Pulmonary Fibrosis on the Rise

Death rates from idiopathic pulmonary fibrosis, a deadly scaring of the lungs, rose steadily between 1992 and 2003, according to research published by National Jewish Medical and Research Center faculty. The rise was greater among women than men, and is predicted to continue climbing for both sexes. The findings, published in the August, 1, 2007, issue of The American Journal of Respiratory and Critical Care Medicine, emphasize the need for additional research on this invariably fatal disease.

"Our research shows that idiopathic pulmonary fibrosis is more common than previously believed and may become more common in the future," said Kevin K. Brown, MD, senior author of the study and vice chair of medicine at National Jewish Medical and Research Center. "In the past decade we have begun to make progress at understanding the disease and identifying potential therapeutic targets. We need, however, to redouble our efforts against this devastating disease."

Idiopathic pulmonary fibrosis (IPF), is an uncontrolled and progressive scarring of lung tissue, leading to a nagging, dry cough, and shortness of breath. The cause of the disease is unknown, and there is no approved treatment for it. Patients live an average of just three years after diagnosis with the disease.

Drs. Brown and Amy Olson with colleagues at National Jewish and the University of Colorado Denver, used data from the U.S. National Center for Health Statistics to determine mortality rates for IPF from 1992 to 2003. Men continued to suffer the disease more frequently than women, but the rate of death among women rose more quickly. The age-adjusted mortality rates for men increased 28 percent among men (from 48.2 per 1,000,000 to 61.9 per 1,000,000) and 41% among women (from 39.0 per 1,000,000 to 55.1 per 1,000,000). The overall IPF mortality rate in 2003 was 50.8 per 1,000,000 people, accounting for about 15,000 IPF deaths per year. Using a statistical model, the researchers predicted that IPF rates will continue to increase significantly among men older than 65 and in women older than 45.

"Although IPF was once considered an orphan disease, our results suggest that it should no longer be considered a rarity," said Dr. Olson. "The IPF mortality rate is now higher than it is for several cancers, including myeloid leukemia, multiple myeloma and bladder cancer."

Since the cause of IPF is unknown, it is impossible to say what caused the increase in mortality rates. The researchers speculate that better diagnostic tools and increased awareness of the disease due to large-scale trials may have increased clinical recognition of the disease. Tobacco smoking may also be a cause for the increase. Previous epidemiologic studies have suggested that smoking is a risk factor for IPF. Women have represented an increasing percentage of smokers in the past 50 years.

There is a tremendous amount of interest at National Jewish and extensive research is being conducted to better understand the mechanisms of scarring in IPF. National Jewish is a member of IPF Clinical Research Network, which is funded by the National Institudes of Health. The doctors and staff at National Jewish are working with basic scientist to broaden understanding of the causes of IPF and to develop new treatment approaches.