Yoshikazu Sato

Objectives: To examine sexual behavior, erectile function, and sexual satisfaction among middle‐aged Japanese men using nationwide survey data. Methods: This secondary analysis used data from a 2023 nationwide online survey of male sexual dysfunction in Japan. Men aged 45–64 years were included. Sexual behavior was assessed by frequencies of sexual intercourse and masturbation. Erectile function was assessed using the Sexual Health Inventory for Men (SHIM) and Erection Hardness Score (EHS), with ED defined as EHS ≤ 2. Sexual satisfaction was assessed using the overall satisfaction domain of the International Index of Erectile Function. Multivariable logistic regression identified factors associated with ED. Results: Overall, 2314 men were analyzed (mean age, 53.8 ± 5.6 years). Sexual intercourse was infrequent: 48.1% reported intercourse less than once per year and 35.1% within the past 6 months, whereas 45.9% reported masturbation once or twice weekly. ED prevalence differed substantially by assessment method: 82.1% according to SHIM versus 26.9% according to EHS. Men with EHS‐defined ED had significantly lower overall sexual satisfaction scores than those without ED ( p < 0.001), although satisfaction scores substantially overlapped. Older age, diabetes mellitus, hypertension, mental illness, and sleep apnea syndrome were independently associated with ED. Conclusions: Among middle‐aged Japanese men, the prevalence of ED varied substantially according to the assessment method, while EHS‐defined ED was associated with lower overall sexual satisfaction despite substantial overlap in satisfaction scores. These findings support considering both erectile function and subjective sexual satisfaction when assessing sexual health.

Objectives: To identify latent classes of sexual activity among Japanese adult men using multiple sexual behavior indicators and to investigate their associations with household income. Methods: This cross‐sectional study analyzed data from a 2023 nationwide Internet‐based survey of 5 735 Japanese men aged 20–79 years. Latent class analysis used six indicators: Sexual intercourse frequency, masturbation frequency, morning erection frequency, and International Index of Erectile Function items 6, 11, and 12. Household income data were available for 4 824 men, who were categorized into low (<¥4 million/year), middle (¥4 to <¥8 million/year), or high (≥¥8 million/year) income groups. Results: Four latent classes were identified: Low desire/inactive (Class 1, 37.3%), high desire/non‐coital (Class 2, 25.8%), moderate desire/sexually active (Class 3, 14.7%), and high desire/high‐function active (Class 4, 22.1%). Higher household income was independently associated with Classes 3 and 4, with dose–response relationships, but not with Class 2. The overall income‐by‐marital‐status interaction was significant ( p = 0.0004), whereas the class‐specific interaction was significant only for Class 3 ( p = 0.021) and not for Class 4 ( p = 0.255). These post hoc interaction findings were considered exploratory. Sensitivity analyses yielded consistent results. Conclusions: Approximately one‐quarter of Japanese men belonged to a class characterized by moderate‐to‐high sexual desire and relatively frequent morning erections despite predominantly little or no intercourse. Household income was associated with intercourse‐involving classes but not with Class 2. These findings support a multidimensional assessment of sexual health and warrant further research on socioeconomic factors associated with partnered sexual activity.

Objective: This study aimed to examine trends in frequency of sexual intercourse and sexual function among Japanese men over the past 30 years by comparing the Nationwide Survey conducted by the Japanese Society for Sexual Medicine in 2023 with the Sapporo Survey conducted by the Department of Urology, Sapporo Medical University, in 1991. Methods: Three domains were analyzed: sexual intercourse, penile rigidity, and morning erections in both studies. To minimize inconsistencies, definitions were standardized. The 2023 survey included 3795 men aged 20–79 years, while the 1991 survey comprised 8893 participants for sexual intercourse, 7517 for morning erections, and 3886 for penile rigidity. Case numbers differed by item in 1991 owing to incomplete responses. The 1991 survey targeted only married individuals; comparable analyses were performed using married participants extracted from the 2023 dataset. Results: 1. Sexual intercourse: Compared with the 1991 Sapporo Survey, the proportion of men reporting sexual intercourse less than once per month was significantly higher across all age groups in the 2023 Nationwide Survey, except among men in their 20s. 2. Penile rigidity: The proportion of men with insufficient penile rigidity for penetration was significantly higher in 2023 than in 1991 across all age groups except those aged ≥ 75 years. 3. Morning erections: Men reporting complete absence of morning erections were significantly more common in 2023 across all age groups. Conclusion: Over the past three decades, Japanese men have shown substantial declines in the frequency of sexual intercourse, penile rigidity, and the frequency of morning erections, particularly in younger and middle‐aged cohorts.

Tsujimura A, et al. World J Mens Health. 2026 ;44:e83. https://doi.org/10.5534/wjmh.260157

Shirai M, et al. World J Mens Health. 2025 Jun;43:e35. https://doi.org/10.5534/wjmh.250094

