CHRONIC KIDNEY DISEASE AS A MODIFIER OF DIABETIC FOOT SYNDROME SEVERITY: A COMPARATIVE ANALYSIS OF THE WAGNER AND TEXAS CLASSIFICATION SYSTEMS

The objective was to evaluate the impact of chronic kidney disease (CKD) on the severity of diabetic foot syndrome (DFS) and to compare the diagnostic utility of the Wagner and University of Texas classification systems in patients with type 2 diabetes mellitus (T2DM). This cross-sectional study included 200 patients with confirmed T2DM and CKD, categorized into four groups based on CKD stage. Statistical analysis involved Firth-corrected logistic re­gression, ROC analysis, calculation of the Net Reclassification Improvement (NRI) index, and Decision Curve Analysis (DCA). Severe DFS was identified in 36% of patients according to the University of Texas classification (stages 3–4), compared to only 17% according to the Wagner classification (grades ≥4) (p<0.001). The area under the ROC curve (AUC) was 0.753 for the University of Texas system and 0.640 for the Wagner system (NRI = 0,49; Р<0,001). The neuroischemic phenotype emerged as the strongest predictor of severity (odds ratio >3000; Р<0,001). An estimated glomerular filtration rate (eGFR) of approximately 30 mL/min corresponds to an inflection point on the risk curve (AUC = 0,628 for the University of Texas system). A bedside risk score (9-point scale; AUC = 0,74) was developed, where a score of ≥6 indicates a >65% probability of severe DFS. CKD exacerbates the severity of DFS through vas­cular-ischemic mechanisms; however, eGFR loses its independent predictive value when adjusted for the neuro­ischemic phenotype. The University of Texas classification is significantly superior to the Wagner classification in pa­tients with CKD.