Smoking Heightens Women`s Arthritis Risk
Joyce Frieden / Reuters Health 3nov00

PHILADELPHIA - Female smokers have nearly twice the risk of developing early-onset rheumatoid arthritis as their non-smoking counterparts, researchers say.

In a way, this is good news, because "smoking is a potentially modifiable risk factor," according to Dr. Kenneth Saag, from the University of Alabama, in Birmingham. "We can tell people that if they stop smoking, it may lower their risk."

Saag, along with co-authors, studied the health records of more than 30,000 women, ages 55 to 69, who were enrolled in the Iowa Women's Health Study beginning in 1986. The study was presented this week at a meeting of the American College of Rheumatology.

The researchers found current smokers had a nearly two-fold increase in the risk of developing early-onset rheumatoid arthritis compared to those who never smoked. Former smokers also had a slightly higher risk than non-smokers, but those women who had stopped smoking at least 10 years prior to the start of the study did not have an increased risk, Saag reported.

The researchers are not sure what it is about smoking that increases a woman's rheumatoid arthritis risk. "It's a complex phenomenon," he said. "There are interactions with a woman's immune system that may be involved, and also interactions with estrogen. Smoking may lower estrogen levels." He noted that smoking also appears to raise the body's level of rheumatoid factor, which is generally found in patients with more severe arthritis.