Body mass index is associated with hyperparathyroidism in pediatric kidney transplant recipients

Background: Hyperparathyroidism persists in up to 50% of pediatric kidney transplant recipients. The aims of this study were to describe the evolution of parathyroid hormone (PTH) in the first year after transplantation and to identify factors associated with hyperparathyroidism. Methods: This retrospective study included children who underwent kidney transplantation at the University Hospitals of Ghent, Leuven, Rotterdam, or Amsterdam. Data from 149 patients were collected before and up to 12 months after transplantation. Severe hyperparathyroidism was defined as PTH 2-fold above the reference value. Factors associated with hyperparathyroidism and severe hyperparathyroidism were identified using multivariate logistic regression analysis. Results: Before transplantation, 97 out of 137 patients (71%) had hyperparathyroidism. The probability of hyperparathyroidism and severe hyperparathyroidism declined from 0.49 and 0.17 to 0.29 and 0.09 at 3 and 12 months after transplantation, respectively. BMI SDS (β: 0.509; p = 0.011; 95% CI: 1.122–2.468), eGFR (β: − 0.227; p = 0.030; 95% CI: 0.649–0.978), and pre-transplant hyperparathyroidism (β: 1.149; p = 0.039; 95% CI: 1.062–9.369) were associated with hyperparathyroidism 12 months after transplantation. Pre-transplant hyperparathyroidism (β: 2.115; p = 0.044; 95% CI: 1.055–65.084), defined as intact parathormone (iPTH) levels > 65 ng/l (6.9 pmol/l) or 1-84 PTH > 58 ng/l (6.2 pmol/l), was associated with severe hyperparathyroidism at 3 months. Only eGFR (β: − 0.488; p = 0.010; 95% CI: 0.425–0.888) was inversely associated with severe hyperparathyroidism at 9 months after transplantation. Conclusions: Allograft function remains the main determinant of severe hyperparathyroidism after transplantation. Our findings emphasize the importance of BMI and pre-transplant PTH control

Early corticosteroid withdrawal is associated with improved adult height in pediatric kidney transplant recipients

Background: Catch-up growth after pediatric kidney transplantation (kTx) is usually insufficient to reach normal adult height. We aimed to analyze the effect of pre-transplant recombinant human growth hormone (rhGH) and corticosteroid withdrawal on linear growth in the first year after kidney transplantation and identify factors associated with final height (FH). Methods: Patients who underwent kTx between 1996 and 2018 at below 18 years old in five Belgian and Dutch centers were included. We analyzed the differences between height Z-scores at kTx and 1 year post-transplant (Δ height Z-score) in children with and without corticosteroids at 1 year (CS + /CS −) and with and without rhGH treatment before kTx (rhGH + /rhGH −). Univariable and multivariable linear regression analysis was applied to identify factors associated with height Z-score at 1 year post-kTx, Δ height Z-score, and FH Z-score. Results: A total of 177 patients were included, with median age 9.3 years at kTx. Median height Z-scores pre-kTx and 1 year later in the CS − /rhGH − , CS + /rhGH − , CS − /rhGH + , and CS + /rhGH + groups were − 1.42/ − 0.80, − 0.90/ − 0.62, − 1.35/ − 1.20, and − 1.30/ − 1.60 (p = 0.001). CS use 1 year post-kTx was the only factor associated with Δ height (p = 0.003) on multivariable analysis. CS use at 1 year was the only variable associated with FH (p = 0.014) in children with pre-transplant height Z-score below − 1 (n = 52). Conclusions: Increase in height Z-score in the first year post-kTx was highest in the CS − /rhGH − group and lowest in the CS + /rhGH + group. The use of corticosteroids at 1 year post-kTx is associated with catch-up growth and in children with pre-transplant height Z-score below − 1 also with final height. Graphical abstract: A higher resolution version of the Graphical abstract is available as Supplementary information [Figure not available: see fulltext.]