Association of serum alkaline phosphatase with coronary artery calcification in maintenance hemodialysis patients.
OBJECTIVE
Recent in vitro studies have shown a link between alkaline phosphatase and vascular calcification in patients with chronic kidney disease (CKD). High serum levels of alkaline phosphatase are associated with increased death risk in epidemiologic studies of maintenance hemodialysis (MHD) patients. We hypothesized that coronary artery calcification is independently associated with increased serum alkaline phosphatase levels in MHD patients.


METHODS
We examined the association of coronary artery calcification score (CACS) and alkaline phosphatase in 137 randomly selected MHD patients for whom markers of malnutrition, inflammation, and bone and mineral disorders were also measured.


RESULTS
Serum alkaline phosphatase was the only measure with significant and robust association with CACS (P < 0.003), whereas either other biochemical markers had no association with CACS or their association was eliminated after controlling for case-mix variables. Serum alkaline phosphatase >120 IU/L was a robust predictor of higher CACS and was particularly associated with the likelihood of CACS >400 (multivariate odds ratio 5.0 95% confidence interval 1.6 to 16.3; P = 0.007). Serum alkaline phosphatase of approximately 85 IU/L seemed to be associated with the lowest likelihood of severe coronary artery calcification, but in the lowest tertile of alkaline phosphatase, the CACS predictability was not statistically significant.


CONCLUSIONS
An association between serum alkaline phosphatase level and CACS exists in MHD patients. Given the high burden of vascular calcification in patients with CKD, examining potential therapeutic interventions to modulate the alkaline phosphatase pathway may be warranted.
Harold Simmons Center for Kidney Disease Research and Epidemiology, Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance, California 90502, USA.
Ronney
R
Shantouf
Csaba P
CP
Kovesdy
Youngmee
Y
Kim
Naser
N
Ahmadi
Amanda
A
Luna
Claudia
C
Luna
Mehdi
M
Rambod
Allen R
AR
Nissenson
Matthew J
MJ
Budoff
Kamyar
K
Kalantar-Zadeh
D000328:Adult; D000368:Aged; D000469:Alkaline Phosphatase / Q000097:blood*; D002114:Calcinosis / Q000453:epidemiology* / Q000378:metabolism; D003324:Coronary Artery Disease / Q000453:epidemiology* / Q000378:metabolism; D005260:Female; D006801:Humans; D007676:Kidney Failure, Chronic / Q000453:epidemiology* / Q000378:metabolism / Q000628:therapy; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D012044:Regression Analysis; D006435:Renal Dialysis / Q000706:statistics & numerical data*; D012307:Risk Factors
D000469:Alkaline Phosphatase