Five-year Estimated Glomerular Filtration Rate in Patients With Hypoparathyroidism Treated With and Without rhPTH(1–84)

CONTEXT: Chronic hypoparathyroidism (HypoPT) is conventionally managed with oral calcium and active vitamin D. Recombinant human parathyroid hormone (1–84) (rhPTH[1–84]) is a therapy targeting the pathophysiology of HypoPT by replacing parathyroid hormone. OBJECTIVE: To compare changes in the estimated glomerular filtration rate (eGFR) in patients with chronic HypoPT receiving or not receiving rhPTH(1–84) during a 5-year period. DESIGN/SETTING: A retrospective analysis of patients with chronic HypoPT treated with or without rhPTH(1–84). PATIENTS: Sixty-nine patients with chronic HypoPT from 4 open-label, long-term trials (NCT00732615, NCT01268098, NCT01297309, and NCT02910466) composed the rhPTH(1–84) cohort and 53 patients with chronic HypoPT not receiving rhPTH(1–84) from the Geisinger Healthcare Database (01/2004–06/2016) composed the historical control cohort. INTERVENTIONS: The rhPTH(1–84) cohort (N = 69) received rhPTH(1–84) therapy; the historical control cohort (N = 53) did not receive rhPTH(1–84). MAIN OUTCOME MEASURES: Changes in eGFR from baseline during a 5-year follow-up were examined in multivariate regression analyses. RESULTS: At baseline, demographic characteristics and eGFR were similar between cohorts, though the proportions with diabetes and cardiac disorders were lower in the rhPTH(1–84) cohort. At the end of follow-up, mean eGFR increased by 2.8 mL/min/1.73 m(2) in the rhPTH(1–84) cohort, while mean eGFR fell by 8.0 mL/min/1.73 m(2) in the control cohort. In the adjusted model, the difference in the annual eGFR change between the rhPTH(1–84) cohort and the control cohort was 1.7 mL/min/1.73 m(2) per year (P = 0.009). CONCLUSIONS: Estimated glomerular filtration rate was preserved for over 5 years among patients with chronic HypoPT receiving rhPTH(1–84) treatment, contrasting with an eGFR decline among those not receiving rhPTH(1–84).