The ratios of pro-inflammatory to anti-inflammatory cytokines in the serum of chronic periodontitis patients with and without type 2 diabetes and/or smoking habit

ObjectiveThis study assessed the impact of chronic periodontitis (CP) and CP associated with type 2 diabetes mellitus (DM) and/or smoking on the serum ratios of pro- to anti-inflammatory cytokines.Materials and methodsSubjects were assigned into one of the following groups: control (n=25, non-diabetic non-smokers with no history of periodontitis), CP (n=26, non-diabetic non-smokers with CP), DMCP (n=30, non-smokers with DM and CP), SCP (n=27, non-diabetic smokers with CP), and SDMCP (n=22, smokers with type 2 DM and CP). Serum levels of 18 cytokines were measured using multiplex immunoassays.ResultsSix ratios of pro-inflammatory to anti-inflammatory cytokines were significantly higher in the CP group than in the control group (p<0.05). Eleven, seventeen and nine ratios of pro-inflammatory to anti-inflammatory cytokines were significantly higher in the DMCP, SCP and SDMCP groups than in the control group, respectively (p<0.05). The SCP group presented higher serum ratios of tumor necrosis factor (TNF)-/interleukin (IL)-4, TNF-/IL-5, IL-17/IL-13 and IL-6/IL-13 (p<0.05) than the CP group. Cluster analysis revealed a relevant cluster composed of ten cytokines (IL-17, IL-23, interferon-, IL-12, IL-1, IL-2, IL-21, IL-6, IL-4 and granulocyte-macrophage colony-stimulating factor [GM-CSF]) in the serum of subjects from the DMCP group.ConclusionsThe ratios of pro- to anti-inflammatory cytokines shift to favor a pro-inflammatory status in the serum of patients with CP and even more when CP is associated with one or both risk factors.Clinical relevanceCP and CP associated with hyperglycemia and/or smoking might contribute to a systemic inflammatory burden and increased risk of systemic complications.