Published Sep 21, 2022 | 9:05 AM ⚊ Updated Sep 21, 2022 | 9:05 AM
People in the age groups of 65 and older who contracted COVID-19 were more prone to developing Alzheimer’s disease in the year following their COVID diagnosis. (Creative Commons)
On Wednesday, 21 September, as the world celebrates World Alzheimer’s Day, a study has found that older people who were infected with Covid-19 show a substantially higher risk — as much as 50 to 80 percent — of developing Alzheimer’s disease within a year, according to a study of more than six million patients in the age group 65 and older.
Alzheimer’s disease is a progressive neurologic disorder that causes the brain to shrink (atrophy) and brain cells to die. Alzheimer’s disease is the most common cause of dementia — a continuous decline in thinking, behavioural and social skills that affects a person’s ability to function independently.
In a study published in the Journal of Alzheimer’s Disease, researchers report that people in the age group 65 and older who contracted Covid-19 were more prone to developing Alzheimer’s disease in the year following their diagnosis. And the highest risk was observed in women at least 85 years old.
The findings showed that the risk for developing Alzheimer’s disease in older people nearly doubled (0.35 percent to 0.68 percent in 6.2 million people) over a one-year period following infection with Covid. The researchers say it is unclear whether Covid-19 triggers new development of Alzheimer’s disease or accelerates its emergence.
“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 co-author in a statement.
“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.
The research team analysed the anonymous electronic health records of 6.2 million adults 65 and older in the US who received medical treatment between February 2020 and May 2021 and had no prior diagnosis of Alzheimer’s disease.
They then divided this population into two groups: One composed of people who contracted Covid-19 during that period, and another with 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.
“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,” the study said.
Now, so many people 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.”
Previous Covid-related studies have found that people with dementia are twice as likely to contract Covid.
