Long-term follow-up study on bone mineral density and fractures after simultaneous pancreas-kidney transplantation

Abstract

In type 1 diabetic patients with end-stage renal failure, low bone mass is prevalent and the incidence of fractures high after simultaneous pancreas kidney transplantation (SPK). Data are scarce on preexisting skeletal morbidity or the long-term effects of SPK on bone mass and risk of fractures. We conducted a prospective study addressing these issues in 19 consecutive SPK recipients before and at 3, 6, and 12 months, and 2.5 to 4 years after establishment of graft function. Prior to transplantation, 13 patients (68%) had hyperparathyroidism, 7 of whom had osteoporosis. Mean bone mineral density (BMD) was significantly lower at the femoral neck than at the lumbar spine (T-scores -2.0 +/- 0.89 vs. -0.66 +/- 0.84). There was a significant decrease in BMD at both lumbar spine and femoral neck at 6 months post-transplantation (-6.0 +/- 5.4% and -6.9 +/- 4.3%, respectively). No further loss was observed in the following 6 months. At 1 year post-transplantation, 9 patients had osteoporosis associated with hyperparathyroidism in 8, and none had sustained a clinical fracture. A significant albeit small increase in BMD was observed 6 months after start of alfacalcidol 0.25 microg/day. At end-evaluation, osteoporosis and hyperparathyroidism persisted in the patients in whom it was documented at 1 year. Five patients who had lower BMD at the femoral neck pretransplantation sustained a clinical fracture. Cortical osteoporosis is prevalent in SPK recipients at the time of transplantation, progresses early post-transplantation, and is associated with relatively high incidence of fractures. Reversal of persistent hyperparathyroidism with the use of alfacalcidol may contribute to a decrease in skeletal morbidity.