The Effect of Kidney Transplantation On Bone Metabolic Markers and Bone Mineral Density.

Abstract

Background Osteodystrophy is one of the most serious complications in end stage renal diseases, and affects quality of life in the patients. We investigated the changes of bone metabolic markers and bone mineral density (BMD) during the first six months after successful kidney transplantation. Patients and methods Twelve male patients aged 19 to 54 were enrolled in this study. They received immunosuppressive regimen including corticosteroids. We measured plasma osteocalcin (OC) and bone specific alkaline phosphatase (BAP) as bone formation markers, and intact parathyroid hormone (iPTH), tartrate resistant acid phosphatase (TRAP) and osteoprotegerin (OPG) as bone resorption markers from day 0 to 6 months after the surgery. We also measured 1, 25-(OH)2 vitamin D (VD) and BMD at lumbar spine. During the study period, the patients have received neither bisphosphonates nor active vitamin D. The study was approved by the local ethical committee. Results Bone formation markers tended to increase. OC increased from 7.9±4.6 to 15.4±9.2 ng/mL (p<0.01), and BAP from 20.7±10.5 to 36.0±19.5 μg/L (p<0.01). Bone resorption markers tended to decrease. TRAP decreased from 21.0±5.5 to 18.7±3.7 pg/mL and OPG from 89.8±39.2 to 60.2±41.5 pg/mL, however, they did not reach statistical significance. VD increased from 8.3±6.5 to 40.5±13.8 pg/mL (p<0.01). BMD levels decreased in almost all patients, with their t-score from -0.6±1.1 to -1.0±1.2 (p=0.015).Figure: No Caption available.Conclusion Increased bone formation markers and VD, and the tendency of the decreased bone resorption markers suggested the improvement of bone turnover after transplantation. However, BMD levels decreased presumably because of high dose of corticosteroids. Further understanding of the osteodystrophy even after successful kidney transplantation is crucial for the better treatment in the future.