Natural history of bone disease following kidney transplantation

Background: Knowledge of the impact of kidney transplantation on bone is limited and fragmentary. The aim of this study was to characterize the evolution of bone disease in the first post-transplant year. Methods: We performed a prospective, observational cohort study in patients referred for kidney transplantation under a steroid-sparing immunosuppressive protocol. Bone phenotyping was done prior to, or at the time of, kidney transplantation, and repeated at 12 months post-transplant. The phenotyping included bone histomorphometry, bone densitometry by dual-energy x-ray absorptiometry, and biochemical parameters of bone and mineral metabolism. Results: Paired data were obtained for 97 patients (median age 55 years, 72% male, 21% diabetics). Bone turnover remained normal or improved in the majority (65%). Bone histomorphometry revealed decreases in bone resorption (eroded perimeter 4.6% to 2.3%, p<0.001) and disordered bone formation (fibrosis 27% pre-vs 2% post-transplant, p<0.001). While bone mineralization was normal in all but 1 patient pre-transplant, delayed mineralization was seen in 15% of patients at 1 year post-transplant. Hypophosphatemia was associated with deterioration in histomorphometric parameters of bone mineralization. Changes in bone mineral density were highly variable, ranging from -18 to +17% per year. Cumulative steroid dose was related to bone loss at the hip, while resolution of hyperparathyroidism was related to bone gain at both spine and hip. Conclusions: Changes in bone turnover, mineralization, and volume post-transplant are related to both steroid exposure and ongoing disturbances of mineral metabolism. Optimal control of mineral metabolism may be key to improving bone quality in kidney transplant recipients.

Trefwoorden:A1 Journal article

Toegankelijkheid:Open