LCN2 and diabetic kidney disease: Statistical analysis included correlation analysis, receiver operating characteristic (ROC) curve assessment, and multivariate logistic regression.<h4>Results</h4>Urinary NGAL levels increased progressively with the severity of diabetic nephropathy, rising from 49.1 ± 14.2 ng/mL in controls (within the normal reference range < 70 ng/mL) to 547.7 ± 31.7 ng/mL in patients with stage IV disease (p < 0.001).