Supplementary Material for: Association Between Hemoglobin-to-red Cell Distribution Width Ratio and Left Ventricular Hypertrophy in Non-Dialysis CKD Stage 3–5 Patients: A Cross-Sectional Study

Introduction: Left ventricular hypertrophy (LVH) is a common cardiovascular complication in chronic kidney disease (CKD), driven by anemia and nutritional deficiencies. The hemoglobin-to-red cell distribution width ratio (HRR) reflects these factors, but its association with LVH in CKD remains unclear. This study aimed to investigate the relationship between HRR and LVH in non-dialysis CKD stage 3–5 patients. Methods: In this cross-sectional study, 195 patients were included. HRR was calculated from hemoglobin and red cell distribution width. LVH was diagnosed by echocardiography (LV mass index >115 g/m² men, >95 g/m² women). Logistic regression assessed HRR-LVH association, including subgroup and restricted cubic spline analyses. Mediation analysis explored the role of intact parathyroid hormone (iPTH) and N-terminal pro-brain natriuretic peptide (NT-proBNP). Results: Patients with LVH (n=40) had significantly lower HRR (median 0.62 vs. 0.81, P<0.001). HRR was inversely associated with LVH (adjusted OR 0.41 per SD increase, P=0.005), with the highest HRR tertile showing the lowest LVH risk (adjusted OR 0.23, P=0.044). Subgroup analyses showed consistent associations. Mediation analysis indicated iPTH and NT-proBNP explained 37% and 21.1% of the HRR-LVH relationship. Conclusion: HRR may be a simple marker for cardiovascular risk stratification in CKD. Prospective studies should assess whether interventions targeting HRR reduce LVH incidence.