Association between high serum ferritin and periodontitis: A population-based cross-sectional preliminary study.

Background: The aim of this study was to investigate the association between high serum ferritin levels and periodontitis considering pathways induced by sociodemographic and behavioral factors, serum inflammation, and metabolic risk.

Methods: Data from 7283 individuals who participated in the Third National Health and Nutrition Examination Survey (NHANES III) were analyzed. We estimated indirect and direct pathways for the association between high serum ferritin levels (in quintiles) and periodontitis. A theoretical model was constructed to evaluate the association between high serum ferritin and periodontitis, considering direct and indirect (mediated) pathways, including poverty, age, smoking, alcohol consumption, obesity, iron consumption, serum inflammation (C-reactive protein [CRP]), and insulin resistance (Homeostatic Model Assessment of Insulin Resistance [HOMA-IR]), analyzing through structural equation modeling (SEM).

Results: Higher ferritin levels were directly associated with periodontitis (standardized coefficient [SC] = 0.074, standardized error [SE] = 0.033, p-value = 0.025). Furthermore, higher ferritin mediated the association between serum inflammation (SC = 0.012, SE = 0.005, p-value = 0.033) and periodontitis.

Conclusion: Higher ferritin levels may play a role in periodontitis as part of a systemic inflammation mechanism.

Plain language summary: Mechanisms that justify the association between increased ferritin and periodontitis are still poorly understood. Ferritin is the main marker of iron stores, but it can be influenced by several factors that are also related to periodontitis. Our study investigated indirect (inflammatory) and direct (local) mechanisms for the association between ferritin and periodontitis. The systemic inflammatory mechanism partially explained the association between ferritin and periodontitis. Elevated ferritin levels remained directly associated with periodontitis even after adjustment for confounding, indicating the possibility of a direct mechanism. Elevated levels of ferritin may contribute to the severity and extent of periodontitis.