Periodontal disease may induce liver fibrosis in an experimental study on Wistar rats

Background The aim was to assess the effects of periodontal disease in promoting liver fibrosis in a rat model of ligature-induced periodontitis. Methods Twenty-four Wistar rats were divided into four groups: control (CTRL), experimental periodontitis group at day 7 (PER7), at day 14 (PER14), at day 21 (PER21). Experimental periodontitis was induced by the placement of a silk ligature around mandibular incisors. The following parameters were assessed: gingival index, tooth mobility; liver status, and portal vein caliber by ultrasound examination; bone retraction, bone mineral density (BMD), bone volume/tissue volume (BV/TV) by micro-CT analysis; aspartate aminotransferase (ASAT) and alanine aminotransferase (ALAT); oxidative stress (malondialdehyde [MDA], reduced glutathione/oxidative glutathione ratio [GSH/GSSG]), and matrix metalloproteinase-8 (MMP-8) levels; and histopathological evaluation of periodontal and liver tissues. Results Periodontal parameters showed the development of periodontitis in experimental groups. Micro-CT results indicates an increase of bone retraction and BMD values and a decrease of BV/TV value in PER groups. Liver fibrosis could not be diagnosed with ultrasound examination in any of the groups. Elevated levels of ASAT and ALAT in PER groups compared with CTRL group were found. MDA have indicated elevated levels and a decrease of GSH/GSSG ratio in PER group compared with the CTRL group. Levels of MMP-8 have indicated high values in PER21 compared with the other groups. Histological analysis of the periodontal and liver tissues sustains the link between periodontal and hepatic injury. Conclusion This study demonstrates a positive correlation between periodontal lesions and liver disease. Periodontitis may be an independent risk factor for liver fibrosis.