Effect of ibandronate on bone loss and renal function after kidney transplantation

Abstract

Severe osteoporosis frequently is observed after organ transplantation. In kidney transplantation, it adds to pre-existing renal bone disease and strategies to prevent osteoporosis are not established. Eighty kidney recipients were included in a randomized controlled prospective intervention trial. Treated patients (n = 40) received an injection of ibandronate, a bisphosphonate, immediately before and at 3, 6, and 9 mo after transplantation. The primary outcome measured was the change in bone mineral density. Secondary measures included graft outcome, spinal deformities, fracture rate, body height, and hormonal and metabolic data. Loss of spongy and cortical bone after transplantation was prevented by ibandronate. Changes of bone mineral density (ibandronate versus controls) were as follows: lumbar spine, -0.9 +/- 6.1% versus -6.5 +/- 5.4% (P < 0.0001); femoral neck, +0.5 +/- 5.2% versus -7.7 +/- 6.5% (P < 0.0001); and midfemoral shaft, +2.7 +/- 12.2% versus -4.0 +/- 10.9% (P = 0.024). Fewer spinal deformities developed with ibandronate (7 patients with 7 deformities versus 12 patients with 23 deformities; P = 0.047). Loss of body height was 0.5 +/- 1.0 cm versus 1.1 +/- 1.0 cm in control subjects (P = 0.040). Two bone fractures occurred in each group. There were fewer acute rejection episodes with ibandronate (11 versus 22; P = 0.009). Graft function after 1 yr was comparable. Bone loss, spinal deformation, and loss of body height during the first year after kidney transplantation are prevented by injection of ibandronate at intervals of 3 mo. The smaller number of rejection episodes of the ibandronate-treated group should be confirmed and its mechanism should be explored in additional studies.