Post-Renal Transplantation Bone Health in Children Evaluated by Means of Quantitative Ultrasound and Densitometry

Background. Patients with end-stage renal disease develop bone mineral disease, which is not always resolved after a successful renal transplantation; moreover, some of the immunosuppressants used to prevent graft rejection may affect bone health. The aim of this study was to evaluate bone health in post-renal transplantation children with the use of quantitative ultrasound (QUS) and dual-energy X-ray absorptiometry (DXA). Methods. A descriptive study was performed in children >3 months after renal transplantation and with stable function of graft. Radial QUS and DXA (lumbar spine and total body less head (TBLH) were performed on the same day. Results. A total of 35 patients were included. Mean age was 13.9 +/- 3.9 years. Ten subjects had total bone density score <2 (28.5%), 4 a lumbar spine (Ll-L4) Z-score of <2 (11.4%) as well as TBLH <2, and 6 subjects had a radial QUS Z-score of <2 (17.1%), and only 2 of them had concomitant Z-score <2 with the use of DXA. There was a positive non-significant correlation between TBLH and radial QUS Z-scores (Pearson r = 0.317; P =.016) and a positive significant correlation of DXA lumbar spine and radial QUS Z-scores (Pearson r = 0.452; P =.014). Conclusions. Despite a good correlation between TBLH and QUS Z-scores, there are subjects that can be considered normal by QUS and have osteopenia by TBLH DXA and vice versa; this could be due to the different bone areas evaluated.