Renal dysfunction in primary hyperparathyroidism; effect of Parathyroidectomy: A retrospective Cohort Study.

INTRODUCTION: Renal dysfunction associated with primary hyperparathyroidism was studied mostly in patients with mildly asymptomatic or asymptomatic parathyroid disorders. Clinical and biochemical profile of asymptomatic and symptomatic disease vary grossly. The present study analyzed renal function in patients with primary hyperparathyroidism and the relation with clinical features, biochemical features and sonologic changes of kidneys in a cohort of primary symptomatic hyperparathyroidism.

STUDY DESIGN: Cross-sectional study was done in a cohort of surgically proven patients of primary symptomatic hyperparathyroidism. Urinary tract was evaluated with high definition Ultrasonography and renal function was estimated using Modification of Diet in Renal disease (MDRD) Study equation before and after parathyroidectomy.

RESULT: Case records 145 patients were studied and there were 44 patients (30.4%) with estimated Glomerular Filtration Rate (eGFR) less than 60 mL/min/1.73 m(2). Associated renal complications, coincident hypertension and high serum level of calcium were strongly associated with renal dysfunction. Renal dysfunction marginally improved after 1 year following surgical cure of hyperparathyroidism in 25% of patients with renal dysfunction. There was no detectable change in renal function during the follow up period.

CONCLUSION: There was high prevalence of renal dysfunction among symptomatic hyperparathyroidism. Patients with primary hyperparathyroidism should undergo complete sonological assessment of kidneys which may include presence of nephrocalcinosis and cortical echogenicity. Successful parathyroidectomy prevented deterioration of renal function in most of patients and a significant subset with renal dysfunction showed improvement of functional status.