The calcium challenge test in determining secondary hyperparathyroidism in post gastric bypass patients

Distinguishing primary from secondary hyperparathyroidism can be difficult in some patients with non-localizing Sestamibi scans. In this era with many patients who have undergone gastric bypass surgery for morbid obesity, secondary hyperparathyroidism resulting in hyperplasia of the parathyroid glands can be their only method of calcium homeostasis. This results from an inability to absorb calcium in gut. We have devised a simple method to help distinguish patients with an inability to absorb calcium in the gut. With this method patients who would potentially be devastated by parathyroidectomy can be identified and spared.