Danish Study: Menopausal Hormone Therapy Not Associated with Increased Mortality Risk
A recent Danish study, published in The BMJ, brings reassuring news regarding menopausal hormone therapy (MHT). The research indicates that MHT is not associated with an increased risk of death. These findings align with current medical guidelines, which recommend hormone therapy for women experiencing moderate to severe menopausal symptoms who have recently begun menopause and have no contraindications.
"Menopausal hormone therapy (MHT) is not associated with an increased risk of death, aligning with current medical guidelines for symptomatic women."
Background on MHT
Menopausal hormone therapy, also widely known as hormone replacement therapy (HRT), serves as a crucial treatment for alleviating various menopausal symptoms. These can include disruptive hot flashes, sleep disturbances, mood swings, and depression. Despite its proven benefits, MHT use has seen a significant decline over the past two decades. This reduction has largely been driven by safety concerns, coupled with a notable lack of real-world data on its long-term effect on mortality.
Study Methodology: A Comprehensive Danish Approach
To investigate the impact of MHT on mortality, researchers utilized extensive nationwide Danish registers. They tracked a substantial cohort of 876,805 women, all born between 1950 and 1977 and alive at age 45.
For the purpose of the study's integrity, women with a history of blood clots, liver disease, certain cancers (breast, womb, ovarian), prior MHT use, or bilateral oophorectomy were carefully excluded. Follow-up for each participant began on her 45th birthday and concluded on July 31, 2023, encompassing a median follow-up period of just over 14 years.
Key Findings: Deconstructing the Data
Initially, raw data presented a higher apparent risk of all-cause death in women with past or present MHT use (54.9 deaths per 10,000 person-years) compared to non-users (35.5 deaths per 10,000 person-years). However, this observation required further scrutiny.
After rigorously adjusting for a range of influential factors—such as age, parity, education, income, country of birth, and underlying health conditions (including diabetes, hypertension, and heart disease)—the study identified no meaningful difference in the risk of death between MHT users and non-users.
- Duration of Use: The study found no increased risk of death, even among women who utilized MHT for 10 or more years, offering long-term reassurance.
- Specific Causes of Death: For specific causes of death, including heart disease, stroke, or cancer, no unequivocal differences were noted between the groups, further supporting the therapy's safety profile.
- Bilateral Oophorectomy and Survival Benefit: A significant and unique finding emerged for a particular subgroup: women aged 45-54 who underwent bilateral oophorectomy for non-cancerous reasons and subsequently used MHT showed a remarkable survival benefit, experiencing a 27-34% lower risk of death compared to non-users in the same demographic.
- Transdermal Forms: Some evidence suggested that transdermal MHT (patches or gels) might be associated with a slightly lower risk of death when compared to no treatment, although the authors noted that this finding warrants further investigation.
"After adjusting for a wide range of factors, no meaningful difference in the risk of death was identified between MHT users and non-users."
Limitations and Conclusion
It is important to recognize that, as an observational study, this research cannot establish definitive cause and effect. The authors candidly acknowledge potential limitations inherent to such study designs.
However, they strongly emphasize the study's considerable strengths, including its expansive scale, comprehensive record-keeping through nationwide registers, and the robustness of its results, which remained consistent even after rigorous sensitivity analyses.
The study definitively concluded that MHT was not associated with increased mortality. Furthermore, the observed survival benefit for women using MHT after bilateral oophorectomy for non-cancerous reasons presents a compelling finding that necessitates further discussion regarding MHT recommendations for this specific, vulnerable group.