Background: Tertiary hyperparathyroidism is one of the causes of bone demineralisation, nephrolithiasis and a potential risk factor influencing blood pressure and excretory graft function in patients after kidney transplantation (Tx). The aim of the study is to analyse the influence of parathyroidectomy (PTx) on graft function and blood pressure control in these patients. Methods: 392 subsequent patients after kidney Tx were included into this analysis. Records of 84 patients (21.4%) with elevated plasma calcium concentration (>2.6mmol/l) during observation were reviewed. In 39 patients (9.9%) calcaemia remained elevated for over I year after kidney Tx. Eleven patients (2.81%) were referred for PTx. In 2 cases PTx were performed within the first 6 months, while the 9 others undergone surgery between 16 and 36 months after Tx. We have evaluated the influence of PTx on renal allograft excretory function, blood pressure and the number of antihypertensive drugs in kidney transplant patients. Results: In 7 out of II patients the indication for PTx was renal osteodystrophy, while in other cases the indication was the asymptomatic hypercalcaemia. Shortly after surgery normalisation of calcaemia was observed in all cases. However the creatinine clearance did not changed shortly after PTx (64:t 12 vs 63:t 16 ml/min), and a slight deterioration of transplanted kidney excretory function was observed in 2 patients. 12 months after PTx deterioration of GFR (5320 ml/min) of borderline significance was found. All patients before PTx suffered from arterial hypertension, ten of them were receiving antihypertensive drugs (average 1.6 medicine per patient). Two weeks after PTx a transient decline of both systolic and diastolic blood pressures (-13:t 14 mmHg; p=0.02 and -46 mmHg; p=0.06, respectively) was observed. However there was a negative correlation between initial plasma calcium concentration and decline of diastolic blood pressure (R=-0.884; p=0.0003). Six and twelve months after PTx blood pressure values were at the same magnitude as before PTx. Conclusions: I) Parathyroidectomy and normalisation of calcaemia did not influence significantly the excretory allograft kidney function. 2) Patients benefit from PTx only with the transient improvement of their blood pressure control.

Keywords: Parathyroidectomy, Kidney Transplantation, Blood Pressure, creatinine clearance