Physician-authored summaries and commentary on the most important medical research, provided by the NEJM Group, a division of the Massachusetts Medical Society.
© Massachusetts Medical SocietyAugust 2023
An observational study suggests the answer is ‘no’ in people older than 60 years.
For patients with mild primary hyper parathyroidism (PHPT), one rationale for parathyroidectomy is to prevent decline in renal function. However, evidence to support this rationale is limited.
In this observational study of patients with PHPT in the US Veterans Affairs health system, researchers compared renal outcomes in 3800 patients who underwent early parathyroidectomy and 40,000 patients who were managed nonoperatively. At baseline, mean age was 67 years, mean serum calcium level was 2.7 mmol/L and mean estimated glomerular filtration rate (eGFR) was 72 mL/min/1.73 m2; most patients were men. Patients with eGFR 30 mL/min/1.73 m2 or lower were excluded. Statistical techniques were used to adjust for substantial baseline differences between groups.
Incidence of the primary endpoint, a 50% or larger decline in eGFR, was not significantly different between the parathyroidectomy and observation groups – 5% at five years and about 11% at 10 years. However, in the subgroup of patients younger than 60 years, parathyroidectomy was associated with somewhat lower risk for the primary endpoint (number needed to treat to prevent one case of eGFR decline, about 70 [personal communication from the authors]).
Comment: Parathyroidectomy was not associated with slower decline in renal function overall, but the subgroup of patients younger than 60 years comprised a possible exception. Interestingly, in other recent observational studies with as long as eight years of follow up, parathyroid ectomy was not associated with fewer symptomatic kidney stones (NEJM JW Gen Med Sep 1 2022 and J Clin Endocrinol Metab 2022; 107: 2801-2810). A randomised trial large enough to show definitively whether parathyroidectomy preserves renal function in patients with mild PHPT is unlikely. For now, the authors’ conclusion seems reasonable: ‘Potential benefits related to kidney function should not be the primary consideration for PHPT treatment decisions.’
Allan S. Brett, MD, Clinical Professor of Medicine, University of Colorado School of Medicine, Aurora, USA.
Seib CD, et al. Estimated effect of parathyroidectomy on long-term kidney function in adults with primary hyperparathyroidism. Ann Intern Med 2023 Apr 11; e-pub (https://doi.org/10.7326/M22-2222).
This summary is taken from the following Journal Watch titles: General Medicine, Ambulatory Medicine, Hospital Medicine.