The sex hormones are responsible for the development and regulation of the reproductive system and the characteristics that distinguish adult men and women. Oestrogens are usually associated with women and androgens are usually associated with men. However, both kinds of sex hormone are vital for men and women.
Although MS is more common in women, the course of the disease is often more severe in men. Women of reproductive age are three times more likely to develop MS than men in the same age group. However, before puberty and after menopause the rates are about the same.
Similarly, hormone levels are raised during pregnancy and pregnant women with MS usually have less disease activity. After giving birth, when hormone levels fall again, there is an increased chance of relapse.
These observations suggest that sex hormones have an effect on MS and could be potential treatments. Sex hormones may have both an anti-inflammatory and a neuroprotective effect.
Oestriol (estriol in America) is an oestrogen hormone that is produced towards the end of pregnancy. A small trial of oral oestriol (marketed as Trimesta) suggested that taking oestriol reduces MRI activity in women with relapsing remitting MS, but not in those with secondary progressive MS.
A larger two-year trial involved 164 women with RRMS who were taking glatiramer acetate (Copaxone). Taking oestriol tablets alongside the Copaxone reduced the number of relapses slightly over the next two years. Other studies showed that taking oestriol reduced the loss of brain tissue and reduced the number of lesions seen on an MRI.
Testosterone is the major androgen in males, but it also has important roles in women. Men with MS are more likely to have low testosterone levels than men without MS. If you're a man with MS and you have low testosterone levels, you may also experience poorer physical and cognitive activity than those with higher tesotsterone levels. This link could be due to the experience of chronic disease affecting the levels of testosterone in your body.
In people without MS, testosterone levels can affect mood, libido, cognitive speed and fatigue. Testosterone could be a useful treatment for several MS symptoms, and may also stimulate the formation of new myelin. However, testosterone treatment also has risks for cardiovascular health. Although it is a promising area for research, proper study and monitoring is necessary.
Researchers are currently looking for ways to provide a safe dose of testosterone to men with MS. A small study in California looked at ten men with RRMS who used a testosterone skin gel. After a year, they found improvements in cognitive function and a slower rate of brain tissue loss.
Estradiol and progesterone are oestrogen hormones that are produced by the ovaries and fluctuate with a woman's menstrual cycle. Progestin is a synthetic form of progesterone that is often included alongside estradiol in oral contraceptives and hormone replacement therapies. Many women report that they have fewer and less severe MS symptoms when they take oral contraceptives.
Oral contraceptives, whether with or without progestin, are also associated with higher physical quality of life among post-menopausal women with MS. These hormones may protect against bone loss as well as having a neuroprotective effect.
- Progress in Brain Research 2009;175:239-251. Full article Estrogen and testosterone therapies in multiple sclerosis.
- Multiple Sclerosis Journal 2018 24(1) 36-41 Summary The role of testosterone in MS risk and course
- Lancet Neurology 2016;15(1):35-46 Summary Estriol combined with glatiramer acetate for women with relapsing-remitting multiple sclerosis: a randomised, placebo-controlled, phase 2 trial.
- Journal of Neuroscience Research 2016 95(1/2) 633-643 Summary The importance of studying sex differences in disease: The example of multiple sclerosis
- Brain 2013 136 (1) 132-146 Summary The neural androgen receptor: a therapeutic target for myelin repair in chronic demyelination