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Prevalence and Risk Factors for Erectile Dysfunction in Chinese Adult Males
Prevalence and Risk Factors for Erectile Dysfunction in Chinese Adult Males Xinyu Zhang, MD, PhD,1,2 Bin Yang, MD,1 Ni Li, MD,3 and Hongjun Li, MD, PhD1
ABSTRACT
Background: There is a lack of nationwide epidemiologic survey data on the prevalence estimate of erectile dysfunction (ED) in Chinese men living on the mainland China. Aim: To attain the representative prevalence estimate of ED in the Chinese male population and to analyze potential risk factors associated with ED by demographics, socioeconomic status, and medical comorbidities. Methods: The study was community based. The five-item Internation Index of Erectile Function questionnaire and in-person interview were used to obtain data. The survey subjects were 5,210 non-institutionalized Chinese men at least 40 years old residing in 30 provinces and autonomies of China. Multiple logistic regression analysis was used to disclose risk factors associated with ED. Outcomes: The prevalence estimate of ED was 40.56% in Chinese men at least 40 years old. Results: The prevalence of ED increased with increasing age. A significant high prevalence of ED was observed in men who smoked heavily, were estranged from a partner, had diabetes, and lower urinary tract symptoms from benign prostatic hyperplasia. Smoking more than 30 cigarettes daily and obesity (body mass index 30 kg/m2) significantly increased the risk for ED by multivariable-adjusted odds ratios. Stable or erratic sexual partners, personal incomes, alcohol consumption, and cardiovascular and/or cerebrovascular diseases were not risk factors associated with ED prevalence. Other sexual problems commonly seen in this group of men included difficulty achieving erectile rigidness, ejaculation, and climax during intercourse. Clinical Translation: Knowledge on the prevalence of ED and its associated risk factors will help physicians in the clinical management and prevention of ED with the use of counseling for lifestyle adjustment and drug therapy. Strengths and Limitations: Data on the influence of psychological conditions on ED were not collected. ED was not categorized as minor, moderate, or severe for analysis during processing of data. Conclusion: The national representative prevalence of ED was determined for the first time in the Chinese male population. Zhang X, Yang B, Li N, Li H. Prevalence and Risk Factors for Erectile Dysfunction in Chinese Adult Males. J Sex Med 2017;XX:XXXeXXX. Copyright 2017, International Society for Sexual Medicine. Published by Elsevier Inc. All rights reserved.
Key Words: Erectile Dysfunction; Prevalence; Risk Factors; Demographics; Socioeconomic Status; Medical Comorbidities
INTRODUCTION Erectile dysfunction (ED) is a common problem affecting more than 150 million men worldwide. ED is defined as the persistent inability to attain an erection sufficient to permit satisfactory sexual intercourse.1 ED has biological, psychological, and social effects on the quality of life of Received May 25, 2017. Accepted August 11, 2017.
men and their sexual partners.2 ED can cause frustration, anxiety, and depression in men and therefore can affect job performance, social activities, and family stability.3e5 It is evident that ED has become a measurable health disorder for men globally that requires medical and public health attention. 3
1
Program Office for Cancer Screening in Urban China, Cancer Hospital and Institute, Chinese Academy of Medical Sciences, Beijing, China
2
Copyright ª 2017, International Society for Sexual Medicine. Published by Elsevier Inc. All rights reserved. http://dx.doi.org/10.1016/j.jsxm.2017.08.009
Department of Urology, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China; Department of Urology, Navy General Hospital of Chinese PLA, Beijing, China;
J Sex Med 2017;-:1e8
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The prevalence of ED in different nations and races has been surveyed and the outcomes have been published in a substantial body of literature. The latest consensus from the Fourth International Consultation on Sexual Medicine in 2015 described a great variation of ED prevalence estimates based on studies published after 2000.6 Higher prevalence estimates were reported in Southeast Asia (22e28%) and East Asia (27%) than in Europe, Central and South America, and the Middle East (8e15%).7e9 Wong et al10 reported the highest overall prevalence estimate of ED (88%) in a Chinese survey, in which severe ED was as high as 77%. However, the subjects in that survey were limited to the Hong Kong district of China. Another Chinese study involved 1,472 subjects from a region in northern China.11 The ED prevalence was reported to be 78%, and prevalences of 55.3%, 88.2%, and 91.8% were found for men 40 to 49, 50 to 59, and 60 to 69 years old, respectively. Differences between the prevalence estimates of ED and the limits of these surveys imply the lack of true national prevalence estimates of ED in the non-institutionalized Chinese male population. Because of its population (1.4 billion) and use of global health care resources, it is very important to obtain the true prevalence of ED in China. This first nationwide and population-based study was designed to attain the representative prevalence estimate of ED in Chinese men at least 40 years old and to analyze risk factors associated with ED under different demographics, socioeconomic conditions, and medical comorbidities from Western countries. The data are essential not only to understand the current status of the epidemiology of ED in China and to develop adequate measurements, education programs, prevention, and treatment of ED, but also to provide future direction for studies on the etiology of ED.
