People With Endometriosis May Have Higher Risk of Stroke

Research suggests that people with endometriosis may have a higher risk of stroke. More than 11% of people with female anatomy in the United States are believed to have endometriosis. The potentially higher risk of stroke for people with endometriosis may influence how the disease is treated.

Study Linking Endometriosis With Risk of Stroke

A 2022 study found that women with endometriosis had a 34% higher risk of having a stroke than those without the chronic inflammatory condition. The researchers did not have access to data on people assigned female at birth and who do not identify as female.

Researchers suggest that healthcare providers should look at the health of the whole patient, including elevated blood pressure, high cholesterol, and other new stroke factors, not only symptoms specifically associated with endometriosis, such as pelvic pain or infertility.

What Is Endometriosis?

Endometriosis occurs when tissue similar to that which lines the uterus—or the endometrium—grows outside of the uterus, commonly on the ovaries, fallopian tubes, bowels, or bladder. This can cause extreme pain, often timed with your period, as well as infertility, extremely heavy periods, and digestive problems, among other complications.

According to study authors, treatments that are often used to relieve symptoms—including hysterectomy (surgical removal of the uterus) and/or oophorectomy (surgical removal of the ovaries), and postmenopausal hormone therapy—made up the largest proportion of stroke risk among women with endometriosis.

What Is a Stroke?

A stroke is a medical emergency that happens when blood flow to the brain is blocked. This can happen for multiple reasons, including a blood clot or bleeding in the brain. Lack of blood flow can damage parts of the brain, possibly leading to brain damage, disability, or death. Prompt treatment is required to restore blood flow and prevent severe complications.

Why Endometriosis May Increase Risk of Stroke

"There has been very limited research on endometriosis and risk of stroke," lead study author Leslie V. Farland, ScD, an assistant professor of epidemiology and biostatistics at the University of Arizona, told Health.

That lack of research is what prompted Farland and her colleagues to look into how endometriosis might impact stroke risk—especially because prior research from her team "observed an association between endometriosis and increased risk of cardiovascular disease endpoints including hypertension, high cholesterol, and myocardial infarction," said Farland.

For the study, Farland and her team analyzed data from 112,056 women between the ages of 25 and 42 who were enrolled in the Nurses' Health Study II—one of the largest investigations into the risk factors of major chronic diseases in women. Of the study participants, 5,244 had clinically diagnosed endometriosis.

The researchers analyzed data that was collected every two years for 28 years, looking for other confounders or risk factors for stroke, including alcohol intake, body mass index (BMI), oral contraceptive use, and diet. Among all participants, 893 women had a stroke during that time.

People who had a hysterectomy (removal of the uterus) and/or oophorectomy (removal of the ovary or ovaries) had the greatest risk of stroke, at 39%, followed by those who received postmenopausal hormone therapy, at 16%. The researchers didn't find a link between endometriosis and stroke when it came to other factors like age, infertility history, BMI, or menopausal status.

Risks of Certain Treatments

It's not entirely clear why endometriosis may raise the risk of stroke, and Farland noted that the study didn't explore the reason for the connection—it simply found a link. The study also wasn't able to separate the risk of having different types of stroke, like ischemic stroke and hemorrhagic stroke.

However, researchers have some theories. "We hypothesize that it may be a combination of inflammation, increased risk of cardiovascular disease risk factors, such as hypertension and high cholesterol, and possibly earlier age at menopause, induced by gynecologic surgery," said Farland.

Because the majority of strokes among women with endometriosis occurred in those who underwent treatments like surgical procedures or hormone therapy, those are likely factors—but it's also unclear why, study senior author Stacey Missmer, ScD, a professor of obstetrics, gynecology, and reproductive biology at Michigan State University College of Human Medicine, said in a press release. She theorizes that—though the treatments are meant to reduce symptoms and inflammation—the procedures and treatments themselves could increase the risk of stroke.

"There are circumstances when a hysterectomy and/or oophorectomy is the best choice for a woman, however, we also need to make sure that patients are aware of the potential health risks associated with these procedures," said Missmer in the release. "Other research also suggests that hysterectomy is associated with elevated stroke risk even if there is no history of endometriosis."

Menopause and Risk of Stroke

Although previous research linking hysterectomy and oophorectomy did not look into causes, experts believe that menopause, triggered by the procedures, can impact the risk of stroke.

"The data is limited on whether hysterectomy alone has any impact on cardiovascular health," Angela Chaudhari, MD, chief of gynecology and gynecologic surgery at Northwestern Medicine, told Health. "However, there is data to suggest an increased risk of cardiovascular events such as heart disease and stroke are associated with oophorectomy that results in surgical menopause."

The distinction between hysterectomy alone and a hysterectomy and oophorectomy is an important one. A hysterectomy alone should not affect hormone production, but a hysterectomy with an oophorectomy, or an oophorectomy alone, will affect hormone levels, as ovaries are the main source of estrogen production in the body.

Premature Menopause

"Hysterectomy when combined with bilateral oophorectomy can increase risk of stroke, particularly in younger patients for which the surgery would result in premature menopause," Tamisa Koythong, MD, assistant professor of obstetrics and gynecology and minimally invasive gynecologic surgery at Baylor College of Medicine, told Health.

Hysterectomy without the removal of ovaries does not have this same increased risk. This is because a hysterectomy alone does not affect your hormonal status, as that is dependent on ovarian function.

Postmenopausal hormone therapy—or hormone replacement therapy—can also affect hormone levels. "There is an increased risk of cardiovascular disease and stroke in women placed on hormone replacement therapy, specifically a combined estrogen-progesterone combination," said Dr. Chaudhari. Research indicates the risk of stroke is highest in the first year of hormone replacement therapy.

More research is needed to understand this increased risk and long-term health outcomes completely.

Whole-Body Care and Prevention

Although patients and their healthcare providers should be aware of the additional health risks of endometriosis, experts stress that the overall risk of stroke is low.

There is no reason to panic that everyone who has endometriosis is going to get a stroke, said Missmer. She referenced other, greater risk factors for stroke, like smoking, which increases stroke risk by 63%. "We're not seeing effects anywhere close to that for endometriosis," said Missmer.

However, people with endometriosis need to pay attention to their whole-body health. It's key for people with endometriosis to be aware of the signs and symptoms of stroke, heart problems, and cerebrovascular disease. Healthcare providers should also take age and other factors into account when discussing surgical interventions with patients.

"[This is] part of the reason why treatment of endometriosis is so difficult. We have to balance treatment of the disease itself while also considering the patient as a whole, who is still at risk for other chronic diseases," said Dr. Koythong.

When To See a Healthcare Provider

Contact a healthcare provider if you have any questions or concerns about your risk of stroke or treatment for endometriosis. Seek medical care right away if you exhibit any signs of stroke, including sudden:

• Confusion
• Difficulty with vision in one or both eyes
• Difficulty speaking or understanding speech
• Dizziness
• Severe, unexplained headache
• Trouble with movement, balance, or coordination
• Weakness or numbness of the face, arm, or leg, particularly on one side of the body
  

A Quick Review

Research suggests that people with endometriosis may be at higher risk of stroke, especially for those who have treatments impacting hormone levels. However, the overall risk of stroke remains relatively low. See a healthcare provider if you have questions about how endometriosis and your treatments may impact your risk of stroke.