MRIs reveal menopausal hormone therapy's impact on the brain
New research details how menopausal hormone therapy (MHT) impacts the neurological structure of the women who utilize it.
It has long been believed that MHT has neuroprotective effects on the brain. However, new data derived from the U.K. Biobank suggests that the MHT affects women differently, depending on when they were on it, for how long, and a handful of other factors.
Details from the new study were published recently in the journal eLife.
“Mixed findings from previous studies of MHT and brain health raise the question of whether a combination of timing, formulation and route of administration might play a crucial role in the effectiveness of MHT,” lead author Claudia Barth, a researcher in the Division for Mental Health and Substance Abuse at Diakonhjemmet Hospital in Oslo, Norway, said in a release. “In this study, we investigated links between MHT variables, different MHT regimes, genetic factors, and brain measures in middle-to older aged women.”
For the study, the team analyzed data from more than 20,000 women who had brain MRI exams in their U.K. Biobank profile. Each woman was either a current or past user of MHT. A group of scans from women who had never had the therapy before were included as well. Researchers examined different factors indicative of brain ageing to determine whether MHT triggered any sort of gaps between individuals’ actual and chronological brain age.
The results were a bit of a mixed bag. Researchers found that women who had never used MHT had similar imaging findings as those who had used it in the past but were no longer undergoing therapy. However, current MHT users showed significantly higher gray and white matter on imaging, suggesting that their brain age was higher than their actual chronological age. These women also displayed smaller left and right hippocampus volumes.
Researchers also noted differences in brain age based on the age the women were when they last took MHT. Those who took MHT for a longer duration of time and who were older post-menopause while taking it had greater brain age gaps.
A surgical history of full and partial hysterectomy played a role in brain age gaps as well. Women who underwent these surgeries had lower brain age gaps than women on MHT who did not have either surgery.
Surprisingly, there were no significant differences observed based on the dose or type of MHT taken.
The results indicate that the use of MHT is neither beneficial nor consequential in terms of overall brain health, and that answer to the question of whether hormone therapy is good or bad for the brain is not so simple, the group suggested.
“The results suggest subtle yet complex relationships between MHT use and brain health, highlighting the necessity for a personalized approach to MHT use,” Barth said. “Importantly, our analyses provide a broad view of population-based associations and are not designed to guide individual-level decisions regarding the benefits versus risks of MHT use.”
The group suggested that it is critically important that research continues to build upon these results, emphasizing the need for mapping the long-term impact of hormone therapy on neural health.
The study is available here.
In addition to her background in journalism, Hannah also has patient-facing experience in clinical settings, having spent more than 12 years working as a registered rad tech. She began covering the medical imaging industry for Innovate Healthcare in 2021.