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autonomies, Qinghai Province, Tibet, and Hong Kong. The study was approved by the medical ethic committee of the Peking Union Medical College Hospital (Beijing, China).
Assessment of ED and Other Sexual Dysfunctions Having been recognized as a valuable tool for diagnostics and epidemiologic studies of ED, the five-item International Index of Erectile Function (IIEF-5) questionnaire combined with interview in-person was used for the study. An IIEF-5 score no higher than 21 identifies ED.12 Subjects with IIEF-5 scores no higher than 21 were interviewed further by urologists and andrologists for information about their sexual activities. This information included intercourse within a 1-month period (yes or no, frequency), erectile rigidity (from grade IV to I), ejaculation (weakened, difficult, or none), amount of semen (decreased or none), climax (yes or no), libido (high, average, low, or no), impulsive erection (yes or no), and specific reason for stopping sexual activities. The questionnaires were collected from 6,338 subjects.
Assessment of Demographic, Socioeconomic Factors, and Medical Comorbidities Information on age, sex, ethnicity, marital status, couples’ relationship, sexual partners, sexual activity, smoking, drinking habits, education levels, personal incomes, and medical histories of cardiovascular and/or cerebrovascular problems, diabetes, and lower urinary tract symptoms (LUTS) from benign prostatic hyperplasia (BPH) were collected. Weight and waist and hip circumferences were measured and body mass index (BMI) and waist-to-hip ratio were calculated.13 The information was subjected to prevalence estimates and risk analysis of innate, socioeconomic, and medical conditions associated with ED.
METHODS Study Population, Participant Selection, and Sample Distribution This cross-sectional survey was directed to noninstitutionalized Chinese men at least 40 years of age who inhabited the mainland of China from 2010 to 2013. The study was community based. Urologists, andrologists, physicians in general practice, nurses, and social workers from 76 local hospitals and communities across the nation were involved with the study. A series of public lectures on men’s health were given. Male audience members were asked whether they are willing to take part in the survey. Men who agreed to be involved were selected and their medical histories were obtained. Those who had had severe diseases such as prostate cancer, heart diseases, or stroke and those who required assisted living were excluded from the study. Detailed instruction was given to discretionary participants before the survey questionnaire was completed. Questions relating to sexual activities were explained by the urologists and andrologists who administered the survey. All subjects consented by signing the informed consent form. The survey covered 30 provinces and autonomies except for Xinjiang
Statistical Analysis All statistical analyses were performed using SPSS 13.0 (SPSS, Inc, Chicago, IL, USA). The prevalence estimates of ED and its variations in different age groups were calculated. The raw and age-adjusted prevalences of ED by demographic, socioeconomic, and medical conditions were analyzed using c2 test. Age- and multivariable-adjusted odds ratios (ORs) and their 95% CIs were analyzed using multiple logistic regressions. A statistical significance level was set at a P value less than 0.05.
RESULTS Prevalence Estimates of ED The 5,210 completed questionnaires were counted as valid responses. The response rate was 82.2%. Of 5,210 Chinese men, 2,113 had IIEF-5 scores no higher than 21. Thus, the prevalence estimate of ED was 40.56% in the general Chinese male population at least 40 years old. The prevalence of ED increased steadily in relation to age (Table 1). There was a significant difference in ED prevalence among different age groups (P < .04 J Sex Med 2017;-:1e8
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Prevalence and Risk Factors for ED in Chinese Men
Table 1. Prevalence estimates of ED in 5,210 surveyed Chinese men and variations of ED in different age groups Age (y), range (average ± SD)
Subjects, n
Age distribution of all subjects, %
ED cases, n
Prevalence, %*
40e49 (43.9 ± 4.1) 50e59 (55.7 ± 2.4) 60e69 (65.2 ± 3.4) 70 (74.6 ± 2.6) Total
1,167 1,078 1,348 1,617 5,210
22.40 20.69 25.87 31.04 100
211 254 652 996 2,113
18.08 23.56 48.37 81.60 40.56
ED ¼ erectile dysfunction. *Prevalence estimates of ED were not adjusted by age.
