Study suggests hormones linked to migraines
By Suzanne Rostler
NEW YORK, Nov 27 (Reuters Health) - Irregularities in hormones produced by the hypothalamus, the area of the brain that regulates such basic functions as hunger and body temperature, may underlie chronic migraines, researchers report.
The findings provide hope for the 2% to 3% of the general population who suffer from the debilitating headaches, since drugs that regulate these hormones could prevent or reduce the severity of the headaches, Dr. Mario Peres, the study's lead author, told Reuters Health.
"The hypothalamic involvement is one of the mechanisms (thought to be involved) in chronic migraine," said Peres from the Sao Paulo Headache Center in Brazil. "The clinical implications are the potential use of drugs interfering with dopaminergic neurotransmission, and melatonin supplementation, although clinical trials are necessary to support this idea."
According to the report, chronic migraine sufferers had higher levels of cortisol, a stress hormone that is involved in the control of blood pressure and blood sugar metabolism, and were more likely to have delayed peak levels of melatonin, the hormone that controls sleep cycles. Nearly half of patients with migraines had a delay in peak melatonin levels, compared with none of the healthy volunteers, and those with migraines and insomnia had lower peak melatonin concentrations.
Normally, melatonin levels are highest 6 to 8 hours after sunset but levels were found to peak after 3 AM in people with chronic migraines, Peres explained.
Levels of prolactin, a hormone that rises during pregnancy to stimulate milk production, were lower among those with migraines, the report indicates. Peak levels of prolactin were low in 53% of patients compared with 22% of those without headaches. This hormone is partially regulated by a brain chemical called dopamine.
Concentrations of growth hormone did not differ between patients and healthy volunteers, according to the report in the Journal of Neurology, Neurosurgery and Psychiatry.
Chronic migraines may occur with other conditions such as depression, anxiety disorder and insomnia. While the headaches take a toll on patients' quality of life and place an economic burden on society, little is known about their cause.
To examine whether the hypothalamus, an area involved in other types of headaches, plays a role, the investigators took hourly blood samples from 17 people who experienced chronic migraines and 7 healthy individuals whose average age was 31 years. The team measured levels of the four hormones during the night.
"Overall, these results support the involvement of the hypothalamus in the pathophysiology of chronic migraine," Peres and colleagues conclude.
SOURCE: Journal of Neurology, Neurosurgery and Psychiatry 2001;71:747-751. Copyright © 2001 Reuters Limited.