Association of Dialysis Adequacy and Estimated Kidney Function with Mineral Metabolism Parameters in Patients Undergoing Peritoneal Dialysis

Abstract

Introduction. In terminal CKD, imbalance of calcium and phosphate 
can lead to complications such as skeletal and cardiovascular 
involvements. Disturbances in mineral metabolism are common 
among patients with advanced CKD and may be influenced by 
dialysis adequacy and estimated kidney function. We aimed to 
evaluate selected serum mineral metabolism parameters and 
their associations with dialysis adequacy and estimated kidney 
function in patients undergoing PD.
Methods. This cross-sectional study included 85 adult patients 
undergoing PD. eGFR was calculated using the CKD-EPI equation, 
and urea Kt/V was used as a measure of dialysis adequacy. An 
independent-samples t-test was used to compare calcium and 
phosphate levels between patients with Kt/V < 1.7 and those 
with Kt/V ≥ 1.7. 
Results. The mean age was 55.91 ± 16.45 years, and 52.9% were 
male. The mean serum calcium level differed significantly according 
to the number of daily PD exchanges (P = .034). Tukey’s post
hoc analysis showed a significant difference between patients 
receiving two and three exchanges per day (P = .048), with a higher 
mean calcium concentration in patients receiving two exchanges 
per day. Serum calcium showed a modest positive correlation 
with eGFR, while serum phosphate showed significant inverse 
correlations with urea Kt/V and eGFR. No significant differences 
in serum calcium or phosphate were observed between patients 
with Kt/V < 1.7 and those with Kt/V ≥ 1.7.
Conclusions. These findings suggest an association between dialysis 
adequacy, estimated kidney function, and selected biochemical 
parameters of mineral metabolism. However, the cross-sectional 
design does not permit causal inference.