by c2 test). The most remarkable increase in ED prevalence per decade was observed in groups 60 to 69 and at least 70 years old (33.2%) and then in groups 50 to 59 and 60 to 69 years old (24.9%). Prevalence estimates of ED by demographic characteristics, socioeconomic conditions, and medical comorbidities are listed in Table 2. The age-adjusted prevalence of ED in men smoking more than 30 cigarettes daily was significantly higher than in men smoking fewer cigarettes or men who did not smoke. A high prevalence of ED was observed for men who had estranged relationships with their spouses. There also was a significant difference of ED prevalence in men with vs without diabetes and BPH-related LUTS. When BMI was at least 30 kg/m2, the prevalence of ED increased. However, age-adjusted prevalence of ED did not show a significant difference. Personal income seemed to affect ED prevalence inversely, that is, a higher prevalence of ED was seen in men with lower income. Statistically there was no significant difference of ED prevalence for different marital statuses, waist-to-hip ratios, education levels, or area of residence, and for the absence vs presence of cardiovascular and cerebrovascular diseases. Interestingly, a very low prevalence of ED was observed in subjects from two minorities, Zhuang and Muslim. However, the numbers of subjects in these ethnic groups were relatively small.
Risk Factors Associated With ED by Demographics, Socioeconomic Conditions, and Medical Comorbidities Table 3 presents age- and multivariable-adjusted ORs associated with ED prevalence by demographics, socioeconomic status, and medical histories. Age- and multivariable-adjusted ORs were significantly higher for heavy smokers or those with BPH-related LUTS compared with ORs for other demographic, socioeconomic, and medical conditions. A high multivariable-adjusted OR was observed when BMI was at least 30 kg/m2 and diabetes was present as the comorbidity. An estranged relationship with a partner also seemed to be a significant risk factor for ED by age-adjusted OR. Stable or erratic sexual partnerships, personal incomes, alcohol consumption, and cardiovascular and cerebrovascular diseases were not risk factors associated with ED prevalence in the study. J Sex Med 2017;-:1e8
Other Sexual Dysfunctions in Surveyed Subjects Of 5,210 subjects, 4,269 self-reported having regular sex (81.9%), whereas 941 reported no sex (18.1%). Erectile rigidity was assessed for men with regular sex by the question, “How would you describe your ability to keep an adequate erection for satisfactory intercourse?” To this question, 1,855 answered “always or almost always” (grade IV; 43.5%), 1,829 answered “usually able to insert but not rigid enough” (grade III; 42.9%), 299 answered “sometimes able to but unable to insert” (grade II; 7.0%), and 286 answered “not able to” (grade I; 6.7%). In addition, 2,224 self-reported a noticeable decrease of semen (52.1%), 1,097 reported weakened ejaculation (25.7%), 551 reported difficult ejaculation (12.9%), and 397 reported no ejaculation (9.3%); of those who reported no ejaculation, 128 reported climaxing and 269 reported no climax. Of 941 subjects without partnered sexual activity, high, average, and low to no libido were self-reported by 111 (11.8%), 541 (57.5%), and 289 (30.7%), respectively. Moreover, 556 men reported having a spontaneous erection (59.1%), whereas 385 reported no spontaneous erection (40.9%) during the night. For more than half (381 or 54.1%) of the 704 who acknowledged responsibility for not having sex, ED was the cause. One hundred sixty-three (excluding 74 widowers) ascribed the lack of sex to their partners’ problems (17.3%). The latter resulted in 60 divorces or separations (36.8%) and 25 estrangements from spouses (15.3%).
