Secondary Hyperparathyroidism After Kidney Transplantation: A Cross-Sectional Study

Abstract

Introduction. The purpose of the present study was to investigate the prevalence of hyperparathyroidism among a population of kidney graft recipients. Patients and Methods. We investigated biochemical bone parameters of 509 renal transplant recipients with a mean follow-up of 113 Ϯ 76 months. Among these patients, 257 patients were treated with either vitamin D or calcium supplements or both.Results. The mean estimated glomerular filtration rate (eGFR) was 47.2 Ϯ 18.4 mL/min/1.73 m 2 and the mean intact parathyroid hormone (iPTH) level was 144 Ϯ 149 pg/mL. A total of 70 patients (13.7%) had hypercalcemia defined by a corrected serum calcium Ͼ10.2 mg/dL. When the patients were classified according to iPTH concentrations following the Kidney Disease Outcome Quality Initiative (K/DOQI) clinical practice guidelines: 22.4% had iPTH Ͻ70 pg/mL; 30.8% between 70 and 110 pg/mL; 16.5% between 110 and 150 pg/mL; 24.3% between 150 and 300 pg/mL; and 6.9% Ͼ300 pg/mL. There were no differences in biochemical bone parameters between those that were or were not on calcium and vitamin D supplements, but there was a higher percentage of patients with normal iPTH among the treated group (28.0% vs 16.7%; P ϭ 0.003). In patients not receiving calcium and/or vitamin D supplements, multiple linear regression demonstrated that only time on dialysis, eGFR, and serum 25-hydroxyvitamin D (25OHD) levels were significantly predictive of iPTH concentrations (R 2 ϭ 0.21; P ϭ .000).

Early Development of Secondary Hyperparathyroidism following Renal Transplantation

“…This underlines the importance of a well-regulated SHPT prior to RT. The relation between time on dialysis and magnitude of SHPT after RT that has been observed in several studies [2,14] was not shown in our data. Instead, we found a significant correlation between iPTH levels at 12 months and type of graft even when adjusted for pre-transplant iPTH.…”

“…However, the value of using total calcium measurements (or calcium adjusted for albumin) is questioned [15,16] and determination of ionized calcium is preferred for several reasons. Previous studies have reported between 17 and 22% hypercalcemic patients at 6 months and between 2 and 14% at 12 months [10,14,17]. We found 32% of patients to be hypercalcemic 6 months after RT and 17% 1 year after RT.…”

“…Early post-transplant hypophosphatemia is well recognized and is associated with high levels of iPTH and fibroblast growth factor 23 [10,11,12]. Prior studies have shown an increase in total calcium adjusted for albumin after RT [10,13,14]. However, the value of using total calcium measurements (or calcium adjusted for albumin) is questioned [15,16] and determination of ionized calcium is preferred for several reasons.…”

Distúrbio mineral e ósseo após o transplante renal

“…8 No entanto, 25% dos pacientes, após 1 ano, persistem com os níveis de PTH elevados, relacionado ao tempo de diálise e à gravidade do HPS antes do transplante (provável hiperplasia nodular). 1,9 Outra causa de secreção aumentada de PTH é a disfunção do enxerto que leva ao desenvolvimento do HPS "de novo", 10 estando associado à taxa de filtração glomerular (TFG) entre 40-50 mL/min, levando a alterações ósseas semelhantes às do período dialítico. 11 A hipovitaminose D também colabora para o aumento da secreção do PTH, sendo sua reposição importante no controle do HPS.…”

Prevalence of Vitamin D Deficiency Among Patients After Kidney Transplantation in Latvia

“…Mostly, compared to the general population, adult post-renal transplant patients have an increased prevalence of 25(OH)D deficiency and elevated parathyroid hormone (PTH) levels (Marcen et al, 2009a;2009b).…”