Spectrum of renal dysfunction after curative parathyroidectomy in symptomatic primary hyperparathyroidism

Objective. - The long-term renal consequences of curative parathyroidectomy (PTX) in symptomatic pri-mary hyperparathyroidism (sPHPT) are not well characterized. We aimed to assess renal glomerular and tubular functions in an sPHPT cohort at >= 1 year's follow-up.Design. - Retrospective-prospective study.Methods. - sPHPT patients with preoperative eGFR >= 60 mL/min/1.73m2 and in remission (normocal-cemic) for >= 1 year after PTX underwent clinical and biochemical assessment (calcium profile, renal parameters). Ammonium chloride and bicarbonate loading tests were performed in patients with renal tubular dysfunction (RTD).Results. - Forty-eight patients (31 females) with median plasma PTH 1,029 (338-1604) pg/mL and mean eGFR 109.2 +/- 26.0 mL/min/1.73m2 at diagnosis were evaluated at 5.62 +/- 3.66 years after curative PTX. At follow-up, eGFR was < 60 mL/min/m2 in 5 patients (10.4%). Patients with > 10% drop in eGFR (n = 31) had significantly higher pre-PTX plasma PTH (1,137 vs. 687 pg/mL), and longer time to post-PTX evalu-ation (6.8 vs. 3.4 years). RTD was seen in 11 patients (22.9%): urinary low molecular weight proteinuria (14.6%), distal renal tubular acidosis (12.5%), hypophosphatemia (8.3%), and hypokalemia (8.3%); RTD was associated with significantly lower post-PTX eGFR (72.7 vs. 95.4 mL/min/m2). Five of the 7 RTD patients undergoing loading test had impaired urinary acidification, whereas none had impaired bicarbonate resorption. Conclusions. - Reduction in eGFR and subclinical RTD were prevalent at long-term follow-up in the present Asian-Indian cohort with cured sPHPT. Further studies are warranted to understand the clinical implications of these various renal abnormalities.(c) 2022 Elsevier Masson SAS. All rights reserved.

Automated summary

This study aimed to assess renal glomerular and tubular functions in patients with symptomatic primary hyperparathyroidism (sPHPT) at long-term follow-up. The findings revealed that a reduction in eGFR and subclinical renal tubular dysfunction were prevalent in the Asian-Indian cohort with cured sPHPT.