Bone Biology Laboratory http://www.iupui.edu/~bonelab/ Department of Anatomy and Cell Biology Indiana University School of Medicine Department of Biomedical Engineering IUPUIBackground/Aims: Patients with chronic kidney disease (CKD) have high prevalence of
periodontal disease that may predispose to tooth loss and inflammation. The goal of this study
was to test the hypotheses that a genetic rat model of progressive CKD would exhibit altered
oral bone properties and that treatment with either bisphosphonates or calcium could attenuate
these adverse changes. Methods: At 25 weeks of age, rats were treated with zoledronate,
calcium gluconate, or their combination for 5 or 10 weeks. Mandible bone properties were
assessed using micro-computed tomography to determine bone volume (BV/TV) and cementenamel
junction to alveolar crest distance (CEJ-AC). Results: Untreated CKD animals had
significantly lower BV/TV at both 30 (-5%) and 35 (-14%) weeks of age and higher CEJ-AC (+27
and 29%) compared to normal animals. CKD animals had significantly higher PTH compared to
normal animals yet similar levels of C-reactive protein. Zoledronate-treatment normalized
BV/TV over the first 5 weeks but this benefit was lost by 10 weeks. Calcium treatment, alone or
in combination with zoledronate, was effective in normalizing BV/TV at both time points. Neither
zoledronate nor calcium was able to correct the higher CEJ-AC caused by CKD. Calcium, but
not zoledronate, significantly reduced serum parathyroid hormone (PTH) while neither treatment
affected C-reactive protein. Conclusions: 1) this progressive animal model of chronic kidney
disease shows a clear mandibular skeletal phenotype consistent with periodontitis, 2) the
periodontitis is not associated with systemic inflammation as measured by C-reactive protein,
and 3) reducing PTH has positive effects on the mandible phenotype.This work was supported by NIH grant (AR058005). We would like to thank Dr. Xianming Chen, Mr. Alex Carr and Mr. Drew Brown for their assistance with the biochemical assays, breeding colony and micro CT scanning/analysis, respectively
