Rheumatoid arthritis (RA) is a disease that affects more women than men and studies have suggested that sex hormones may have a part to play. In the case of men, lower testosterone levels have been linked to RA but previous research did not provide an answer as to whether hormonal changes came before or after the disease. This has now been done by a team from Lund University in Malmo, Sweden.
The researchers used data and blood samples collected as part of a long-running health survey. They studied blood samples from 104 men diagnosed with RA and 174 men who did not develop the disease. The samples were collected between one and 28 years before the RA diagnosis was established. The team conducted analyses of the levels of testosterone and other reproductive hormones, concluding that lower testosterone levels were linked to the subsequent development of RA. The likelihood remained higher even when risk factors such as smoking and body mass index were taken into consideration.
The results of the study have been published in the April issue of the Annals of the Rheumatic Diseases. Presenting their findings, the authors state that the development of RA in men seems to be preceded by hormonal changes, one possible explanation being the body´s reduced ability to fight inflammation due to a decrease in testosterone. However, they make a point of noting that this is the first major study of its kind and further research is needed to verify the findings in other populations.