Alzheimer Disease Patients Who Survived COVID-19 Have Rapid Disease Progression and a Higher Risk of Death at 5-year Follow-up

Purpose: Alzheimer disease (AD) is the most common neurodegenerative disorder, affecting millions worldwide. COVID-19 has increased the risk of acute complications and death for patients with AD, but the long-term effects on survivors have been little studied. Thus, given the potential role of SARS-CoV-2 in accelerating cognitive decline, this study aimed to assess the effect of COVID-19 on functional deterioration, AD progression, and mortality in these patients. Methods: This retrospective cohort study examined medical records of patients with mild to moderate AD treated at a public dementia clinic in southern Brazil between March 2020 and March 2025. Sociodemographic and clinical data were extracted, including COVID-19 status confirmed by molecular testing. AD progression was assessed using the Mini-Mental State Examination (MMSE) and the Katz Index. Multivariate statistical analyses were conducted to identify associations between COVID-19 infection and disease progression. Survival was described by Kaplan-Meier test and analyzed by Cox regression. Results: A total of 105 individuals with DA were included, of whom 28 (26.7%) were COVID-19 survivors during the follow-up period. COVID-19 patients showed rapid AD progression compared with the control group (OR 4.76; 95% CI: 1.04-21.7; P = 0.044). Likewise, SARS-CoV-2 infection decreased patients’ functionality, as indicated by the Katz index ( P =0.001). Functional impairment was observed in both mild and hospitalized cases of COVID-19. Hospitalized patients during COVID-19 demonstrated lower survival rates at the 5-year follow-up. Conclusion: These findings suggest that SARS-CoV-2 infection may accelerate AD progression and reduce survival, particularly in cases requiring hospitalization. Future multicenter studies with large sample sizes are needed to confirm these findings.