A new study published online February 1, 2023 found that people with higher cumulative estrogen exposure throughout their lives may have a lower risk of stroke. neurology®, the medical journal of the American Academy of Neurology. A lower risk was found for both ischemic stroke and intracerebral hemorrhage.
Ischemic stroke is caused by blockage of blood flow to the brain and is the most common type of stroke. Intracerebral hemorrhage is caused by bleeding in the brain.
“Our study suggests that elevated estrogen levels from many reproductive factors, including increased reproductive lifespan and use of hormone therapy and contraceptives, are associated with reduced risk of ischemic stroke and intracerebral hemorrhage. study author Peige Song, Ph.D. , of Zhejiang University School of Medicine, Hangzhou, China. “These findings may inform new ideas for stroke prevention, such as considering screening people with short lifetime exposures to estrogen.”
The study involved 122,939 postmenopausal female participants with a median age of 58 years living in China who were stroke-free at study entry.
Participants answered questions about personal factors such as age, gender and occupation, as well as lifestyle habits such as smoking, drinking, exercise and medical history. They also answered questions about reproductive health information, including age at menarche and onset of menopause, number of pregnancies and miscarriages, and oral contraceptive use.
Researchers looked at health insurance and disease registry data to determine which participants had a stroke. During an average follow-up period of 9 years, 15,139 had a stroke. Of these, 12,853 had ischemic stroke, 2,580 had intracerebral hemorrhage, and 269 had subarachnoid hemorrhage.
Participants were divided into four groups determined by reproductive lifespan, the number of years from the first menstrual period to menopause. Participants in the shortest reproductive lifespan group had a maximum of 31 reproductive years. The participant in the group with the longest reproductive lifespan had more than 36 years of reproductive years.
As a percentage, participants in the longest group had slightly more strokes than participants in the shortest group, 13.2% versus 12.6%. However, when the researchers adjusted for other factors that could influence stroke risk, such as age, smoking, physical activity, and high blood pressure, participants in the longest group had a higher risk of any kind of stroke. % found to be low.
Looking at different types of stroke, female participants with the longest reproductive lifespan had a 5% lower risk of ischemic stroke and a 13% lower risk of intracerebral hemorrhage compared with women with the shortest reproductive lifespan.
Researchers also looked at other factors that influence estrogen levels, such as number of births and oral contraceptive use. Both of these are associated with high levels and length of breastfeeding is associated with low levels. Use represents a relatively high sustained blood estrogen level. They found that higher estrogen levels were associated with a lower risk of all types of stroke, ischemic stroke, and intracerebral hemorrhage.
“Lifetime estrogen exposure may be a useful indicator of risk for different types of stroke after menopause,” Song said. Further research is needed on the biological, behavioral, and social factors that may contribute to the association with
A limitation of this study was that information on reproductive factors was collected primarily based on participants’ ability to recall events, and it is possible that participants did not remember such events correctly.