To assess whether the association between lower urinary tract symptoms (LUTS) and erectile dysfunction (ED) is confounded by age or whether LUTS represent an independent risk factor for ED.

Men aged 20 to 80 years, who were participating in a health-screening project in the area of Vienna, completed the International Prostate Symptom Score (IPSS) and the International Index of Erectile Function-5. In parallel, all men underwent a detailed health evaluation, including physical examination, evaluation of various lifestyle factors, and a blood laboratory study with 14 parameters.

Within the total study population (n = 2858; mean age 45.8 years, range 20 to 80), the prevalence of LUTS and ED increased statistically significantly with age (P <0.0001). In multivariate analysis controlling for age, comorbidities, and lifestyle, the IPSS (P = 0.0001), the obstructive score of the IPSS (P = 0.0001), nocturia (P = 0.04), and the LUTS bother score (P = 0.002) correlated statistically significantly with the presence of ED (International Index of Erectile Function-5 score less than 22). The odds ratio for the presence of ED was 2.2 (95% confidence interval [CI] 1.8 to 2.8) for LUTS (IPSS greater than 7), 2.0 (95% CI 1.7 to 2.4) for voiding symptoms, 1.4 (95% CI 1.1 to 1.7) for nocturia (score greater than 2), and 2.5 (95% CI 2.0 to 3.1) for the LUTS bother score.

The presence of LUTS, in particular voiding symptoms, nocturia, and the quality-of-life impairment due to LUTS, is an independent risk factor for the presence of ED. These findings have implications for the treatment of elderly men with LUTS and open a new area for research.