Low Testosterone Linked to Rheumatoid Arthritis Risk

In that rheumatoid arthritis (RA) is less common among men than women, sex hormones have been suggested to play a part in the pathogenesis. Lower levels of testosterone have been demonstrated in men with RA, and it is thought that proinflammatory cytokines suppress the hypothalamic-pituitary-gonadal axis to result in low testosterone levels as a consequence of RA-associated inflammation.  Mitra Pikwer, from Lund University (Sweden), and colleagues reviewed data from the Malmo (Sweden) Preventive Medicine Program, which involved 22,444 men born in Malmo from 1921 to 1949 and 10,902 women born from 1925 to 1938.  The median time from program screening to RA diagnosis was 12.7 years.  The team observed that the RA group had a lower body mass index (BMI) at enrollment, and that BMI was negatively correlated with testosterone and free testosterone levels, but not with other hormones. Low testosterone raised the odds for subsequent diagnosis of rheumatoid factor (RF)-negative RA by 69% as compared with men who had normal values. Men who developed RF-negative RA also had significantly higher levels of follicle-stimulating hormone prior to diagnosis. The study authors conclude that: “Lower levels of testosterone were predictive of RF-negative [rheumatoid arthritis], suggesting that hormonal changes precede the onset of [rheumatoid arthritis] and affect the disease phenotype.”