Arthritis More Prevalent in Women Than Men

Arthritis affects women more often than men. This is true for many — but not all —​ types of arthritis. After decades of being on the decline, the prevalence of rheumatoid arthritis is rising among women as well. Why are women more affected by arthritis?

We asked rheumatologist Scott J. Zashin, MD, to explain why more women than men have arthritis. Zashin said:

Autoimmune diseases are more common in women. Lupus is a good example of this phenomenon. Women prior to menopause may have a 15 fold increased the risk of lupus compared to men. Yet, after menopause, that risk decreases to only two fold, suggesting female sex hormones may increase the risk of lupus. Furthermore, it is thought that high dose estrogens that were used in oral contraceptives in the past may have played a role in triggering lupus or lupus activity.

The new low dose estrogens are felt to be safer in this regard if the patient does not have risk factors for blood clots (such as anti-phospholipid antibodies). On the other hand, animal studies have shown that male hormones may suppress the disease in mice. Why hormonal influence plays a role in these conditions is unclear. One theory is that estrogen plays a role in affecting the B and T cells which are involved in the immune response.

In rheumatoid arthritis, women are up to three times more likely to develop the condition than men. What is fascinating is that many women with rheumatoid arthritis go into remission during pregnancy. To date, no one has been able to determine the exact cause of this beneficial effect, but one theory is that changes in hormone levels may effect the level of proteins in the blood that contribute to inflammation.

According to a Mayo Clinic Study, after 40 years of decline (during the years 1955 to 1994), the incidence (frequency of occurrence) and prevalence (total number of cases in a given population) of rheumatoid arthritis among women is rising. From 1995 to 2005, the incidence of rheumatoid arthritis among women was 54 per 100,000 compared to 36 per 100,000 for the previous 10 years.

For men, the incidence was stable at 29 per 100,000. Researchers concluded that an environmental factor could explain the reverse in trend for women.