At a time when the world is fighting its biggest battle against the ferocious second wave of the novel coronavirus, experts have said that people with dementia, particularly Alzheimer’s disease are at threefold risk of dying as a result of infection by SARS-CoV-2, the virus behind Covid-19. The experts also added that the risk is six times greater if they are over 80. Speaking to the media, Sergio Verjovski-Almeida, principal investigator for the project and a professor at USP’s Chemistry Institute, said, “We found that all causes of dementia are risk factors for severity and death in Covid-19 and that these risks are more pronounced for Alzheimer’s patients.” “Some factor that hasn’t yet been identified increases the predisposition of Alzheimer’s patients to progress to severe Covid-19 and die from the viral disease,” Verjovski said. “The results of our study point to a need for special attention to these patients when hospitalized.”
Alzheimer’s 3X Raises COVID-19 Severity, Death Risk
For the study, the researchers investigated data on positive diagnoses, hospitalisations, and deaths from Covid-19 for a cohort of 12,863 patients over 65, who tested positive or negative for Covid between March and August 2020. They were classified into three age groups: 66-74 (6,182), 75-79 (4,867), and 80-86 (1,814). Statistical analysis showed that all causes of dementia, especially Alzheimer’s, were risk factors for severity of the disease and death in the case of hospitalised patients, regardless of age.
A possible explanation is that chronic inflammatory conditions or defective immune responses due to ageing of the immune system (immunosenescence) may increase the vulnerability of these patients and reduce their capacity to mount an effective response to infection by the virus. Another hypothesis is that Alzheimer’s alters the permeability of the blood-brain barrier, making infection of the central nervous system more likely, the researchers said.