Low Testosterone Levels in Men May Lead to Rheumatoid Arthritis
Low testosterone levels may increase the risk of rheumatoid arthritis in men, according to a new study
Previous studies have linked sex hormones to the development of rheumatoid arthritis. Studies have shown that both men and women with autoimmune disease tend to have lower levels of testosterone in their blood compared to healthy people. However, researchers say it is not clear whether low testosterone is a risk factor or a consequence of the disease.
Investigators based their findings on data from the Swedish Malmo Preventive Medicine Program (MPMP), which began in 1974 and tracked the health of more than 33,000 people born between 1921 and 1949. Researchers identified all the partiicpants who were subsequently diagnosed with rheumatoid arthritis up to December 2004.
Researchers said stored blood samples were available for 104 of the men who developed rheumatoid arthritis and for 174 men of the same age who did not develop the disease. The time that elapsed between donating the blood sample and diagnosis of rheumatoid arthritis ranged from one to 28 years.
Scientists noted that rheumatoid factor status, an antibody used to indicate disease severity and identification, was known at diagnosis for 73 percent of the men, and the treat tested negative.
Researchers found that even after taking account of rheumatoid arthritis risk factors such as smoking and body mass index, men with lower levels of testosterone in their blood samples were significantly more likely to develop the autoimmune disease. Furthermore, the study found that testosterone levels were also significantly lower in those who tested negative for rheumatoid factor at diagnosis.
Researchers found that men with low levels of testosterone also had significantly higher levels of follicle stimulating hormone, a chemical involved in sexual maturity and reproduction, before they were diagnosed with rheumatoid arthritis. Study authors say that this is likely to be secondary to reduced testosterone production.
The findings, published in the Annals of the Rheumatic Diseases, suggest that hormonal changes may precede the onset of rheumatoid arthritis and could influence disease severity.
The latest study lends support to previous research that found that testosterone reduced immune system response and inflammation. Other studies found that rheumatoid arthritis is also more likely to go into remission in its early stages in men than in women.