Predictive markers for severe hypocalcemia in dialysis patients with secondary hyperparathyroidism after near-total parathyroidectomy

Abstract

Background: Secondary hyperparathyroidism (SHPT) is common in dialysis patients with end-stage renal disease (ESRD). Parathyroidectomy (PTX) is an effective treatment for SHPT. Postoperative severe hypocalcemia (SH) is a common and severe complication after PTX. This study aimed to investigate the potential predictive markers of SH in dialysis ESRD patients with SHPT after near-total PTX (near-tPTX) without autotransplantation (AT). Methods: A retrospective analysis involving 131 dialysis patients with SHPT who were treated with near-tPTX without AT between January and August 2018 was performed. Demographic characteristics (age, gender, type of dialysis modality, etc.) and perioperative laboratory parameters [serum calcium, phosphorus, alkaline phosphatase (ALP), intact parathyroid hormone (iPTH), and bone metabolism markers] were collected and analyzed. Postoperative serum calcium level <1.875 mmol/L (7.5 mg/dL) was defined as postoperative SH. Results: Among the 131 patients, 73 (55.7%) had postoperative hypocalcemia and 43 (32.8%) had postoperative SH. Univariate analysis showed that values of preoperative serum iPTH, calcium, ALP, bone-specific alkaline phosphatase (BAP), and osteocalcin (OC) were significantly different between the SH and non-SH groups. In the multivariate logistic regression model, preoperative serum ALP was an independent risk predictor of postoperative SH. The receiver operating characteristic (ROC) curve for preoperative serum ALP was 277 U/L. The sensitivity of preoperative serum ALP was 73.8% and the specificity was 63.2%. Conclusions: The incidence rates of postoperative hypocalcemia and SH in dialysis patients with SHPT after near-tPTX without AT were 55.7% and 32.8%, respectively. Preoperative serum ALP was an independent predictor for the occurrence of postoperative SH, and dialysis patients with SHPT were susceptible to postoperative SH when preoperative serum ALP level was >277 U/L. Hence, we recommend that preoperative serum ALP be utilized to complement clinical protocols for postoperative SH management of dialysis ESRD patients with SHPT after near-tPTX without AT.