DISCUSSION The high prevalence of ED has become a global health concern as the lifespan of men has increased remarkably from improved living conditions and health care since World War II.14 According to the Sexual Life Survey, the prevalence estimate of ED was 33.7% in American men vs 27% in Taiwanese men.15,16 The prevalence of ED varied in Europe from 6% to 64% in various age subgroups, showing a clear trend of an ageassociated increase.17 Ramezani et al18 reported that the prevalence of ED was 56.1% in middle-age and elderly Iranian men. In this nationwide survey, the overall prevalence of ED was 40.56% in Chinese men, which is much lower than that reported in studies in Hong Kong (88%) and northern China (78%).10,11 Differences of prevalence of ED in these three Chinese studies
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Table 2. Prevalence estimates of ED by demographics, socioeconomic factors, and medical comorbidities in 5,210 non-institutionalized Chinese men Prevalence of ED, % Factors Residence Urban Rural Ethnicity Han Zhuang Mongolian Muslim Others BMI (kg/m2) <18 18e24 25e29 30 WHR <0.9 0.9 Smoking (cigarettes/d) 0 1e9 10e19 20e29 30 Alcohol consumption (g/d) Socially 1e199 200e299 300 Marital status Married Widower Couples’ relationship Good Moderate Estranged Education Less than elementary Middle school At least university Personal income (U/mo) <2,000 2,000e3,999 4,000e5,999 6,000e7,999 8,000 Medical comorbidities Cardiovascular diseases Cerebrovascular diseases Diabetes BPH-related LUTS
Subjects, n
Age (y), average (SD)
ED cases, n
Raw
Age adjusted
3,838 1,272
50.5 (11.5) 51.4 (9.8)
1,608 505
41.90 39.70
40.96 40.02
4,861 83 63 52 151
60.5 50.6 48.6 51.7 47.8
(10.7) (9.1) (9.9) (8.2) (11.2)
2,008 9 21 10 65
41.31 10.84* 33.33 19.23* 43.05
39.88 10.94* 33.35 19.24* 36.54
115 1,578 2,471 1,046
74.1 52.5 59.5 63.6
(6.8) (11.8) (8.2) (6.8)
45 518 1,033 517
39.13 32.83 41.80 49.42
40.06 29.66 40.56 45.12
2,223 2,987
68.4 (5.8) 52.9 (8.8)
962 1,151
43.27 38.53
42.22 40.26
2,246 1,489 624 508 343
64.1 56 59.6 62.1 54.4
(6.4) (9.8) (8.5) (9.4) (7.8)
435 602 239 244 188
19.36* 40.43 38.30 48.03 54.80*
30.48 38.66 42.56 49.24 55.98*
1,365 2,062 510 1,138
64.1 56.5 62.1 53.08
(6.4) (8.0) (9.4) (7.2)
615 554 280 664
45.05 26.87 54.90 58.35
38.46 26.74 48.86 48.88
4,804 406
64.1 (6.4) 56.5 (9.8)
1,970 143
41.00 35.22
36.34 36.22
2,809 1,261 734
62.1 (7.4) 59.7 (8.8) 54.1 (6.9)
1,003 540 425
35.71 42.82 57.90*
36.66 38.46 49.66*
646 2,350 2,214
72.8 (3.9) 67.2 (5.4) 46.7 (8.7)
265 948 1,000
41.02 40.34 38.45
41.44 38.78 39.66
1,193 2,016 1,021 359 621
72.8 67.2 47.7 57.4 43.5
(3.5) (5.7) (8.7) (9.7) (5.7)
580 923 355 146 109
48.62* 45.78 34.77 40.67 17.55*
42.26 43.42 40.12 41.88 38.04
921 1,067 948 1,980
59.6 64.5 52.7 60.2
(6.9) (8.6) (6.8) (9.4)
465 488 503 965
50.49 45.74 53.06* 48.74
45.34 42.16 52.68* 49.26*
BMI ¼ body mass index; BPH ¼ benign prostatic hyperplasia; ED ¼ erectile dysfunction; LUTS ¼ lower urinary tract symptoms; WHR ¼ waist-to-hip ratio. *Statistically significant (P < .05 by c2 test). J Sex Med 2017;-:1e8
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Prevalence and Risk Factors for ED in Chinese Men
Table 3. Age- and multivariable-adjusted ORs (95% CIs) for erectile dysfunction by demographics and chronic diseases in Chinese men at least 40 years old (N ¼ 5,210) Age-adjusted OR (95% CI)
Multivariable-adjusted OR* (95% CI)
0.886 1.00 0.934 1.114
0.986 1.00 0.884 1.174
2
Body mass index (kg/m ) <18 18e24 25e29 30 Waist-to-hip ratio <0.9 0.9 Smoking status (cigarettes/d) Never 1e9 10e19 20e29 30 Alcohol consumption (g/d) Socially 1e199 200e299 300 Sexual partners Stable Erratic Couples’ relationship Good Moderate Estranged Personal income (U/mo) <2,000 2,000e3,999 4,000e5,999 6,000e7,999 8,000 Cardiovascular disease No Yes Cerebrovascular disease No Yes Diabetes No Yes BPH-related LUTS No Yes
(0.775e1.005) (ref) (0.862e1.119) (0.996e1.221)
(0.895e1.015) (ref) (0.852e1.192) (1.028e1.221)†
1.00 (ref) 0.957 (0.868e1.214)
1.00 (ref) 0.978 (0.886e1.333)
1.00 0.891 0.995 1.110 1.221
(ref) (0.789e1.208) (0.891e1.196) (0.981e1.156) (1.175e1.278)†
1.00 0.882 0.955 1.172 1.312
(ref) (0.799e1.258) (0.863e1.296) (0.984e1.212) (1.166e1.348)†
1.00 0.892 1.006 1.083
(ref) (0.877e1.101) (0.864e1.291) (0.886e1.095)
1.00 0.892 1.036 1.185
(ref) (0.877e1.000)† (0.846e1.266) (0.986e1.198)
1.00 (ref) 0.778 (0.719e1.118)
1.00 (ref) 0.978 (0.829e1.105)
1.00 (ref) 1.074 (0.963e1.201) 1.133 (1.071e1.357)†
1.00 (ref) 1.094 (0.903e1.261) 1.243 (0.996e1.257)
