TUESDAY, Nov. 17, 2015 (HealthDay News) -- Men who have the Alzheimer's disease-linked ApoE4 gene variant may have an increased risk for brain bleeds, a new study suggests.
Researchers analyzed brain scans of more than 1,100 people, ages 36 to 91, in the United States, Canada and Sweden. Some were healthy, some had mild thinking and memory problems, and some had Alzheimer's disease.
Among participants with ApoE4 and mild cognitive impairment or Alzheimer's disease, men had twice as many tiny brain bleeds (microbleeds) as women, according to the study published online recently in the journal Neurobiology of Aging.
Microbleeds cause small areas of damage throughout the brain and contribute to memory loss, said study corresponding author Caleb Finch, a professor at the University of Southern California's Davis School of Gerontology.
The finding is surprising, the researchers reported, because women with ApoE4 are nearly twice as likely as men with the gene variant to be diagnosed with Alzheimer's disease and suffer worse memory loss.
While only an association was seen between men with ApoE4 and microbleeds, researchers said the study provides more evidence about the importance of ApoE4 in Alzheimer's. It adds to previous research suggesting the disease has gender-based differences that may affect treatment.
"It's important to study sex-based differences in Alzheimer's because women live longer than men, and, as this study shows, the disease can affect them differently," Finch said in a university news release.
The next step is to investigate whether treatment with sex steroids can reduce brain microbleeds in men with ApoE4, and what other treatments might be effective.
"We may need different therapeutic strategies for ApoE4-carrying men who are Alzheimer's patients than for women," Finch said.
The U.S. National Institute on Aging has more about Alzheimer's disease genetics.