To evaluate which among the lower urinary tract symptom (LUTS)/benign prostatic hyperplasia (BPH) measures is the most relevant to erectile dysfunction (ED) and elucidate the role of metabolic syndrome (MetS) and testosterone in their relationship.
A total of 2564 policemen aged 40-59 years who had participated in a health examination were included. LUTS/BPH and ED were evaluated by the international prostate symptoms score (IPSS), transrectal ultrasonography, uroflowmetry, postvoid residual urine volume (PVR), and international index of erectile function questionnaire 5 (IIEF-5). Spearman correlation tests, multiple linear regression tests, and logistic regression analyses were used.
The median age was 49.0 years; the median total IPSS and IIEF scores were 9 and 19, respectively. Among the LUTS/BPH measures, IPSS (r = -0.311, P <.001) showed the highest correlation coefficient with IIEF, followed by total prostate volume (r = -0.082, P <.001), PVR (r = -0.080, P <.001), and maximal flow rate (r = 0.049, P = .014). In addition, only IPSS was significantly correlated with the IIEF score after adjusting for age, testosterone, and MetS. The severity of LUTS, as assessed by IPSS, was also significantly correlated with moderate to severe ED (IIEF ≤ 11), after adjusting for age, testosterone, MetS, and other LUTS/BPH measures. On multiple linear regression test, adjustment of Mets changed the P value and beta value of LUTS/BPH measures. However, there were no changes after adjusting testosterone.
IPSS is the most powerful predictor of ED among the LUTS/BPH measures in middle-aged policemen. In addition, MetS might be a plausible explanation for the relationship between LUTS/BPH and ED.