by Justin Jackson, Phys.org
edited by Sadie Harley, reviewed by Robert Egan
Credit: Pixabay/CC0 Public Domain
Researchers led by the National Heart, Lung, and Blood Institute report that menopausal hormone therapy relieved vasomotor symptoms without raising cardiovascular risk in younger women, but increased risk was evident in women aged 70 years and older.
Concerns about the safety of hormone therapy have discouraged many women and clinicians from using it to treat hot flashes and night sweats. Some previous studies have suggested increased risk of coronary heart disease linked to hormone use, particularly in older women. At the same time, vasomotor symptoms remain among the most common and distressing consequences of menopause, and effective treatment options have been limited.
In the study, “Menopausal Hormone Therapy and Cardiovascular Diseases in Women With Vasomotor Symptoms: A Secondary Analysis of the Women’s Health Initiative Randomized Clinical Trials,” published in JAMA Internal Medicine, researchers analyzed outcomes from two hormone therapy trials to assess the safety of treatment in women experiencing vasomotor symptoms.
A total of 27,347 postmenopausal women aged 50 to 79 years were enrolled from 40 clinical centers across the United States. Among them, 10,739 had undergone hysterectomy and were randomized to receive conjugated equine estrogens (CEE) or placebo, while 16,608 with an intact uterus were randomized to CEE plus medroxyprogesterone acetate (MPA) or placebo.
Women were followed for a median of 7.2 years in the CEE trial and 5.6 years in the CEE plus MPA trial. Vasomotor symptoms were assessed at baseline and year one, with nearly all women who reported moderate or severe symptoms recalling onset near menopause.
CEE alone reduced vasomotor symptoms by 41% across all age groups. CEE plus MPA also reduced symptoms but with age-related variation, showing strong benefit in women aged 50 to 59 years and diminished or absent benefit in women 70 years and older.
Analysis of cardiovascular outcomes found neutral effects of both CEE alone and CEE plus MPA in women aged 50 to 59 years with moderate or severe symptoms. No clear harm was observed in those aged 60 to 69 years, although risk estimates were elevated for CEE alone.
Women aged 70 years and older had significantly higher rates of atherosclerotic cardiovascular disease, with hazard ratios of 1.95 for CEE alone and 3.22 for CEE plus MPA, corresponding to 217 and 382 excess events per 10,000 person-years, respectively.
Investigators concluded that hormone therapy can be considered for treatment of vasomotor symptoms in younger women aged 50 to 59 years, while initiation in women aged 60 to 69 years requires caution. For women 70 years and older, the findings argue against the use of hormone therapy due to substantially increased cardiovascular risk.
Written for you by our author Justin Jackson, edited by Sadie Harley, and fact-checked and reviewed by Robert Egan—this article is the result of careful human work. We rely on readers like you to keep independent science journalism alive. If this reporting matters to you, please consider a donation (especially monthly). You’ll get an ad-free account as a thank-you.
More information: Jacques E. Rossouw et al, Menopausal Hormone Therapy and Cardiovascular Diseases in Women With Vasomotor Symptoms, JAMA Internal Medicine (2025). DOI: 10.1001/jamainternmed.2025.4510
Deborah Grady et al, Hormone Therapy for Menopausal Vasomotor Symptoms—Better Understanding Cardiovascular Risk, JAMA Internal Medicine (2025). DOI: 10.1001/jamainternmed.2025.4521
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