Incidence of and risk factors for hungry bone syndrome in 84 patients with secondary hyperparathyroidism

Joerg Latus,¹ Meike Roesel,¹ Peter Fritz,² Niko Braun,¹ Christoph Ulmer,³ Wolfgang Steurer,³ Dagmar Biegger,⁴ M Dominik Alscher,¹ Martin Kimmel<sup>1

1</sup>Department of Internal Medicine, Division of Nephrology, Robert Bosch Hospital, Stuttgart, Germany; ²Department of Diagnostic Medicine, Robert Bosch Hospital, Stuttgart, Germany; ³Department of Surgery, Robert Bosch Hospital, Stuttgart, Germany; ⁴Margarete Fischer-Bosch Institute of Clinical Pharmacology, University of Tuebingen, Stuttgart, Germany

Introduction: Secondary hyperparathyroidism develops in nearly all patients with end-stage renal disease. Parathyroidectomy is often performed when medical therapy fails. The most common postoperative complication, hungry bone syndrome (HBS), requires early recognition and treatment.
Materials and methods: A total of 84 patients who underwent parathyroidectomy because of secondary hyperparathyroidism were investigated. Detailed analysis of laboratory parameters (calcium, phosphate, parathyroid hormone, hemoglobin, and urea levels) and baseline characteristics (age at time of surgery, duration of renal replacement therapy, and medication) was performed to detect preoperative predictors for the development of HBS.
Results: Average overall follow-up of the cohort was 4.7 years. Within this time frame, 13 of 84 patients had to undergo a second surgery because of recurrent disease, and HBS occurred in 51.2%. Only decreased preoperative calcium levels and younger age at time of surgery were significant predictors of HBS. Minimal levels of calcium were detected 3 weeks after surgery. Preoperative vitamin D therapy could not prevent HBS and could not shorten the duration of intravenous calcium supplementation.
Conclusion: HBS is a very common complication after parathyroidectomy. Younger patients and patients with low preoperative calcium levels were at higher risk for the development of HBS. Remarkably, preoperative vitamin D therapy could not prevent HBS and had no impact on the length of intravenous calcium supplementation. Intensive monitoring of calcium levels must be performed for at least 3 weeks after surgery.

Keywords: secondary hyperparathyroidism, parathyroidectomy, hungry bone syndrome