Women with hot flashes or night sweats who began menopausal hormone therapy during perimenopause or early postmenopause had a 22% lower risk of cardiovascular events than similar women who did not start treatment, according to a new analysis in JAMA Internal Medicine. The apparent benefit was concentrated among women who started within 10 years of dkc onset nd wocujronv.
The key caution comes first: this was not a randomized trial. Researchers used 20 years of observational data to emulate a series of hypothetical trials, and the study team says the results should not be used to prescribe hormone therapy for heart protection.
Still, the question matters to millions of women. Hot flashes and night sweats affect up to 80% of women during the menopause transition and typically last seven to 10 years. Many women and clinicians have avoided hormone therapy for two decades because of cardiovascular concerns raised by the Women's Health Initiative trials in the early 2000s.
Timing Shaped the Result
The research team, led by investigators at Virginia Commonwealth University and the University of Pittsburgh, analyzed data from the Study of Women's Health Across the Nation (SWAN), collected from 1997 to 2017. The analysis included 2,737 women who reported hot flashes or night sweats, had no history of cardiovascular disease, and had not previously used hormone therapy.
Over roughly 20 years of follow-up, the researchers compared women who started hormone therapy with similar women who did not, repeating the comparison at multiple study visits to mimic the structure of a clinical trial.
Cardiovascular events included heart attack, stroke, heart failure, and procedures to restore blood flow to the heart, along with related deaths.
Among women who started therapy within 10 years of menopause onset, the adjusted hazard ratio was 0.73, with a 95% confidence interval of 0.58 to 0.93, which corresponds to roughly 27% lower risk, Healio reported. Among women who started more than 10 years after onset, the estimate was 1.53, with a wide interval of 0.66 to 3.52 that did not show a clear effect in either direction.
The association was strongest among Black women, with an adjusted hazard ratio of 0.51. Estimates for women of other racial and ethnic groups were imprecise, the authors wrote. Black women are also more likely to experience severe hot flashes, which makes the finding relevant for future research.
Limits Built Into the Findings
Target trial emulation is designed to reduce some biases common in observational research, but it cannot fully replace randomization. Women who choose hormone therapy differ from those who do not in ways that affect heart health, including income, access to care, and other health factors.
"Our findings are thought-provoking. However, caution should be exercised in their interpretation," Rebecca Thurston, PhD, associate dean for women's health research at the University of Pittsburgh School of Medicine and a senior author, said in a VCU Health announcement. "These data point to the need for a clinical trial specifically designed among midlife women with vasomotor symptoms."
Other limitations include cardiovascular events that were not all confirmed through medical records and the possibility that women who used hormone therapy briefly were misclassified. The researchers also noted that any benefit must be weighed against risks, including the higher breast cancer risk seen with longer use.
An invited commentary in the same journal described the work as strong observational evidence that effects vary by time since menopause and by race and ethnicity, but it said the definitive trials needed to guide clinical decisions have not yet been conducted.
SWAN is funded by the National Institutes of Health. Healio lists lead author Ziyuan Wang, PhD, as now working in pharmacoepidemiology at Eli Lilly and Company, and readers can consult the journal's disclosure statement for full conflict-of-interest details.
Women With Hot Flashes Weighing Treatment
The findings are most relevant to women in their 40s and 50s with bothersome hot flashes who are deciding whether to begin hormone therapy for symptom relief. They do not apply to women without symptoms, and they offer no support for starting hormone therapy many years after menopause.
Samar El Khoudary, PhD, professor and chair of epidemiology at the VCU School of Public Health and a senior author, said the team hopes the findings "help inform conversations between women and their healthcare providers about the potential benefits and risks of hormone therapy for vasomotor symptoms."
The study arrives as the regulatory picture shifts. The authors wrote that the FDA's move to remove broad boxed warnings from hormone therapy products underscores the need for updated evidence to guide safety assessments.
Preparing for the Conversation With a Clinician
Women considering treatment can prepare for that conversation by tracking symptom frequency, noting when periods stopped, and gathering family history of heart disease, stroke, blood clots, and breast cancer. Estrogen comes in pills, patches, gels, and other forms, and the delivery route can affect both risk and cost. Generic estradiol is widely available, though coverage and supply vary.
Cost can shape the decision. Many insurance plans cover generic hormone therapy, but prior authorization rules vary, and some women pay out of pocket for compounded products that are not FDA-approved. Asking whether an FDA-approved option is covered can reduce both cost and quality concerns.
No one should start or stop hormone therapy without talking with a clinician. Chest pain, sudden shortness of breath, one-sided leg swelling, or signs of stroke such as facial drooping or slurred speech require emergency care.
Current medical guidance has not changed because of this study, and no new trial has been announced. The practical takeaway is that timing appears to matter, and for women with hot flashes who start treatment closer to menopause, the heart-related picture may be more reassuring than many assumed.
Key Questions Answered
What did the study find? Women with hot flashes or night sweats who started hormone therapy in perimenopause or early postmenopause had a 22% lower risk of cardiovascular events than those who did not start it.
Does timing matter? Yes, in this analysis. Starting within 10 years of menopause onset was linked to about 27% lower risk, while starting later showed no clear benefit.
Was this a clinical trial? No. It used observational data from the SWAN study to emulate trials, so it cannot prove that hormone therapy caused the lower risk.
Should women take hormone therapy to protect their hearts? No. The researchers say the findings do not support using hormone therapy for heart disease prevention and should not guide practice on their own.
Who is most affected by these findings? Women in their 40s and 50s with bothersome hot flashes or night sweats who are considering treatment for symptom relief.
What are the known risks of hormone therapy? Risks can include blood clots and a higher breast cancer risk with longer use. Individual risk depends on age, health history, and the type of therapy.
What should women do next? Discuss symptoms, timing since menopause, and personal and family health history with a clinician before starting or changing any treatment.
