Older adults with dementia face a three-fold risk of severe COVID-19 infection when compared to those without dementia, according to a study yet to be peer reviewed. These adults may need greater protections when social distancing measures are eased, the researchers say. 

The reasons for the link between dementia and severe disease are uncertain, said investigators. High exposure to the virus in environments such as nursing homes or the disease process itself may contribute to the problem, they theorized in a paper available in preprint

The findings are part of a larger study examining which pre-existing diseases may put older people at high risk in COVID-19. Investigators analyzed health histories from 448 people ages 65 to 86 years old who tested positive for COVID-19 in hospitals at the epidemic’s peak in England. Their health data was compared with that of healthier peers as part of the UK Biobank study.

Results showed that seniors diagnosed with dementia, depression, atrial fibrillation and pre-existing kidney disease faced the worst odds for severe infection, with risks increased by up to 80%. Chronic lung disease and diabetes were also problematic. In contrast, heart disease and stroke did not confer significantly greater risk.

“The findings may…have implications for how the current isolation of older people could be managed as the epidemic recedes,” said Professor David Melzer from University of Exeter Medical School. “A more precise approach may be possible, given the different risks that different older people face.”

Studies published on pre-print platforms are technically drafts, and are subject to change.