Older adults who were once infected with Covid-19 are at a much higher risk of developing Alzheimer’s disease within a year, with women above the age of 85 occupying the highest risk group, a new study of more than 6 million patients has found.
The researchers, who published their findings in the Journal of Alzheimer’s Disease on Tuesday (September 13), found that people aged 65 and above who developed Covid-19 were at a 50-80% higher risk of developing Alzheimer’s, expanding upon the little we currently know about the long-term consequences of the pandemic.
However, the researchers have maintained that it is unclear “whether Covid-19 might trigger new onset of Alzheimer’s disease or accelerate its emergence.”
The research team analysed the anonymous electronic health records of 6.2 million people who were 65 and older in the US, and who had visited healthcare organisations between February 2020 and May 2021. Those studied had not been previously diagnosed with Alzhiemer’s.
They were then divided into two groups: one composed of people who had contracted Covid-19 during the period of study, and another group which had no documented cases of the infectious disease. There were more than 400,000 people enrolled in the Covid-19 study group, while the non-infected group contained 5.8 million people.
The findings indicated that over the one-year period following the infection, older adults in the Covid-19 cohort faced a risk of 0.68%, nearly double that of the non-Covid-19 cohort, which faced a risk of 0.35%.
“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, Distinguished University Professor at the Case Western Reserve School of Medicine and the study’s co-author.