Rheumatoid arthritis on the rise in women

SAN FRANCISCO, Oct. 27 (UPI) -- After four decades on the decline, rheumatoid arthritis is on the upswing among U.S. women, researchers at the Mayo Clinic said.

"This is a significant finding and an indicator that more research needs to be done to better understand the causes and treatment of this devastating disease," lead investigator Dr. Sherine Gabriel Mayo Clinic rheumatologist said in a statement.

From 1955 to 1994, the incidence of rheumatoid arthritis had continually been on the decline; but the Rochester, Minn., researchers analyzed patient data from early 1995 to the start of 2005 and found that both the incidence and prevalence of the condition were rising.

Compared to the previous decade when approximately 36 women out of every 100,000 developed rheumatoid arthritis each year, the new study showed a jump to 54 women in the more recent decade. The incidence for men remained at about 29 per 100,000. Overall, the percentage of the entire population with the condition rose from 0.85 percent to 0.95 percent, the study said.

Researchers said it's not clear why the disease is increasing, but an environmental factor may have a role in the shifting incidence and prevalence among women.

The findings were presented at the annual meeting of the American College of Rheumatology/Association of Rheumatology Health Professionals in San Francisco.