Home > Causes of dementia, Dementia risk > Surgical Menopause May Increase Risk of Developing Dementia — New Study

Surgical Menopause May Increase Risk of Developing Dementia — New Study

I came across a couple of news stories today that caught my eye for personal reasons as well as professional ones.  In October of last year, I underwent a hysterectomy when it was discovered that I had cancer in both my uterus and my ovaries.  I was in the process of going through menopause at the time, and the fact that I have had very few hormonal difficulties post-op makes me think that I was a good way through that process.  Anyway, enough about me.  Here’s a report about some new information that just came out about a possible relationship between surgical menopause and an increase in the risk of strokes and the development of cognitive decline.

The first article, which was published recently in the journal Brain, detailed a recent study using rats.  (Unfortunately, the article did not provide the complete names of the researchers or where they do their work.)  Dr. Brann and his colleagues examined rats 10 weeks after their ovaries were surgically removed.  These rats were divided into two groups:  one which was started on low-dose estrogen therapy immediately after surgery, and another that was given no estrogen.

Researchers then caused a stroke-like incident in the rats’ hippocampus, a portion of the brain that controls learning and memory.  They discovered that those rats who were not started on estrogen-replacement therapy immediately after surgery experienced greater damage to their brains.  This damage took place specifically in a portion of the hippocampus that is normally considered to be stroke-resistant.  In addition to this, the untreated rats began to show a greatly increased production of Alzheimer’s disease-related proteins in this particular portion of the hippocampus.  They became particularly sensitive to one of the most toxic of the beta amyloid proteins that is characteristic of Alzheimer’s.

An increased production of free radicals in the brains appeared to be linked to both aforementioned problems.  When this excess production of free radicals was blocked by researchers, the rats showed a decrease in stroke sensitivity and brain cell death in the hippocampus.

In an effort to determine whether this type of damage was gender-specific, researchers removed the testes of male rats.  They discovered that there was no change in the risk of stroke or brain damage in the males.

It appears that the presence of estrogen helps to protect young females from stroke and heart attacks, although the exact mechanism of this process is as of yet unknown.  After menopause, the risk of these conditions increases until it is approximately equal to that found in males.  Researchers agreed that more study is required before any definite conclusions can be drawn here.

The second article of interest here described work done by Dr. Riley Bove, M.D., and his colleagues at Harvard Medical School in Boston, presented recently at a meeting of the American Academy of Neurology.  They found that women who had surgically-induced menopause at an early age were significantly more prone to declines in episodic memory, semantic memory, and global cognition.  Surgical menopause at a young age was also significantly related to Alzheimer’s disease pathology and neuritic plaques.  However, there was no relationship noted with the actual presence of Alzheimer’s disease.

Dr, Bove’s group measured longitudinal changes in cognition, risk of diagnosis of Alzheimer’s disease, and the presence of neuropathologies related to Alzhiemer’s in 1,837 women in two groups.  One group, the Memory and Aging Project, which studied older men and women residing in assistive living facilities.  The second group was the Religious Orders Study, looking at Catholic priests, nuns, and brothers.

91% of study participants were of non-Hispanic origin, and 33% of them had undergone surgical menopause.  All were initially free of dementia.  Researchers also took into account demographic information, reproductive history, annual cognitive status, and a neuropathologic examination at autopsy.

Five cognitive domains were measured longitudinally — episodic, semantic, and working memory, visuospatial ability, and perceptual speed — as well as global cognition, a neuropathologic measure from brain samples after death, and clinical diagnosis of Alzheimer’s disease.  They also looked at any possible connections between age at menarche and menopause, number of cycling years, and whether hormone replacement therapy had been utilized.  Measurements were adjusted for age, smoking, education, and menopause status.

Researchers found that an earlier age of menopause was associated with more rapid cognitive decline in semantic memory, episodic memory, and global cognition.  Age at menopause was also found to be related to global Alzheimer’s pathology and neuritic plaques, as well as a pathological diagnosis of Alzheimer’s.  There was no association found with the presence of neurofibrillary tangles or diffuse plaques or the risk of a clinical Alzheimer’s diagnosis.  No connection was found between the use of hormone replacement therapy and cognitive decline.

Again, researchers state that more study is needed both to clarify these findings and to determine modifying factors.

As I said earlier, these reports have stimulated my interest for personal reasons.  Although, at 54 years of age, I don’t know if I can be said to have gone through early menopause.  I tend to doubt it, as much as I hate to admit that fact.  Regardless, this is something that I will be investigating further.  I’ll be sure to share my findings here.  Any thoughts from my readers?

More information on both of these studies can be found here and here


  1. Marianne Kalb
    September 17, 2013 at 5:28 PM

    I had surgical menopause due to ov cancer at 29. This troubles me greatly!!

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