To determine, using the Asian Survey of Aging Males (ASAM), the prevalence of lower urinary tract symptoms (LUTS) and sexual disorders in Asian men aged 50–80 years, and to investigate the relationship between LUTS and sexual dysfunction, as community-based studies have shown a relationship between LUTS and sexual dysfunction.
SUBJECTS AND METHODS
The ASAM survey was conducted in selected cities in five Asian countries, using a combination of face-to-face and mail-survey methods. The survey evaluated demographics, urinary symptoms (using the International Prostate Symptom Score, IPSS, and bother score), functional problems (using the Danish Prostatic Symptoms Score, DAN-PSS-Sex, and International Index of Erectile Function, IIEF) and comorbidity factors. In all, 1155 men aged 50–80 years completed the survey.
The prevalence of LUTS varied among the countries, ranging from 14% in Singapore to 59% in the Philippines. Moderate to severe LUTS were reported by 36% of men aged 50–59 years, 50% aged 60–69 years and 60% aged 70–79 years. About three-quarters of all respondents (72%) aged 50–80 years were sexually active. Erectile dysfunction was reported by 63% of men in the study, of whom 57% were bothered by their symptoms. Ejaculation disorders were present in 68% of respondents (52% reported bothersomeness) and pain on ejaculation was experienced by 19% of the men in the study (88% reported bothersomeness). Sexual disorders increased with age and increasing severity of their LUTS. Erectile and ejaculation problems were more common in subjects with diabetes or hypertension; these two groups showed the same relationship between LUTS severity and sexual disorders.
These results confirmed that sexual activity is common in Asian men aged 50–80 years, even at an advanced age. They also confirmed the correlation between LUTS and sexual dysfunction.
LUTS are common in men age >50 years  and are often caused by BPH [2–4]. LUTS include ‘voiding’ symptoms, such as reduced stream, hesitancy and straining, and ‘storage’ symptoms, including frequency, nocturia and symptoms of incontinence [3,4]. Current thinking suggests that patients with LUTS and BPH often have coexisting sexual problems, which can significantly affect their quality of life [3,5,6]. The relationship between LUTS and sexual dysfunction has been controversial , but recent community-based studies suggest that erectile dysfunction (ED) and ejaculation disorders (EjD) are related to increasing age and the severity of LUTS [3,8–11]. The recent Multinational Survey of the Aging Male (MSAM-7), carried out in the USA and Europe, also showed a strong association between LUTS and sexual disorders . In this large survey, 12 815 respondents were analysed and in men aged 50–80 years with severe LUTS the odds ratios (OR) for ED, EjD and painful ejaculation were 7.67, 6.25 and 16.18, respectively .
ED is often associated with chronic conditions such as cardiovascular diseases, diabetes and depression [7,8,13]; it is considered a symptom of vascular endothelium damage, which can be induced by hypertension, diabetes, hyperlipidaemia and smoking . In a Japanese study of men's health, diabetes mellitus, heart disease and hypertension correlated significantly with ED .
There might be intercultural differences in the prevalence of LUTS . In a community-based study, the prevalence of LUTS was reported to be higher in Japan and the USA than in France or Scotland . Further, in a Malaysian study of different ethnic groups residing in Kuala Lumpur, the prevalence of moderate to severe LUTS in Malay, Chinese and Indian men aged ≥ 50 years was 70%, 59% and 50%, respectively .
Others have suggested that the prevalence of sexual dysfunction varies among different countries . In an epidemiological study of ED in four countries, the incidence of ED was higher in Japan (34%) and Malaysia (22%) than in Italy (17%) and Brazil (15%) . Community-based studies comparing sexual function in Japanese and American populations also reported a higher incidence of sexual problems in ageing Japanese men .
The Asian Survey of Aging Males (ASAM) was conducted to determine the prevalence of LUTS and sexual disorders in Asia, and to investigate the relationship between LUTS and sexual dysfunction in this population. In all, 1155 men aged 50–80 years from five Asian countries completed a questionnaire. Internationally validated, standardized questionnaires were used to assess urinary symptoms and various aspects of male sexual function.
