Several recent studies have found that smoking cigarettes may trigger rheumatoid arthritis (RA) or hinder the treatment of RA, and can lead to negative effects in patients with other rheumatic diseases, Arthritis Today reported Oct. 17.

In one study, researchers examined the medical histories of more than 1,000 people in Sweden suffering from RA to find out how well the current smokers responded to methotrexate treatment and anti-TNF therapy, the leading treatments for the disease.
 
Researchers found that methotrexate was not effective for 40 percent of the participants who were current smokers, whereas only 28 percent of people who had never smoked failed to benefit from the treatment.

The study also found that the anti-TNF therapy was ineffective for 40 percent of current smokers compared to 25 percent of non-smokers. The more patients lit up, the less likely they were to benefit from the medicine, according to the study.

"The findings indicate that RA patients who smoke have increased risk of not getting better on the standard first line of treatment for RA, namely methotrexate," said Saedis Saevarsdottir, M.D., Ph.D., who led the research and is from the Karolinska University Hospital in Sweden. "Moreover, those who needed the immunologically designed anti-TNF drugs, which are now the second-line treatment of choice for those who do not respond to methotrexate, also risked having poor effect of this expensive medication if they smoked."

In a separate study, researcher Carl Turesson of Sweden's Malmo University Hospital found that smokers were at greater risk of developing rheumatoid arthritis.

The results of the studies were presented at the American College of Rheumatology’s annual meeting in October 2009.