People with dementia have double the risk for COVID‐19 compared with those without dementia, according to a data analysis by the Case Western Reserve University School of Medicine, Cleveland. 

The risk is even higher for Black patients — who have three times the odds of receiving a COVID-19 diagnosis compared with white patients, said investigators, who reviewed electronic health records of more than 61 million adults in the United States. 

The findings held true even after the study team adjusted for nursing home residence and the presence of comorbidities and known COVID-19 risk factors. These included obesity, asthma, diabetes and cardiovascular disease, reported Rong Xu, Ph.D., director of the CWRU medical school’s Center for Artificial Intelligence in Drug Discovery.

Xu and colleagues speculate that there are at least two reasons underlying the increased risk of COVID-19 infection in patients with dementia, aside from age and comorbidities. Those include brain changes associated with dementia, including a “leaky blood-brain barrier, impaired cerebral blood flow, and damaged endothelium” that may predispose patients with dementia and Alzheimer’s disease to SARS-CO-2 viral infection, Xu told McKnight’s Clinical Daily.  

In addition, memory impairment may interfere with a patient’s ability to adhere to preventive measures for COVID-19, such as social distancing, mask-wearing and frequent hand sanitizing, the researchers theorized.

Dementia type or condition may have a role in risk as well, the study showed. Vascular dementia appeared to confer the highest risk, followed by presenile dementia, senile dementia, Alzheimer’s disease and post-traumatic dementia.

In addition, patients with dementia who contracted COVID-19 had significantly worse hospitalization and mortality outcomes than those who had COVID-19, but not dementia. Those findings were not adjusted for nursing homes residence or underlying medical conditions, however.

The study results were published Tuesday (Feb. 9) in Alzheimer’s & Dementia.