Alendronate prevents bone loss in patients with acute spinal cord injury: a randomized, double-blind, placebo-controlled study.

Abstract

Patients who sustain an acute spinal cord injury (SCI) experience rapid dramatic reductions in bone mineral density (BMD), especially marked in sublesional areas and sometimes leading to hypercalcemia and hypercalciuria, as well as increased fracture risk. In this prospective, double-blind, randomized, placebo-controlled study, we evaluated the hypothesis that oral alendronate administration would preserve BMD when administered soon after acute SCI. Thirty-one patients with acute SCI were randomly allocated to receive oral alendronate 70 mg/wk or placebo, within 10 d of acute SCI, for 12 months. At entry and at 3, 6, 12, and 18 months, total body bone density, lumbar and hip BMD, ultrasound of the calcaneus, 24-h urinary calcium, and serum C-telopeptide (betaCTX) were measured. At study entry, patients in the two groups were well matched for age, gender, severity of neurological deficit, BMD, urinary calcium, and betaCTX. BMD indices declined steadily in the placebo group, and this effect was attenuated significantly by alendronate. After 12 months, there was a 5.3% difference (P<0.001) in total body BMD and a 17.6% difference (P<0.001) in the total hip BMD between the two groups. Alendronate compared with placebo induced significant (P<0.001) reductions in urinary calcium excretion and serum betaCTX. No treatment-related side effects were noted. We conclude that alendronate therapy, 70 mg/wk, initiated soon after acute SCI, prevents bone loss and is not associated with side effects.