From the Research
Normocalcemic hyperparathyroidism should be managed with monitoring and medical therapy, rather than immediate surgery, unless complications such as kidney stones, significant bone loss, or hypercalcemia develop, as suggested by the most recent study 1.
Diagnosis
Normocalcemic hyperparathyroidism is a condition characterized by persistently elevated parathyroid hormone (PTH) levels with normal total and ionized calcium levels, after excluding secondary causes of hyperparathyroidism, such as vitamin D deficiency, renal failure, medications, malabsorption, and hypercalciuria 2.
- The diagnosis is one of exclusion, and it is essential to demonstrate that PTH values remain consistently elevated and to measure ionized calcium levels to make the diagnosis.
- Patients should have calcium, PTH, vitamin D, and renal function checked every 6-12 months to assess for disease progression.
Treatment
- Adequate vitamin D supplementation (typically 1000-2000 IU daily) is recommended to maintain levels above 30 ng/mL, as vitamin D deficiency can stimulate PTH secretion 1.
- Patients should maintain normal calcium intake (800-1000 mg daily) but avoid excessive supplementation.
- Bone density testing is advised to monitor for osteoporosis.
- Parathyroidectomy is generally reserved for patients who develop complications such as kidney stones, significant bone loss, or hypercalcemia.
- A preoperative calcium challenge can be used to differentiate primary from secondary hyperparathyroidism and avoid unnecessary surgery, as shown in a recent study 1.
Complications
- Occult renal calcifications are common in normocalcemic primary hyperparathyroidism and are associated with increased serum PTH, 1.25(OH)2D, and 24-hour urinary calcium 3.
- The clinical manifestations and complications of normocalcemic primary hyperparathyroidism are similar to those of hypercalcemic primary hyperparathyroidism, without a significant difference in the frequency of osteoporosis, nephrolithiasis, gastrointestinal disorders, and low-energy fractures 4.