[Sex differences in joint diseases: pathophysiological basis].

Gender affects the susceptibility to many joint diseases, in particular autoimmune rheumatic disorders; women have an increased risk of rheumatoid arthritis, systemic lupus erythematosus or Sjögren's syndrome. In rheumatoid arthritis alterations of sex hormone levels such as androgen deficiency or prolactin excess might, at least in part, explain the excess incidence in women. Osteoarthritis of the hand and the knee as well as generalized osteoarthritis is more frequent in women than in men. Nevertheless, until now there is no explanation for the increased incidence of osteoarthritis in women.