Recent study outcomes suggest that among women with multiple sclerosis, the age of the first menstrual cycle may be associated with the age a woman experiences the first symptoms of MS.

To evaluate the affect of hormone changes during a first menstrual cycle on MS risk, the investigators sent a survey to 438 female patients with relapsing-remitting MS living in the provinces of Newfoundland and Labrador. Participants were asked questions regarding their place of residence, relatives with MS and the age at which the subjects experienced their first period, also called menarche.

A total of 150 women with MS returned the survey. After calculating the average age of the menarche and the age of first MS symptoms, the authors detected a parallel relationship between these two variables. In addition, the researchers found that for every year increase in the age of menarche, the first clinical symptoms of MS appeared 1.16 year later. This finding was consistent for an age of menarche between 10 and 15 years.

The study results also showed that when menarche occurred at a younger age, the first symptoms of MS also occurred at a younger age among the female patients with relapsing-remitting MS. For example, on average, women who reported menarche from 10 to 12 years of age experienced their first MS symptom at 28.96 years of age. The average age of first MS symptoms was 31.83 years among women who reported menarche between ages 13 and 15 years. The difference between onset of menarche in these two age groups was significant, the authors noted.

"Further work is required to clarify the potential link between menarche and the onset of MS," investigators concluded.

This study can be found in the June issue of the journal Multiple Sclerosis.