Change of Bone Mineral Density after Kidney Transplantation and Factors Influencing Post-transplant Bone Mineral Density Loss

Kim, Hyun Jung; Kim, Myoung Soo; Kim, Yu Seun; Jee, Sun Ha; Ahn, Hyung Joon; Huh, Kyu Ha; Jeon, Kyung Ock; Kim, Soon Il

Abstract

PURPOSE
Osteoporosis is one of the common complications following kidney transplantation which causes profound morbidity. Using the pre-transplant bone mineral density (BMD) data, post-transplant change in the BMD of recipients was retrospectively evaluated. The risk factors affecting the post-transplant BMD changes were also evaluated in this study. METHODS: Between Jan. 1996 and Sep. 2003, 294 kidney transplant recipients were enrolled in this study. The BMD was expressed as the T-score of the spine and femur. The gender, age, the presence of pre-transplant diabetes mellitus, the matching degree of ABO blood types, the mode and duration of dialysis, and the history of previous transplantation were considered as variables possibly affecting the pre-transplant BMD and post-transplant BMD loss. Comparison analysis in each group was performed by a Students t-test or ANOVA. RESULTS: According to the pre-transplant BMD study, the mean of the spine T-score was significantly lower in the retransplant group. The mean femur T-score was also significantly lower in the retransplant group as well as the elderly (more than 45 years) and female recipients. In the 3 years following transplantation, rapid bone loss occurred particularly in the first post-transplant year. After a kidney transplantation, the normal pre-transplant BMD group (T- score>-1.0) showed a significantly higher bone loss than the abnormal pre-transplant BMD group (T-score< or =-1.0). Prolonged pre-transplant hemodialysis (more than 12 months) and a retransplant were risk factors affecting the BMD loss in the first post-transplant year. The early application of anti-osteoporosis management (such as alfacalcidol, alendronate sodium, or risendronate sodium) was effective in ameliorating the post-transplant BMD loss. However, anti- osteoporosis management after the first post- transplant year was not effective. CONCLUSION: A pre-transplant evaluation of the BMD and the significant BMD loss during the first post-transplant year should not be overlooked. Prophylactic management against the bone loss and the treatment of osteoporosis should be started as soon as possible after transplantation in recipients with both normal and abnormal pre-transplant BMD.