The effect of periodontal status in the associations between socioeconomic status and cognitive performance: a mediation analysis in older adults

Introduction The aim of this study is to analyse the association of socioeconomic status (SES) with cognitive performance, and the mediation effect of periodontal status in this relationship in the National Health and Nutrition Examination Survey (NHANES) database from 2011-2014.Methods The SES was evaluated based on poverty-income ratio (PIR), occupation, educational level, and health insurance using latent class analysis. Multivariable logistic regressions were used to determine the association of cognitive performance, examined by Consortium to Establish a Registry for Alzheimer's Disease (CERAD) test, animal fluency test (AFT), and digit symbol substitution test (DSST), with SES, attachment loss (AL) and probing depth (PD). Multivariable linear regressions were used to explore the association of mean AL and mean PD with SES. A mediation analysis was conducted to examine the impact of mean AL and mean PD on the relationship between SES and cognitive performance.Results The study included 1,812 participants aged 60 years or older. In the fully adjusted model, SES showed a positive correlation with all three cognitive tests. Meanwhile, mean AL [odds ratio (OR) = 1.61; 95% confidence interval (CI): 1.33 to 1.95] and mean PD (OR = 2.14; 95% CI: 1.54 to 2.96) were inversely related to the DSST scores, accounting for 12.17 and 6.91% of the relationship between SES and DSST, respectively. The mediation effect of periodontal status in this association was significant only in non-HSB participants or in younger participants.Conclusion SES was negatively associated with periodontal status in older adults in the United States. Furthermore, the link between SES and cognitive performance can be partially explained by periodontal status.