The relationship between urinary MMP-9, proteinuria, and pulse wave velocity in patients with diabetic kidney disease: a cross-sectional study

Abstract Objective Matrix metalloproteinase-9 (MMP-9) influences extracellular matrix remodeling, inflammation, and renal hemodynamics in patients with various kidney diseases, including diabetic kidney disease (DKD). Methods This cross-sectional study investigated the relationship between urinary MMP-9, proteinuria, and pulse wave velocity (PWV) in 67 patients with DKD and 21 healthy controls. Biochemical and clinical parameters were analyzed, and urinary MMP-9 levels were measured and normalized to creatinine. Results Both urinary MMP-9 levels and PWV were significantly higher in patients with DKD compared to healthy controls. Urinary MMP-9 levels correlated positively with proteinuria (r = 0.360, p = 0.003), SBP (r = 0.333, p = 0.006), and PWV (r = 0.316, p = 0.009), and negatively with eGFR (r= − 0.350, p = 0.004). Logistic regression analysis identified urinary MMP-9 as the only independent predictor of proteinuria in patients with DKD. Conclusion Our study highlights urinary MMP-9 as a potential biomarker reflecting not only renal dysfunction but also systemic vascular complications in DKD. These findings emphasize the dual role of MMP-9 in mediating renal and vascular pathology, highlighting its potential prognostic and therapeutic significance.