Association of Neutrophil-to-Lymphocyte Ratio, Platelet-to-Lymphocyte Ratio, and Lymphocyte-to-Monocyte Ratio with Benign Prostatic Hyperplasia: A Propensity Score-Matched Analysis

Abstract

Introduction: The neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and lymphocyte-to-monocyte ratio (LMR) have recently been proposed as easily accessible inflammatory biomarkers and as surrogate markers for metabolic disease, cardiovascular disease, and malignancies, including prostate cancer. However, scant studies have investigated the association of NLR, PLR, and LMR with benign prostatic hyperplasia (BPH). Methods: Data from 8,727 middle-aged men who had participated in a health checkup were analyzed. BPH was defined as prostate volume ≥30 mL, International Prostate Symptom Score > 7, and maximal flow rate <15 mL/s. Propensity score matching was considered for 269 men with BPH (cases), and 7,136 men with no BPH (controls), but ultimately, propensity scores were matched at a 2:1 ratio of controls to cases (538 men in the control group and 269 men in the case group). Results: After propensity score matching, age, International Index of Erectile Function-5, testosterone, and number of metabolic syndrome component variables were evenly distributed and did not differ significantly between the groups. After matching, PLR and LMR were not significantly different between the 2 groups. However, NLR was significantly higher in the case group than in the control group (median [interquartile range]: 1.4 [1.1; 1.8] vs. 1.5 [1.2; 1.9]; p = 0.024) after matching. Conclusion: High NLR was significantly associated with the presence of BPH. Our results suggest the possible effect of inflammation on BPH development. A prospective study is needed to investigate the potential role of NLR as a candidate biomarker of BPH.