1.132 1.00 0.974 0.868 0.994
(0.817e1.161) (ref) (0.587e1.124) (0.801e1.113) (0.971e1.114)
1.262 1.00 0.953 0.879 1.006
(0.816e1.281) (ref) (0.767e1.225) (0.832e1.213) (0.998e1.114)
1.00 (ref) 0.886 (0.813e1.266)
1.00 (ref) 0.998 (0.713e1.116)
1.00 (ref) 0.863 (0.697e1.113)
1.00 (ref) 0.892 (0.747e1.091)
1.00 (ref) 1.376 (0.982e1.395)
1.00 (ref) 1.269 (1.007e1.364)†
1.00 (ref) 1.386 (1.114e1.515)†
1.00 (ref) 1.332 (1.284e1.521)†
BPH ¼ benign prostatic hyperplasia; LUTS ¼ lower urinary tract symptoms; OR ¼ odds ratio; ref ¼ reference. *Multivariable analysis includes age, ethnicity, marital status, couple’s relationship, sexual partners, smoking, drinking, education levels, personal incomes, and medical history. † P < .05.
reflect some bias derived from the numbers of subjects, assessment methods, and organizational issues of surveys rather than from the ethnic groups involved. This study covered 30 provinces and territories with a large sample and a wide range of age J Sex Med 2017;-:1e8
groups of non-institutionalized men. Therefore, the prevalence estimate of ED obtained is representative of the national prevalence of ED in the Chinese male population. The results demonstrate that the prevalence of ED in Chinese men is higher
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than the ED prevalence in Taiwan and Europe,16,17 lower than the prevalence in Iran,18 and equivalent to the prevalence reported from a large sample in New York State (46.3%).19 The common consensus is that prevalence of ED increases with age. Stranne et al20 investigated 10,845 older men in Sweden and followed the change of ED prevalence for 11 years. The prevalence of ED increased from 68.7% in 1992 to 74.2% in 2003. The most significant increase of ED prevalence per decade (33.2%) was observed at 60 and 70 years in our study. Therefore, the prevalence estimates of ED are affected greatly by the ages of participants in different epidemiologic surveys. This could explain the great variations of ED prevalence observed in published studies. Medical comorbidities commonly seen in older men have been presumed to be contributing factors to increased ED prevalence. However, there is still a lack of direct evidence on any correlation between medical comorbidities and ED occurrence in elderly men. Psychological problems and couples’ relationships were considered predisposition factors in one third of middle-age and elderly men with clinically symptomatic ED.21 Among demographic, socioeconomic, and medical conditions, heavy smoking, obesity, diabetes, and BPH-related LUTS were found to be significant risk factors associated with ED in Chinese middle-age and elderly men. The effect of smoking on ED has been documented in several studies.22e25 Smoking is considered to adversely alter the response of arterial blood vessels to vasodilation stimulants that are an essential component of erection. Nicotine could damage arterial and sinus endothelia of the corpus cavernosum and affect its veno-occlusive function.26 Our results support the assumption that harmful components from cigarettes in the circulation have a detrimental effect on ED.27 BMI higher than 30 kg/m2 was shown to be a significant risk factor associated with the prevalence of ED, although 80% of subjects had BMI below 30 in this study.28 People with a high BMI are more susceptible to diabetes and dyslipidemia, which are risk factors associated with ED prevalence.29,30 Drinking alcohol was not a risk factor associated with ED.31 ED seemed slightly higher in the low-income groups. Attenuation of the ageand multivariable-adjusted ORs suggests that the association of low income with ED was likely mediated in part by age and other factors because most elderly men were included in the lowincome groups. Multivariable logistic regression analysis showed that the risk ratio for ED was high in Chinese men with diabetes. The same conclusion has been drawn from different epidemiologic studies on ED using the IIEF-5 and other questionnaires.29,30,32 BPHrelated LUTS also was a significant risk factor associated with the prevalence of ED. A high comorbidity of ED with BPH-related LUTS was observed in an epidemiologic survey on ED in Germany.32 Martinez-Salamanca et al33 summarized relevant epidemiologic studies of the association between LUTS and ED and provided ORs of LUTS for ED from 2.3 to 3.4 in Denmark to 3.7 to 7.6 in the United States and six European countries. Pathophysiologic hypotheses regarding the common basis of
