Risedronate therapy for the prevention of steroid-induced osteoporosis in patients with minimal-change nephrotic syndrome.
BACKGROUND
Minimal-change nephrotic syndrome (MCNS) is treated by the administration of prednisolone (PSL) at high doses. Steroid-induced osteoporosis is a serious adverse effect of this drug.


METHODS
Patients with MCNS were randomly assigned to two groups, the risedronate (2.5 mg/day) + alfacalcidol (0.25 µg/day) group (n=20) and the alfacalcidol (0.25 µg/day)-alone group (n=20). All the patients had received PSL and the clinical characteristics were compared between the two groups at baseline and at 12 months.


RESULTS
A significant decrease of the mean bone mineral density (BMD) of the lumbar spine from 0.710±0.162 (g/cm(2)) to 0.588±0.125 was observed in the alfacalcidol-alone group (p=0.02), while no such decrease of the bone mineral density was found in the risedronate + alfacalcidol group (0.663±0.169 at baseline and 0.626±0.129 at 12 months). No significant differences in the results of other biochemical tests performed at the baseline and at 12 months were observed between the two groups. The likelihood of development of steroid-induced osteoporosis was influenced by the cumulative dose of PSL, the mean BMD at the baseline, occurrence of disease relapse, and risedronate therapy.


CONCLUSION
Risedronate appears to be effective in preventing steroid-induced osteoporosis. It is necessary to use bisphosphonates to maintain the BMD in patients with MCNS receiving prolonged steroid therapy.