Effects of lowering dialysate calcium concentrations on arterial stiffness in patients undergoing hemodialysis.
OBJECTIVE
We assessed changes in hemodynamic and arterial stiffness parameters following reductions of dialysate calcium concentrations in patients undergoing hemodialysis.


METHODS
In this prospective study, 20 patients on maintenance hemodialysis (10 females, 10 males) with dialysate calcium concentrations of 1.75 mmol/L were enrolled. At the start of the study, the dialysate calcium level was lowered to 1.50 mmol/L. Serial changes in biochemical, hemodynamic, and arterial stiffness parameters, including pulse wave velocity (PWV) and augmentation index (AIx), were assessed every 2 months for 6 months. We also examined changes in the calcification-inhibitory protein, serum fetuin-A.


RESULTS
During the 6-month study period, serum total calcium and ionized calcium decreased consistently (9.5 ± 1.0 to 9.0 ± 0.7, p = 0.002 vs. 1.3 ± 0.1 to 1.1 ± 0.1, p = 0.035). Although no apparent changes in blood pressure were observed, heart-femoral PWW (hf-PWV) and AIx showed significant improvement (p = 0.012, 0.043, respectively). Repeated-measures ANOVA indicated a significant effect of lowering dialysate calcium on hf-PWV (F = 4.58, p = 0.004) and AIx (F = 2.55, p = 0.049). Accompanying the change in serum calcium, serum fetuin-A levels significantly increased (95.8 ± 45.8 pmol/mL at baseline to 124.9 ± 82.2 pmol/mL at 6 months, p = 0.043).


CONCLUSIONS
Lowering dialysate calcium concentration significantly improved arterial stiffness parameters, which may have been associated with upregulation of serum fetuin-A.
Department of Internal Medicine, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Korea.
Jwa-Kyung
JK
Kim
Sung Jin
SJ
Moon
Hyeong Cheon
HC
Park
Jae Sung
JS
Lee
Soung Rok
SR
Sim
Sung Chang
SC
Bae
Sung Kyu
SK
Ha
D000368:Aged; D000704:Analysis of Variance; D055109:Ankle Brachial Index; D001158:Arteries / Q000187:drug effects* / Q000503:physiopathology; D015415:Biomarkers / Q000097:blood; D001794:Blood Pressure / Q000187:drug effects; D002118:Calcium / Q000008:administration & dosage* / Q000009:adverse effects; D003187:Compliance; D005260:Female; D015312:Hemodialysis Solutions / Q000008:administration & dosage* / Q000009:adverse effects / Q000737:chemistry; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011673:Pulsatile Flow / Q000187:drug effects*; D006435:Renal Dialysis; D056910:Republic of Korea; D013997:Time Factors; D016896:Treatment Outcome; D060749:alpha-2-HS-Glycoprotein / Q000378:metabolism
C556354:AHSG protein, human; D015415:Biomarkers; D015312:Hemodialysis Solutions; D060749:alpha-2-HS-Glycoprotein; D002118:Calcium