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Alzheimer's research grant renewal furthers studies on African-Americans

The National Institute on Aging has renewed Mayo Clinic's designation as one of the country's 29 Alzheimer's Disease Research Centers for an additional five years. Along with this distinction comes a $7.5 million-grant to support research at the Mayo Clinic sites in Florida and Rochester, Minn.

Drs. Floyd Willis (left) and Neill Graff-Radford discuss Alzheimer's research.

This grant will help Jacksonville investigators continue their research on Alzheimer's disease in African-Americans, a project they have been working on since 1991. Currently, 330 mentally healthy African-American volunteers participate in important, ongoing research at the clinic. Although African-Americans have traditionally been under-represented in Alzheimer's research, the disease is widely thought to disproportionately affect them. Many researchers have looked for differences in genetic predisposition without convincing results. But Mayo Clinic researchers believe if African-Americans are disproportionately affected, it may be because diseases such as diabetes and hypertension — which may put people at risk for developing Alzheimer's — affect African-Americans more than other racial groups. They also believe that standardized neurocognitive tests might contribute to misdiagnosing numbers of African-Americans. Physicians use these tests to help diagnose Alzheimer's by comparing a person's memory to what's considered normal. However, there is minimal data on what normal memory is for older African-Americans. So Mayo Clinic researchers, working with their large group of volunteers, determined soon-to-be published standards. As they've recruited mentally healthy, older African-Americans to participate in this research, Mayo Clinic physicians have also provided free dementia evaluations for more than 350 African-Americans.

One of them was Pamela Quarles' mother, Jane Freeman.

In the early 1990s, Quarles began noticing changes in her mother's behavior that she couldn't attribute to normal forgetfulness that comes with age.

Jane Freeman was diagnosed at Mayo Clinic with probable Alzheimer's disease. She was treated and followed until her death in the spring of 2004 by Mayo Clinic neurologist Dr. Neill Graff-Radford and family practice physician Dr. Floyd Willis. Freeman's husband committed to taking care of his wife at home until he became ill with diabetes and its related issues and could no longer do so. Then Quarles took on the responsibility of caring for both of her parents.

"For a while I literally ran a hospital in their home," she says.

Quarles says unfortunately her father, who predeceased his wife, denied she had a problem for too long. If Freeman had been diagnosed sooner, she may have benefited from some of the newer treatments for early stage Alzheimer's.

Willis and other researchers are beginning to study early memory loss, in part for that reason. The forthcoming standards defining what normal memory is in older African-Americans will provide unique opportunity to detect very early memory loss in elderly African-Americans. If these people can be identified earlier, they will be the ones to benefit most from existing or yet-to-be discovered therapies that slow the progression of the disease.

On the other hand, Willis says there might be some causes of early memory loss in African-Americans and the general population that can be effectively treated now. These causes include high blood pressure, diabetes and high cholesterol.

"This work is extremely important to me because significantly more African-Americans are theorized to have memory problems from little strokes," says Willis. "Where do these little strokes come from? Hypertension and diabetes. So if there are large numbers of African-Americans who actually have their memory loss because of these small strokes, that's significant because you can fix these problems. We can't yet arrest and correct Alzheimer's disease, but it is possible to correct hypertension and diabetes, or at least find them much earlier before they start causing problems."

Willis says people generally don't know if a slight memory problem is part of normal aging or if it could be a sign of dementia.

"One way to gain insight is to decide whether a memory problem is worse than in friends and relatives who are the same age," he says.