Changes in bone mineral density in patients undergoing kidney transplantation

Background and Aims: Bone health in chronic kidney disease (CKD) and its changes after kidney transplantation has been a subject of considerable interest. Kidney transplantation could potentially impact this process positively by reversing hyperparathyroidism, but immunosuppression including steroids could be deleterious to bone health. We studied the baseline and posttransplant bone mineral density (BMD) and factors affecting the changes in BMD after transplantation. Methods: Patients who were included in the study underwent biochemical tests and dual-energy absorptiometry for BMD. These tests were performed at baseline and 8 months after transplantation. Results: The mean BMD in lumbar spine was 1.09 +/- 0.15 g/cm(2) at baseline and 1.06 +/- 0.15 g/cm(2) posttransplantation (P = 0.002). The mean BMD at left forearm was 0.88 +/- 0.10 g/cm(2) at baseline and 0.89 +/- 0.10 g/cm(2) after transplantation (P = 0.013). The mean BMD at femur was 0.91 +/- 0.16 g/cm(2) and 0.89 +/- 0.10 g/cm(2) (P = 0.77) after transplantation. At baseline, intact parathyroid hormone (iPTH) had a significant negative correlation with femoral BMD (r = 0.44, P = 0.02) and 25-hydroxy Vitamin D (25(OH) Vit-D) had a positive correlation with forearm BMD (r = 0.50, P = 0.004). Eight months after transplantation, 25(OH) Vit-D levels showed a positive correlation with lumbar spine BMD (r = 0.36, P = 0.04). Cumulative steroid dose negatively correlated with spine BMD (r = -0.43, P = 0.01) posttransplantation. Conclusions: In this study, the baseline BMD was well preserved. Higher iPTH was associated with lower femoral BMD. Low 25(OH) Vit-D was associated with reduced forearm BMD. There was worsening of spinal BMD and improvement in forearm BMD 8 months after transplantation. No significant change in femoral BMD was noted. Cumulative steroid dose had a significant negative impact on BMD at spine. There were no fractures noted during the study, but two patients had avascular necrosis of the femur.