Characteristics of Mineral Bone Disease Profile in Kidney Transplant Recipients - A 9-Year Retrospective Cohort Study at a Tertiary Center.

Background: The progression of chronic kidney disease (CKD) into end-stage kidney disease and the eventual kidney transplantation is linked to substantial changes in bone mineral metabolism, predisposing to bone-related complications, including osteoporosis and fractures. Understanding the bone profile in kidney transplant recipients could improve post-transplant care and long-term outcomes.

Methods: This retrospective study at the University Malaya Medical Centre (UMMC) involved all kidney transplant recipients from January 2015 to December 2023. Patients without baseline serum intact parathyroid hormone levels or who had graft failure within 1 year were excluded. All baseline characteristics, medications, and pre- and post-transplant bone mineral profiles were collected from electronic medical records (EMRs) and analyzed using Statistical Package for the Social Sciences version 29.0.2.

Results: A total of 179 patients were included, with a mean age of 40.6 ± 11.0 years old (57% men). The median dialysis vintage was 18 (interquartile range [IQR] = 36), with 19% undergoing pre-emptive transplants. Before the transplant, 57% of the patients received calcium carbonate, 51.4% were on vitamin D receptor analogues (VDRAs), 26.3% were on sevelamer, 5.6% were on cinacalcet, 2.2% were on lanthanum, and 0.6% were on sucroferric oxyhydroxide. All patients received induction methylprednisolone during the transplant. At 1 year post-transplant, 90% of the patients remained on prednisolone at a median dose of 5.0 mg. Parathyroidectomy was performed on two patients (1.1%) before transplant and another two (1.1%) after transplant. No patient had a fracture post-transplantation during the study period. Biochemically, mean serum intact parathyroid hormone (iPTH), calcium, phosphate, and hemoglobin were significantly improved from pre-transplant to 2 years post-transplant (P < .001), with serum iPTH and calcium showing improvement as early as 3 months and maintained thereafter. Both serum phosphate and hemoglobin levels continuously showed improvement up to 2 years post-transplant (P < .05).

Conclusions: Our study showed significant improvements in biochemical bone profile and hemoglobin levels as early as 3 months post-transplant, which had continued to improve or maintain for up to 2 years post-transplant.