WEDNESDAY, April 3 (HealthDay News) -- Men with low levels of
the hormone testosterone may be at greater risk for rheumatoid
arthritis, according to a new study.
Both men and women with rheumatoid arthritis have lower levels
of testosterone in their blood than people without the disease. But
it has not been known whether low testosterone levels are a cause
or effect of rheumatoid arthritis.
Rheumatoid arthritis causes pain, swelling, stiffness and loss
of joint function. Severe cases can last a lifetime.
In this study, Swedish researchers analyzed blood samples
collected from 104 men who were later diagnosed with rheumatoid
arthritis and 174 men of the same age who did not develop the
disease. The average time between collection of the blood sample
and a diagnosis of rheumatoid arthritis was just less than 13
years, but ranged from 1 to 28 years.
After taking into account known rheumatoid arthritis risk
factors such as smoking and weight, the researchers found that men
with lower testosterone levels were more likely to develop
rheumatoid arthritis. They did not, however, prove a
cause-and-effect link between the two.
These men also had significantly higher levels of follicle
stimulating hormone -- a chemical involved in sexual maturity and
reproduction -- before they were diagnosed with rheumatoid
arthritis, according to the study, which was published online April
3 in the journal
Annals of the Rheumatic Diseases.
The findings suggest that hormonal changes occur before
rheumatoid arthritis develops and could influence disease severity,
the researchers said in a journal news release.
Rheumatoid arthritis results from the immune system attacking
the body's own tissues. Previous research suggests that
testosterone may dampen the immune system, the researchers
The American Academy of Family Physicians has more about