Relationship between serum calcium level at dialysis initiation and subsequent prognosis

Abstract

Background: In patients on maintenance dialysis, increased serum calcium levels are known to be associated with a poor prognosis. However, it is not known whether serum calcium levels at dialysis initiation have an impact on subsequent prognosis. Methods: The subjects were patients who were newly initiated dialysis at the 17 Aichi Cohort Study of Prognosis in Patients Newly Initiated into Dialysis (AICOPP) group centers. The study included 1524 patients who were at least 20 years old, had CKD, and provided written consent. We excluded one patient whose serum adjusted calcium was not assessed and six patients whose outcomes were unknown. Thus, we enrolled 1517 subjects into the study. The patients were divided into the following five groups: (1) G1 with a serum adjusted calcium level <7.0 mg/dL, (2) G2 with 7.0 to <8.0 mg/dL, (3) G3 with 8.0 to <9.0 mg/dL, (4) G4 with 9.0 to <10.0 mg/dL, and (5) G5 with ≥10.0 mg/dL. The study outcomes included: (1) comparisons of all-cause mortality rates in the five groups; (2) extraction of factors influencing all-cause mortality. Results: There were 268 deaths during the follow-up period (G1, 9 cases; G2, 30 cases; G3, 91 cases; G4, 110 cases; G5, 28 cases). Significant differences were observed between the five groups' cumulative survival rates (Logrank test p = 0.005) by using Kaplan-Meier method. There were significant differences in the incidence of either aortic or cardiac valve calcification among the five groups (aortic calcification: p = 0.006, cardiac valve calcification: p = 0.008). Moreover, lower Barthel Index, which evaluated activities of daily living, were associated with higher serum adjusted calcium levels (p < 0.001). Multivariate Cox proportional hazard analysis using the stepwise method indicated that increasing serum adjusted calcium was associated with all-cause mortality (every 1 mg/dL increase, HR = 1.267, 95% CI = 1.092 − 1.470, p = 0.002). In addition, high mortality was associated with advanced age, male gender, low systolic blood pressure, history of cardiovascular disease, and no prior use of calcium carbonate. Conclusions: Serum adjusted calcium levels at dialysis initiation were demonstrated to be associated with all-cause mortality after dialysis initiation.

Serum Calcium Levels in Chronic Kidney Disease Patient Stratified By Body Mass Index

“…These findings are consistent with other studies in Canada and Japan. 15,16 These studies have also resulted that most of the patients are over 50 years old, confirming that CKD is more frequent to be found in older age, as the glomerular filtration rate (GFR) decreases. 2 Patients with CKD have decreased kidney function, marked by the declining of GFR.…”

“…The Glomerular filtration rate is higher, blood phosphorus and FGF-23 levels are decreased, so that 1.25(OH)2D level increase. 16 Increased levels of 1.25(OH)2D will cause blood calcium levels to increase, 16 resulting in higher calcium levels in the overweight/obese group of CKD patients.…”

“…15 Blood calcium level higher than normal is correlated with a worse prognosis. 16 In light with those contradicting results, this study aimed to explore blood calcium levels in CKD patients stratified based on body mass index (BMI).…”

Evaluation of the Predictive Value of the Serum Calcium-Magnesium Ratio for All-Cause and Cardiovascular Mortality in Incident Dialysis Patients

“…The severity of aortic arch calcification was classified into four grades (grades 0-3) [15]. Furthermore, cardiac valve calcification was evaluated according to the presence or absence of a calcified aortic valve and mitral valve [16]. …”

Risk of cardiovascular mortality predicted by the serum calcium level and calcification score at the initiation of dialysis

“…However, although a high serum CCa level has been recognized as an independent risk factor for all-cause mortality [5], its relationship to CVC-specific mortality was not investigated. A recent report on the serum CCa levels at dialysis initiation more completely showed that, in a Japanese cohort of 1524 incidental HD patients, a high level of CCa was associated with a higher incidence of all-cause mortality [6]. The authors suggested that patients with high CCa were introduced to HD at a higher eGFR because of advanced organ calcification.…”