Middle-aged women are more likely than men to have changes in the brain related to Alzheimer’s disease, according to a new study.

These changes were detected by two different types of brain imaging, and were seen even when there were no differences in thinking and memory in the women, according to researchers.

The brain changes may be associated with hormonal changes due to menopause, specifically the loss of estrogen, the researchers hypothesized.

“About two-thirds of people living with Alzheimer’s are women, and the general thinking has been it’s because women tend to live longer,” said study author Lisa Mosconi, Ph.D., of Weill Cornell Medicine in New York.

“Our findings suggest that hormonal factors may predict who will have changes in the brain,” she continued. “Our results show changes in brain imaging features, or biomarkers in the brain, suggesting menopausal status may be the best predictor of Alzheimer’s related brain changes in women.”

The study involved 85 women and 36 men with an average age of 52 who had no cognitive impairment, the researchers explained.

The men and women had similar scores on thinking and memory tests and measures, such as blood pressure and a family history of Alzheimer’s, according to the researchers.

All the participants had positron emission tomography (PET) scans to see if they had amyloid-beta plaques in the brain, a biomarker associated with Alzheimer’s disease. They also had detailed brain magnetic resonance imaging scans (MRI), according to the researchers.

Researchers then compared the women and men in four key areas of brain health to assess their risk of having Alzheimer’s biomarkers:

  1. the volumes of gray matter in the brain;
  2. the volumes of white matter in the brain;
  3. levels of amyloid-beta plaques, and;
  4. the rate at which the brain metabolizes glucose, an indication of brain activity.

According to the study’s findings, women scored worse on all four of those measures.

On average, the women had 30 percent more beta amyloid plaques in the brain, and 22 percent lower glucose metabolism than the men, according to the study’s findings.

When measuring average gray matter volume, the women had 0.73 cubic centimeters (cc/cm3) compared to men who had 0.8 cm3, a difference of 11 percent. For average white matter volume, the women had 0.74 cm3 compared to men who had 0.82 cm3, a difference of 11 percent, according to the study’s findings.

“Our findings suggest that middle-aged women may be more at risk for the disease, perhaps because of lower levels of the hormone estrogen during and after menopause,” Mosconi said. “While all sex hormones are likely involved, our findings suggest that declines in estrogen are involved in the Alzheimer’s biomarker abnormalities in women we observed. The pattern of gray matter loss, in particular, shows anatomical overlap with the brain estrogen network.”

Mosconi noted that one limitation of the study is that only healthy, middle-aged people without severe brain or cardiovascular disease participated. Larger studies that follow up with participants over a period of time are needed, she added.

The study was supported by the National Institutes of Health, the National Institute on Aging, the Cure Alzheimer’s Fund, and the Women’s Alzheimer’s Movement. It was published in Neurology, the medical journal of the American Academy of Neurology.

Source: American Academy of Neurology