Normocalcemic primary hyperparathyroidism: an update on diagnostic and management challenges

Area of Science:

• Endocrinology
• Biochemistry
• Surgical Research

Background:

• Normocalcemic primary hyperparathyroidism (NPHPT) is characterized by elevated parathyroid hormone (PTH) with normal serum calcium.
• Increased biochemical screening reveals more NPHPT cases, highlighting knowledge gaps in its natural history and management.
• NPHPT shares clinical issues with hypercalcemic primary hyperparathyroidism (HPHPT), including bone disease and kidney stones.

Purpose of the Study:

• To review current evidence on NPHPT epidemiology, diagnosis, clinical features, and management.
• To address uncertainties regarding NPHPT's natural history, diagnostic criteria, and optimal treatment strategies.
• To summarize findings on surgical outcomes and identify areas for future research in NPHPT.

Main Methods:

• Literature review of epidemiological data, diagnostic criteria, and clinical manifestations of NPHPT.
• Analysis of studies reporting outcomes of parathyroidectomy for NPHPT.
• Synthesis of evidence regarding bone mineral density (BMD), quality of life (QOL), and renal outcomes post-surgery.

Main Results:

• NPHPT diagnosis requires repeated biochemical tests, confirmed normal ionized calcium, and exclusion of secondary causes.
• Osteoporosis, fragility fractures, and nephrolithiasis are common in NPHPT patients.
• Parathyroidectomy shows promise for selected NPHPT patients, improving BMD and QOL, but recurrence risk may be higher than in HPHPT.

Conclusions:

• Parathyroidectomy is a viable option for select NPHPT individuals, with reported improvements in bone health and quality of life.
• NPHPT may have a higher recurrence rate compared to HPHPT, necessitating careful follow-up.
• Further research is needed to clarify NPHPT's long-term renal outcomes and optimize management strategies.