Calcium, phosphorus, pth and death rates in a large sample of dialysis patients from Latin America. The cores study.

Abstract

Mineral metabolism parameters may play a role in the survival of patients with chronic kidney disease (CKD). In the CORES study we analyzed the association between calcium, phosphorus and PTH and mortality (all-cause and cardiovascular) in 16173 haemodialysis (HD) patients over 18 years from 6 Latin American countries, who underwent haemodialysis up to 54 months. Unadjusted, case-mix and time-dependent multivariable-adjusted hazard ratio (HR) of death were calculated for categories of serum albumin-corrected calcium (CaAlb), phosphorus and PTH using as “reference values” the range in which the lowest death rate was observed. Age, gender, vitamin D treatment, diabetes, vintage, vascular access, weight, blood pressure and laboratory variables (serum albumin, haemoglobin, creatinine, ferritin, and Kt/V) were used as confounding variables. Low (< 9.5 mg/dL) and high (>10.5 mg/dL) CaAlb increased the HR for all-cause mortality. Low (<9.0 mg/dL) CaAlb increased the HR for cardiovascular mortality. High phosphorus (>5.5 mg/dL) increased the HR for both all-cause and cardiovascular mortality. Low phosphorus (< 4.0 mg/dL and < 3.0 mg/dL) increased the HR for both all-cause and cardiovascular mortality. Furthermore, low (<150 pg/mL) and high (>500 pg/mL and >300 pg/mL) PTH increased the HR for both all-cause and cardiovascular mortality. In addition, only phosphorus higher than 6.0 mg/dL increased the HR for cardiovascular hospitalizations. No effect was observed with CaAlb or PTH. In summary, in 16,173 HD patients, elevated and reduced serum levels of albumincorrected calcium, phosphorus and PTH levels were associated with increments in allcause mortality. Similar results were obtained when only CV mortality was analyzed.