Beneficial effect of periodontal therapy on insulin resistance and lipid metabolism in obese rats with periodontitis

CHAI Qiaoxue; ZHONG Sulan; NI Jia; CHEN Lei; ZHOU Lei; ZHANG Jincai

doi:10.3969/j.issn.1673-4254.2017.05.16

Abstract：Objective To investigate the effect of periodontal therapy in controlling periodontitis and on insulin resistance and lipid metabolism in obese rats with periodontitis.Methods Sprague-Dawley rats were randomized into normal group (group C),obese group (group O),periodontitis combined with obesity group (group P) and periodontal treatment group (group T).The obese rats in groups P and T were subjected to ligation of the maxillary second molar with silk thread to induce experimental periodontitis,and the rats in group T received periodontal therapy after the ligation.All the rats were sacrificed at the age of 24 weeks for measurement of blood lipids,insulin and blood glucose levels,and insulin resistance index (HOMA-IR) was calculated.The expressions of insulin receptor substrate-1 (IRS-1) and IRS-2 in the liver tissues were detected using real-time quantitative polymerase chain reaction (RT-PCR).Results Compared with the obese rats in group O,the rats in group P showed significantly higher HOMA-IR and LDL-C and lower expressions of IRS-1 and IRS-2 mRNA expression and HDL-C level (P＜0.05).Compared with those in group P,the mRNA expressions of IRS-1 and IRS-2 and HDL-C level were significantly increased and LDL-C level,TC level and HOMA-IR were all decreased in group T (P＜0.05),but the level of TG was comparable between the two groups.Pathological examination revealed lessened inflammatory cell infiltration and tissue destruction in the upper jaw of the rats in group T;the rats in group P presented with the most obvious upper jaw destruction and steatosis and inflammatory cell infiltration in the liver.Conclusion Periodontal inflammation can downregulate the expression of IRS-1 and IRS-2 and increase insulin resistance and dyslipidemia in obese rats.Periodontal therapy produces a beneficial effect in improving insulin resistance and reducing dyslipidemia in obese rats.