Association between total body bone mineral density and periodontitis: A Mendelian randomization study

The purpose of the study was to examine the association between total body bone mineral density (BMD) and periodontitis using Mendelian randomization (MR) analysis.We used 81 single nucleotide polymorphisms (SNPs) associated with BMD at a p-value of < 5 × 10-8 from a genome-wide association study (GWAS) of 66,628 individuals of European descent. The GWAS for periodontitis was derived from a meta-analysis of seven cohort studies that included 17,353 cases and 28,210 controls of European ancestry.MR showed no association between BMD and periodontitis (odds ratio per standard deviation increment in genetically predicted BMD = 1.00; 95% confidence interval: 0.92-1.08). Leave-one-out analyses and pleiotropy-robust methods did not indicate any bias.The MR study provided no evidence that BMD might be causally linked to periodontitis. Hence it may be concluded as the key finding that BMD depletion does not increase the risk of periodontitis.