Roughly one in four women has been given diagnoses of arthritis, compared with about one in five men, according to national health figures.
But there are more than a hundred different kinds of arthritis, said Dr. Kelly Weselman, a rheumatologist who spoke on behalf of the American College of Rheumatology, and while some types disproportionately affect women, there are also forms that affect men more.
Osteoarthritis, the most common form of arthritis, affects both genders equally, though different joints may be affected in men and women, Dr. Weselman said. Age, weight and trauma play a role, and those “who have played a lot of sports like soccer and football tend to get osteoarthritis in the joints early.”
Other arthritic disorders affect far more women than men, with rheumatoid arthritis affecting three times as many women as men and lupus, an autoimmune condition that affects many organs, including the joints, affecting nine times as many women.
Gout or gouty arthritis is more prevalent among men until the older ages, when women catch up and the incidence between the sexes evens out.
Over all, Dr. Weselman said, “There are more female-predominant forms of arthritis than there are male-predominant forms. If you add it up, more women are going to be affected.”
Why that is the case isn’t entirely clear. Both rheumatoid arthritis and lupus are autoimmune disorders, which result when the immune system attacks the body’s own healthy cells, and autoimmune diseases are more common among women.
Many hypotheses have been put forth to explain why, said Dr. Robert H. Carter, deputy director of the National Institute of Health’s National Institute of Arthritis and Musculoskeletal and Skin Diseases. “There’s no question female hormones have an effect on the immune system,” he said, though “it’s less clear that drives dominance of the disease in women.”
Women have more robust immune systems than men generally; they tend to fight infections better and their immune system “revs up faster,” said Kathryn Sandberg, director of the Center for the Study of Sex Differences in Health, Aging & Disease at Georgetown University Medical Center. “That may be a kind of double-edged sword,” she said, “You’re more resistant to infections, but you’re also more at risk for having the immune system go a little nuts and attack your own self.”