14 DAY TRIAL // A new study carried out by a neurointerventional expert from Rush University Medical Center was presented at the Society of Neurointerventional Surgery (SNIS) 7th annual meeting. This first-of-its-kind research says that oral contraceptives and hormone replacement therapy (HRT) may also protect women against the formation and rupture of brain aneurysms.
Dr. Michael Chen, neurointerventionalist at Rush and study leader said that this study was determined by the fact that the most frequent cerebral aneurysms occur in post-menopausal women. This was the conclusion of two trials - the International Subarachnoid Aneurysm trial and the International Study of Unruptured Intercranial Aneurysms. Research found that 70 percent of aneurysms occurred in post-menopausal women with an average age of 52, a time of their life when they experienced a serious decrease in estrogen levels.
Chen, who also is assistant professor of neurology, neurosurgery and radiology at Rush University, said that “"By understanding the potential link between low levels of estrogen and aneurysms, we can focus our areas of study with the hope of providing women who are at risk for brain aneurysms with preventative therapies.”
From 2008 to 2010, researchers at Rush also studied a group of 60 women with both ruptured and unruptured aneurysms, of which 65% were unruptured and 35% were cases where women had ruptured aneurysms. Participating women were aged 31-80 and were under the care of Dr. Chen and his team.
A control group of 4,682 random women, representing national population averages, was compared with the case group, as Chen and his team wanted to see if a link existed between lower estrogen levels and aneurysm.
Both groups were analyzed following the same criteria and some of the variables were similar, average age of 53, BMI of 27.1 for the case group and 25.2 for the control group, average age of menstrual onset of 13 and as for the first pregnancy over 30, the averages were 10% for the case group and 11% for the control group.
The biggest difference occurred concerning the use of oral contraceptives or hormone replacement therapy. The rate of oral contraceptive use in the case group was 60% compared to 77.6% for the control group. Also, the rate of hormone replacement therapy usage was 23.7% for the case group and 44.8% for the control group.
When scientists compared the average use duration of oral contraceptives, they found out that is was of 2.6 years for the case group and of 5.2 years for the control group.
“These differences in the usage of estrogen modifying agents qualify as statistically significant and indicate that women with brain aneurysms use oral contraceptives and hormone replacement therapy less frequently than the general population,” Chen said. “It is reasonable to conclude that the data results support our hypothesis that drops in estrogen that occur in menstruation and particularly at menopause may explain why cerebral aneurysms are more frequently found in women, particularly at menopause.”
“For neurointerventional practitioners, this study provides another piece of evidence that estrogen stabilization may play a protective role in women who are at risk of aneurysms,” he added.
The researchers next step is to further examine the effects of estrogen on the blood vessels of the brain, according to e! Science News.