A 3‐year longitudinal study of skeletal effects and growth in children after kidney transplantation

Abstract

This prospective study investigated growth and skeletal development for 3 years after kidney transplantation in pediatric patients, 3.4-15.0 years of age. Growth, BMD, bone resorption markers (CTX and TRACP5b), bone formation markers (PINP, ALP, and osteocalcin), PTH, and vitamin D were assessed at start, 3, 12, and 36 months after transplantation. Median GFR was 63 (range 37-96) mL/min/1.73 m after 3 years. The median height SDS increased from -1.7 to -1.1, and median BMI SDS increased from -0.1 to 0.6 over 3 years, which shows that transplantation had a favorable outcome on growth. Fat mass increased after transplantation at all time points, whereas lean mass increased after 1 year and 3 years. Total BMC increased at all time points. No changes were observed for total BMD. Bone resorption markers decreased initially after 3 months and remained stable throughout the study, whereas the bone formation markers decreased initially, but successively increased over the study period. In conclusion, this study demonstrates that height SDS and BMI SDS increased, along with the increased formation markers that reveal a positive bone acquisition after kidney transplantation, which was reflected by the significant increase in total body BMC.

Altered cortical bone strength and lean mass in young women with long-duration (19 years) type 1 diabetes

“…Power calculations were made regarding total body BMC. To detect a difference of 250 g (SD 272 g) 21 with the power of 80% using the Mann–Whitney test for unpaired observations (significance level of 0.05); it was found that a sample size of 20 individuals was needed in each group. Descriptively, number and percentages were shown for categorical variables, and mean, SD, median, minimum and maximum were shown for continuous variables.…”

Height‐adjusted lean body mass and its associations with physical activity and kidney function in pediatric kidney transplantation

“…Since height is directly proportional to absolute LBM, 75 adjusting for height is important in order to compare pediatric studies of LBM. 23,73 Ht-LBM was determined using DXA scans with the Hologic Discovery A bone densitometer, which were obtained as part of bone health surveillance. Routine bone health surveillance included DXA scan pre-transplant, at approximately 6 months and 2 years post-transplant in children >5 years of age who could tolerate the scan.…”

“…One report showed no LBM change at 12 months, 20 another showing increases after 16 months, 21 and a third showing decreases after 12 months post-transplant. 22 Studies investigating changes in LBM in pediatric kidney transplant recipients are limited [23][24][25] and small in size, but suggest accrual of LBM after transplantation. One study (n = 13) showed an increase of 27% in absolute LBM after 3 years compared to baseline, 23 while another study (n = 16) reported decreased LBM SDS scores of −0.6 SDS at 3 months compared to baseline, with a non-significant trend to improvement thereafter at 24 months post-transplant.…”

“…22 Studies investigating changes in LBM in pediatric kidney transplant recipients are limited [23][24][25] and small in size, but suggest accrual of LBM after transplantation. One study (n = 13) showed an increase of 27% in absolute LBM after 3 years compared to baseline, 23 while another study (n = 16) reported decreased LBM SDS scores of −0.6 SDS at 3 months compared to baseline, with a non-significant trend to improvement thereafter at 24 months post-transplant. 24 While similar studies are lacking in children, LBM in adults with CKD is associated with greater survival on dialysis 26,27 and after transplantation.…”

Canadian Society of Nephrology Commentary on the Kidney Disease Improving Global Outcomes 2017 Clinical Practice Guideline Update for the Diagnosis, Evaluation, Prevention, and Treatment of Chronic Kidney Disease-Mineral and Bone Disorder

“…From the pediatric perspective, the CSN pediatric working group agrees with the use of vitamin D and/or calcitriol in children following kidney transplantation but would caution against the use of antiresorptives in this population given that standard steroid-tapering regimens are often sufficient for improvement in BMD in children. [129][130][131] The longterm effect of inhibiting bone reabsorption in a growing skeleton is currently not known. There are insufficient data to guide treatment recommendations in children with kidney transplants.…”