Abstract Objective The objective of this study is to evaluate the correlation between erectile dysfunction (ED) and lower urinary tract symptoms (LUTSs) using the International Index of Erectile Function‐5 (IIEF‐5) and the International Prostate Symptom Score (IPSS). Methods An online survey was conducted among 4800 Japanese men using the International Index of Erectile Function‐5 (IIEF‐5), International Prostate Symptom Score (IPSS) and Overactive Bladder Symptom Score (OABSS). After excluding one incomplete response, data from 4799 participants were analysed. Participants were grouped by ED severity according to IIEF‐5 score. The total and subcategory scores of the IPSS and OABSS were compared among the groups. LUTSs were categorized as post‐micturition, storage, voiding symptoms and incontinence. An additional analysis was conducted by age group: younger (40s–50s) and older (≥70s). Results Lower ED severity was associated with significantly lower IPSS and OABSS total scores ( p < 0.001). Voiding symptoms and incontinence scores increased with ED severity ( p < 0.001). Severe ED (IIEF‐5 to <8) was significantly associated with worse scores across all the LUTS domains. Younger men without ED had significantly lower scores in all LUTS categories ( p < 0.001). However, among older men, no significant differences in LUTS scores were observed according to ED status. Conclusion ED severity is positively correlated with LUTS severity, particularly voiding symptoms and incontinence. This relationship was more prominent in younger men.
Yamaguchi et al. (Fri,) studied this question.