Elevated parathyroid hormone levels after parathyroidectomy for primary hyperparathyroidism

Background. Curative parathyroidectomy is associated with elevated levels of parathyroid hormone (PTH) with eucalcemia. This study sought to determine the frequency, clinical significance, and risk factors of this finding. Methods. Seventy-six consecutive patients surgically treated for primary hyperparathyroidism due to a single parathyroid adenoma in 2006 to 2007 were monitored for 1 month postoperatively; those with elevated PTH levels (>70 pg/mL) were monitored for 18 months. Results. Nineteen patients (25%) had high postoperative PTH levels with normal calcium levels. Compared with the remaining patients, this group had a significantly higher average preoperative PTH level (224.89 vs 156.86 pg/mL) and a lesser intraoperative decrease in PTH. Conclusions. About 25% of eucalcemic patients may have elevated PTH levels after parathyroidectomy. A high preoperative PTH level (>225 pg/mL) may predict a persistently high postoperative level. Evaluation of blood and urine calcium, bone density, and cardiac function should be considered in affected patients.