The role of testosterone and other hormonal factors in the development of rheumatoid arthritis

Sex-specific incidence patterns and differences in the disease phenotype between men and women suggest that hormone-related factors are important in the pathogenesis of rheumatoid arthritis (RA). Sex hormones have immunomodulatory properties that may be important in this context. Early menopause has been shown to be a predictor of RA, independent of factors such as smoking, and long-term breast feeding may reduce the risk of RA. Recently, a prospective study reported a negative association between testosterone levels and the risk of rheumatoid factor-negative RA in men. This is compatible with data indicating important anti-inflammatory effects from testosterone. These findings may improve our understanding of the RA disease process, and possibly also lead to new therapeutic strategies, including hormone substitution.