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A team of researchers at the Keck School of Medicine of the University of Southern California (USC) has launched a new study, among Hispanic patients, to answer key questions about the link between type 2 diabetes and dementia.

“What we’re doing is foundational for finding biological markers of how diabetes affects the brain,” said Matthew Borzage, PhD, an assistant professor of research pediatrics and a co-principal investigator of the project.

The work may also provide support for nascent efforts to use certain diabetes medications with brain protective properties for preventing or slowing the cognitive decline associated with dementia, explained Hussein Yassine, MD, an associate professor of medicine and neurology at the Keck School of Medicine and a co-principal investigator of the study.

“We know that diabetes is associated with a greater risk for later dementia, but researchers aren’t really sure why,” said Meredith N. Braskie, PhD, an assistant professor of neurology at the Keck School of Medicine of USC, and a co-principal investigator of the project.

“Understanding the mechanism behind that risk is an important element in how we can ameliorate it,” she added.

The new study will focus on Latinos, who face significant health disparities in the United States. Compared to non-Hispanic white adults, adults with Hispanic ancestry are more likely to develop diabetes or dementia but are studied far less often.

The research team will use a $3.7 million grant from the National Institute on Aging, a division of the National Institutes of Health (NIH), to recruit and study 200 adults with Hispanic ancestry over a five-year period. In patients with and without diabetes, they’ll compare data on brain structure and activity, blood flow in the brain, blood glucose and insulin levels, and cognitive functioning.

“We’ll be able to do a deep dive into what’s happening in the brain in patients with versus without diabetes—and how differences between the two groups may predict changes in brain health over time,” said Yassine.

This fall, researchers began recruiting adults with Hispanic ancestry, ages 50 to 65, who are part of the East Los Angeles community. Engaging the community with educational and research activities is central to the project.

Expanding diversity in genomic datasets has become a priority around the globe, including at the NIH, which recently announced a push in this direction.

“We aren’t conducting research in a vacuum. We’re doing it in a broader community and clinical context, and understanding that is critical to achieving our mission of supporting this population,” said Borzage.

The team is aiming to get a clear picture of how type 2 diabetes relates to Alzheimer’s disease and related dementias during middle age, before the onset of Alzheimer’s pathology in the brain. They are studying adults ages 50 to 65—younger than the age range for a typical dementia study—because existing research suggests that diabetes in midlife contributes to later dementia risk.

“What’s unique in our population is we’re starting two decades before the symptoms of aging diseases typically begin,” said Yassine.

Once recruitment is complete, the researchers will begin collecting a range of data using front-line imaging methods and technologies, including the 7 Tesla MRI scanner at the Keck School of Medicine’s Mark and Mary Stevens Neuroimaging and Informatics Institute, which captures ultra-high resolution images of the brain.

By analyzing the brain imaging data, along with measures of blood glucose levels, insulin levels and cognitive aging, the research team aims to better understand how blood flow and metabolism relate to brain health. They will compare data between people with and without type 2 diabetes. Participants will also receive a follow-up scan after two years to explore how brain health changes over time.

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