Obesity may increase the occurrence of spontaneous periodontal disease in Wistar rats

Objective: To evaluate the effect of body weight on the occurrence of spontaneous alveolar bone loss in Wistar rats.

Methods: Twenty-eight rats were randomly divided in two groups. Control group received standardized rat chow diet and water. Test group received cafeteria (CAF) diet during 17 weeks. Diet was available for both groups ad libitum. Body weight and Lee Index were evaluated. At the end of the experimental period, rats were killed by decapitation and maxillae were defleshed with 9% sodium hypochlorite. Morphometric analysis was performed in digital standard photographs. Presence of spontaneous periodontitis was considered when mean alveolar bone loss was ≥0.51mm (75th percentile). Statistical analysis was performed with chi-square test, Mann-Whitney test and independent samples t-test (significance level P≤0.05).

Results: After 17 weeks of exposure to standard CAF diet, a statistically significant mean difference in body weight (g±SD) (478±43 vs. 580±60) and Lee Index (3.07±0.05 vs. 3.24±0.07) was observed between control and obesity groups, respectively. Median (interquartile range) of alveolar bone loss in control group was 0.344 (0.313-0.367) and 0.491 (0.427-0.506) for buccal and palatal site, respectively. For obese group was 0.308 (0.289-0.354) and 0.549 (0.482-0.616) for buccal and palatal site, respectively. In animals submitted to CAF diet, 20 sites were classified as spontaneous periodontal disease, whereas in control animals, only 8 sites exhibited periodontal breakdown according cut-off point. A significant difference between groups was detected (P=0.009).

Conclusions: It may be concluded that obesity increases the occurrence of spontaneous periodontal disease in Wistar rats.