The Effect of obesity on dental caries: A mendelian randomization study

Background Clinical and retrospective studies suggest obesity increases the risk of dental caries, but causal mechanisms remain unclear. We employed the Mendelian randomization (MR) method to explore obesity's potential causal link to dental caries. Methods We extracted body mass index (BMI) and waist circumference (WC) data from the IEU OpenGWAS project database. These data were used to identify single-nucleotide polymorphisms (SNPs) associated with obesity as instrumental variables. Additionally, dental caries data were extracted from the same database. Using the R package ‘TwoSampleMR’, we conducted inverse-variance weighted (IVW) analyses and various sensitivity analyses to assess the impact of obesity on dental caries. Results The IVW analysis indicated that every 1-SD increase in BMI was associated with a higher incidence of dental caries (odds ratio [OR] = 1.286; 95% confidence interval [CI] = 1.122–1.474; P  = 2.94E-04), as was every 1-SD increase in WC (OR = 1.242; 95% CI = 1.032–1.496; P  = 2.20E-02). These findings were consistent across additional MR sensitivity analyses. Conclusion Our results provide evidence of a probable causal relationship between genetic susceptibility to obesity and an increased risk of dental caries. Therefore, individuals with obesity should take preventive measures to reduce the risk of dental caries.