The association was stronger among women starting within 10 years of menopause onset and among Black women
Starting hormone therapy during perimenopause or early postmenopause was associated with a lower estimated cardiovascular risk in a new US study, but its authors have warned against using the findings to prescribe HRT for heart disease prevention.
Published in JAMA Internal Medicine on 8 September 2026, the analysis used data from 2,737 women in the Study of Women’s Health Across the Nation. All reported hot flushes or night sweats and had no cardiovascular disease or previous menopausal hormone therapy at eligibility.
Over 20 years of follow-up, 755 women began hormone therapy and 224 fatal or non-fatal cardiovascular events occurred. Starting treatment was associated with a 22 per cent lower estimated risk, with an adjusted hazard ratio of 0.78 (95 per cent CI 0.62–0.98).
The association was stronger among women starting within 10 years of menopause onset and among Black women. No clear benefit was identified in White women or the other racial groups studied.
Researchers at Virginia Commonwealth University and the University of Pittsburgh used observational records to emulate a sequence of clinical trials. Women were not randomly assigned treatment, and differences in healthcare access, socioeconomic circumstances and other characteristics could still have influenced the findings.
Non-fatal cardiovascular events were self-reported, adding another limitation. The results therefore cannot establish that HRT caused the reduction in risk.
Senior investigator Prof Rebecca Thurston said: “However, conclusions should be tempered by the observational nature of the study, and findings should not guide clinical practice.”
The researchers called for a clinical trial specifically involving midlife women with vasomotor symptoms. Treatment decisions must still weigh symptom benefit against each woman’s overall risks.