SUBJECTS AND METHODS
The ASAM survey was conducted in 1155 men aged 50–80 years; they were interviewed in Hong Kong, Singapore, Malaysia (Klang Valley, Penang and Johor Bahru), Philippines (Metro Manila, Metro Cebu, Metro Davao) and Thailand (inner, middle and outer Bangkok). A combination of face-to-face interviews and mail-survey methods was used. Respondents were recruited from representative households face-to-face by interviewers, and the respondents completed the questionnaire in the presence of the interviewer. The respondents then mailed back the questionnaire to ensure confidentiality. The respondents could also return the questionnaire directly if they were willing; the questionnaire is shown in Appendix 1. Age groups were predefined, with a minimum of 20% for the 70–80 year age group and then equally divided between the 50–59 and 60–69 year age groups.
The IPSS was used to assess LUTS in the respondents (question one of the ASAM questionnaire). The IPSS is a validated eight-item scale which assesses the severity of incomplete emptying, urinary frequency, intermittency, urgency, weak stream and nocturia. The first seven items have an ordered categorical response that can be scored 0–5, with an overall score of 0–35. The severity of symptoms is classified as none (IPSS 0) or symptomatic: mild (IPSS ≤ 7), moderate (8–19) or severe (≥20). The eighth question (bother score) assesses the degree of bother and dissatisfaction associated with the symptoms, with responses scored from 0–6. The IPSS is the internationally accepted standard questionnaire for assessing LUTS.
Sexual function was assessed using two independent questionnaires, the Danish Prostatic Symptoms Score (DAN-PSS-Sex) and the International Index of Erectile Function (IIEF). The DAN-PSS-Sex consists of six questions (questions 6–11 of the ASAM questionnaire) on ED, EjD and pain and/or discomfort during ejaculation, and their respective bothersomeness. The DAN-PSS-Sex questionnaire was used to assess ED in all 1155 respondents and EjD in all 1042 respondents who were able to achieve erections. The IIEF is a 15-item (questions 12–26 of the ASAM questionnaire), standardized scale of male sexual function, which assesses separate domains of erectile function, orgasmic function, sexual desire, intercourse satisfaction and overall satisfaction. The IIEF is the ‘standard’ measure of male sexual function used in clinical trials of treatments for ED. The IPSS, DAN-PSS-Sex and IIEF were linguistically validated using a translation and back-translation process.
Additional questions provided information on age and demographic characteristics (questions S1–S8 of the ASAM questionnaire). Respondents were questioned about other chronic illnesses or comorbidities (diabetes, hypertension, cardiac disease, hyperlipidaemia) and, where present, were asked if they were receiving treatment for these conditions. Lifestyle factors that might affect LUTS were also included in the questionnaire (obesity, smoking, alcohol consumption).
Prevalence was calculated using sampling weights in each country. LUTS and sexual function scores were calculated for the total sample, and by country, age category (50–59, 60–69 and 70–80 years) and comorbidities (diabetes, hypertension and cardiac disease). A multivariate analysis using a logistic regression was used to measure the correlation between LUTS and sexual dysfunction, adjusting for confounding factors. Two-sided tests were used with a type I error of 5%, and 95% CI were provided.
Participants were recruited by face-to-face interviews in Hong Kong (201 men), Singapore (204), Malaysia (250), Philippines (250) and Thailand (250); Table 1 summarizes the age and health characteristics of the respondents. Moderate to severe LUTS, assessed using the IPSS, were reported by 46% of respondents. The prevalence of moderate to severe urinary symptoms was 59% in the Philippines, 48% in Hong Kong, 39% in Thailand, 34% in Malaysia and 14% in Singapore. The prevalence and severity of LUTS were age-related; moderate to severe LUTS were reported in 36% of men aged 50–59 years, and this increased to 50% and 60% in those aged 60–69 and 70–80 years, respectively (P < 0.001).
Table 1. The demographic characteristics of the respondents
bothered, a little bit/moderately/very much.
Proportion receiving treatment
Proportion receiving treatment
Proportion receiving treatment
Proportion receiving treatment
Urinary symptoms (IPSS)
DAN-PSS-Sex; prevalence and bothersomeness of functional problems
From the total sample population, 72% were still sexually active; the level of sexual activity was highest in respondents from the Philippines (90%) and Hong Kong (82%). In Malaysia, Singapore and Thailand, 70%, 61% and 56% were sexually active. The mean monthly frequency of sexual intercourse or sexual activity was 3.7 across all five countries, being 4.0 in the Philippines, followed by 3.4 in Thailand and Hong Kong, 3.1 in Malaysia and 2.8 in Singapore.
