Prediction effect of chronic inflammatory marker MLR and clinical Metric on postoperative symptom recovery in patients with BPH and Non-Linearity Association Analysis.

BACKGROUND: To explore the predictive value of preoperative systemic inflammatory markers combined with clinical parameters for the improvement of lower urinary tract symptoms in patients with lower urinary tract symptoms (LUTS) secondary to benign prostatic obstruction (BPO) after surgery. METHOD: This study was a single-center observational cohort study that consecutively enrolled 180 patients with benign prostatic hyperplasia (BPH) who underwent transurethral prostate surgery. Data on preoperative inflammatory markers (neutrophil-to-lymphocyte ratio [NLR], platelet-to-lymphocyte ratio [PLR], systemic immune-inflammation index [SII], monocyte-to-lymphocyte ratio [MLR]), prostate-specific antigen (PSA), postvoid residual urine volume, etc., were collected. The primary outcome was poor symptom response at 6 months after surgery (IPSS improvement rate < 50%). Elastic net regression and the Boruta algorithm were used to screen variables, and a logistic regression model was constructed to identify independent predictors. A generalized additive model (GAM) was also applied to explore the nonlinear relationship between key variables and symptom improvement. RESULTS: Preoperative postvoid residual urine volume, MLR, and total PSA levels in the poor symptom response group were significantly higher than those in the good response group (P < 0.05). Multivariate logistic regression showed that preoperative postvoid residual urine volume (odds ratio [OR] = 1.32, 95% confidence interval [CI]: 1.11-1.57), total PSA (OR = 1.52, 95%CI: 1.08-2.13), and MLR (OR = 1.85, 95%CI: 1.28-2.67) were independent predictors of poor symptom response. GAM analysis further revealed a nonlinear association: when postvoid residual urine volume was greater than 90 mL, its negative impact on the improvement of postoperative storage symptoms was significantly intensified; the negative effects tended to ease after MLR > 0.25. The predictive effect of MLR was specific for the improvement of storage symptoms. CONCLUSIONS: Preoperative MLR, postvoid residual urine volume, and PSA level are independent factors for predicting the improvement of postoperative symptoms in patients patients with BPO.. Among them, MLR, as a biomarker reflecting the state of chronic inflammation, has specific predictive value for the improvement of storage symptoms. These preoperative parameters are helpful in identifying high-risk patients with poor postoperative symptom improvement and provide references for individualized clinical decision-making.