Jan. 18, 2005 -- Sex hormones may play a role in multiple sclerosis (MS), researchers say. Abnormal levels of estrogen and testosterone may affect inflammation or damage to brain tissue caused by multiple sclerosis.
Carlo Pozzilli and colleagues report the finding in February's Journal of Neurology, Neurosurgery, and Psychiatry. Pozzilli is a neurological sciences professor at Rome's La Sapienza University.
It's not the first time that gender differences have been noted in multiple sclerosis. The disease, which affects the brain and spinal cord, strikes three times as many women as men. But several studies have suggested that men tend to suffer a more severe and progressive disease.
To explore the gender gap, the researchers studied 60 people with multiple sclerosis. All had the disease's relapsing-remitting form, in which a person has attacks followed by periods of total or partial remission of symptoms that can last months or years.
Participants were about 32 years old. They'd had multiple sclerosis for roughly six years. None had used disease-modifying treatments such as interferon. They also hadn't had relapses or used steroids in the previous two months.
The women studied weren't using oral contraceptives and hadn't had hormone replacement therapy. Their menstrual cycles were also normal.
Hormone Tests, Brain Scans Done
Women's hormones were measured throughout their menstrual cycle. That's because women's hormones ebb and flow during the menstrual cycle, so the researchers wanted to take into account variations in hormonal changes.
Those with multiple sclerosis also underwent brain imaging scans. These scans help in the diagnosis of MS, which requires patches or scars to be seen on images of the brain.
Scanning allowed the researchers to see how multiple sclerosis had damaged or inflamed the brain.
Testosterone, Estrogen Highlighted
Only two of the sex hormones -- testosterone and estrogen --- appeared to be important to multiple sclerosis.
The women with multiple sclerosis had lower testosterone levels than the healthy women. That was true throughout their menstrual cycle.
However, irreversible brain tissue damage was more common in women with multiple sclerosis and abnormally high levels of testosterone.
The results were different for the men. Men with multiple sclerosis and healthy men had similar sex hormone levels.
Testosterone didn't affect the men's results. Instead, estradiol was important. Men with multiple sclerosis and the highest estradiol levels had a greater degree of brain tissue damage.
That suggests that estrogens and testosterone could both affect the development of brain tissue damage in multiple sclerosis, say the researchers. They call for more studies on the topic.