By Robert Preidt
Rheumatoid arthritis is an autoimmune disease. That means the body's immune system mistakenly attacks healthy tissue instead of foreign invaders such as bacteria. This causes inflammation, which causes symptoms such as red, swollen and painful joints, according to the Arthritis Foundation.
COPD includes diseases such as emphysema and chronic bronchitis. Symptoms include shortness of breath, frequent coughing, a feeling of tightness in the chest and wheezing, the COPD Foundation says. Smoking and secondhand smoke are among the most significant risk factors for COPD.
Canadian researchers reviewed information on more than 24,600 people in the province of British Columbia who were diagnosed with rheumatoid arthritis between 1996 and 2006. The investigators compared the people with rheumatoid arthritis to more than 25,000 people in the general population.
The researchers adjusted the data to account for other factors that might increase the risk of lung disease.
"These findings are novel because it has only recently been recognized that inflammation plays a role in the development of COPD, and clinicians treating people with rheumatoid arthritis are not aware that their patients are at increased risk of developing COPD," said study leader Dr. Diane Lacaille, from Arthritis Research Canada and the University of British Columbia.
"Our results emphasize the need to control inflammation, and in fact to aim for complete eradication of inflammation through effective treatment of rheumatoid arthritis," she added.
Lacaille is with Arthritis Research Canada and the University of British Columbia.
The study findings were published in the journal Arthritis Care & Research.
While the study didn't prove one disease causes the other, doctors and rheumatoid arthritis patients need to watch for early symptoms of COPD, Lacaille said.
"That way, appropriate tests can be administered to diagnose COPD early, at the onset of symptoms, so that effective treatments for COPD can be initiated before irreversible damage to the lungs occurs," she said in a journal news release.
It would also be important to try to control risk factors for COPD, such as smoking, the researchers said.