Objectives: Following the 2022 revision of the Japanese clinical practice guidelines for late‐onset hypogonadism, more flexible diagnostic criteria have been recommended, emphasizing both clinical symptoms and testosterone levels. This study aimed to evaluate the clinical characteristics of late‐onset hypogonadism syndrome and the effectiveness of testosterone replacement therapy combined with daily phosphodiesterase‐5 inhibitors in symptomatic men, including those with normal testosterone levels. Methods: From 2019 to 2023, 704 men presenting with late‐onset hypogonadism‐related symptoms were assessed for serum testosterone levels and symptom profiles. Of these, 227 received combination therapy with testosterone replacement therapy and daily phosphodiesterase‐5 inhibitors. Changes in mood, vitality, sexual function and lower urinary tract symptoms were evaluated using validated questionnaires. Results: The most frequent symptoms were depressive mood, loss of energy, and easy fatigue, which may represent core features of late‐onset hypogonadism syndrome. No significant association was found between testosterone levels and symptom severity. Combination therapy significantly improved symptom scores, as well as subjective feelings of vigor, confidence, and masculinity. Among the patients, 48.4% reported feeling “better” or “much better,” 47.2% reported feeling “slightly better,” and 4.4% experienced “no change” or “worsening.” Patients with normal testosterone levels showed greater improvement in symptom scores. Recovery of morning erections independently predicted overall improvement. Conclusions: Testosterone replacement therapy combined with daily phosphodiesterase‐5 inhibitors is effective for late‐onset hypogonadism‐related symptoms, even in patients with normal testosterone levels. These findings support the revised Japanese guidelines, which promote a symptom‐oriented treatment strategy alongside biochemical evaluation.

Background: Among causes of male sexual dysfunction, the prevalence of delayed ejaculation (DE) is lower than that of premature ejaculation or erectile dysfunction (ED), and its epidemiology remains poorly characterized, particularly in Asian populations. Aim: To estimate DE prevalence and identify associated factors of DE in a nationwide sample of Japanese men. Methods: A cross-sectional, internet-based survey conducted by the Clinical Research Promotion Committee of the Japanese Society for Sexual Medicine between May 29 and June 24, 2023, targeted Japanese men aged 20-79 years through a general population panel. Among 6228 valid responses, 5331 men who reported sexual activity were included in the analysis. DE-related distress was used to define the condition. Data on demographics, medical comorbidities, lifestyle factors, and sexual function were collected. Participants were also asked whether they desired treatment for DE and whether they had consulted a physician regarding this condition. Associated factors were identified through multivariate logistic regression analysis. Outcomes: Prevalence of DE, associated demographic and clinical factors, treatment-seeking desire, and actual help-seeking behavior among sexually active Japanese men. Results: The prevalence of DE was 5.16%. Of the affected individuals, 58.18% desired treatment, but only 11.88% actually sought it. Multivariate analysis revealed that psychotropic drug use (odds ratio [OR] = 2.41), pelvic trauma (OR = 2.39), low partnership satisfaction (OR = 2.27), ED (OR = 2.04), neurological diseases (OR = 2.02), obesity (OR = 1.51), high frequency of masturbation (OR = 1.24), and high frequency of sexual intercourse (OR = 1.17) were significantly associated with DE (all P < .05). Conversely, having children showed an independent association with a lower likelihood of DE (OR = 0.57, P < .001). Clinical Implications: These findings highlight that DE is associated with multiple psychological, sexual, and physical health factors and that treatment-seeking behavior remains low despite substantial distress. Strengths and Limitations: This large, nationwide epidemiological study on DE in Japan is the first with a robust sample size and multivariate analysis. However, the reliance on self-reported data and internet-based sampling may introduce reporting bias and limit generalizability. Conclusion: DE affects approximately 5% of sexually active Japanese men and shares many risk factors with ED. Although more than half of those with DE desire treatment, only a minority seek care. Greater clinical awareness and patient education are warranted.

Objectives: We assessed sexual symptoms and function in perimenopausal and postmenopausal Japanese women and examined the association between sexual regularity and their symptoms. Methods: Sexually active women aged 40-79 (n = 911) were selected from the genitourinary syndrome of menopause (GSM) in Japanese Women study (n = 4,134) and then divided into 2 groups: regular sexual activity group, which comprised women with sexual activity in the past 3 months (n = 716), and lower sexual activity group, which comprised women with sexual activity in the past year but not in the past 3 months (n = 195). We evaluated sexual function and symptoms in the regular sexual activity group using the Female Sexual Function Index and compared GSM-related symptoms between the two groups. Results: Sexual desire, arousal, and lubrication ability declined significantly with age. Sexual pain increases with age. However, orgasm and satisfaction did not decline significantly with age. Regular and lower sexual activity groups did not differ significantly in sexual symptoms; however, vulvar symptoms in daily life were significantly lower in the regular sexual activity group than in the lower activity group. Sexual activity in the past 3 months was associated with lower odds of vulvar pain, dryness, and irritation. Conclusions: This study reveals an association between regular sexual activity and low prevalence of GSM-related symptoms in daily life. The direction of this relationship could not be evaluated in this study and needs to be explored using prospective studies.

This third edition of the Japanese Clinical Practice Guidelines for Urinary stones (2023) has been developed under the leadership of the Japanese Urological Association, the Japanese Society of Endourology and Robotics, and the Japanese Society on Urolithiasis Research. This revision adheres to the Minds Manual for Guideline Development (2017) and incorporates new findings from a nationwide survey conducted in 2015, which highlighted the epidemiological characteristics of urolithiasis in Japan since the previous guidelines were published in 2013. A significant advancement in this edition is the systematic review (SR) methodology applied to formulate recommendations for 12 clinical questions (CQs). Both quantitative and qualitative SRs were performed, leading to recommendations determined through consensus among 21 members of the guideline development group. Additionally, nine algorithms were created to support clinical decision‐making based on these findings. Topics not addressed by the CQs, considered as foundational knowledge, are outlined in an “Explanation of Related Matters” section, which includes 26 items. This article provides an overview of these guidelines. This section ensures that practitioners have access to comprehensive information, covering aspects of urolithiasis management beyond the scope of the systematic reviews. This article provides an overview of the guidelines, emphasizing their relevance and importance in improving the management and treatment outcomes for patients with urinary stones. The guidelines are designed to be a practical resource for clinicians, facilitating evidence‐based care in the evolving landscape of urolithiasis treatment.