Background: The coronavirus disease 2019 (COVID-19) pandemic has had an unprecedented impact on the healthcare system, economy, and society. Studies have reported that COVID-19 may cause various neurologic symptoms, including cognitive impairment. We aimed to assess the causal effect of COVID-19 on neurodegenerative diseases using two-sample Mendelian randomization (MR) study.
Methods: Genetic variants were obtained from genome-wide association studies (GWAS) summary-level data and meta-analyses. We used the inverse variance-weighted (IVW) method as the primary analysis to estimate causal effects. Sensitivity analyses were performed to make the conclusions more robust and reliable.
Results: We found that the COVID-19 infection phenotype was associated with a higher risk of AD and inverse associated with the risk of ALS and MS. The hospitalized COVID-19 phenotype was associated with the risk of AD and wasn't associated with ALS and MS. We also found that the severe COVID-19 (main analysis) phenotype was associated with the AD outcome from UK biobank datasets but was not associated with other outcomes. The severe COVID-19 infection phenotype, the severe COVID-19 (subtype analysis) phenotype and the hospitalization risk of COVID-19 were not associated with each outcome.
Conclusion: This MR study suggests a potential association between genetically predicted COVID-19 and a higher risk of AD and a reduced risk of ALS and MS. Further elucidations of this association and underlying mechanisms may inform public health messages to prevent COVID-19 and AD.
© 2022 The Authors. Annals of Clinical and Translational Neurology published by Wiley Periodicals LLC on behalf of American Neurological Association.