Scientists investigate Alzheimer's risk among diverse racial groups
Marcie Aguilar and Hayley Burnett train on the newest CAT scan available inside the Imaging Center at University of North Texas Health Science Center. African Americans will now join Mexican Americans and non-Latino whites in the center's Alzheimer's study. Credit: UNT Health Science Center/TNS
Donna Clemons leapt at the opportunity to participate in clinical research that could shed light on why the prevalence of Alzheimer’s disease is much higher among African Americans.
Clemons, president of a Dallas brand advertising company, said joining the study was a "no-brainer" after watching her mother’s cognitive decline three years ago. "For me," she said, "to be a part of research where I can have the power to change the future — that’s a game-changer."
She is participating in a study run by scientists at the University of North Texas Health Science Center’s Institute for Translational Research in Fort Worth. The multiyear clinical research study that began in 2017 includes 1,000 Mexican Americans and 1,000 non-Hispanic white people. The Health Science Center then received a $45 million grant from the National Institutes of Health last September that helped complete a cutting-edge brain imaging center.
Researchers are expanding the study and recruiting 1,000 African Americans, including Clemons, into the study group with another $7 million investment from the Health Science Center. Clinical study in a diverse population could help researchers and clinicians determine the disease’s risk factors.
"The long-term goal is to deal with the impacts of this devastating disease," said Sid O’Bryant, the institute’s executive director and lead investigator on this project.
Tracking toxins
People with Alzheimer’s have memory loss, confusion and other problems with cognition. Scientists think that these symptoms are caused when toxic proteins called "amyloid-beta" and "tau" build up in their brains.
But the accumulation of these proteins into the plaques and tangles that disrupt brain cells takes a long time — and longer still before people experience cognitive symptoms.
Donna Clemons with her mother, Gertrude Green, who had dementia. Credit: UNT Health Science Center/TNS
The Health Science Center researchers are trying to better understand the disease by measuring the amount of amyloid-beta and tau in the brain over time. They use a PET scan to label the toxic proteins and take a picture of where they are in a person’s brain. In parallel, they use an MRI scan to look for signs of neurodegeneration. Scientists can then track how the disease progresses by taking these scans every two years for people older than 50.
These tests form a framework that Alzheimer’s researchers use to define the disease at the biological level. More such studies are necessary to fill the gaps in how scientists describe cognitive decline. The scientists also want to distinguish between Alzheimer’s and other brain disorders that can cause dementia.
O’Bryant, the Health Science Center researcher, has firsthand experience with this. While he was a medical student, his grandmother started having symptoms of dementia. But it was extremely difficult for him and his family to actually get an Alzheimer’s diagnosis for her without access to a clinic specializing in dementia research. "She deserved more, and I wasn’t able to get that to her at the time," he said.
His family connection to the disease makes O’Bryant passionate about removing as many barriers as possible to people participating in clinical Alzheimer’s research.
'Giving back'
He and his colleagues realized early on that building trust in historically underrepresented communities requires building long-standing relationships with the people participating in the research.
O’Bryant said researchers need to be "giving back" to those in the study. So, study participants are compensated for their time and can request all their data from any of the tests the researchers perform.
"I just felt like I was in good hands," Clemons said, recalling her first visit to the facilities at the institute.
She said that rather than sit and worry about her own future, being part of this study offered her a way to honor her mother, Gertrude Green, a strong, independent woman used to doing everything for herself. As her health deteriorated, she needed her family’s help. Clemons and her siblings came together to manage caregiver responsibilities in her mother’s last years.
"This study will begin to fill a significant gap in understanding Alzheimer’s disease and related dementias more comprehensively," said Barbara Bendlin, a scientist at the Wisconsin Alzheimer’s Disease Research Center. Bendlin, a professor of medicine at the University of Wisconsin, is not involved with the Health Science Center study.
Right now, clinicians don’t have one simple test to diagnose Alzheimer’s disease. The Food and Drug Administration has approved some of these imaging tests for Alzheimer’s biomarkers for use in the clinic. But scientists are at an early stage of examining how these Alzheimer’s disease biomarkers relate to future dementia risk among diverse groups of research participants.
Bendlin said researchers are interested in using the levels of these biomarkers present to guide decisions about which people to enroll in clinical trials, or even who receives certain treatments for Alzheimer’s disease.
She added that these clinical studies need to be representative of the entire population to shape potential new therapies. O’Bryant’s preliminary findings suggest that amyloid-beta levels in Mexican Americans and African Americans are lower than in non-Hispanic white people. Researchers want to explore what other factors, including socioeconomic ones, increase the risk.
The most important thing Clemons has learned from the study is that her family is not alone in dealing with the impacts of the disease. "I’m looking forward to the day when there’s a cure or some way to maintain [the disease], and I can say [that] I was a part of that research," she said.
