Relationship between biomarkers of tubular injury and intrarenal hemodynamic dysfunction in youth with type 1 diabetes

Background: Early identification of youth with type 1 diabetes (T1D) at risk for diabetic kidney disease may improve clinical outcomes. We examined the cross-sectional relationship between kidney biomarkers neutrophil gelatinase–associated lipocalin (NGAL), copeptin, interleukin-18 (IL-18), kidney injury molecule-1 (KIM-1), chitinase-3-like protein-1 (YKL-40), and monocyte chemoattractant protein-1 (MCP-1) and intrarenal hemodynamic function in adolescents with T1D. Methods: Urine albumin-to-creatinine ratio (UACR), renal vascular resistance (RVR), glomerular filtration rate (GFR), intraglomerular pressure (P_GLO), efferent arteriole resistance (R_E), afferent arteriolar resistance (R_A), and renal plasma flow (RPF), and the above indicated biomarkers were assessed in youth aged 12–21 years with and without T1D of < 10 years duration. Results: Fifty adolescents with T1D (16.1 ± 3.0 years, HbA1c 8.6 ± 1.2%) and 20 adolescents of comparable BMI without T1D (16.1 ± 2.9 years, HbA1c 5.2 ± 0.2%) were enrolled. Adolescents with T1D demonstrated significantly higher GFR, RPF, R_E, and P_GLO than controls (39%, 33%, 74%, and 29%, respectively, all p < 0.0001). Adolescents with T1D also exhibited significantly lower RVR and R_A than controls (25% and 155%, respectively, both p < 0.0001). YKL-40 and KIM-1 concentrations, respectively, were positively associated with GFR (r: 0.43, p = 0.002; r: 0.41, p = 0.003), RPF (r: 0.29, p = 0.08; r: 0.34, p = 0.04), UACR (r: 0.33, p = 0.02; r: 0.50, p = 0.0002), and P_GLO (r: 0.45, p = 0.006; r: 0.52, p = 0.001) in adolescents with T1D. Conclusions: Higher concentrations of biomarkers YKL-40 and KIM-1 may help define the risk for intraglomerular hemodynamic dysfunction in youth with T1D. Graphical abstract: A higher resolution version of the Graphical abstract is available as Supplementary information. [Figure not available: see fulltext.].