Persistent Hyperparathyroidism Post- Kidney Transplantation: A Single Center Experience

Abstract

Background and aim: Persistent hyperparathyroidism after renal transplantation, termed tertiary hyperparathyroidism, is not uncommon. We aimed to identify the prevalence of persistent hyperparathyroidism after successful kidney transplantation and to study the associated risk factors. Methods: This is a cross-sectional study including 63 patients who underwent renal transplantation for the first time &for at least a year. Data was collected about demographic characteristics, duration of chronic kidney disease& dialysis therapy, history of hypertension, diabetes mellitus, coronary heart disease and use of medications including vitamin D. Levels of serum calcium and phosphate and renal function test were recorded prior and post- transplantation. Serum parathyroid hormone was tested only post- transplantation. The association of those variable with hyperparathyroidism was studied by Pearson’s correlation. P≤0.05 was considered statistically significant. Results: Hyperparathyroidism was found in 53 (84.10%) patients, there was a strong positive correlation of parathyroid hormone level and serum levels of calcium and phosphate with (p-value<0.001). While the correlation was negative of parathyroid hormone level and estimated glomerular filtration rate after transplantation. None of the variables apart from hypertension was strongly associated as a risk factor before transplantation for persistant hyperparathyroidism. Conclusions: In this single center study; more than 80% of post-transplant patients with normal transplant function, have elevated levels of parathyroid hormone more than one year after transplantation. This may have a major impact on clinical treatment guidelines. However, no association was observed between pre-transplant age, duration of transplant, duration on dialysis as risk factors for persistent hyperparathyroidism.