Delta parathormone value as an indicator of postoperative hypocalcemia in patients with parathyroid adenoma

Abstract

<b>Aim</b>: In primary hyperparathyroidism patients, avoiding hypoparathyroidism and hypocalcemia after surgery is essential. We aimed to evaluate if the delta parathormone percent value (ΔPTH%) can identify patients with an increased risk of developing hypocalcemia after parathyroid surgery for primary hyperparathyroidism.<br /> <b>Material and methods</b>: Eighty patients with parathyroid adenomas who underwent single parathyroidectomy were analyzed, and demographical data, preoperative, and postoperative laboratory data were collected were included in the study. Postoperative hypocalcemia was defined as a corrected calcium value below 8.5 mg/dL calculated from the blood values taken on the first postoperative day. The ΔPTH value was calculated by finding the difference between the preoperative PTH value and the postoperative PTH value, and the percentage of ΔPTH was calculated by dividing the ΔPTH value by the preoperative PTH (ΔPTH = Preoperative PTH – Postoperative PTH, and ΔPTH% = ΔPTH / Preoperative PTH).<br /> <b>Results</b>: Postoperative hypocalcemia developed in 7.5% of the patients. Hypocalcemic patients had higher ΔPTH and ΔPTH% values. The selection of 130.95 ng/L as ΔPTH level cutoff level divided patients with and without postoperative hypocalcemia with 83.3% sensitivity and 62.2% specificity. As for ΔPTH%, a cut-off value of 71.4% had 100.0% sensitivity, 56.8% specificity, and a 16-fold increase in odds of postoperative hypocalcemia.<br /> <b>Conclusion</b>: ΔPTH and ΔPTH% values are helpful predictors of postoperative hypocalcemia after parathyroidectomy and can be used as a guiding tool.