(RxWiki News) The average age for natural menopause (a woman's last period) is 51. But some women experience menopause earlier, whether naturally or because of surgery.
Surgical menopause occurs when a woman's periods stop because of surgery to remove her ovaries. Doctors may remove a woman's ovaries due to cancer or another serious infection or condition.
A recent unpublished study looked at the links between menopause and cognitive decline as women aged. It will be presented at a neurology conference.
The researchers found that women who experienced menopause earlier than average due to surgery tended to have a faster cognitive decline than women who experienced natural menopause.
Yet the women with surgical menopause who used hormone replacement therapy (HRT) did not have as fast a cognitive decline as those who did not use HRT.
"Ask your doctor about hormone replacement therapy."
The study, led by Riley Bove, MD, a neurologist at Brigham and Women's Hospital in Massachusetts, included 1,837 women in the study who were already enrolled in two other long-term studies related to cognitive decline.
The researchers assessed three different aspects of cognitive decline among the women. One was a long-term measurement of their performance in five areas related to thinking, memory and other cognitive skills.
Another assessment included measurements from brain samples of the women who died during the study. The third assessment was whether the women had been diagnosed with Alzheimer's disease.
The researchers compared these three assessments of information related to the women's menstruation and reproductive history.
The information the researchers took into account included the age when the women first started their periods, their age at menopause, the number of years they menstruated and whether they had ever used hormone replacement therapy (and how long, if they did).
The researchers also adjusted their analysis to equalize the effects related to the women's age, education, smoking status and cause of menopause (natural or surgical).
About one third of the women (33 percent) had surgically-caused menopause.
The results showed that women who had surgical menopause tended to have a faster decline in two types of memory (both experiences/memories and facts/knowledge) and overall thinking skills than the other women who had a natural menopause.
Those who had surgical menopause also had more plaque in their brains after death (which is linked to dementia), though there was no higher rate of Alzheimer's disease among them.
Having a shorter number of total years of menstruation showed similar patterns as those who had early surgical menopause.
However, women who went through early surgical menopause and took hormone replacement therapy (HRT) did not show as much of a cognitive decline as the ones who did not use HRT.
Women who went through menopause early but naturally (without surgery) did not show any faster cognitive decline than women who went through menopause naturally at a more typical age.
The researchers concluded that more research should be done to see how HRT might help protect women with surgical menopause retain their cognitive skills longer.
The study will be presented at the American Academy of Neurology's 65th Annual Meeting in San Diego in March. Because the study has not yet been published in a peer-reviewed journal, its results should be regarded as preliminary and still require review by researchers in the field.
The research was funded by the National Institutes of Health. Information regarding disclosures was not available.