Normocalcemia with persistent increase of parathyroid hormone: a prospective study.

Twelve patients were followed up for 3 months after parathyroidectomy. Serial measurements of serum parathyroid hormone (PTH), calcium, and phosphate were made. Four patients had an increased serum PTH postoperatively, which was already apparent by the third postoperative day. All patients became normocalcemic. Their hyperparathyroid-like phosphate parameters indicated that we were dealing with a biologically active PTH. Using preoperative biochemical parameters it was impossible to predict which patients would have an increased PTH postparathyroidectomy (PTX). Probably the patients with high PTH post-PTX had higher parathyroid volumes. In our opinion after PTX, a normocalcemic high PTH situation should be avoided by 3 1/2 parathyroid gland extirpation in all cases.