Mediation analysis of systemic inflammation on the association between periodontitis and glycaemic status

Abstract

© 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd Aim: This cross-sectional study investigated the associations between periodontitis, systemic inflammation and glycaemic status. Materials and Methods: The participants were divided into three groups: normoglycaemia, impaired fasting glucose (IFG) and diabetes. Multinomial logistic regression was used to examine the associations between periodontitis severity and glycaemic status, adjusting for potential confounders. Mediation analysis of four systemic inflammatory biomarkers, C-reactive protein (CRP), white blood cell count (WBC), neutrophil–lymphocyte ratio (NLR) and platelet–lymphocyte ratio (PLR), was performed. Results: This study comprised 2,036 participants, aged 39-66 years. Severe periodontitis was associated with IFG and diabetes with odds ratios of 1.6 (95% confidence interval [CI]: 1.1-2.4, p =.023) and 2.4 (95% CI: 1.3-4.5, p =.006), respectively. The CRP, WBC and PLR were associated with both periodontitis severity and glycaemic status (p <.05). In contrast, the NLR was associated with periodontitis severity (p <.05) but not glycaemic status (p >.05). The CRP, WBC and PLR mediated 8%, 13% and 6%, respectively, of the association between severe periodontitis and diabetes. Similar proportions mediated were observed for the periodontitis-IFG association. Conclusions: Our findings support the role of systemic inflammation as mediators of the associations between periodontitis and IFG or diabetes.