Women who started menopausal hormone therapy during perimenopause or shortly after menopause while experiencing hot flashes and night sweats had an estimated 22% lower risk of cardiovascular disease than similar women who did not start treatment, according to an analysis published this week in JAMA Internal Medicine.
Timing was the decisive variable. Women who began within 10 years of menopause onset showed an estimated 27% lower risk. Among women who started more than a decade after menopause, no clear benefit was estimated, and the range around that result was wide enough that it cannot be read as either protective or harmful. The strongest single association appeared among Black women, at an estimated 49% lower risk.
Before anyone books an appointment on that number, the researchers attached a blunt caveat to their own work: these findings should not be used to justify hormone therapy for heart disease prevention. That distinction is the whole story for the U.S. women entering menopause each year who face a real decision about symptom treatment.
Two Decades of Data from a Long-Running U.S. Cohort
The analysis, led by researchers at Virginia Commonwealth University and the University of Pittsburgh, drew on the Study of Women's Health Across the Nation, a multisite U.S. cohort that has followed midlife women since the 1990s. Researchers examined 2,737 women who reported hot flashes or night sweats, had no prior cardiovascular disease and had not previously used hormone therapy, using clinical data collected from 1997 through 2017. Of those women, 755 started hormone therapy, and 224 fatal and nonfatal cardiovascular events occurred across 20 years of follow-up.
Outcomes counted included heart attack, stroke, heart failure, revascularization and cardiovascular death. The overall adjusted hazard ratio was 0.78, the source of the 22% figure.
Method matters. This was not a randomized trial. Researchers used target trial emulation, which structures observational data to mimic a series of hypothetical trials. Samar R. El Khoudary, professor and chair of epidemiology at the VCU School of Public Health and one of the study's senior researchers, described the approach in the university announcement and said timing of initiation may influence cardiovascular outcomes.
The journal published an accompanying invited commentary alongside the analysis, framing the work as groundwork for a future trial rather than a substitute for one.
The Limits the Authors Put on Their Own Result
The published conclusion states that all estimates warrant caution given the potential for residual confounding, and that given inconsistent cardiovascular findings across the literature and the need to weigh overall risk and benefit, the results should not support hormone therapy for cardiovascular prevention.
Residual confounding is the central worry. Rebecca C. Thurston of the University of Pittsburgh School of Medicine, another senior researcher on the study, said women who choose hormone therapy differ from those who do not on characteristics including socioeconomic position and access to health care that the study cannot fully address, and that the findings "should not guide clinical practice."
The team also flagged the trade-off any patient conversation has to include: longer duration of hormone therapy has been associated with increased breast cancer risk. Every participant had vasomotor symptoms, so the results do not extend to women without them.
The wider regulatory picture has shifted separately. The FDA this year removed boxed warnings from menopausal hormone therapy products, reflecting evolving evidence on benefits and risks. Cardiovascular prevention is still not an indication for the treatment, which remains the most effective option for vasomotor symptom relief.
Access and Cost Shape Who Actually Gets Treated
The finding that hormone therapy started within 10 years of menopause was associated with benefit, and later initiation was not, has an uncomfortable practical implication. Women who reach a clinician early are in a different position than women who spend years without a diagnosis or without coverage.
Vasomotor symptoms are not a fringe complaint. They affect up to 80% of women during the menopause transition and last seven to ten years on average, typically peaking in early postmenopause. That is a long window in which delays in reaching care become a clinical variable rather than a scheduling inconvenience.
Practical steps are ordinary ones. Hot flashes and night sweats that disrupt sleep or work are a legitimate reason to see a clinician rather than something to endure. Anyone considering hormone therapy should ask about personal and family history of breast cancer, blood clots, stroke and liver disease, and whether a pill or a patch better fits their cardiometabolic risk. Anyone already on it should not stop or change a dose based on a news article.
There is still no randomized trial testing cardiovascular outcomes in women with vasomotor symptoms during perimenopause. Until one exists, this remains a symptom decision made with a clinician.
Key Questions Answered
What did the analysis report? Among 2,737 U.S. women with hot flashes or night sweats, starting hormone therapy during perimenopause or early postmenopause was associated with an estimated 22% lower risk of cardiovascular events.
Does this prove hormone therapy protects the heart? No. This was an observational analysis structured to emulate trials, not a randomized trial. The authors explicitly said the findings should not be used to support hormone therapy for cardiovascular prevention.
Who saw the largest association? Women who began therapy within 10 years of menopause onset, and Black women. No clear benefit was estimated for women starting more than a decade after menopause.
What are the known risks? Longer duration of use has been associated with increased breast cancer risk, and route and formulation affect clot and stroke risk. These belong in a clinician conversation.
Should anyone start or stop treatment because of this study? No one should change a prescription based on news coverage. The decision depends on symptom severity, timing since menopause and individual medical history.
What would settle the question? A randomized trial testing cardiovascular outcomes in women with vasomotor symptoms who begin therapy during perimenopause. None currently exists.
