Estrogen ingested in pill form may increase the risk of high blood pressure

The type of estrogen-based menopausal hormone therapy had varying impacts on developing high blood pressure.


According to a new study, women ingesting oral estrogen hormone therapy for menopause may have an increased risk of high blood pressure.

Menopausal women under the age of 60 or for whom menopause has occurred within the past ten years may benefit from some hormone therapies to lower their risk of cardiovascular disease, according to previous studies. Hormone therapy may be prescribed to relieve menopause symptoms, for gender-affirming care, and contraception.

Although high blood pressure is a modifiable risk factor for cardiovascular disease, the possible effects of various hormone therapy treatments on blood pressure in menopausal women are unknown, according to the study’s authors.

A new study dives deeper into factors associated with hormone therapy, such as the route of administration (oral vs. non-oral) and type of estrogen, and how they may affect blood pressure.

To conduct this study, a sizable cohort of approximately 112,000 women aged 45 and over who filled at least two consecutive prescriptions for estrogen-only hormone therapy (a six-month cycle) was used. These women were found in Alberta, Canada, between 2008 and 2019. Health data were used to identify hypertension as the primary effect of elevated blood pressure.

The likelihood of acquiring high blood pressure at least a year after beginning estrogen-only hormone therapy was first examined by researchers in relation to the delivery method. The three ways to provide hormone therapy were orally (by mouth), transdermally, and vaginally. Researchers also looked at the potential for hypertension as well as the estrogen formulation that was being used.

The researchers examined the medical records of people receiving estrogen-only hormone therapy for this study. Estradiol, a synthetic estrogen that most closely resembles the estrogen produced by women’s bodies before menopause, and conjugated equine estrogen, the oldest form of estrogen therapy, were the two most popular forms of estrogen used by study participants.

It was found that compared to women using transdermal estrogen, women receiving oral estrogen medication had a 14% higher risk of hypertension, while women using vaginal estrogen creams or suppositories had a 19% higher risk. After taking age into consideration, ladies under the age of 70 showed a stronger correlation than women above the age of 70.

Compared to estradiol, conjugated equine estrogen was associated with an 8% increased risk of developing high blood pressure.

Scientists noted, “Taking estrogen for a longer period or taking a higher dose was associated with greater risk of high blood pressure.”

Study author Cindy Kalenga, an M.D./Ph.D.-candidate at the University of Calgary in Alberta, Canada, said, “The study’s findings suggest that if a menopausal woman takes hormone therapy, there are different types of estrogen that may have lower cardiovascular risks.”

“These may include low-dose, non-oral estrogen — like estradiol, in transdermal or vaginal forms — for the shortest possible time period, based on individual symptoms and the risk–benefit ratio. These may also be associated with the lowest risk of hypertension. Of course, this must be balanced with the important benefits of hormone therapy, which include treatment of common menopausal symptoms.”

The authors will be conducting more research investigating combined estrogen and progestin, as well as progestin-only formulations of hormone therapy and their impact on heart and kidney diseases.

Journal Reference:

  1. Cindy Z. Kalenga, Amy Metcalfe, Magali Robert, Kara A. Nerenberg, Jennifer M. MacRae and Sofia B. Ahmed. Association Between the Route of Administration and Formulation of Estrogen Therapy and Hypertension Risk in Postmenopausal Women: A Prospective Population-Based Study. Hypertension. DOI: 10.1161/HYPERTENSIONAHA.122.19938
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