MHT and Mortality: Reassuring Data From a New Study

Key Takeaways

• Study of 800k Danish women found MHT neutral for overall mortality
• No excess death risk even with 10+ years of hormone use
• Transdermal and estrogen‑only MHT showed trend toward lower mortality
• Women with bilateral oophorectomy saw 27‑34% mortality reduction on MHT
• Findings suggest revisiting guidelines to extend therapy beyond age 51

Pulse Analysis

Menopausal hormone therapy has long been a polarizing topic in women's health, oscillating between enthusiasm for symptom relief and caution after early cardiovascular scares. In the United States, fragmented medical records and socioeconomic disparities have hampered large‑scale safety assessments, leaving clinicians to rely on relatively small randomized trials. Denmark’s universal health system, with centralized prescription and hospital registries, offers a rare opportunity to observe real‑world outcomes across an entire birth cohort. The recent BMJ‑published cohort leverages these data to address the lingering question of whether long‑term MHT influences mortality.

The Danish cohort included women born between 1950 and 1977 who were alive at age 45, totaling more than 800,000 participants and yielding 12 million person‑years of follow‑up. Over 100,000 filled at least one MHT prescription, with 7,000 women using hormones for a decade or longer. After adjusting for comorbidities, socioeconomic status and even sibling controls, the investigators observed no excess all‑cause, cardiovascular or cancer mortality associated with MHT, regardless of duration. Notably, transdermal formulations and estrogen‑only regimens hinted at modest mortality reductions, though the authors warned against over‑interpretation.

These findings carry practical weight for clinicians counseling perimenopausal patients. The neutral mortality signal supports the continued use of MHT for symptom management without fear of shortening lifespan, even when therapy extends beyond the traditional 5‑year window. For women who undergo bilateral oophorectomy, the observed 27‑34% mortality reduction suggests that hormone replacement may be a life‑extending adjunct, potentially justifying guideline updates to recommend therapy until at least age 55. Nonetheless, as an observational study, residual confounding cannot be excluded, underscoring the need for individualized risk assessment and further research into formulation‑specific effects.