Abstract: Objective To establish Zucker diabetic fatty rats with periodontitis model， to explore the effect of periodontitis on the severity of diabetesrelated complications in models， and to analyze its mechanism. Methods 48 female Zucker diabetic fatty (ZDF， fa/fa) rats were included and randomly divided into Group A and B， each group further randomized into Group 1 and 2. Group A was made model of periodontitis， in which Group A1 was given high fat diet， in order to induce insulin resistance (IR)， while Group A2 was given low fat diet. Group B was not made model of periodontitis， in which Group B1 was given high fat diet， while Group A2 was given low fat diet. Glucose tolerance test was carried out， fasting insulin and blood glucose were measured every week. 13 weeks later， the rats were sacrificed， and the health condition of periodontal tissue was detected， in order to evaluate the reliability of modeling. Serum TNFα， IL1β， CRP and pathological changes in aorta， fundus， pancreatic tissues were detected and analyzed statistically. Results ① The modeling scheme is reliable. Fasting blood glucose， fasting insulin， and HOMAIR in Group A1 and B1 were respectively higher than in Group A2 and B2， and the difference was statistically significant (P<0.05). There was obvious periodontal inflammation， periodontal soft tissue destruction， and bone resorption in Group A. ② The serum TNFα， IL1β， CRP in Group A1 and B1 were respectively higher than in Group A2 and B2， and the difference was statistically significant (P<0.05). There was a positive correlation between the above indexes and HOMAIR (P<0.05). ③ The pathological changes of aorta， fundus and pancreatic tissue were significantly higher in A1 group than in other groups， and the difference was statistically significant (P<0.05). Conclusion Periodontitis can lead to the increase of IR degree and the severity of diabetesrelated complications in Zucker diabetic fatty rats， which may be related to the increase of serum inflammatory factors in rats with periodontitis.

Key words: periodontitis, diabetes mellitus, obesity, Zucker rats, complications