The aim of this study was to assess the causal association between age at menarche (AAM) and periodontitis by use of a 2-sample 2-way Mendelian randomization (MR) study. A 2-sample bidirectional MR analysis was performed based on genome-wide association study data from European populations of AAM and chronic periodontitis, using single nucleotide polymorphisms as instrumental variables. Inverse-variance weighting, weighted median, weighted multinomial, and MR-Egger were used to assess the bidirectional causal association between AAM and chronic periodontitis. The inverse-variance weighting method showed a significant negative correlation between genetically predicted AAM and chronic periodontitis (odds ratio: 0.733; 95% confidence interval: 0.583-0.922; P = .0081), Cochran Q test showed no heterogeneity, MR-Egger showed there was no pleiotropic, leave-one-out confirmed the robustness of the results, and reverse MR analysis demonstrated no reverse causality. AAM may be negatively associated with chronic periodontitis.
Hou et al. (Fri,) studied this question.