Influencing factors of hungry bone syndrome in maintenance hemodialysis patients after parathyroidectomy

Abstract

Objective To investigate the influencing factors of hungry bone syndrome (HBS) in maintenance hemodialysis patients with secondary hyperparathyroidism (SHPT) after parathyroidectomy (PTX). Methods A retrospective study was conducted on maintenance hemodialysis patients with SHPT undergoing successful parathyroidectomy with autotransplantation. Clinical data and perioperative indicators of the selected patients were collected. The enrolled patients were divided into HBS group and non-HBS group based on whether the lowest level of blood calcium less than 2.0 mmol/L after surgery. The difference of general clinical data and perioperative indicators between the two groups were compared. The risk factors of HBS were analyzed by logistic regression analysis. Multiple linear regression method was used to analyze the independent factors affecting the maintenance time of intravenous calcium supplementation, the total amount of calcium supplementation during intravenous calcium supplementation and the highest serum level of potassium within 24 h after surgery. Results A total of 306 patients were included in the study. All patients had low levels of serum calcium after operation. There were 230 patients (75.16%) with the lowest blood calcium<2.00 mmol/L after PTX (HBS group), and 76(24.84%) cases in the non-HBS group. Predialysis coefficient of serum calcium=(preoperative blood calcium-2.20) mmol/L÷0.01 mmol/L. Logistic regression analysis showed that higher predialysis coefficient of serum calcium (B=-0.063, OR=0.939, 95% CI 0.894-0.987, P=0.013) and lower level of preoperative serum alkaline phosphatase (ALP) (B=0.035, OR=1.033, 95% CI 1.019-1.050, P<0.001) were independent risk factors for HBS. Multiple linear regression analysis revealed that preoperative blood intact parathyroid hormone (iPTH) (B=0.017, P<0.001 and B=0.041, P<0.001), preoperative serum ALP (B=0.052, P<0.001 and B=0.107, P<0.001) and preoperative hemoglobin (Hb) (B=-0.453, P=0.041 and B=-1.058, P=0.007) were independent factors affecting the maintenance time of intravenous calcium supplementation and the total amount of calcium supplementation in HBS patients. Preoperative predialysis level of serum potassium (B=0.859, P<0.001) was the independent influencing factor of the maximum level of serum potassium within 24 hours after surgery. Conclusions Patients with lower levels of preoperative serum calcium and higher levels of serum ALP are prone to HBS after PTX. Postoperative calcium supplementation may need to be strengthened in HBS patients with higher preoperative iPTH and ALP levels and lower preoperative Hb levels. High preoperative basal potassium levels may increase the risk of hyperkalemia after PTX. Key words: Hyperparathyroidism, secondary; Parathyroidectomy; Hypocalcemia; Hungry bone syndrome; Hyperkalemia