THURSDAY, Jan. 17 (HealthDay News) -- Although current smokers have a lower mortality from idiopathic pulmonary fibrosis (IPF) than former smokers -- in accordance with the literature -- survival is higher in lifelong non-smokers than former smokers or current and former smokers together, according to research published in the Jan. 15 American Journal of Respiratory and Critical Care Medicine.
Katerina M. Antoniou, M.D., Ph.D., of the Royal Brompton Hospital in London, United Kingdom, and colleagues analyzed data from 249 patients with IPF. To deal with the "healthy smoker" paradox -- those with more severe disease may be more likely to quit smoking -- they calculated survival adjusting for severity using factors including computed tomography and composite physiologic index (CPI).
After adjusting for CPI, there was no difference in survival between current and former smokers. However, adjusting for CPI bumped up non-smokers' increase in survival compared to former smokers (hazard ratio 0.51). The study findings support the idea that the improved outcomes previously reported for current smokers may be due to the "healthy smoker" effect.
"The better survival among non-smokers was the major positive finding in our study, but it is not clear whether this was linked to pathogenesis. Cigarette smoke may prime the lung toward a fibrotic response when other injuries are encountered and may injure lung fibroblasts, partly by means of oxidative stress, which may have a critical role in the gene expression of a variety of profibrotic factors," the authors write.
A study co-author has received compensation from several pharmaceutical companies.
Abstract
Full Text (subscription or payment may be required)
