Supplementary Material for: Serum Alkaline Phosphatase Level Predicts Cardiac Valve Calcification in Maintenance Hemodialysis Patients

Purpose: Cardiac valve calcification (CVC) is frequently occurred in maintenance hemodialysis (MHD) patients and is associated with cardiovascular and all-cause mortality. This study aimed to evaluate the relationships between risk factors and extent of CVC and further provide the treatment target in MHD patients. Methods: One hundred and forty-five patients who received MHD ≥3 months were enrolled. CVC was assessed by an echocardiographic, semi-quantitative manner called global cardiac calcium scoring system (GCCS), and demographic, clinical, and laboratory parameters including mineral metabolism markers were collected. Results: The average age of the patients was 50 ± 12 years, and 54.5% were men. The mean GCCS was 1.8 ± 2.4; 57.2% of patients had GCCS ≥1. Age, dialysis vintage, serum alkaline phosphatase (ALP), and intact parathyroid hormone levels were positively correlated with CVC, whereas serum albumin levels were negatively related to CVC, based on univariate analysis. With multivariate linear regression analysis, serum ALP was the only bone-derived biomarker that showed significant correlation with CVC. Serum ALP ≥232 U/L was a robust predictor of CVC and was associated with the likelihood of GCCS ≥1 (OR 3.92, 95% CI 1.37–11.2, p = 0.011). The decision tree model was used to identify ALP ≥232 U/L and age ≥60 years as important determinative variables in the prediction of CVC in MHD patients. Conclusion: Serum ALP level is significantly associated with CVC in MHD patients. ALP is suggested to be a promising interventional target for cardiovascular calcification in MHD patients.