Persistent Elevation of Parathormone Levels after Surgery for Primary Hyperparathyroidism

Area of Science:

• Endocrinology
• Surgical Oncology
• Nephrology

Background:

• Persistent elevated parathyroid hormone (PTH) after parathyroidectomy, despite normal calcium levels, occurs in 8-40% of patients.
• The clinical significance of this postoperative finding requires further investigation.

Purpose of the Study:

• To determine the clinical significance of persistently elevated PTH levels post-parathyroidectomy.
• To identify factors associated with persistent PTH elevation after surgery for primary hyperparathyroidism (PHPT).

Main Methods:

• A retrospective case series of 201 patients diagnosed with PHPT between April 2010 and January 2020.
• Analysis of postoperative PTH levels at 1 month and long-term follow-up, correlating with preoperative and postoperative biochemical and clinical data.

Main Results:

• 30% (54/180) of patients exhibited persistently elevated PTH (PePTH) at 1 month post-surgery.
• PePTH was associated with older age, higher preoperative calcium, iPTH, alkaline phosphatase, lower phosphate, lower 25-hydroxy vitamin D3, and reduced creatinine clearance.
• Preoperative 25-OH D3 concentration, creatinine clearance, and iPTH were identified as key factors influencing PePTH. None of the patients with PePTH developed recurrent hyperparathyroidism.

Conclusions:

• Persistent elevation of PTH despite normocalcemia after parathyroidectomy is a common finding.
• A multifactorial mechanism, likely involving preoperative vitamin D status and renal function, contributes to this phenomenon.
• While the exact pathogenesis needs further elucidation, PePTH in this context does not appear to predict recurrent hyperparathyroidism.