Estimated Effect of Parathyroidectomy on Long-Term Kidney Function in Adults With Primary Hyperparathyroidism

Background: Multidisciplinary guidelines recommend parathyroidectomy to slow the progression of chronic kidney disease in patients with primary hyperparathyroidism (PHPT) and an estimated glomerular filtration rate (eGFR) less than 60 mL/min/1.73 m(2). Limited data address the effect of parathyroidectomy on long-term kidney function. Objective: To compare the incidence of a sustained decline in eGFR of at least 50% among patients with PHPT treated with parathyroidectomy versus nonoperative management. Design: Target trial emulation was done using observational data from adults with PHPT, using an extended Cox model with time-varying inverse probability weighting. Setting: Veterans Health Administration. Patients: Patients with a new biochemical diagnosis of PHPT in 2000 to 2019. Measurements: Sustained decline of at least 50% from pretreatment eGFR. Results: Among 43 697 patients with PHPT (mean age, 66.8 years), 2928 (6 .7%) had a decline of at least 50% in eGFR over a median follow-up of 4.9 years. The weighted cumulative incidence of eGFR decline was 5.1% at 5 years and 10.8% at 10 years in patients managed with parathyroidectomy, compared with 5.1% and 12.0%, respectively, in those managed nonoperatively. The adjusted hazard of eGFR decline did not differ between parathyroidectomy and nonoperative management (hazard ratio [HR], 0.98 [95% CI, 0.82 to 1.16]). Subgroup analyses found no heterogeneity of treatment effect based on pretreatment kidney function. Parathyroidectomy was associated with a reduced hazard of the primary outcome among patients younger than 60 years (HR, 0.75 [CI, 0.59 to 0.93]) that was not evident among those aged 60 years or older (HR, 1.08 [CI, 0.87 to 1.34]). Limitation: Analyses were done in a predominantly male cohort using observational data. Conclusion: Parathyroidectomy had no effect on long-term kidney function in older adults with PHPT. Potential benefits related to kidney function should not be the primary consideration for PHPT treatment decisions.