Treatment of established bone loss after renal transplantation with etidronate

Osteoporosis is a well-documented complication of organ transplantation. Bisphosphonates have been shown to be effective in preventing corticosteroid-induced osteoporosis in renal transplant recipients, but data are lacking for treatment of established osteoporosis. This study reports our clinical experience of treatment with the bisphosphonate etidronate in a single renal transplant center.

To establish the effectiveness of etidronate in treating established low bone mineral density (BMD), all newly transplanted patients treated with etidronate were compared with controls. Twenty-five patients treated with etidronate (14 males, 11 females) and 24 controls (15 males, 9 females) were identified from the cohort of patients who underwent transplantation between January 1, 1994, and December 31, 1996.

There was no difference in mean age, weight, or cumulative dose of corticosteroids between the treatment and control groups. The baseline BMD measurement was performed at 10.4 +/- 5.3 months after transplantation for treated patients and at 10.7 +/- 4.5 months for controls (P=0.78). Over the subsequent 1-year study period, patients treated with etidronate demonstrated a greater increase in BMD at sites with a preponderance of trabecular bone. Lumbar spine BMD increased 4.3 +/- 6.1% in the treatment group versus 0.55 +/ -5.3% in controls (P<0.03) and trochanter BMD increased 10.3 +/- 11.9% and 2.2 +/- 5.7%, respectively, in the treatment and control groups (P<0.02).

This study establishes the effectiveness of etidronate for treatment of low BMD in renal transplant recipients. Patients selected for treatment had lower baseline BMD than control subjects, yet still showed a clinically important increase in BMD.