Hormone Replacement Therapy: Study Says Taking Oral Estrogen Increases Risk Of Hypertension

Women taking estrogen pills as part of their menopausal hormone therapy are at a greater risk of developing hypertension, a recent study has found.

As a woman goes through menopause, her ovaries no longer produce high levels of estrogen and progesterone as before. This sudden drop in hormones causes several discomforts such as hot flashes, night sweats, mood swings and difficulty sleeping.

Hormone replacement therapy is often recommended for menopausal women to relieve the symptoms, and to reduce the risk of osteoporosis and cardiovascular diseases associated with the drop in hormones.

There are two main types of hormone replacement therapies – estrogen therapy and estrogen progesterone/progestin hormone therapy (EPT).

Estrogen therapy involves the use of estrogen in the form of a pill, patch, cream, vaginal ring, gel, or spray. EPT, also known as combination therapy, combines doses of estrogen and progesterone.

The type of hormone treatment is decided based on several factors, including if the patient has undergone a hysterectomy. A combination of estrogen and progesterone is used in women with a uterus to reduce the risk of endometrial cancer. However, estrogen-alone treatment is believed to have fewer long-term risks compared to combination therapy.

In the latest study, published in the American Heart Association journal Hypertension, researchers examined data from more than 112,000 women who were 45 years or older after they were put on estrogen-only hormone therapy for a year.

Researchers examined the relationship between the method of estrogen administration – oral, transdermal and vaginal application – and the risk of developing hypertension.

According to the researchers, taking oral estrogen increased the risk of high blood pressure by 14% when compared to hormone treatment using transdermal estrogen creams. The risk of estrogen pills was 19% in comparison with the use of vaginal estrogen creams or suppositories.

"We know estrogens ingested orally are metabolized through the liver, and this is associated with an increase in factors that can lead to higher blood pressure," said Cindy Kalenga, the lead author of the study.

The research team also found that taking estrogen for an extended period or use of a higher dose was associated with a greater risk of high blood pressure.

"We know that post-menopausal women have an increased risk of high blood pressure when compared to pre-menopausal women, furthermore, previous studies have shown that specific types of hormone therapy have been associated with higher rates of heart disease. We chose to dive 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," Kalenga said.