The Reason: Why More Women Than Men Have 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 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.
Rheumatoid Arthritis Is On Rise Among Women
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.
Rheumatoid Arthritis May Be On the Rise in Women. Gabriel S. et al. American College of Rheumatology.
Dr. Zashin is clinical assistant professor at University of Texas Southwestern Medical School and an attending physician at Presbyterian Hospitals of Dallas and Plano. Dr. Zashin is author of Arthritis Without Pain - The Miracle Of TNF Blockers. The book is useful for anyone on one of the biologic drugs or considering the biologic drugs.