Nov. 11, 2011 (Chicago) -- Women under 50 with rheumatoid arthritis (RA) are more than twice as likely to break a bone as those without the condition, a large study shows.
While it’s known that rheumatoid arthritis is associated with a higher rate of fractures in older men and women, "there is an increased risk even before a woman turns 50," says study leader Shreyasee Amin, MD, associate professor of rheumatology at the Mayo Clinic in Rochester, Minn.
Women under 50 with RA face a two in 100 chance of fracturing a bone vs. one in 100 for younger women without the condition, the study showed.
"This is a very important study," says Joanne Jordan, MD, MPH, director of the Thurston Arthritis Research Center at the University of North Carolina at Chapel Hill. She was not involved with the work.
"It's not uncommon for young women to be put on steroids, which, while an effective treatment, can increase the risk of fracture," Jordan tells WebMD.
The findings were presented at the annual meeting of the American College of Rheumatology.
Women Twice as Likely to Have RA
About 1.5 million Americans have RA, and the condition affects twice as many women as men. It usually develops in middle age, but some people start experiencing symptoms in their 20s, or even earlier.
In rheumatoid arthritis, the immune system inappropriately attacks the body's own tissues, causing inflammation, predominantly in the joints. This, in turn, can cause pain and stiffness and lead to permanent joint damage.
Amin and colleagues analyzed the medical records of 1,171 people who were diagnosed with RA between 1955 and 2007; nearly one-third were men. Their fracture rates were compared with a similar number of men and women of the same ages without RA.
A total of 308 women with RA and 110 men with RA were younger than 50. All were followed for an average of about nine years.
Among the findings:
- Women with RA had a 63% greater risk of fracture than women without RA.
- Women with RA aged 50 and older had a 43% greater risk of fracture.
- Men with RA had a 40% greater risk of a fracture, compared with men without the condition.
- Men aged 50 and older had a 34% increased risk.
"There were too few fractures among younger men to draw any conclusions," Amin says.
Why Are Younger Women With RA at Higher Risk of Fracture?
The next step is to figure out why young women are at increased risk of broken bones, Amin says. It could be steroid use, or even the disease itself, she says. "The inflammation [associated with RA] affects cells of the bone that increase bone loss," she explains.
It's also possible that women with the condition stop being physically active or that they somehow have a propensity to fall, both of which are also associated with increased risk of fracture, Amin says.
None of these possible risk factors was taken into account in the current analysis.
Amin says that the study primarily involved white people, so the results may not apply to people of other races.
These findings were presented at a medical conference. They should be considered preliminary as they have not yet undergone the "peer review" process, in which outside experts scrutinize the data prior to publication in a medical journal.