Women on hormone replacement therapy who experience an increase in migraine severity of 1 grade or more are at increased risk for ischemic stroke, according to study results presented at the 2016 International Stroke Conference.
“We found that women who are currently taking hormone replacement therapy and have had a worsening severity of migraines have a 30% increased risk of having strokes, as compared to women who have worsening migraines but are not currently on hormone replacement therapy,” Haseeb A. Rahman, MD, lead author from the Zeenat Qureshi Stroke Institute in Minneapolis, told Neurology Advisor.
According to Dr Rahman, there is a large number of postmenopausal women on hormone replacement therapy, many of whom have a history of migraines, and women can develop more severe migraines while taking hormone replacement therapy.
“We wanted to investigate if a worsening of migraines while taking hormone replacement therapy increases the risk of stroke in these women,” he said. “To our knowledge, a correlation between worsening severity of migraines while taking hormone replacement therapy and increased stroke risk had never been studied before.”
Although previous studies had addressed the relationship between hormone replacement therapy and migraines as risk factors for stroke, Dr Rahman noted that they had sometimes come to differing conclusions. “There are still certain ‘grey areas’ in our understanding of the correlation of hormone replacement therapy and migraines as stroke risk factors,” he said.
For the current study, Dr Rahman and colleagues culled data for 82 208 women who were aged 50 to 79 years and were enrolled in the observational arm of the Women’s Health Initiative study. Researchers defined hormone replacement therapy as unopposed estrogen and/or estrogen plus progesterone, and examined the risk for ischemic stroke among women with migraines who were receiving hormone replacement therapy or who had previously or never received hormone replacement therapy.
Patients were divided into 2 groups: those who had an increase in migraine severity of 1 grade or more at 3 years, and those who experienced no change or a decrease in migraine severity at that same time point. Researchers compared the relative risk for developing ischemic stroke among patients who were currently on hormone replacement therapy with those who were either previously on hormone replacement therapy or who had never received hormone replacement therapy.
Overall, 45.8% of patients were on hormone replacement therapy and 54.2% were either past users or had never used hormone replacement therapy therapy.
Results indicated that 20.6% of patients who were currently on hormone replacement therapy demonstrated an increase in migraine severity compared with 18.7% of those previously on hormone replacement therapy and 17.3% of those never on hormone replacement therapy (P<.0001).
Compared with women who were current users of hormone replacement therapy and had experienced no change or a decrease in migraine severity, those who never or only in the past used hormone replacement therapy had a decreased odds ratio (OR) for ischemic stroke (0.91 vs 1.1; P<.0001). This discrepancy in ischemic stroke likelihood was also observed when researchers compared patients who had never or only in the past used hormone replacement therapy (OR=0.81) with those who were current hormone replacement therapy users and had experienced an increase in migraine severity (OR=1.3; P<.0001).
As a result of the findings, Dr Rahman said neurologists should keep a close watch on migraines in postmenopausal women taking hormone replacement therapy.
“Aside from addressing the migraines as they worsen, it would be helpful to keep in mind a potential increase in stroke risk that may be related to this,” he said. “It is important to work in collaboration with the prescribing physician, who is often a primary care physician or gynecologist, to address the potential risks and benefits of placing a patient on hormone replacement therapy, or continuing them on it once started. It is also necessary to identify and improve other stroke risk factors as best as possible.”
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- Rahman HA, Malik A, Saeed O, et al. Abstract WMP 57. Worsening Migraines in Current Hormone Replacement Therapy Users Predicts Higher Risk of Stroke. Presented at: International Stroke Conference; February 16-19, 2016; Los Angeles.
This article originally appeared on Neurology Advisor