Relationship between TNF-α,IL-1βexpression and insulin resistance in obese rats with periodontitis

XU Zhe; NI Jia; XIE Bao-yi; XUAN Dong-ying; ZHANG Jin-cai

Abstract：AIM:To investigate the expression of TNF-αand IL-1βin serum and gingival tissue in differ-ent rat models so as to analyze the relationshiop of periodontitis with insulin resistance.METHODS:32 SPF SD rats were randomly divided into control (C),obese (OB),chronic periodontitis (CP)and obese plus periodontitis (OB+CP)groups(n=8).Obese rat model was established by subcutaneous injection of sodium glutamate.Chronic peri-odontitis was induced by periodontal ligation and inoculation of periodontal pathogens.Serum and gingival TNF-αand IL-1βexpression was measured by ELISA and immunohistochemical staining respectively.The relationship of TNF-αand IL-1βexpression with insulin resistance index (HOMA-IR)was analyzed by statistical methods.RESULTS:OB+CP group showed the highest serum TNF-αand IL-1βlevels than other groups (P<0.05 ),while OB and CP groups showed higher levels of TNF-αand IL-1βthan group C (P<0,05 ).Furthermore,OB+CP group had the highest HOMA-IR score.Corralation analysis showed that serum TNF-αand IL-1βlevels were positively related to HOMA-IR (rTNF-α=0.854,rIL-1β=0.730).In gingival tissues,the expression of TNF-αand IL-1βwere in the following group order:CP>OB+CP>C and OB.Gingival TNF-αand IL-1βexpression in OB+CP group was lower than that in CP group but was higher than that in C and OB groups (P<0.05).Gingival TNF-αand IL-1βex-pression in OB and C groups was not significantly different (P>0.05).CONCLUSION:Periodontitis might enhance insulin resistance in obese rats through increasing the secretion of serum inflammatory factors.