Mediators of the association between education and periodontitis: Mendelian randomization study

Abstract

Aim: To estimate the causal link between the risk of chronic periodontitis and educational attainment (EA). Methods: The biggest genome-wide association studies (GWAS) were used to conduct two-sample univariable Mendelian randomization (MR) analyses to evaluate the direct and combined effects of body mass index (BMI), smoking, household income, alcohol drinking, major depression, and EA on chronic periodontitis. To determine if putative mediators are causally involved in the pathway that mediates the relationship between EA and chronic periodontitis, a two-step MR analysis is performed. Results: MR evidence suggested a causal relationship between higher educational level and lower chronic periodontitis risk (OR: 0.72; 95% confidence interval (CI), 0.63 to 0.82; P < 0.001). The proportions mediated of the total effect of genetically predicted education on chronic periodontitis were 12.9%, 30.7%, 89.9%, 9.7%, and 16.4% for BMI, smoking, household income, alcohol drinking, and major depression, respectively. Conclusion: The risk of chronic periodontitis is protected by higher EA. Obesity, smoking, income, alcohol drinking, major depression seem to be significant factors. Measures to alleviate the risk burden of chronic periodontitis caused by educational disparities may be achieved by addressing these factors.