Bone-Mineral Density In Children After Renal-Transplantation

Successful renal transplantation is supposed to correct the majority of bone mineral metabolism disturbances induced by chronic renal failure. We examined bone mineral density (BMD) in 14 children (8 girls, 6 boys) aged 8 ± 4 years at the time of renal transplantation (Tx). Dual energy X-ray densitometry of lumbar vertebrae (L1-L4) was performed within one year preceding Tx (T0), 6, 12 and 24 months after Tx (T6, T12 and T24 respectively). The results of BMD obtained in g of hydroxyapatite per cm2 of spine projected area were subsequently transformed to Z scores (Z) for normal pediatric population. All patients had a well functioning renal graft at T6, T12 and T24, median serum creatinine levels were 54, 63 and 84 μmol/l, respectively. BMD ± SD decreased from initial level of 0.65 ± 0.18 at T0 to 0.59 ± 0.16 at T6 (p < 0.05). BMD ± SD measured at T12 (0.61 ± 0.15) and T24 (0.67 ± 0.16) was not significantly different from T0. Similar significant (p < 0.01) decrease of BMD expressed in median Z was observed between T0 (0.19) and T6 (−1.04), remained significantly (p < 0.01) lower at T12 (−0.93) and increased to −0.52 at T24 (p < 0.05 vs T0). In conclusion, children after kidney transplantation experienced a significant decrease of bone mineral density during the first 6 months after operation despite normal graft function. Progressive improvement of BMD was noted 12 and 24 months after Tx.