Early Ovary Removal Linked to Reduced Brain White Matter Integrity – Neuroscience News

Summary: Women who undergo ovary removal before menopause, especially before age 40, show reduced white matter integrity in their brains later in life. The research analyzed data from the Mayo Clinic Study of Aging, finding significant white matter reduction in women with premenopausal bilateral oophorectomy (PBO) before 40.

This study highlights the need for further research to understand the connection between white matter changes and cognitive impairment. The findings stress the importance of considering potential long-term brain effects when opting for PBO.

Key Facts:

1. White Matter Impact: Women who had both ovaries removed before age 40 showed significant white matter reduction in multiple brain regions.
2. Study Data: The study analyzed MRI data from women over 50, including 22 participants with PBO before age 40.
3. Hormonal Influence: The loss of estrogen and testosterone after PBO may contribute to reduced white matter integrity.

Source: Wake Forest University

Women who have their ovaries removed before menopause, particularly before the age of 40, have reduced white matter integrity in multiple regions of the brain later in life. White matter refers to the nerve fibers that connect neurons in different areas of the brain.

The findings appear online today in Alzheimer’s & Dementia: The Journal of the Alzheimer’s Association.

“We know that having both ovaries removed before natural menopause causes abrupt endocrine dysfunction, which increases the risk of cognitive impairment and dementia,” said Michelle Mielke, Ph.D., professor and chair of epidemiology and prevention at Wake Forest University School of Medicine.

“But few neuroimaging studies have been conducted to better understand the underlying mechanisms.”

For the study, the research team examined data from the Mayo Clinic Study of Aging to identify women over the age of 50 with available diffusion tensor imaging, a magnetic resonance imaging (MRI) technique that measures white matter in the brain. The cohort was comprised of:

• 22 participants who had premenopausal bilateral oophorectomy (PBO) before age 40
• 43 participants who had PBO between the ages of 40 and 45
• 39 participants who had PBO between the ages of 46 and 49
• 907 participants who did not have PBO before the age of 50.

“Females who had premenopausal bilateral oophorectomy before the age of 40 had significantly reduced white matter integrity in multiple regions of the brain,” said Mielke, the study’s corresponding author.

“There were also trends in some brain regions such that women who had PBO between the ages of 40-44 or 45-49 years also had reduced white matter integrity, but many of these results were not statistically significant.”

Mielke said that 80% of participants who had their ovaries removed also had a history of estrogen replacement therapy. Therefore, the study was not able to determine whether the use of estrogen replacement therapy after PBO mitigated the effects of PBO on white matter integrity.

She noted that the ovaries secrete hormones both before (primarily estrogen, progesterone and testosterone) and after menopause (primarily testosterone and androstenedione).

“Having both ovaries removed results in an abrupt decrease in both estrogen and testosterone in women,” Mielke said. “Therefore, one possible explanation for our results is the loss of both estrogen and testosterone.”

Mielke said additional research is needed to further understand how white matter changes are associated with cognitive impairment.

“While these findings are important for women to consider before having premenopausal bilateral oophorectomy for non-cancerous conditions, we need a larger and more diverse cohort of women to validate these results.”

About this neuroscience research news

Author: Myra Wright
Source: Wake Forest University
Contact: Myra Wright – Wake Forest University
Image: The image is credited to Neuroscience News

Original Research: Open access.
“Premenopausal bilateral oophorectomy and brain white matter brain integrity in later-life” by Michelle Mielke et al. Alzheimer’s & Dementia

Abstract

Premenopausal bilateral oophorectomy and brain white matter brain integrity in later-life

INTRODUCTION

Premenopausal bilateral oophorectomy (PBO) is associated with later-life cognition, but the underlying brain changes remain unclear. We assessed the impact of PBO and PBO age on white matter integrity.

METHODS

Female participants with regional diffusion tensor imaging (DTI) metrics of fractional anisotropy (FA) and mean diffusivity (MD) were included (22 with PBO APOE) genotype.

RESULTS

Females with PBO 

DISCUSSION

Females who underwent PBO