Association Between Cardiac and Renal Biomarkers in IgA Nephropathy: Insights into Cardiorenal Interaction: A Cross-Sectional Study

Background: IgA nephropathy (IgAN) is the most common primary glomerular disease worldwide and is associated with increased cardiovascular (CV) morbidity and mortality. Galectin-3 is a marker of fibrosis and adverse CV outcomes in chronic kidney disease (CKD), while mid-regional pro-atrial natriuretic peptide (MR-proANP) and heart-type fatty acid-binding protein (H-FABP) reflect myocardial wall stress and subclinical myocardial injury. Data on the combined behavior of these biomarkers in IgAN are limited. We investigated their association with renal function and cardiovascular parameters in IgAN. Methods: In this cross-sectional study, 90 patients with biopsy-proven IgAN were examined, but 76 patients’ data were evaluated. Serum galectin-3, MR-proANP, and H-FABP concentrations were measured by ELISA. Renal function was assessed using estimated glomerular filtration rate (eGFR, CKD-EPI). All patients underwent transthoracic echocardiography and arterial stiffness assessment, including pulse wave velocity of the aorta (PWVao) and central systolic blood pressure (SBPao). Results: Patients with reduced renal function (eGFR <60 mL/min/1.73 m2) had significantly higher galectin-3 (p = 0.011), MR-proANP (p < 0.001), and H-FABP (p < 0.001) concentrations. Biomarker levels increased progressively with declining eGFR. Galectin-3 concentrations were higher in patients with increased left ventricular mass index (p = 0.015). All three biomarkers were elevated in patients with higher central aortic systolic pressure. MR-proANP and H-FABP increased with worsening albuminuria, whereas galectin-3 did not. In multivariate analyses, eGFR was the only independent predictor of all three biomarkers. Conclusions: In IgAN, galectin-3, MR-proANP, and H-FABP concentrations are closely linked to renal function and markers of cardiovascular remodeling. These findings suggest that galectin-3, MR-proANP, and H-FABP provide complementary information regarding the complex interaction between renal dysfunction and cardiovascular remodeling in IgA nephropathy. Prospective multicenter studies are warranted to determine their incremental prognostic value and potential clinical utility for cardiovascular risk stratification.