Rheumatoid arthritis, one of the most common forms of arthritis, is an autoimmune disease that affects more than two million Americans. The overwhelming majority of patients are women, according to the Arthritis Foundation. New research presented at the Annual European Congress of Rheumatology reveals further gaps between the sexes in this often debilitating disease. Swedish researchers report that women are less likely to go into remission, or experience an absence or decrease in symptoms, after being treated for the disease.

The reason for the sex differences is not entirely understood. Although disease activity was similar between men and women in the study at the start of treatment, “women had a much lower remission rate than men,” the researchers noted, while also calling for more research to investigate the gender discrepancy.

Rheumatoid arthritis involves the immune system, which attacks joint tissue and causes inflammation and permanent joint damage. The most common physical symptoms of rheumatoid arthritis include stiffness, predominantly in the morning or when sitting for a long time, fatigue, difficulty moving, joint swelling and pain.

Patients often experience pain and swelling of joints in corresponding points on both sides of the body. In some cases, people with rheumatoid arthritis have nodules or bumps under the skin. The disease affects everyone differently and can be mild or severe.

Like other autoimmune diseases, rheumatoid arthritis predominates in women. “Women are affected with autoimmune diseases collectively more than men,” says Virginia Ladd, president and executive director of the American Autoimmune Related Disease Association. “More research is needed to look into why women are afflicted more than men.”

Because many more women are affected by the disease, hormonal influences are likely to be involved. Most studies agree that the development of rheumatoid arthritis depends on the interplay of several factors.

“The sex ratios probably do not reflect hormones only,” explains Michael Lockshin, M.D., professor of rheumatology at the Hospital for Special Surgery at Cornell Medical Center in New York City. “There is a real possibility that exposure difference to some unknown stimulus accounts for at least some of the sex ratios.” In other words, maybe some biological or environmental trigger affects men and women differently.

Genetic risk factors make some individuals more susceptible to the disease, but genetics does not tell the entire story. Research published this month in the Annals of the Rheumatic Diseases indicates that smoking nearly doubles the chance that a woman who does not have a genetic risk factor for rheumatoid arthritis will develop the disease.

There is currently no cure for rheumatoid arthritis and treatment varies from person to person. One of the main objectives of treatment is to control a person’s symptoms and if possible, bring about remission. Treatment can involve medication, physical and occupational therapy, counseling and in some cases, surgery. There are new treatments on the horizon, “these are mostly biological interventions,” says Lockshin, or drugs that modify the immune system’s response.

Because women are less likely to go into remission, patients need to be followed carefully so that their symptoms are controlled. The researchers call for “reinforced vigilance in the frequency and quality of follow-up in order to achieve optimal suppression of the inflammatory process in all patients, regardless of gender.” Other studies have shown that early diagnosis and proper management can slow the progression and damage of the disease.

Society for Women’s Health Research (SWHR)