Systemic Immune-Inflammation Index and Systemic Inflammation Response Index are Associated With Periodontitis: Evidence From NHANES 2009 to 2014

Introduction and aims Periodontitis, a chronic inflammatory condition affecting the supporting structures of the teeth, is a substantial public health burrden whilst impacting the life quality of those affected. Elevated levels of systemic immune-inflammation index (SII) and systemic inflammation response index (SIRI) have been implicated in various inflammatory conditions. This study aimed to investigate the relationship between SII and SIRI with periodontitis. Methods The study examined a total of 8666 participants in the 2009 to 2014 National Health and Nutrition Examination Survey (NHANES). The study compared the weighted prevalence of periodontitis among various groups. The association between SII, SIRI levels, and periodontitis was analyzed using binary logistic regression. Additionally, we explored nonlinear relationships between SII, SIRI, and the prevalence of periodontitis using restricted cubic spline (RCS) plots. Results Among participants in the fourth quartile (Q4) of SII and SIRI, the highest prevalence of periodontitis was observed, with rates of 44.87% and 48.41%, respectively. After adjusting for all covariates, the odds ratio (OR) for periodontitis associated with SII Q4 was 1.19 (95% CI 1.02, 1.39, P = .03), while for SIRI Q4, it was 1.18 (95% CI 1.01, 1.39, P = .04). In addition, the results of sensitivity analysis revealed consistent findings, indicating that after adjusting for all covariates, the OR for periodontitis associated with SII Q4 and SIRI Q4 remained statistically significant. Specifically, the OR for periodontitis associated with SII Q4 was 1.19 (95% CI 1.02, 1.39, P = .03), while for SIRI Q4, it was 1.19 (95% CI 1.01, 1.40, P = .04). Conclusions These results indicate that elevated SII and SIRI levels are associated with an increased prevalence of periodontitis. Clinical relevance These findings suggest a potential connection between systemic inflammation and periodontitis, highlighting the importance of periodontitis patients being aware of their systemic diseases that are inflammatory in nature such as chronic cardiovascular afflictions.