Impact of 25-hydroxyvitamin D deficiency on perioperative parathyroid hormone kinetics and results in patients with primary hyperparathyroidism

Background. Successful parathyroidectomy for sporadic primary hyperparathyroidism (pHPT) is predicted by a 50% drop in PTH intra-operatively. Vitamin D is a known inhibitor of PTH secretion and is associated with secondary HPT following adenoma resection. This study examined the impact of 25-hydroxyvitamin D (250HD) deficiency on perioperative PTH kinetics and outcomes following parathyroidectomy. Methods. Patients undergoing adenoma resection for pHPT (n=93) had PTH levels recorded at six perioperative time points. Preoperative 25OHD levels were examined retrospectively. Patients were. considered 25OHD deficient if the level was < 25 ng/mL (n=47) and adequate if the level was >= 25 ng/mL (n=46). Results. Patients with 25OHD-deficiency had significantly higher preoperative calcium, alkaline phosphatase, and PTH levels. PTH levels were significantly higher in 25OHD-deficient patients at incision, at 1 week postop and 1-3 months postop. Average drop in PTH Level five minutes post resection was 79 +/- 14 % in the deficient group and 72 +/- 22 % in the non-deficient group (P= .03). 250HD levels inversely correlated with adenoma weight (P=.03) and postoperative PTH measurements (P= .008). Conclusions. Sporadic pHPT patients with 250HD deficiency have higher baseline and postoperative PTH Levels compared to non-deficient patients but do not have altered intraoperative. PTH kinetics. Vitamin D deficiency is associated with postoperative elevation of PTH.