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LUTS and ED have been discussed in the literature.34 The underlying mechanisms of the impact of LUTS on ED remain largely unknown. However, we observed that successful management of LUTS clinically alleviates LUTS and ED.35 The survey showed that impairment of a couple’s relationship was a significant risk factor associated with ED (age-adjusted only). A previous study showed that deterioration of a couple’s relationship led to a decreased frequency of intercourse and low penile blood flow in patients with ED.36 The relational factors assessed by the Structured Interview on Erectile Dysfunction Scale 2 not only caused erectile difficulty and delayed ejaculation but also showed significant correlations with increased extramarital affairs and depressive symptoms.37 Boddi et al38 reported an association of a high prevalence of conflicts within couples (21.2%) with a high risk of ED as determined subjectively (selfreported) and objectively (systolic velocity at penile color-duplex ultrasound). To our knowledge, this study is one of few studies to explore the relational risk factors associated with ED. Other sexual dysfunctions are commonly present in surveyed Chinese men. Most men (more than two thirds) who had regular sex could not achieve climax. Of men without sexual activity, lack of libido was self-reported in a relatively large percentage and only half had ED. With the increasing lifespan in China, elderly men still have the desire and ability for sexual activity. However, a knowledge gap on sexual dysfunction, sexual activities, aging, and sexual partners’ issues exists between urologists, andrologists, and physicians in practice and the general population. An educational program is duly required for physicians and the public in China to promote their understanding of sexual dysfunction and the availability of pharmacotherapy for ED. Education should include awareness that lifestyle modification such as smoking cessation, improvement of couples’ relationships, and relief of psychological stress is an important component for the prevention and treatment of ED.25,39 This study has some limitations, such as lack of data on the influence of psychological conditions on ED and the analysis of ED prevalence without further categorizing ED as minor, moderate, or severe. The cross-sectional nature of this study did not permit us to draw a conclusion of direction and causation of significantly associated risk factors observed but did provide clues for future study on ED etiology.
CONCLUSION This nationwide survey provides representative prevalence estimates of ED (40.56%) in non-institutionalized Chinese men. Heavy smoking, deteriorated couple relationships, diabetes, and BPH-related LUTS were risk factors associated with the prevalence of ED.
ACKNOWLEDGMENTS The authors acknowledge the following individuals for their contributions to this study (names are listed in analphabetic J Sex Med 2017;-:1e8
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Prevalence and Risk Factors for ED in Chinese Men
order of family name): Fubao Chen, Liting Gao, Lijun Guan, Weidong Huang, Baofang Jin, Fengshuo Jin, Tong Li, Xiangru Li, Xijun Liu, Jinxing Lv, Baoguang Shi, Yanxin Song, Yan Tan, Yuxin Tang, Huiyu Wang, Jiahui Wang, Rui Wang, Yijue Wang, Zhiping Wang, Junping Xing, Guogen Xiong, Jixiu Xu, Peng Xu, Changhai Yang, Guosheng Yang, Shuwen Yang, Wentao Yang, Dongxu Yi, Ning Yu, Bin Zhang, Rui Zhang, Xiansheng Zhang, Xinrong Zhang, and Lianwen Zheng. The authors also express their sincere thanks to Dr Tiejun Gao (Department of Laboratory Medicine and Pathology, the Faculty of Medicine and Dentistry, University of Alberta, Canada) for scientific discussion and English editing. They are grateful to Gayle Simonson, MA, for her tireless editing of the English and examining the context of this report. Corresponding Author: Hongjun Li, MD, PhD, Department of Urology, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing 100730, China; E-mail: [email protected] Conflicts of Interest: The authors report no conflicts of interest. Funding: This work was supported by the National Family Planning Committee of China (grant 2009GJKJS05) and the National Natural Science Foundation of China (grants 81370698 and 81671448). The funding sources had no influence on the design and conduct of the study; collection, analysis and interpretation of data; the writing of the report; and the decision to submit the article for publication.
