Neutrophil gelatinase-associated lipocalin, kidney injury molecule-1, and periostin: Novel urinary biomarkers in diabetic nephropathy

BACKGROUND: Globally, diabetic nephropathy (DN) is the primary cause of chronic kidney disease. Currently, renal function is monitored indirectly using measures of serum creatinine, estimated glomerular filtration rate (eGFR), and proteinuria. Novel urinary biomarkers utilized in the early stages of DN have been described; these indicators can be used in the early identification of the disease, which is important for initiating treatment to halt or impediment the advance of diabetic nephropathy. AIM: To estimate neutrophil gelatinase-associated lipocalin (NGAL), kidney injury molecule-1 (KIM-1), and periostin (POSTN) levels as novel urinary biomarkers in DN. METHODS: = 40) groups as per urine albumin creatinine ratio (uACR). Blood urea, serum creatinine, uACR were measured. Urine NGAL, KIM-1, and POSTN were measured by enzyme linked immunosorbent assay. The eGFR was calculated and compared with urinary markers. RESULTS: NGAL, KIM-1, and POSTN levels increased significantly in normo, micro, and macroalbuminuria with the highest in the macroalbuminuria group. Albumin creatinine ratio (ACR) showed a positive correlation with NGAL, KIM-1, and POSTN levels. The eGFR showed a weak negative correlation with ACR, NGAL, KIM-1, and POSTN. NGAL was significantly lower in stage 1 compared to stage 2, 3, and 4 kidney disease. KIM-1 was significantly decreased in stage 1 compared to stage 4 kidney disease. POSTN was significantly decreased in stage 1 compared to stage 3 and 4 kidney disease. The receiver operator curve analysis of ACR, NGAL, KIM-1, and POSTN showed good sensitivity of 80%, 75.8%, 63.3%, and 80 % respectively with a cut-off of 12.5 mg/g, 4.5 μg/L, 1.5 ng/mL, and 37.5 ng/mL. CONCLUSION: Urinary NGAL and POSTN are independent markers of DN.