Significance of elevated parathyroid hormone after parathyroidectomy for primary hyperparathyroidism.

To provide a clinical update on persistent parathyroid hormone (PTH) elevation after surgical resection for primary hyperparathyroidism (PHPT) and to suggest a schedule for follow-up monitoring and strategies for future study. We reviewed the literature targeting studies with detailed analysis of biochemical parameters before and after parathyroidectomy for PHPT. We focused on potential etiologies and currently available outcome data. PTH elevation with eucalcemia after parathyroidectomy for PHPT occurs in 12% to 43% of patients. Underlying etiology is probably multifactorial, and possible causes include bone hunger, vitamin D deficiency, inadequate calcium intake or absorption, reduced peripheral sensitivity to PTH, underlying chronic kidney disease, and/or a renal leak of calcium. No consensus exists on how to follow-up and treat these patients. Although most patients with PTH elevation after parathyroidectomy will have normalization of PTH levels with time and/or calcium and vitamin D supplementation, this finding may be an early indicator of autonomous parathyroid secretion in a small number of patients. Patients with persistent PTH elevation should be monitored over time for recurrence of PHPT and other possible complications. A standardized follow-up protocol is needed to better study and elucidate the clinical significance of elevated PTH after parathyroidectomy.