Rheumatoid arthritis and periodontitis in adults: Using the Korean National Health Insurance Service-National Sample Cohort

Background Using the database of the National Health Insurance Service-National Sample Cohort (NHIS-NSC), we aimed to assess the relationship between the prevalence of rheumatoid arthritis (RA) and periodontitis. Methods Participants aged >= 19 years with a previous health check-up at the NHIS between 2009 and 2015 were selected. In total, 559,280 participants were included after implementing appropriate exclusion criteria. The Chi-squared test was used to compare the general and health-related characteristics of participants with and without RA or periodontitis. Univariate and multivariate logistic regression analyses with consecutive adjustment for confounders, were used to assess the association between the prevalence of rheumatoid arthritis and periodontitis. Results The prevalence of rheumatoid arthritis in patients with and without periodontitis was 6.2% and 5.2%, respectively. The prevalence of periodontitis in patients with and without rheumatoid arthritis was 19.6% and 16.6%, respectively. The possibility of having rheumatoid arthritis was greater in patients with periodontitis than in individuals without periodontitis (odds ratio [OR]; 1.22, P <0.001), and remained high (OR; 1.07, P <0.001) after adjusting for confounders. Conclusion Our results revealed a significant association between the prevalence of rheumatoid arthritis and periodontitis.