Since rheumatoid arthritis (RA) is more common in women than men, many studies have considered the effects of estrogen on the risk and severity of the disease. Generally, study results have offered conflicting evidence. A new study published in the March 2008 issue of Arthritis Care & Research, which used data from the Women's Health Initiative clinical trials on hormone replacement therapy, concluded that there were no significant differences in the risk of developing RA or the severity of RA between postmenopausal women who were on hormone replacement therapy and women who took placebo.

There were over 27,000 postmenopausual women between 50 and 79 years old in the study. The women took either estrogen and progestin, estrogen alone, or placebo. Women who had RA were identified through self-reported information and whether they took prescription medications to treat the disease. There were 105 new cases and 63 existing cases of RA identified in the study. No statistically significant differences were found with regard to new RA cases after approximately 6 years and none were found regarding the severity of RA after one year. The study also found no protective effect of hormones in preventing RA which had been reported in earlier studies.

Related Resources:

• Rheumatoid Arthritis Screening Quiz
• Fast Facts About Rheumatoid Arthritis
• Test Your Knowledge: Rheumatoid Arthritis
• Rheumatoid Arthritis: Explained With Pictures
• Recognizing the Signs and Symptoms of Rheumatoid Arthritis

_{Photo by Brad Killer (iStockphoto)}