Keeping calcium, phosphorus, and intact parathyroid hormone (iPTH) within target ranges, while taking extra care to avoid hypercalcemia, may prolong survival of patients on hemodialysis (HD), according to new study findings published in Kidney Research and Clinical Practice.
Kook-Hwan Oh, MD, of Seoul National University Hospital in Korea, and colleagues examined the relationships between serum markers of mineral metabolism and all-cause mortality in 21,433 HD patients on the Korean Society of Nephrology’s nationwide registry. Patients in the the highest quintile of corrected calcium (9.61 mg/dL or more) at enrollment had a significant 39% greater risk for mortality within 2 years than those in the middle quintile, whereas those with the lowest quintile (8.4 mg/dL or less) had a significant 16% lower death risk. The findings support the hypercalcemia warning in the 2017 Kidney Disease: Improving Global Outcomes (KDIGO) update on chronic kidney disease mineral bone disorder (CKD-MBD).
Out-of-range iPTH levels in either direction were associated with greater risks for early death. Patients in the highest (311 pg/mL or more) and lowest (59.6 pg/mL or less) quintiles of iPTH had 24% and 18% increased risks for death from any cause, respectively. The study found no association between hyperphosphatemia and mortality. Only patients in the lowest quintile of serum phosphorus (3.59 mg/dL or less) had a 24% greater risk for early mortality compared with those in the middle quintile.
Having no mineral markers within target ranges defined by the Kidney Disease Outcomes Quality Initiative (KDOQI) guideline was associated with a 37% increased mortality risk compared with attaining all 3 targets.
All told, study results prompted Dr Oh and his peers to conclude: “In managing CKD-MBD, we need to avoid hypercalcemia and hypophosphatemia as well as to control Ca, P, and iPTH together.”
Kim Y, Don Yoo K, Jin Kim H, et al. Association of serum mineral parameters with mortality in hemodialysis patients: Data from the Korean end-stage renal disease registry. Kidney Res Clin Pract 37:266-276. DOI:10.23876/j.krcp.2018.37.3.266