Does renal function improve after parathyroidectomy in primary hyperparathyroidism? / ¿Mejora la función renal tras la paratiroidectomía en el hiperparatirodismo primario?

INTRODUCTION: Primary hyperparathyroidism (PHPT) is a common endocrine disorder characterised by hypercalcaemia and parathormone increase. Decreased glomerular filtration rate (<60ml/min) continues to be a parathyroidectomy (PTX) criterion in asymptomatic PHPT. The influence of PTX on renal function evolution is the subject of debate. OBJECTIVE: To analyse the clinical, laboratory and histological characteristics of patients undergoing PHPT, as well as renal function evolution after PTX. MATERIAL AND METHODS: Retrospective study of 297 patients diagnosed with PHPT and referred to surgery in a single centre between 1998 and 2016. Laboratory parameters were determined at baseline, one week and one year after PTX. RESULTS: The Incidence of PTX was 38 cases/million/year. Mean age was 60±14 years and 80.5% of the patients were female. Approximately 65.3% were asymptomatic. Nephrolithiasis was the most common clinical finding (33%), followed by bone involvement (29.5%). PTX indications were: clinical symptoms (34.7%), hypercalcaemia>11.2mg/dl (27%), nephrolithiasis (13%), low bone mass (12%), age<50 years (11%) and decreased glomerular filtration rate<60ml/min (2.3%). For diagnostic localisation, spect-MIBI had a sensitivity of 92% and cervical ultrasound of 70%. A total of 94.3% of PHPT cases were due to a parathyroid adenoma. After PTX, normalisation of PHPT-related parameters was observed. We found a significant increase in serum creatinine levels (0.81 vs 0.85mg/dl, P<.001) from the first week post-PTX until the end of the first year. The renal function was only found to be significant in patients with glomerular filtration rate>60ml/min (baseline serum creatinine levels 0.77mg/dl vs serum creatinine levels after one year 0.81mg/dl, P<.001). CONCLUSIONS: PHPT was asymptomatic in most patients who underwent surgery. Hypercalcaemia and nephrolithiasis were the most common indications of parathyroidectomy in asymptomatic patients. MIBI scan was the most useful localisation method. Surgical treatment of PHPT is followed by renal function impairment, which persists after the first week post-PTX.