The frequency of sexual activity was lower in respondents with moderate to severe LUTS than in those with no or mild symptoms (3.6 vs 3.16 per month, P = 0.08). In men aged 50–59 years the frequency of sexual intercourse/activity per month was 4.6 in patients with no or mild LUTS and 4.0 in those with moderate to severe LUTS, respectively (P = 0.04). Sexual activity remained high in men aged 60–69 years (3.2 vs 2.6; P = 0.02) and those aged 70–80 years (3.3 vs 3.0).
As assessed using the DAN-PSS-Sex questionnaire, 63% of men reported difficulty achieving an erection, or complete absence of erection (Table 1). Those with more severe LUTS reported greater difficulty in achieving an erection (Fig. 1). Erectile problems were present in 33%, 61% and 87% of men with no or mild LUTS aged 50–59, 60–69 and 70–80 years, respectively, and in 54%, 84% and 91% of men with moderate to severe LUTS. The impact of the severity of LUTS on erectile function was less pronounced in men aged 70–80 years. The prevalence of ED was higher in men with diabetes or hypertension but there was an association between LUTS severity and erectile problems irrespective of comorbidities. Bothersomeness with ED was 57% for the total sample, ranging from 30% in Thailand to 78% in the Philippines. Erectile function, assessed using the IIEF, showed a similar decline with age and LUTS severity (Fig. 2). When categories were collapsed to never/mild and moderate/severe, the IIEF score was 25.6, 22.9 and 21.0 in men with no or mild LUTS aged 50–59, 60–69 and 70–80 years, respectively, and 22.7, 18.4 and 17.8 in men with moderate to severe LUTS.
Reduced or no ejaculation was reported by 68% of the total sample. EjD increased with age and severity of LUTS (P < 0.01), being reported in 41%, 66% and 86% of men with no or mild LUTS, and by 60%, 87% and 88% of men with moderate to severe LUTS aged 50–59, 60–69 and 70–80 years, respectively. There was an increase in EjD in men with moderate to severe LUTS in the presence and absence of hypertension or diabetes. Overall, 52% of men were bothered by a reduced or no ejaculation, ranging from 30% in Thailand to 71% in the Philippines. Among respondents who reported ejaculation problems, bothersomeness increased with LUTS severity. In men aged 50–59 years, 53% with no or mild LUTS reported bother, vs 62% in those with moderate to severe LUTS; bother associated with EjD was 43% and 56% in men aged 60–69 years, and 37% and 55% in those aged 70–80 years, respectively.
Bothersomeness with ejaculatory problems was slightly greater in men aged 50–59 years, who were more sexually active, but was not significantly affected by age. Pain or discomfort with ejaculation was reported by 19% of the total sample, and was considered bothersome by 88% of those affected (Table 1).
Overall satisfaction (IIEF Q24–25) was significantly reduced in respondents with moderate to severe LUTS (7.29 vs 6.35, P = 0.001). Sexual desire declined with age but was not significantly affected by the severity of LUTS. The IIEF sexual desire index was 6.5 in men with no to mild LUTS, and 6.2 in those with moderate to severe symptoms in men aged 50–59 years, 5.2 vs 4.9 in those 60–69 years and 4.2 vs 4.1 in those aged 70–80 years.
A logistic regression of the DAN-PSS-Sex items related to erection or ejaculation problems showed a statistically significant association between ED or EjD and LUTS, adjusted for other variables included in the analysis, such as age and comorbidities. Men with severe LUTS were three times more likely to have ED than men with no LUTS (OR 3.17; 95% CI 1.8–5.6). Similar ORs were obtained for the effects of LUTS on EjD, controlling for the other variables (OR 3.29; 1.84–5.9, for men with severe LUTS compared with men with no LUTS). Painful ejaculation was almost six times more likely in men with severe LUTS (OR 5.95; 3.03–8.39). The logistic regression analysis also confirmed the strong association between LUTS and age as an independent predictive factor (Table 2).
Table 2. Logistic regression results for ED and EjD
Sexual activity remains high in Asian men aged 50–80 years, even at an advanced age. The proportion of men who were sexually active and the average frequency of intercourse or sexual activity per month was lower in Asian men (72% and 3.7) than the mean in the USA and Europe surveyed in MSAM-7 (83% and 5.8) .
