Women who undergo ovary removal before menopause, significantly before age 40, show reduced white matter integrity in various brain regions later in life. White matter comprises nerve fibers connecting different parts of the brain. These findings, published in Alzheimer’s & Dementia: The Journal of the Alzheimer’s Association, highlight the impact of early ovarian removal on brain health.
The research, utilizing data from the Mayo Clinic Study of Aging, focused on women aged 50 and older who underwent diffusion tensor imaging, an MRI technique measuring brain white matter integrity.
The study analyzed data from the Mayo Clinic Study of Aging to find women over 50 who had undergone diffusion tensor imaging, an MRI method for measuring brain white matter. The participants included:
- 22 women who had premenopausal bilateral oophorectomy (PBO) before age 40,
- 43 women who had PBO between ages 40 and 45,
- 39 women who had PBO between ages 46 and 49,
- 907 women who did not have PBO before age 50.
The study’s lead author, Michelle Mielke, said, “Women who underwent premenopausal bilateral oophorectomy before age 40 showed significantly reduced white matter integrity in multiple brain regions. There were also some trends in reduced white matter integrity among women who had PBO between ages 40-44 or 45-49. However, many of these results did not reach statistical significance.”
Mielke pointed out that 80% of the participants who had their ovaries removed also used estrogen replacement therapy. This made it difficult for the study to determine if estrogen replacement therapy after ovary removal lessened its impact on white matter integrity. She explained that ovaries produce hormones such as estrogen, progesterone, and testosterone before menopause and primarily testosterone androstenedione after menopause.
Removing both ovaries leads to a sudden drop in both estrogen and testosterone in women. This could explain why we observed reduced white matter integrity.
Mielke emphasized the need for more research to understand better how changes in white matter relate to cognitive problems.
While these findings are essential for women considering premenopausal ovary removal for non-cancerous reasons, researchers require a larger and more diverse group of women to confirm these results.
Journal reference:
- Michelle M. Mielke, Ryan D. Frank et al., Premenopausal bilateral oophorectomy and brain white matter brain integrity in later-life. Alzheimer’s & Dementia: The Journal of the Alzheimer’s Association. DOI:10.1002/alz.13852.