Secondary hyperparathyroidism (HPT) is a known complication of chronic renal failure. Elevated concentrations of parathyroid hormone (PTH) play a role not only in the pathogenesis of renal bone disease, but also in the development of cardiovascular risk factors such as disturbed lipid metabolism, glucose intolerance, and hypertension. HPT is also known to play an important role in the development of structural abnormalities of both large arteries and the heart (left ventricular hypertrophy, interstitial fibrosis). In the last couple of years there has been increasing evidence from animal studies that the endothelium is a target organ of PTH.

Hypothesis: PTH has clinically relevant effects on renal hemodynamics, renal function and endothelial function.

Aims:

1. To evaluate the effect of parathyroidectomy (PTX) on renal hemodynamics in stable renal transplant recipients
2. To evaluate the effect of PTX on endothelial function in stable renal transplant recipients/chronic kidney disease (CKD) stage 5 patients
3. To evaluate the effect of PTX on blood pressure in stable renal transplant recipients/CKD stage 5 patients