A new study in npj Dementia using data from the UK Biobank shows that COVID-19 survivors aged 50 and older had a higher likelihood of developing new-onset dementia (NOD) compared to uninfected controls.
A total of 54,757 participants met the inclusion criteria for the study, including 16,017 with COVID-19 and 38,740 non-COVID participants. The median observation period was 24.1 months.
According to the authors, compared with matched non-COVID controls, prior COVID-19 infection was associated with a 41% increased risk of all-cause dementia (hazard ratio [HR], 1.41; 95% confidence interval [CI], 1.13 to 1.75). Men, unvaccinated participants, those with high blood pressure, and those with frequent alcohol use had the highest association with NOD.
Other respiratory illnesses also linked to dementia
But when COVID-19 patients were compared to participants with non-COVID respiratory disease, the association disappeared. Moreover, the association was age-dependent. There was no statistically significant association observed among individuals younger than 65 years (HR, 0.55; 95% CI, 0.23 to 1.30).
The observed associations may reflect a broader impact of respiratory conditions on cognitive health .
“The observed associations may reflect a broader impact of respiratory conditions on cognitive health rather than a COVID-19–specific effect,” the authors wrote. “Given the substantial societal burden of dementia, continued surveillance and research into the long-term cognitive consequences of COVID-19 are crucial.”