Bone Metabolism‐related Serum Biomarkers and Nutritional Markers for Bone Fractures in Living‐donor Kidney Transplant Recipients

Abstract

Background/Aim: The clinical importance of fracture prevention in patients with end‑stage renal disease is well‑ established. We investigated the roles of bone metabolism‑related serum biomarkers and nutritional markers for fractures in Japanese living‑donor kidney transplant recipients. Patients and Methods: We included 204 consecutive patients who underwent kidney transplantation at Nara Medical University between 2003 and 2022 and retrospectively reviewed their medical charts. The cumulative incidence of fractures was investigated by focusing on bone metabolism‑related serum biomarkers and nutritional markers, and related markers were explored. Results: The age at surgery in the fracture group was significantly higher than that in the no‑fracture group (p=0.018). Patients with fractures had a significantly higher risk of mortality than those without fractures (p=0.0018); cardiovascular mortality was higher in the fracture group than in the non‑fracture group (p=0.052). The cumulative incidence of fractures (median follow‑up period, 98 months) was 4.6% at 1 year, 8.6% at 2 years, 12.3% at 3 years, and 15.5% at 5 years after transplant. Particularly, patients with a survival index <26.1 had a significantly higher risk of fracture (p=0.014). Serum intact parathyroid hormone level (a bone metabolism‑related biomarker) and survival index (a nutritional marker) were independently related to fractures (p=0.046 and p=0.022, respectively). Conclusion: Serum intact parathyroid hormone level and the survival index may play important roles in determining the incidence of fractures in living donor kidney transplant recipients. Identifying patients at high risk of fractures and providing optimal intervention and education may contribute to improved and personalized management strategies.