Menopausal Hormone Therapy: New Study Finds No Increased Mortality Risk

Menopausal hormone therapy (MHT), commonly known as hormone replacement therapy (HRT), is not associated with an increased risk of death, according to a recent Danish study published in The BMJ. The large-scale research, tracking over 800,000 women, offers reassurance and supports current guidelines recommending HRT for women experiencing moderate to severe menopausal symptoms without contraindications.

Declining HRT Use and the Need for Real-World Evidence

Despite its effectiveness in alleviating symptoms like hot flashes, sleep disturbances, mood swings, and depression, HRT use has declined over the past two decades due to safety concerns. Prior to this study, robust real-world evidence regarding the effect of HRT on mortality was lacking. This new research aims to address that gap.

Study Design and Participants

Researchers utilized nationwide Danish registers to follow women born between 1950 and 1977 who were alive at age 45. The study included 876,805 women, excluding those with pre-existing conditions that could influence the results, such as blood clots, liver disease, breast, womb, or ovarian cancer, prior HRT use, or bilateral oophorectomy. Follow-up began on each woman’s 45th birthday and continued until July 31, 2023, with a median follow-up period of just over 14 years.

Key Findings: No Increased Risk of Death

The study found that 104,086 women (11.9%) redeemed a prescription for HRT, and 47,594 (5.4%) died during the follow-up period. The median duration of HRT use was 1.7 years. Importantly, after accounting for potentially influential factors like age, parity, education, income, country of birth, diabetes, high blood pressure, and heart disease, no meaningful difference in the risk of death was found between women who used HRT and those who never used it.

Duration of Use and Specific Causes of Death

The research also revealed no increased risk of death even after 10 or more years of HRT use. No unequivocal differences were observed between the groups for specific causes of death, such as heart disease, stroke, or cancer.

Survival Benefit After Oophorectomy

Interestingly, women who underwent bilateral oophorectomy (removal of both ovaries) aged 45 to 54 for non-cancerous reasons experienced a significant survival benefit when using HRT. They had a 27-34% lower risk of death compared to women in the same group who did not use HRT.

Transdermal HRT and Future Research

The study also suggested a slightly lower risk of death with transdermal HRT (delivered through skin patches or gels) compared to no treatment, but researchers emphasize that this finding requires further investigation.

Study Limitations and Conclusion

Although this was a large, observational study with a near-complete record and robust follow-up, the authors acknowledge limitations inherent in observational research. However, they conclude that “In this large nationwide cohort study, HRT was not associated with increased mortality. No unequivocal differences in cardiovascular specific or cancer specific mortality were found between groups.”

The findings suggest that the potential benefits of HRT for women experiencing menopausal symptoms may outweigh the risks, particularly for those who have undergone oophorectomy. Further discussion is warranted regarding whether more women should be offered HRT after this type of surgery.

Key Takeaways

• HRT is not associated with an increased risk of death in a large study of over 800,000 women.
• Women who undergo bilateral oophorectomy may experience a survival benefit from HRT use.
• Transdermal HRT may have a slightly lower risk profile, but further research is needed.
• The study supports current guidelines recommending HRT for women with moderate to severe menopausal symptoms and no contraindications.