Predictive Roles of Serum Biomarkers for Screening Patients for Diabetic Nephropathy

One of the consequences of type 1 and type 2 diabetes is diabetic nephropathy (DN), which can arise from the microvascular effects of the illnesses, often resulting in progressive renal impairment. It predominantly affects individuals in young and middle adulthood. This study included 60 patients diagnosed with DN at Baqubah Teaching Hospital and 30 healthy individuals as controls. Serum levels of MMP-7, YKL-40, KIM-1, and RBP-4 were measured using enzyme-linked immunosorbent assay (ELISA) to evaluate their role in the pathophysiology of DN. Among the DN cohort, 61.7% were male, with the highest representation in age groups 41-50 (23.3%), 51-60 (31.7%), and 61-70 years (23.3%). Most patients (73.3%) were non-obese. Serum levels of MMP-7, YKL-40, KIM-1, and RBP-4 were significantly elevated in DN patients compared to controls (p < 0.05). ROC curve analysis revealed that YKL-40 had the highest diagnostic performance, with 93% sensitivity and 87% specificity at a cut-off value >7.31 ng/mL. This was followed by KIM-1 (83% and 80%), MMP-7 (77% and 80%), and RBP-4 (70% and 71%) at cut-offs (>1.01, >7.31, and >49.39), respectively, in the diagnosis of DN patients. No statistically significant differences were found between biomarker levels in obese versus non-obese patients. Additionally, Pearson correlation analysis demonstrated a significant positive correlation between MMP-7 and YKL-40 (Pearson Correlation 0.442** and **p = 0.001). The elevated levels of MMP-7, YKL-40, KIM-1, and RBP-4 in DN patients reflect underlying kidney damage. Among these biomarkers, YKL-40 and KIM-1 demonstrated superior diagnostic utility due to their higher sensitivity and specificity, suggesting their potential value as reliable markers in the early detection and monitoring of diabetic nephropathy.