STATEMENT OF AUTHORSHIP Category 1 (a) Conception and Design Xinyu Zhang; Ni Li; Hongjun Li (b) Acquisition of Data Xinyu Zhang; Bin Yang; Hongjun Li (c) Analysis and Interpretation of Data Xinyu Zhang; Bin Yang; Ni Li; Hongjun Li Category 2 (a) Drafting the Article Xinyu Zhang; Hongjun Li (b) Revising It for Intellectual Content Xinyu Zhang; Hongjun Li Category 3 (a) Final Approval of the Completed Article Ni Li; Hongjun Li
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15. Shaeer O, Shaeer K. The Global Online Sexuality Survey (GOSS): the United States of America in 2011. Chapter I: Erectile dysfunction among English-speakers. J Sex Med 2012;912:3018-3027. 16. Hwang TI, Tsai TF, Lin YC, et al. A survey of erectile dysfunction in Taiwan: use of the erection hardness score and quality of erection questionnaire. J Sex Med 2010;8:28172824. 17. Corona G, Lee DM, Forti G, et al; EMAS Study Group. Agerelated changes in general and sexual health in middle-aged
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Zhang et al and older men: results from the European Male Ageing Study (EMAS). J Sex Med 2010;7:1362-1380.
29. Selvin E, Burntt AL, Platz EA. Prevalence and risk factors for erectile dysfunction in the US. Am J Med 2007;120:151-157.
18. Ramezani MA, Ahmadi K, Ghaemmaghami A, et al. Epidemiology of sexual dysfunction in Iran: a systematic review and meta-analysis. Int J Prev Med 2015;20:43.
30. Xing JP, Ning L, Chen HM, et al. Risk factors of erectile dysfunction in patients with cardiovascular diseases. Zhonghua Nan Ke Xue 2016;22:219-224.
19. Ansong KS, Lewis C, Jenkins P, et al. Epidemiology of erectile dysfunction: a community-based study in rural New York State. Ann Epidemiol 2000;10:293-296.
31. Chaudhary RK, Shamsi BH, Chen HM, et al. Risk factors for erectile dysfunction in patients with cardiovascular disease. J Int Med Res 2016;44:718-727.
20. Stranne J, Malmsten UG, Areskoug B, et al. Influence of age and changes over time on erectile dysfunction: results from two large cross-sectional surveys 11 years apart. Scand J Urol 2013;47:198-205.
32. Braun M, Wassmer G, Klotz T, et al. Epidemiology of erectile dysfunction: results of the ‘Cologne Male Survey’. Int J Impot Res 2000;12:305-311.
21. Pastuszak AW, Badhiwala N, Lipshultz LI, et al. Depression is correlated with the psychological and physical aspects of sexual dysfunction in men. Int J Impot Res 2013;25:194-199.
33. Martinez-Salamanca JI, Carballido J, Eardley I, et al. Phosphodiesterase type 5 inhibitors in the management of nonneurogenic male lower urinary tract symptoms: critical analysis of current evidence. Eur Urol 2011;60:527-535.
22. Johannes CB, Araujo AB, Feldman HA, et al. Incidence of erectile dysfunction in men 40 to 69 years old: longitudinal results from the Massachusetts Male Aging Study. J Urol 2000;163:460-463. 23. Mannino DM, Klevens RM, Flanders WD. Cigarette smoking: an independent risk factor for impotence? Am J Epidemiol 1994;140:1003-1008. 24. Mobley D, Baum N. Smoking: its impact on urologic health. Rev Urol 2015;17:220-225. 25. DeLay KJ, Haney N, Hellstrom WJ. Modifying risk factors in the management of erectile dysfunction: a review. World J Mens Health 2016;34:89-100. 26. Huang YC, Chin CC, Chen CS, et al. Chronic cigarette smoking impairs erectile function through increased oxidative stress and apoptosis, decreased nNOS, endothelial and smooth muscle contents in a rat model. PLoS One 2015; 10:e0140728. 27. Gades NM, Nehra A, Jacobson DJ, et al. Association between smoking and erectile dysfunction: a population-based study. Am J Epidemiol 2005;161:346-351. 28. Feldman HA, Goldstein I, Hatzichristou DG, et al. Impotence and its medical and psychosocial correlates: results of the Massachusetts Male Aging Study. J Urol 1994;151:54-61.
