WASHINGTON—High dialysate calcium (DCa) is a risk factor for all-cause mortality as well as cardiovascular and infection-related hospitalization in incident hemodialysis (HD) patients, according to new research presented at Kidney Week 2019.

Of 1182 patients from the Clinical Research Center registry in South Korea, 15.4% received high DCa (3.5 mEq/L), 59.3% mid-range DCa (3.0 mEq/L), and 25.3% low DCa (2.5–2.6 mEq/L).

Over a median 16 months, the high DCa group had significant 2.2- and 3.7-fold increased risks for all-cause mortality compared with the mid-range and low DCa groups, respectively, after adjustment for clinical variables, Jong yun Lee, MD, of St. Vincent’s Hospital in South Korea, and colleagues reported. In a propensity score matched analysis of 163 patients in each group, the high DCa group had a significant 2.5- and 4.3-fold higher risk for all-cause mortality compared with the mid-range and low DCa groups, respectively.

Further, compared with the low DCa group, the high DCa group had significant 3.3- and 2.8-fold increased risks for cardiovascular- and infection-related hospitalizations, respectively.

The 2003 Kidney Disease Outcomes Quality Index (KDOQI) practice guidelines for bone metabolism in chronic kidney disease recommended DCa of 2.5 mEq/L for HD and peritoneal dialysis patients based on opinion, with higher or lower DCa permitted for select patients. The 2017 clinical practice guideline update for bone metabolism from Kidney Disease: Improving Global Outcomes (KDIGO) recommended a DCa of 2.5 to 3.0 mEq/L with an evidence grade of 2C.

In an independent review published in 2019 in Blood Purification, “Dialysate Calcium Levels: Do They Matter?,” Frank M. van der Sande, MD, PhD, of the University Hospital Maastricht in the Netherlands, and colleagues acknowledged that data are still lacking on optimal or appropriate DCa to maintain bone and vascular health.

“The choice of the optimal DCa deserves a thoughtful process, taking into account the cardiovascular status, parameters of mineral metabolism, the concomitant use of drugs such as P-binders, cinacalcet or vitamin D analogues and the hemodynamic stability of the patient,” Dr van der Sande and his peers stated.

References

Lee JY, Kim HW, and Kim YK. Impact of dialysate calcium concentration on clinical outcomes in incident hemodialysis patients.Presented at the American Society of Nephrology’s Kidney Week 2019 meeting held November 5 to10 in Washington DC. Abstract FR-PO486.

National Kidney Foundation. K/DOQI clinical practice guidelines for bone metabolism and disease in chronic kidney disease. Am J Kidney Dis 2003; 42(suppl 3):S1–S201.

KDIGO 2017 Clinical Practice Guideline Update for the Diagnosis, Evaluation, Prevention, and Treatment of Chronic Kidney Disease–Mineral and Bone Disorder (CKD-MBD). Kid Intl. doi:10.1016/j.kisu.2017.04.001

van der Sande FM, ter Meulen KJA, Kotanko P, Kooman JP. Dialysate Calcium Levels: Do They Matter? Blood Purif. 2019;47:230–235. doi:10.1159/000494584