A study using data from the recent Women’s Health Initiative (WHI) clinical trials on hormone replacement therapy found that there were no significant differences in the risk of developing rheumatoid arthritis (RA) or the severity of RA between women on hormone replacement therapy and those who took placebos.

The results were presented in the March 2008 issue of Arthritis Care & Research and the research team was lead by Dr. Brian Walitt, et al.

Since RA is more prominent in women, researchers have long suspected that feminine hormones like estrogen play a role in the development of the disease. As a result, many past studies sought to examine the effects of estrogen on the risk and severity of RA.

Unfortunately, the results of such studies have been conflicting and controversial.

For this study, the WHI’s randomized, controlled trials included over 27,000 postmenopausal women between the ages of 50 and 79 who took either estrogen and progestin, estrogen alone, or a placebo.

Led by Brian Walitt of Washington Hospital Center in Washington, DC, the current study identified women suffering from RA based on if they reported having it and were taking prescription medications to treat the condition.

Self-reported information about whether women had RA was collected annually, and they were assessed for disease severity at the beginning of the study and after one year. Measures of self-reported joint pain and stiffness were also collected at that time and participants reported the rate at which the severity of their symptoms increased.

The results showed that there were 105 new cases and 63 existing cases of RA. There were no statistically significant differences found in either new RA cases over an average of five-to-six years or on the severity of present RA symptoms after one year.

While earlier studies had suggested that hormones had a protective effect against developing RA, they were observational. The current study found no significant protective benefit from hormones in preventing RA.

Although the WHI methodology has many advantages over prior studies, the sample size for RA was much less than what would be required to observe the effect of hormone replacement therapy on developing RA.

However, it is unlikely that larger studies will be carried out, due to the health risks of hormone replacement therapy. Also, the study relied on self-reported information — an approach that is not as effective as performing chart reviews or physical exams.

Article References
No Benefit to Rheumatoid Arthritis Found with Hormone Replacement Therapy, site accessed on 03/09/08