The benefits of hormone therapy for the treatment of menopause symptoms outweigh the risks, and what is available now is very different from two decades ago, said researchers at the conclusion of a recent study.
“Among women under 60, we found hormone therapy has low risk of adverse events and is safe for treating bothersome hot flushes, night sweats and other menopausal symptoms,” said study author Dr JoAnn Manson, chief of preventive medicine at Brigham and Women’s Hospital at Harvard Medical School.
This is a departure from the advice many women have been given in the past.
The latest analysis, published in JAMA, is based on two decades of follow-up data from the Women’s Health Initiative study, which followed thousands of women taking hormone replacement therapy.
The study was halted after it was found that those taking Prempro, which is a combination of oestrogen and progestin, had higher risks of breast cancer and stroke.
“The findings were surprising,” Manson said, pointing out that the reason the randomised trial was conducted was because scientists were trying to determine if hormone therapy decreased the risk of heart disease and other conditions.
NPR reports that after the initial findings came out, many women abruptly stopped the therapy. Prescriptions plummeted, and many healthcare providers still hesitate to recommend hormone therapy.
But menopause experts say it’s time to reconsider hormone therapy, because there’s a lot known now that wasn’t known two decades ago.
Most significantly, there are now different types of hormones – delivered at lower doses – that are shown to be safer.
“Women should know that hormone therapy is safe and beneficial,” said Dr Lauren Streicher, a clinical professor of obstetrics and gynaecology at Northwestern University Feinberg School of Medicine.
Looking back, she said, it’s clear the Women’s Health Initiative study was flawed and that some of the risks that were identified were linked to the type of hormones that women were given.
“We learned what not to do,” she added. The type of progestin used, known as medroxyprogesterone acetate, was “highly problematic”.
This was probably responsible for the increase in breast cancer seen among women in the study. “So we don't prescribe that anymore,” Streicher said.
Increasingly, other types of hormones are used, like micronised progesterone which does not increase the risk of breast cancer.
This is a bioidentical hormone that has a molecular structure identical to the progesterone produced by women's ovaries, and tends to have fewer side effects.
Another problem with the study was the age of the women enrolled. Most were over 60, Streicher said.
“And we know that there is a window of opportunity when it is the safest to start hormone therapy and that you get the most benefit.” That window is typically between 50 and 60.
Another risk identified in the Women’s Health Initiative study was an increased incidence of pulmonary embolism among women taking hormones. A pulmonary embolism is a blood clot that blocks blood flow to the lungs.
Since women in the study were taking oestrogen orally, this may have increased their risk, Streicher said. A better option for people at risk of clots is to take oestrogen through the skin, via a patch, a cream or gel.
“The advantage of a transdermal oestrogen is that it is not metabolised by the liver,” she added. “And because of that, we don’t see that increase in blood clots.”
With a range of hormone therapies available now, there is no one-size fits all approach.
“Hormone therapy is beneficial way beyond the benefits to just helping with hot flushes. Ongoing research points to protection against bone loss and heart disease, too.”
Study details
The Women’s Health Initiative Randomised Trials and Clinical Practice: A Review
JoAnn Manson, Carolyn Crandall, Jacques Rossouw et al
Published in JAMA Network on 1 May 2024
Abstract
Importance
Approximately 55m people in the US and 1.1bn people worldwide are postmenopausal women. To inform clinical practice about the health effects of menopausal hormone therapy, calcium plus vitamin D supplementation, and a low-fat dietary pattern, the Women’s Health Initiative (WHI) enrolled 161 808 postmenopausal US women (N = 68 132 in the clinical trials) aged 50 to 79 years at baseline from 1993 to 1998, and followed them up for up to 20 years.
Observations
The WHI clinical trial results do not support hormone therapy with oral conjugated equine oestrogens plus medroxy-progesterone acetate for postmenopausal women or conjugated equine oestrogens alone for those with prior hysterectomy to prevent cardiovascular disease, dementia, or other chronic diseases. However, hormone therapy is effective for treating moderate to severe vasomotor and other menopausal symptoms. These benefits of hormone therapy in early menopause, combined with lower rates of adverse effects of hormone therapy in early compared with later menopause, support initiation of hormone therapy before age 60 years for women without contraindications to hormone therapy who have bothersome menopausal symptoms. The WHI results do not support routinely recommending calcium plus vitamin D supplementation for fracture prevention in all postmenopausal women. However, calcium and vitamin D are appropriate for women who do not meet national guidelines for recommended intakes of these nutrients through diet. A low-fat dietary pattern with increased fruit, vegetable, and grain consumption did not prevent the primary outcomes of breast or colorectal cancer but was associated with lower rates of the secondary outcome of breast cancer mortality during long-term follow-up.
Conclusions and Relevance
For postmenopausal women, the WHI randomised clinical trials do not support menopausal hormone therapy to prevent cardiovascular disease or other chronic diseases. Menopausal hormone therapy is appropriate to treat bothersome vasomotor symptoms among women in early menopause, without contraindications, who are interested in taking hormone therapy. The WHI evidence does not support routine supplementation with calcium plus vitamin D for menopausal women to prevent fractures or a low-fat diet with increased fruits, vegetables, and grains to prevent breast or colorectal cancer. A potential role of a low-fat dietary pattern in reducing breast cancer mortality, a secondary outcome, warrants further study.
NPR article – Hormones for menopause are safe, study finds. Here's what changed (Open access)
See more from MedicalBrief archives:
The evidence base for HRT: What can we believe?
Hormone therapy for menopause symptoms: two decades on, the fear of risks persist
Education needed regarding efficacy of HRT for most women