Alzheimer's disease and oral manifestations: a bi-directional Mendelian randomization study.

Background: Epidemiological studies have provided evidence suggesting an association between Alzheimer's disease (AD) and various oral manifestations. However, conflicting conclusions have been drawn, and whether a causal association truly exists remains unclear.

Methods: In order to investigate the potential causal association between AD and prevalent oral diseases, we conducted a bi-directional two-sample Mendelian randomization analysis based on summary statistics from genome-wide association studies of AD ( = 63,926), as well as mouth ulcer ( = 461,103), oral cavity cancer ( = 4,151), and periodontal disease ( = 527,652).