Smokers and ex-smokers with idiopathic pulmonary fibrosis (IPF), an untreatable progressive lung disease that usually leads to death within a few years of diagnosis, have a worse prognosis than non-smokers, according to research from London.
Previous research had counter-intuitively suggested that current smokers with IPF might live longer than ex-smokers, but the new study establishes that the data likely reflected a healthy smoker effect.
The study appears in the second issue for January of the American Journal of Respiratory and Critical Care Medicine, published by the American Thoracic Society.
Smoking is associated with a higher mortality in IPF, and an earlier finding, suggesting the contrary, was almost certainly due to the fact that smokers tend to stop smoking when disease becomes more severeand so current smoking is linked to milder disease, said Athol U. Wells, M.D., of the Interstitial Lung Disease Unit at the Royal Brompton Hospital in London, who headed the research.
The investigators studied the medical records of 249 patients with IPF, and analyzed the extent and severity of their disease, smoking history and survival. Their initial findings, unadjusted for disease severity, were similar to the earlier study namely that smokers had longer survival times than ex-smokers. But when they adjusted their data to reflect the extent and severity of the disease at presentation, their findings shed a new light on the previous finding.
We established that current smokers live longer, but this is mostly because they have much milder disease. Clearly, many patients stop smoking precisely because their disease is getting worse. This is the healthy smoker effect: that current smoking is a marker for milder disease because advancing disease causes smoking cessation, said Dr. Wells. Symptomatic patients with more severe disease may be more likely to stop smoking for perceived health reasons. It can, therefore, be argu
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American Thoracic Society