Soluble Urokinase Plasminogen Activator Receptor (suPAR) as a Biomarker of Erectile Dysfunction in Diabetic Patients

Background/Objectives: Erectile dysfunction (ED) is a common complication of diabetes mellitus (DM), largely attributable to vascular, neurological and metabolic dysfunctions. Soluble urokinase plasminogen activator receptor (suPAR) is a biomarker of systemic inflammation and endothelial dysfunction, both of which play key roles in ED pathophysiology. This study aimed to evaluate the relationship between serum suPAR levels and ED in patients with type 2 DM, assessing its potential as a biomarker for early detection. Methods: This prospective, cross-sectional study included 127 male patients with type 2 DM and 46 healthy controls. Erectile function was assessed using the International Index of Erectile Function-5. Patients were divided into three groups: controls, diabetic patients without ED (DM-NoED) and diabetic patients with ED (DMED). Serum suPAR levels were measured via ELISA. Statistical analyses included Kruskal-Wallis tests, Dunn's post hoc comparisons and ROC curve analysis to evaluate diagnostic performance. Results: Serum suPAR levels were significantly elevated in the DMED group compared to both the DM-NoED and control groups (p < 0.001). The median suPAR levels were 107.9 pg/mL (controls), 130.3 pg/mL (DM-NoED) and 218.7 pg/mL (DMED). ROC analysis revealed an AUC of 0.836 in distinguishing DMED from DM-NoED with 87.5% sensitivity and 79.2% specificity. Conclusions: Elevated serum suPAR levels are significantly associated with ED in men with type 2 DM, independent of glycemic control and conventional cardiovascular risk factors. These findings suggest that suPAR may be a promising biomarker for the early detection and risk assessment of ED in diabetic patients. Future prospective studies are needed to confirm its clinical utility.