Association Between Postvoid Residual Urine Volume and Estimated Glomerular Filtration Rate in Men with Benign Prostatic Obstruction

Objective: The relationship between postvoid residual urine volume (PVR) and estimated glomerular filtration rate (eGFR) in men with benign prostatic obstruction (BPO) remains controversial. This study aimed to evaluate the association between PVR and eGFR. Methods: This retrospective study included 172 men with lower urinary tract symptoms (LUTS) secondary to BPO. Correlations between eGFR and clinical variables were evaluated using Spearman correlation analysis. Patients were stratified into four PVR categories (<50, 50–99, 100–149, and ≥150 mL), and eGFR values were compared using the Kruskal-Wallis test. Multivariable linear regression identified variables independently associated with eGFR. Results: Median age was 67 years, median PVR was 100 mL, and median eGFR was 84 mL/min/1.73 m². PVR showed a moderate negative correlation with eGFR (ρ = −0.356, p < 0.001). Median eGFR differed significantly across PVR categories (90.5, 85.0, 78.0, and 79.5 mL/min/1.73 m²; p < 0.001). In multivariable analysis, only age (β = −0.369, p < 0.001) and PVR (β = −0.288, p < 0.001) remained independently associated with eGFR. International Prostate Symptom Score (IPSS), prostate volume (PV), and urinary flow parameters were not independently associated with eGFR. Conclusion: Higher PVR was independently associated with lower eGFR in men with BPO after excluding major causes of CKD. PVR may represent a clinically useful marker of reduced eGFR and may provide additional clinical value beyond IPSS, urinary flow parameters, and PV. Prospective studies are warranted to confirm these findings.