Study on urinary biomarkers of tubular injury in type2 diabetes mellitus patients

Abstract

newline Background: newlineDiabetic nephropathy (DN) is a leading cause of chronic kidney disease (CKD) and end-stage renal disease (ESRD) worldwide. Traditional diagnostic methods, such as albuminuria and estimated glomerular filtration rate (eGFR), often fail to detect early tubular injury, which precedes glomerular damage in diabetic patients. Urinary tubular biomarkers may offer earlier and more accurate detection of DN. newlineAim: newlineTo evaluate the diagnostic utility of urinary biomarkers Megalin, Neutrophil Gelatinase- Associated Lipocalin (NGAL), Cystatin-C, and N-Acetyl Glucosaminidase (NAG) in detecting early tubular injury in type-2 diabetic patients. newlineMethods: newlineA cross-sectional analytical study was conducted among 320 type-2 diabetic patients, divided into normoalbuminuria, microalbuminuria, and macroalbuminuria groups based on urinary albumin-to-creatinine ratio (UACR). Urinary biomarkers were estimated and compared across groups. Receiver Operating Characteristic (ROC) analysis, correlation analysis, and regression models were used for statistical interpretation. newlineResults: newlineSignificant elevations in urinary NAG and NGAL were observed in micro- and macroalbuminuric groups (p lt 0.0001). NGAL showed strong discriminative performance (AUC = 0.764), followed by NAG (AUC = 0.719). Megalin exhibited an inverse trend and poor diagnostic utility (AUC = 0.363). Cystatin-C did not show significant variation across groups (p = 0.0949). NAG and NGAL correlated positively with HbA1c, LDL-c, and UACR. newlineConclusion: newlineNGAL and NAG are promising biomarkers for early detection of DN, demonstrating significant associations with albuminuria and glycemic/metabolic parameters. Their inclusion alongside UACR may improve risk stratification in diabetic patients. Megalin and Cystatin-C showed limited diagnostic utility in this context.