Pretransplant Osteoporosis an'd Osteopenia are Risk Factors for Fractures After Kidney Transplantation

Abstract

Background. There is a high risk of fracture after kidney transplantation (KT). Recipients of KT are susceptible to persistent hyperparathyroidism and other disorders of bone and mineral metabolism. However, the risk factors for fractures after KT remain uncertain. The aim of the present study was to investigate the risk factors for fracture after KT. Methods. A total of 941 recipients of KT were enrolled from a multicenter observational cohort study in Korea from 2012 to 2016. The biochemical markers were measured at the time of KT, then annually for 5 years following KT. All fracture events were recorded. A Cox proportional hazards analysis was performed to calculate hazard ratios (HR) for the association of risk factors with fractures. Results. Twenty-two fractures had occurred in 20 patients during the study period. Baseline and serial changes of mineral and bone biochemical markers were similar between fracture and nonfracture patient groups. Among the total study population, 104 patients were diagnosed with osteoporosis and 422 patients were diagnosed with osteopenia in a pretransplant bone mineral density test. In a multivariate Cox analysis, pretransplant osteoporosis (HR = 11.76; 95% confidence interval [CI], 2.28-60.69; P=.003) and pretransplant osteopenia (HR = 5.21; 95% CI, 1.15-23.57; P=.032) were independent risk factors for fracture in recipients of KT. Conclusions. Pretransplant osteoporosis and osteopenia were independent risk factors for fracture after KT. More careful monitoring of bone mineral density before and after KT might be beneficial to predict the risk for fracture after KT.