Could COVID-19 Raise Risk for Dementia?

Rush researchers seeking answer in NIH-funded study
COVID Alzheimer's research

A research team at Rush University Medical Center is investigating how COVID-19 could raise the risk for Alzheimer’s disease, thanks to a $14 million grant from the National Institutes of Health.

Researchers at Rush suspect that COVID-19 could have direct and indirect effects on the brain. One theory is that COVID-19 could trigger the immune system to flood the body with inflammatory proteins, known as cytokines, that might harm the brain.

“There is some very preliminary evidence in clinical studies of these cytokine storms that happen once people get COVID,” says Kumar B. Rajan, PhD, director of the Rush Institute for Healthy Aging and professor of epidemiology, who is leading the study. “Our hypothesis is that there might be some inflammatory mechanisms that could be triggered that could potentially increase the risk for Alzheimer’s disease.”

Yet what may be even more likely to elevate Alzheimer’s risks are the indirect social factors, such as isolation, related to the pandemic, Rajan says. Other studies have shown that loneliness and social isolation can raise Alzheimer’s disease risks in older adults. “We believe the social factors related to COVID-19 probably have a fairly substantial impact on many different disease risks, with Alzheimer’s disease being one of them,” Rajan says.

Assessing risks in minority populations

As part of the five-year project, researchers at Rush will study a diverse population of 4,000 parents 65 and older, and their middle-aged adult children in Beverly, Mount Greenwood, Washington Heights and Morgan Park on Chicago’s South Side. At least half of residents involved in the study will be African Americans. The study will also include a large Hispanic population.

Focusing on minority populations and families with a high risk for COVID-19 transmission is an important focus of the research, as these groups have been disproportionately affected by COVID-19 during the pandemic, Rajan says.

In this population-based community study, Rajan’s team will use detailed questionnaires to understand residents’ health and identify factors, including social isolation, that could raise Alzheimer’s disease risks. They will also take blood tests to measure acute and chronic markers of inflammation in the body that could increase the risk for dementia. For a subset of about 1,200 people in the study population, they will also use magnetic resonance imaging to monitor changes in the brain over time that could be related to COVID-19.

Developing strategies for the future

Understanding the role of COVID-19 infections and acute and chronic inflammation markers will provide a better understanding of brain changes related to COVID-19 and how they might affect the risk of Alzheimer’s disease and related dementias in diverse populations, Rajan says. He believes the research could have a significant impact by helping guide future public health strategies aimed at preventing dementia. It will also help researchers understand the impact of COVID-19 on population health across generations.

“The short- and long-term impact of COVID-19 on brain aging and dementia risk is of intense public health significance, given the impact on families with older adults,” Rajan says.

Funds for this project were awarded from three NIH institutes: the National Institute on Aging, the National Institute of Allergy and Infectious Diseases, and the National Institute on Minority Health and Health Disparities. The new study builds on previous NIH-funded research by the Rush Institute for Healthy Aging’s Chicago Health and Aging Project on the risk factors for and prevalence of Alzheimer’s disease and related dementias in biracial populations.

Rajan is grateful to South Side residents for their participation in this groundbreaking research. “Without these communities, these studies could never happen,” he says.

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