Covid-19 in the elderly is linked to an increased risk of Alzheimer’s, according to the study

A study using the electronic health records of more than 6 million Americans over the age of 65 found that those with covid-19 had more risk of receiving a new diagnosis of Alzheimer’s disease within a year.

The study, led by Case Western Reserve University School of Medicine researchers and published in the Journal of Alzheimer’s Disease, does not show that covid-19 causes Alzheimer’s, but adds to a growing body of work which suggest links between the two.

The findings suggest that researchers should monitor elderly patients recovering from covid to see if they show signs of memory loss, declining brain function or Alzheimer’s disease. The study found that for every 1,000 elderly people with covid-19, seven will be diagnosed with Alzheimer’s within a year, slightly above the diagnosis rate of five in 1,000 for elderly people who did not have covid.

“We know that covid can affect the brain, but I don’t think anyone has looked at new Alzheimer’s diagnoses,” said Pamela Davis, one of the study’s co-authors and a research professor. at Case Western Reserve University School of Medicine. Colleague Rong Xu said he expected to see an increase in older people sick from covid, but was surprised “by the extent of the increase and how quickly it happened”.

The study, while “important and useful” was “limited,” said Gabriel de Erausquin, director of the Brain Development, Modulation and Repair Laboratory at the University of Texas Health San Antonio, who was not involved in the research

He warned that a diagnosis of Alzheimer’s disease is not necessarily confirmation of the disease. Doctors sometimes diagnose Alzheimer’s based on changes in behavior or responses to a memory test. These are considered less accurate than imaging or cerebrospinal fluid tests that measure two types of proteins, beta-amyloid and phosphorylated tau, that accumulate abnormally in the brains of people with Alzheimer’s. Brain scans that look for structural changes, such as shrinking of certain regions, are another, more accurate indicator.

“There are people who look very much like they have Alzheimer’s, but they don’t have Alzheimer’s,” de Erausquin said, adding: “People who have covid for a long time are at risk of being diagnosed with Alzheimer’s disease.” .

In their paper, Case Western Reserve researchers acknowledged that the study was limited by the potential for inaccurate Alzheimer’s diagnoses.

Davis, however, said he thinks doctors are unlikely to mistake covid for long for Alzheimer’s.

“Labeling someone with Alzheimer’s disease is different from the brain fog and confusion associated with prolonged covid,” he said. “When a doctor makes a diagnosis of Alzheimer’s disease, it represents substantial cognitive impairment.”

The Case Western Reserve study used a database representing patients from nearly 70 health care facilities across the country. The scientists focused on patients older than 65 who had a medical visit during a 15-month period from February 2, 2020 to May 30, 2021, dividing them into two groups: those diagnosed with covid- 19 and those without a covid diagnosis.

During much of the study period, the electronic record system did not include a code for long covid, leaving open the possibility that patients who had ongoing health problems after their bout with covid could have been misdiagnosed with Alzheimer’s.

Still, the new study adds to a growing body of research examining the relationship between covid-19 and Alzheimer’s disease. An earlier study by some of the same researchers at Case Western Reserve looked at the electronic health records of nearly 62 million Americans over the age of 18 and found that dementia patients had a significantly higher risk of covid- 19 than patients without dementia.

Thomas Wisniewski, director of NYU’s Langone Alzheimer’s Disease Center, raised the possibility that some patients are already on their way to Alzheimer’s when they arrive. covid-19, causing their brains to “take a second hit”.

He said scientists need to look at whether the Alzheimer’s biomarkers that show up in covid-19 patients “remain elevated over time and lead to a faster disease trajectory?”

Scientists at Columbia University’s Vagelos College of Physicians and Surgeons studied the brains of a small number of patients who died of covid-19 and found they had defective receptors considered indicators of Alzheimer’s disease.

A second study looked at serum, a blood component, from hospitalized covid-19 patients with no history of dementia who had developed markers of neurodegenerative disease at levels comparable to those found in Alzheimer’s disease patients.

Leave a Reply