PTH and hyperinsulinemic hypoglycemia, familial, 4: The other is alow postoperative level of parathyroid hormone reflecting a secretorydeficiency of the parathyroids which is the mechanism underlying postoperativehypoparathyroidism.2,8,9 Thesecretory deficiency predicts a depressed parathyroid hormone leveldespite low serum calcium, a constellation often found in patientsafter thyroid surgery.2,10,11