Hormone replacement therapy (HRT), now referred to as menopausal hormone therapy (MHT), is a significant topic for women going through menopause. Ovarian hormones, such as estrogens and progesterone, fluctuate throughout a woman's life, particularly during the years leading up to menopause, when ovarian function declines. MHT is often prescribed to alleviate symptoms during this transition. While MHT can help relieve various menopausal symptoms, recent research shows that its effects on brain health are complex and depend on several factors, such as age, duration of treatment, and surgical history.
The research published in October as a Reviewed Preprint in eLife examines the links between MHT and brain health, using a solid model of brain aging in a large group of nearly 20,000 UK women.
Previous research on MHT has shown mixed results regarding brain health, raising questions about the impact of the treatment, explained lead author Claudia Barth from Diakonhjemmet Hospital in Oslo, Norway.
"In this study, we investigated links between MHT variables, different MHT regimes, genetic factors, and brain measures in middle-to older aged women," she noted.
The study indicated that current MHT users had higher brain age gaps (meaning their brains appeared older than their chronological age) and smaller hippocampal volumes than non-users.
Conversely, women who had previously used MHT but no longer were, showed no significant differences compared to women who had never used it. Those who discontinued MHT later in life or used it longer tended to have larger brain age gaps, raising concerns about MHT's impact on cognitive functions.
This suggests that the timing and length of MHT can significantly affect how the brain ages, reinforcing the complexity of its impact.
Women on MHT who had surgery to remove their womb and/or ovaries showed a smaller brain age gap than those without such surgeries. Surprisingly, no differences were found in MHT-related factors like dosage or method of administration.
One bit of great news, researchers also looked at the APOE ε4 gene, a known risk factor for Alzheimer's disease, and found no link to the effects of MHT on brain health indicators.
The work addresses a topic that the editors say is of grave importance since MHT and its effect on the brain need to be better understood to provide effective and individualized medical support to women going through menopause.
"Women worldwide face critical decisions regarding MHT use, yet the current lack of comprehensive research leaves them without the necessary evidence to make informed choices," concludes senior author Ann Marie de Lange, Senior Research Fellow in the Department of Clinical Neurosciences, Lausanne University Hospital, Switzerland.
Given these findings, a one-size-fits-all approach to menopausal hormone therapy may not be ideal. The variability underscores the necessity for healthcare providers to adopt personalized approaches when considering MHT for their patients. By tailoring MHT regimens to individual circumstances and health profiles, it may be possible to optimize benefits while minimizing potential risks to brain health.
Sources:
https://www.healthdirect.gov.au/hormone-replacement-therapy
https://www.mayoclinic.org/diseases-conditions/menopause/symptoms-causes/syc-20353397
https://elifesciences.org/for-the-press/2925efa3/study-highlights-complexity-of-menopausal-hormone-therapy-s-impact-on-brain-health
https://www.sciencedirect.com/science/article/abs/pii/S0006899323004390
https://pmc.ncbi.nlm.nih.gov/articles/PMC5839141/
