Effects of chronic periodontitis on renal function in OLETF rats

To investigate the effects of chronic periodontitis on kidney function of OLETF rats.

30 spontaneous type 2 diabetes mellitus (T2DM) OLETF rats aged 4 weeks were selected as the experimental objects, and 20 LETO rats with normal sugar tolerance of the same species and the same week age were selected as the control group. When the rats arrived the glucose tolerance damage stage at the age of 36 weeks, 26 OLETF rats (O group) were divided into diabetes mellitus combined periodontitis group (O CP(+) group) and diabetic group (O CP(-) group) randomly, and 20 LETO rats (L group) were randomly divided into periodontitis group (L CP(+) group) and normal group (L CP(-) group). Then the chronic periodontis models were established on the rats in the O CP(+) group and L CP(+) group, by silk thread ligation combined with coated bacteria. All the rats were executed at the 56 weeks age, when the models were established for 20 weeks. The serum was collected and analyzed by automatic biochemical machine to measure the biochemical indicators of renal function, including the following 4 indexes: serum albumin (ALB), total protein (TP), urea and creatinine (CR).

The levels of serum TP and ALB decreased significantly in O group than in L group (P＜0.01), as the same result when compared O CP(+) group with O CP(-) group (P＜0.01), however, there was no significant difference when compared L CP(+) group to L CP(-) group. Serum CR was significantly higher in O group than in L group (t = 9.099, P = 0.005), the same as that in O CP(+) group when compared with O CP(-) group (t = 4.443, P＜0.001), while there was no significant difference when compared L CP(+) group to L CP(-) group. Serum urea levels in O group was significantly higher than in L group (t = 5.684, P = 0.024), While there was no significant difference between O CP(+) group and O CP(-) group (t = 1.484, P = 0.160), the same as that between L CP(+) group and L CP(-) group (t =0.075, P = 0.932).

It shows that chronic periodontitis may not cause changes in kidney function in normal rats. However, in the case of T2DM, chronic periodontitis may increase the existing kidney damage. It indicates that T2DM and chronic periodontitis may have interactions in the development of diabetic kidney disease.