Why Women Are More Likely to Suffer Migraines

By Pat Anson, PNN Editor

German scientists may have finally proven a link between hormones and migraines, and why women suffer migraines at triple the rate that men do. In studies on animals and humans, researchers found that calcitonin gene-related peptides (CGRPs) increase in females during menstruation.

CGRP is a protein that binds to nerve receptors and dilates blood vessels in the brain, causing migraine pain. Several medications are now on the market that inhibit CGRP, one of the biggest innovations in migraine treatment in decades.

“This elevated level of CGRP following hormonal fluctuations could help to explain why migraine attacks are more likely during menstruation and why migraine attacks gradually decline after menopause,” says Bianca Raffaelli, MD, of Charité – Universitätsmedizin Berlin in Germany. “These results need to be confirmed with larger studies, but we’re hopeful that they will help us better understand the migraine process.”

Raffaelli and her colleagues measured CGRP levels in the blood and tear fluid of 180 women during their menstrual cycles, and found that those who suffer from episodic migraines had significantly higher concentrations of CGRP during menstruation, when estrogen levels are low.

“This means that when estrogen levels drop immediately before the start of a menstrual period, migraine patients release more CGRP,” said Raffaelli, lead author of a study published in the journal Neurology. “This could explain why these patients suffer more migraine attacks just before and during their monthly period.”

In women who take oral contraceptives, there were hardly any fluctuations in their estrogen or CGRP levels. The same was true for postmenopausal women.

“Taking birth control pills and the end of menopause do in fact bring relief for some female migraine patients. But as our study also shows, there are women who suffer from migraine even without any hormonal fluctuations. We suspect that other processes in the body play a role in triggering attacks in those patients. After all, CGRP isn’t the only inflammatory peptide that can cause a migraine attack,” said Raffaelli.

The study also suggests that measuring CGRP levels in tear fluid is feasible and warrants further investigation, because accurately measuring CGRP in the blood is challenging due to its short half-life.

The research team now plans to study how other physical processes are influenced by the menstrual cycle, such as blood vessels and brain function. They also plan to take a closer look at CGRP levels in men of varying age groups.

Migraine affects more than 37 million people in the United States, according to the American Migraine Foundation. In addition to headache pain, migraine can cause nausea, blurriness or visual disturbances, and sensitivity to light and sound.