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 m2. 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. PRIMARY FUNDING SOURCE National Institute on Aging.