According to a large, new study, older people who were infected with COVID-19 show a substantially higher risk of developing Alzheimer’s disease within a year.
By CASE WESTERN RESERVE UNIVERSITY
Researchers report that people 65 and older who contracted COVID-19 were substantially more likely to develop Alzheimer’s disease in the year following their COVID diagnosis.
Furthermore, the highest risk was observed in women at least 85
years old. The study was published on September 13, 2022, in the Journal of Alzheimer’s Disease,
According
to the findings, the risk for developing Alzheimer’s disease in older people
nearly doubled (0.35% to 0.68%) over a one-year period following COVID
infection. It is unclear whether COVID-19 triggers new development of
Alzheimer’s disease or accelerates its emergence, the researchers said.
“The factors that play into the development of Alzheimer’s disease have been poorly understood, but two pieces considered important are prior infections, especially viral infections, and inflammation,” said Pamela Davis, the study’s coauthor. She is a Distinguished University Professor and The Arline H. and Curtis F. Garvin Research Professor at the Case Western Reserve School of Medicine.
“Since
infection with SARS-CoV2 has been associated with central nervous system
abnormalities including inflammation, we wanted to test whether, even in the
short term, COVID could lead to increased diagnoses,” she said.
For
the study, the research team analyzed the anonymous electronic health records
of 6.2 million adults 65 and older in the United States with no prior diagnosis
of Alzheimer’s disease who received medical treatment between February 2020 and
May 2021.
They
then divided this population into two groups. One was composed of people who
contracted COVID-19 during that period, and the other group contained people
who had no documented cases of COVID-19. More than 400,000 people were enrolled
in the COVID study group, while 5.8 million were in the non-infected group.
“If
this increase in new diagnoses of Alzheimer’s disease is sustained, the wave of
patients with a disease currently without a cure will be substantial,
and could further strain our long-term care resources,” Davis said.
“Alzheimer’s disease is a serious and challenging disease, and we
thought we had turned some of the tide on it by reducing general
risk factors such as hypertension, heart disease, obesity and a
sedentary lifestyle. Now, so many people in the U.S. have had COVID and
the long-term consequences of COVID are still emerging. It is important to
continue to monitor the impact of this disease on future disability.”
Rong
Xu, the study’s corresponding author is professor of Biomedical Informatics at
the School of Medicine and director of the Center for AI in Drug Discovery. She
said the research team plans to continue studying the effects of COVID-19 on
Alzheimer’s disease and other neurodegenerative disorders—especially which
subpopulations may be more vulnerable—and the potential to repurpose
FDA-approved drugs to treat COVID’s long-term effects.
Previous
COVID-related research led by CWRU have found that people
with dementia are twice as likely to contract COVID; those
with substance abuse disorder orders are more likely to contract COVID;
and that 5% of people who took Paxlovid for treatment of COVID symptoms
experienced rebound infections within a month.
Reference:
“Association of COVID-19 with New-Onset Alzheimer’s Disease” by Lindsey Wang,
Pamela B. Davis, Nora D. Volkow, Nathan A. Berger, David C. Kaelber, Rong Xu,
13 September 2022, Journal of Alzheimer’s Disease.
DOI:
10.3233/JAD-220717