Three percent of 10,403 adults with COVID-19 pneumonia were diagnosed as having new-onset dementia after a median of 182 days, a significantly higher proportion than that observed with other types of pneumonia, finds a study published in Open Forum Infectious Diseases.

University of Missouri at Columbia researchers conducted a case series of COVID-19 pneumonia patients along with matched contemporary control patients who had non–SARS-CoV-2 pneumonia from 110 US healthcare centers to identify new diagnoses of dementia at least 30 days after hospitalization.

Of the 10,403 patients with COVID-19 pneumonia, 3% (95% confidence interval [CI], 2.7% to 3.4%) were diagnosed as having new-onset dementia over a median of 182 days. In contrast, 2.5% (95% CI, 2.2% to 2.9%) of the 10,403 patients with other pneumonias developed dementia.

The risk of new-onset dementia was significantly greater with COVID-19 pneumonia than with other pneumonias (odds ratio [OR], 1.3; (95% CI, 1.1 to 1.5) after adjustment for age, sex, race, high blood pressure, diabetes, abnormal cholesterol levels, tobacco use, alcohol misuse, atrial fibrillation (abnormally rapid heart rhythm), history of stroke, and congestive heart failure.

The link between COVID-19 pneumonia and new dementia diagnoses remained significant after further adjustment for stroke, septic shock, and mechanical ventilation during hospitalization (OR, 1.3; 95% CI, 1.1 to 1.5).

Risk factors for new-onset dementia were age 55 to 70 years (OR, 13.1), age older than 70 (OR, 49.0), Hispanic race (OR, 1.8), alcohol use or abuse (OR, 1.8), and history of depression (OR, 1.3), encephalopathy (disease that alters brain function or structure; OR, 2.2), delirium (OR, 3.1), or stroke during COVID-19 hospitalization (OR, 1.8).

New-onset dementia may increase the burden of disability among COVID-19 survivors, the study authors noted, including the need for personal care and the financial consequences of an inability to return to work.

“Future studies should investigate the underlying pathophysiological processes associated with SARS-CoV-2 infection to identify optimal strategies to prevent long-term disabling sequelae like new onset dementia,” the researchers concluded.
Mar 7 Open Forum Infect Dis study