Preoperative alkaline phosphatase concentration can predict calcium requirements after parathyroidectomy among patients with stage 5 chronic kidney disease (CKD) and secondary hyperparathyroidism (SHPT), according to researchers.
Hongying Wang, MD, and colleagues from Fudan University Huashan Hospital in Shanghai, China, performed a retrospective study of 68 patients with stage 5 CKD and SHPT who underwent total PTx with or without autotransplantation during the period from 2013 to 2017. Among several preoperative clinical and laboratory factors, multivariate analysis identified alkaline phosphatase (ALP) as the sole independent predictor of post-PTx calcium requirement, including oral and intravenous calcium.
According to the investigators, the present study confirms that, in the context of a high dialysate calcium (1.75 mmol/L) and a stable dose of calcitriol, preoperative ALP could predict calcium requirement after PTx.
“Patients with high preoperative ALP should be monitored more closely and treated aggressively in the postoperative period to prevent postoperative hypocalcemia,” Dr Wang’s team concluded in a paper published in the International Journal of Urology and Nephrology.
Prolonged hypocalcemia increases hospitalization and can lead to cardiac arrhythmias or sudden death, among other adverse events. High serum ALP might reflect bone disease with increased osteoblastic activity, the team suggested.
Preoperative calcium and phosphate levels did not predict post-PTx calcium requirement.
Among the study’s limitations, the investigators acknowledged that dialysate calcium should theoretically be counted towards the total calcium requirement. They also assumed a calcium absorption rate of 20%, but noted that it could be higher in the context of 5 µg daily calcitriol.
Ding Y, Wang H, Zou Q, et al. Factors associated with calcium requirements after parathyroidectomy in chronic kidney disease patients. Intl Urol Nephrol. 2017; published online ahead of print. doi: 10.1007/s11255-017-1759-810.1007