Persistent hyperactivity of the parathyroid glands in treated hypothyroid patients

Abstract

Twelve untreated hypothyroid patients were submitted to EDTA infusion and the parathyroid hormone response to the induced hypocalcemia was studied with an amino-terminal specific assay. Eight of these patients were retested 6 months after achieving clinical and laboratory euthyroidism. The PTH response in the pretreatment condition was significantly higher than that obtained in a group of 10 normal individuals; this increased response had not normalized after 6 months of euthyroidism. This persisting hyperresponsiveness can be a contributory factor to the bone hypersensitivity to thyroid hormone replacement seen in hypothyroid patients.