LUTS, BPH and sexual dysfunction are widely recognized as being more common as age advances. The present study of Asian men confirms the association between LUTS and sexual disorders, reported in previous studies [3,8,9,12]. Several hypotheses have been advanced to account for the observed association between LUTS and ED. In particular, autonomic hyperactivity was proposed as a common link between these disorders and hypertension in ageing men . Other possible explanations of the common underlying cause include decreased nitric oxide production in both the prostate and smooth muscle of the penis, or pelvic atherosclerosis and endothelial dysfunction. Urinary symptoms improved in men being treated for ED with sildenafil , and conversely, there were significant improvements in erectile function after TURP in men with severe LUTS . Studies such as these offer further support for an intrinsic link between LUTS and ED.
The results of the present survey show a higher prevalence of LUTS and sexual dysfunction in Asia than previously reported in the USA and Europe by the MSAM-7 study . This survey is comparable with MSAM-7, as the same questionnaire was used, which is based on standardized and internationally validated scales of LUTS and sexual dysfunction . Moderate to severe LUTS, ED and EjD were reported by 46%, 63% and 68% of respondents in ASAM, compared with 31%, 50% and 47% in MSAM-7 . This may be partly a result of cultural differences in the willingness to seek medical intervention for LUTS and sexual disorders, or limited access to advice and information about their condition. In some countries, geographical factors will influence the level of awareness and treatment of LUTS and sexual disorders. There was a notable difference in the prevalence of moderate to severe LUTS between men in Singapore (14%) and the Philippines (59%) which may be because men in Singapore have easier access to medical care than men in the Philippines. Additionally, men in the Philippines may be less likely to seek medical advice on the appearance of early symptoms, therefore allowing their condition to progress.
In a cross-national survey of men aged 40–70 years there were marked cultural differences in the attitudes towards and reporting of ED . In Japan, only 31% of men said they would consult a doctor or other health professional if they had ED, compared with 72%, 90% and 89% in Malaysia, Brazil and Italy, respectively. Of the 548 men who reported moderate or severe ED, no men in Japan had previously been treated, compared with 6%, 19% and 2% in Malaysia, Brazil and Italy.
A large American cohort study indicated that there may be ethnic differences in the reporting of BPH, LUTS and sexual dysfunction. Asian men were considered less likely to seek medical or surgical intervention for symptoms of BPH . It was also reported that social influence, e.g. advice from others or the media, was a more important factor in the decision to seek medical care than was symptom severity .
It is widely recognized that as men age their ability to obtain an erection decreases, and that hypertension and diabetes are significant independent risk factors for ED [7,8,13,22]. In the present study the prevalence of ED and EjD was, as expected, higher in men who had diabetes or hypertension. There was a significant increase in the OR for abnormal ejaculation in men with hypertension or cardiac disease, and for painful ejaculation in men with hypertension (Table 2). Given the differing causes of the disorders, this finding was unexpected and requires further exploration in future studies before conclusions can be drawn.
The impact of LUTS on sexual disorders in ageing men was greater than expected. The age distribution and incidence of comorbidities in these Asian populations were comparable to those in MSAM-7. The effect of LUTS on sexual function was independent of hypertension, cardiac disease, hyperlipidaemia and tobacco consumption (Table 2). Patients with diabetes and with moderate to severe LUTS had a higher incidence of EjD than had patients with diabetes with no or mild LUTS. Overall, the prevalence of EjD was 68%, and was more common than ED, which was reported by 63% of respondents (Table 1). Pain or discomfort on ejaculation was reported by 19%; not surprisingly, a high proportion of these men (88%) were bothered by this condition.
Amongst patients who had ED and EjD, 57% and 52% of them, respectively, were bothered by their symptoms. Bothersomeness with ED was significantly less in Singapore (46%) and Thailand (30%) (Table 1). This is an interesting finding, and while it is possible that the lower levels of sexual activity reported in these two countries may contribute to a lack of bother when unable to engage in sexual intercourse, a definitive answer cannot be provided by this study.
The IIEF score was higher in all Asian countries that participated than in MSAM-7, but IIEF scores did not necessarily correlate with sexual activity. The Philippines had the lowest IIEF score but was reported to be the most sexually active of the countries studied.
In conclusion, in Asian men aged 50–80 years, an increased severity of LUTS was associated with increased incidence of sexual dysfunction, including ejaculation disorders. To effectively manage LUTS it is important to assess urinary symptoms and sexual function, and to understand the impact of these symptoms on the patient.
This study was supported by a research grant from Sanofi Aventis.
CONFLICT OF INTEREST
None declared. Source of funding: Sanofi Aventis sponsored the ASAM survey.