High or low levels of calcium, phosphorus, and intact parathyroid hormone (iPTH) place hemodialysis (HD) patients at increased risk for death, a new study suggests.
Yu-Shu Chien, MD, and colleagues at Kaohsiung Chang Gung Memorial Hospital in Taiwan, performed a retrospective study of 1126 maintenance HD patients treated at their institution from 2009 to 2013. According to Cox regression models, particular values of markers of chronic kidney disease mineral bone disorder (CKD-MBD) were associated with mortality over 5 years. Hypercalcemia (calcium levels 10.9–11.9 mg/dL) correlated with more than triple the risk of all-cause mortality. Hypophosphatemia (phosphorus levels 2.0–2.5 mg/dL) was significantly associated with a more than five-fold risk, with phosphorus levels below 2.0 mg/dL significantly related with cardiovascular mortality. In addition, iPTH values below 60 and above 1500 pg/mL nearly doubled the risk for death from any cause. At iPTH levels of 500–700 pg/mL and 1500 pg/mL and above, cardiovascular mortality was significantly elevated.
These results differed somewhat from previous studies. For example, hyperphosphatemia above 4.5 mg/dL was not linked with mortality, possibly due to the small number of patients with the condition, according to the investigators.
“Although center-specific effects may have contributed to our results, the findings validate the usefulness of the general rules for clinical management of CKD-MBD recommended in popular guidelines,” Dr Chien and his team concluded in Blood Purification, published online.
Patients were managed according to biomarker targets specified in the 2003 and 2009 Kidney Disease Improving Global Outcomes (KDIGO) clinical guidelines.
Virtually all patients received HD with a dialysate calcium concentration of 3.0 mEq/L. Phosphate binders included aluminum hydroxide, calcium carbonate or acetate, sevelamer carbonate or hydrochloride, and lanthanum carbonate. When iPTH rose above 300 pg/mL, patients received calcitriol. The investigators noted that just a few patients received the following medications because they were not covered by insurance: cinacalcet, lanthanum carbonate, and sevelamer hydrochloride or carbonate.
Zhu JG, Chen JB, Cheng BC, Lee CH, Long G, and Chien YS. Association between extreme values of markers of chronic kidney disease: Mineral and bone disorder and 5-Year mortality among prevalent hemodialysis patients. Blood Purif 2018;45:1–7. doi: 10.1159/000478972