A sizable minority of smokers and former-smokers develop lung conditions that reduce lung capacity, but leave them less likely to have either emphysema or chronic obstructive pulmonary disease (COPD), new research shows.
In fact, the study published in the New England Journal of Medicine found that these rarer abnormalities are only visible on sophisticated CT scans, not on the ones typically used to spot COPD and emphysema. The findings suggest that doctors need to look beyond those measurements, which could be giving false reassurance to patients.
"Tobacco usage can cause more problems to the lung than just emphysema or COPD," said Dr Carl Boethel, an assistant professor of internal medicine at Texas A&M Health Science Center College of Medicine, who was not involved with the study.
"Sometimes the method we use to diagnose COPD and emphysema, which is spirometry, may not give you the full picture of what is going on in the lungs."
Who is at risk
Even though CT scans shouldn't become a routine screening method for smokers and ex-smokers, the authors of the paper are hoping that these findings will spur more research into ways to identify people at risk.
"Our hope is that down the road, we need not perform CT scans on every person but we could identify other noninvasive tests or biomarkers that may predict who has this disease, who is at risk and who will progress with the disease," said study first author Dr George Washko, a physician in the division of pulmonary and critical care medicine at Brigham and Women's Hospital in Boston.
The abnormalities found on the scans in this study indicated interstitial lung disease, the most severe form of which is idiopathic pulmonary fibrosis. "This is rapidly fatal and there is no available treatment," said the study's other first author, Dr Gary M. Hunninghake, also a pulmonary/critical care physician at Brigham and Women's.
Using high-resolution CT scans, the investigators found interstitial lung abnormalities - basically areas of increased lung density - in 8% of almost 2,500 scans.
People with these abnormalities had lower lung capacity but less emphysema and were also 47% less likely to have COPD.
"It is a little bit more common than people would expect," said Hunninghake.
Smoking casues more than COPD
It also suggests that two different physiological patterns are happening in the lungs, he said, "one that led towards emphysema and one toward interstitial lung disease."
"Tobacco smoking can cause more than COPD as far as lungs go," Boethel added. "We really need to get our patients off of these cigarettes."
"There's a terrible, inconvenient truth here about smoking: It's bad," said Dr Len Horovitz, a pulmonary specialist with Lenox Hill Hospital in New York City.
(Copyright © 2010 HealthDay. All rights reserved.)