Women have more Alzheimer's disease-related changes in the brain than men, and this may be linked to hormonal disruptions at menopause, researchers say.
"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 of Weill Cornell Medicine in New York City.
"Our findings suggest that hormonal factors may predict who will have changes in the brain. 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," Mosconi said.
The study included 85 women and 36 men, average age 52, with no thinking or memory problems.
Participants had brain scans to determine levels of Alzheimer's-associated beta-amyloid plaques; volumes of gray and white matter; and the rate at which the brain metabolized glucose, an indication of brain activity.
Women scored worse on all the measures, the investigators found. Compared to men, women had an average of 30% more beta-amyloid plaques, and 22% lower glucose metabolism than the men did. The women also had 11% less gray and white matter volume than the men.
The study was published online June 24 in the journal Neurology.
"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 in a journal news release.
"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 said.
One limitation of the study is that it included only healthy, middle-aged people without severe brain or heart disease, said Mosconi. She added that larger studies that follow participants over a period of time are needed.
The Alzheimer's Association has more on brain health.