Risk of bone loss or fracture among renal transplant recipients: race and steroid.

To the Editor: In a recent issue of Kidney International, El-Agroudy et al suggested that early bone loss that occurs during the first 12 months after renal transplantation could be prevented by alfacalcidol, calcitonin, or alendronate1. They enrolled 60 renal transplant recipients, randomized into 4 groups (alfacalcidol, alendronate, calcitonin, and control group), to perform a prospective open study for prevention of postrenal transplantation bone loss. This study has well controlled 5 in 6 recognized risk factors of hip fracture [old age (adjusted relative risk/RR 1.50 in 40- to 50-year-old group, 3.27 in 55- to 70-year-old group compared with group <40 years old), female sex (adjusted RR 1.64), diabetic nephropathy (adjusted RR 2.96), time on dialysis (adjusted RR 1.91 in patients on dialysis >12 months compared with those <3 months), renal transplantation (adjusted RR 1.34)] identified by Ball et al among 101,039 patients with ESRD placed on the renal transplant waiting list in the United States2. However, we wonder if the impact of the sixth recognized risk factor, race [black (adjusted RR 0.38) and others (adjusted RR 0.42) compared with white]2, was also well adjusted in El-Agroudy's study. In addition, although the study showed no difference in the cumulative dose of steroid at 1 year between groups, the possible different effect of pulse therapy on bone loss from that of maintenance therapy has never been evaluated. If it does make a difference, the recipients receiving frequent courses of steroid pulse therapy (2.5 g/course) should ideally be excluded because the mean cumulative steroid dose (1.21.3 g) and patient number in groups are relatively small.