Apr 10, 2023

High blood pressure: Estrogen pills may increase risk of hypertension

Oral estrogen, taken in pill form, might be connected to a higher risk of high blood pressure when compared to vaginal creams and transdermal patches, according to a study published in the journal Hypertension.

Researchers used health administrative data in Alberta, Canada, from the medical records of 112,000 women aged 45 and older who filled at least two consecutive prescriptions for estrogen-only hormone therapy.

The scientists noted three different methods for taking the medication: oral, transdermal, and vaginal.

High blood pressure for each woman was identified by their health records.

At least one year after the women started the treatment, the researchers looked at the relationship between the method of taking the estrogen-only hormone therapy and the risk of developing high blood pressure.

The findings included:

"In the study, oral estrogen was associated with a higher incidence of hypertension than transdermal or vaginal," said Dr. Monte Swarup, FACOG, an OB/GYN in Chandler, Arizona, and founder of the HPV information site HPV HUB.

"Women using estrogen hormone replacement therapy should be closely monitored for hypertension," Swarup, who was not involved in the study, told Medical News Today. "Estrogen taken orally has a first-path effect. This is a phenomenon where a drug taken orally first passed to the liver before reaching general circulation. Based on the study, any form of estrogen other than oral is preferred. This is because there is less association with hypertension."

Experts say it is essential for medical professionals to look at the overall effect of menopause on women.

"We know that menopausal symptoms such as vasomotor symptoms, when severe and prolonged, can increase cardiovascular risk, cause impaired quality of life, poor sleep, and depression/anxiety. It is important women know they should not suffer with their menopausal symptoms and there are many different treatment options available to them," said Dr. Anais Hausvater, a cardiologist at NYU Langone Heart in New York specializing in cardiovascular diseases that predominantly affect women.

"This study confirms that hormone therapy with estrogen is overall safe, especially when taken vaginally or transdermally," Hausvater, who was not involved in the study, told Medical News Today. "Transdermal or vaginal estrogen creams would be a safer option for women who may already have risk factors for hypertension, such as obesity, metabolic syndrome, or a history of hypertensive disorders of pregnancy."

Experts note that the findings are from a cohort study, which might not provide as much precise data as a study where participants are recruited, given different forms of estrogen, and followed to see how it affects them.

"A cohort study is retrospective," said Dr. G. Thomas Ruiz, the OB/GYN lead at MemorialCare Orange Coast Medical Center in California.

"That means that the scientists found people that fit their criteria," Ruiz, who also was not involved in the study, told Medical News Today. "In this case, they looked for women who took estrogen. They then analyzed the type and the relationship to high blood pressure. This type of study provides information, but it is not the same as a real-time study."

The stages of menopause can affect blood pressure in different ways.

In a 2015 study, researchers reported that although there are few studies about blood pressure during perimenopause, the prevalence of hypertension appears to increase as women continue through this stage.

A statement in 2021 by a group of European cardiologists, gynecologists, and endocrinologists suggests that doctors can overlook high blood pressure in middle-aged women, writing the symptoms off as either stress or menopause. They said this can cause delayed diagnosis and treatment, increasing their risk of heart failure and stroke.

Because hypertension has no symptoms, it is often called the "silent killer." It is also hard to diagnose when women are seen in the doctor's office once a year.

"A blood pressure reading of 135/90 can be dismissed as nervousness," Ruiz said. "But several readings of 135/90 could be considered hypertension. There should be a follow-up visit in six weeks. I also suggest that women get a home blood pressure cuff and take their blood pressure at different times and then average it to get a more accurate reading. Or, many smartwatches or activity bands can give you blood pressure readings. Women can keep track, and we can review the readings at the follow-up visit."

Researchers are reporting that women who take estrogen in pill form may have a higher risk of high blood pressure than women who receive the hormone via different methods. Experts note that menopause can produce a number of health issues, including hypertension, for older women. They recommend women's heart health be monitored as they progress through menopause.