also did not exhibit a faster rate of lung function decline, which is typically measured by the volume of air exhaled in the first second of forced exhalation.

In contrast, participants with COPD displayed a faster rate of lung function decline compared to symptomatic TEPS participants.

Prescott Woodruff, the principal investigator of the initial 5-year study, stated, “These findings suggest that a large proportion of tobacco smoke-exposed individuals without airflow obstruction have a persistent, symptomatic non-obstructive chronic airway disease that is distinct from COPD.”

McKleroy emphasized the need for further research to address the major gap in effective and compassionate care for tobacco-exposed individuals.

(This story has not been edited by News18 staff and is published from a syndicated news agency feed – PTI)