Supplementary Material for: Investigating the Role of Cardiovascular Biomarkers in Children with Pre-Dialysis Chronic Kidney Disease: A Substitute to Echocardiography to Detect Increased Left Ventricular Mass?

Background: Children with chronic kidney disease (CKD) are at increased risk of future cardiovascular (CV) events. Our aim in this prospective single-centre cross-sectional analysis was to assess the relationship of a novel panel of CV biomarkers with left ventricular hypertrophy (LVH). Methods: A panel of five CV biomarkers (asymmetric dimethyl arginine, high sensitivity C-reactive protein, homocysteine, N-terminal pro-B type natriuretic peptide and uric acid) were measured on the same day as an echocardiogram assessment, in paediatric patients with pre-dialysis stages 3-5 of CKD. Results: Of 73 children aged 5-18 years, LVH, all eccentric, was identified in 38%. Systolic blood pressure (BP), glomerular filtration rate (GFR) and higher intake of calcium-based phosphate binders were significantly worse in children with LVH. In multivariate models analysing each biomarker one at a time with confounders [GFR, systolic BP z-score, anti-hypertensive medication (yes/no) and elemental calcium intake], clinic systolic BP z-score and elemental calcium intake consistently displayed a significant relationship with indexed left ventricular mass (LVMI). None of the evaluated CV biomarkers displayed a significant relationship with LVMI. Conclusions: In our cohort of children with moderately severe pre-dialysis CKD we have identified no suitable biomarkers to detect LVH. We would therefore recommend that echocardiographic determination of LVMI remains the technique of choice for detection of LVH in children with CKD.