34. Gacci M, Eardley I, Giuliano F, et al. Critical analysis of the relationship between sexual dysfunctions and lower urinary tract symptoms due to benign prostatic hyperplasia. Eur Urol 2011;60:809-825. 35. Apostolidis A, Rantell A, Anding R, et al. How does lower urinary tract dysfunction (LUTD) affect sexual function in men and women? ICI-RS 2015—Part 2. Neurourol Urodyn 2017; 36:869-875. 36. Corona G, Mannucci E, Lotti F, et al. Impairment of couple relationship in male patients with sexual dysfunction is associated with overt hypogonadism. J Sex Med 2009;6:25912600. 37. Corona G, Petrone L, Mannucci E, et al. Assessment of the relational factor in male patients consulting for sexual dysfunction: the concept of couple sexual dysfunction. J Androl 2006;27:795-801. 38. Boddi V, Fanni E, Castellini G, et al. Conflicts within the family and within the couple as contextual factors in the determinism of male sexual dysfunction. J Sex Med 2015;12:2425-2435. 39. Hehemann MC, Kashanian JA. Can lifestyle modification affect men’s erectile function? Transl Androl Urol 2016;5:187-194.
J Sex Med 2017;-:1e8
ABSTRACT
Background: There is a lack of nationwide epidemiologic survey data on the prevalence estimate of erectile dysfunction (ED) in Chinese men living on the mainland China. Aim: To attain the representative prevalence estimate of ED in the Chinese male population and to analyze potential risk factors associated with ED by demographics, socioeconomic status, and medical comorbidities. Methods: The study was community based. The five-item Internation Index of Erectile Function questionnaire and in-person interview were used to obtain data. The survey subjects were 5,210 non-institutionalized Chinese men at least 40 years old residing in 30 provinces and autonomies of China. Multiple logistic regression analysis was used to disclose risk factors associated with ED. Outcomes: The prevalence estimate of ED was 40.56% in Chinese men at least 40 years old. Results: The prevalence of ED increased with increasing age. A significant high prevalence of ED was observed in men who smoked heavily, were estranged from a partner, had diabetes, and lower urinary tract symptoms from benign prostatic hyperplasia. Smoking more than 30 cigarettes daily and obesity (body mass index 30 kg/m2) significantly increased the risk for ED by multivariable-adjusted odds ratios. Stable or erratic sexual partners, personal incomes, alcohol consumption, and cardiovascular and/or cerebrovascular diseases were not risk factors associated with ED prevalence. Other sexual problems commonly seen in this group of men included difficulty achieving erectile rigidness, ejaculation, and climax during intercourse. Clinical Translation: Knowledge on the prevalence of ED and its associated risk factors will help physicians in the clinical management and prevention of ED with the use of counseling for lifestyle adjustment and drug therapy. Strengths and Limitations: Data on the influence of psychological conditions on ED were not collected. ED was not categorized as minor, moderate, or severe for analysis during processing of data. Conclusion: The national representative prevalence of ED was determined for the first time in the Chinese male population. Zhang X, Yang B, Li N, Li H. Prevalence and Risk Factors for Erectile Dysfunction in Chinese Adult Males. J Sex Med 2017;XX:XXXeXXX. Copyright 2017, International Society for Sexual Medicine. Published by Elsevier Inc. All rights reserved.
Key Words: Erectile Dysfunction; Prevalence; Risk Factors; Demographics; Socioeconomic Status; Medical Comorbidities
INTRODUCTION Erectile dysfunction (ED) is a common problem affecting more than 150 million men worldwide. ED is defined as the persistent inability to attain an erection sufficient to permit satisfactory sexual intercourse.1 ED has biological, psychological, and social effects on the quality of life of Received May 25, 2017. Accepted August 11, 2017.
men and their sexual partners.2 ED can cause frustration, anxiety, and depression in men and therefore can affect job performance, social activities, and family stability.3e5 It is evident that ED has become a measurable health disorder for men globally that requires medical and public health attention. 3
1
Program Office for Cancer Screening in Urban China, Cancer Hospital and Institute, Chinese Academy of Medical Sciences, Beijing, China
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Copyright ª 2017, International Society for Sexual Medicine. Published by Elsevier Inc. All rights reserved. http://dx.doi.org/10.1016/j.jsxm.2017.08.009
Department of Urology, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China; Department of Urology, Navy General Hospital of Chinese PLA, Beijing, China;
J Sex Med 2017;-:1e8
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The prevalence of ED in different nations and races has been surveyed and the outcomes have been published in a substantial body of literature. The latest consensus from the Fourth International Consultation on Sexual Medicine in 2015 described a great variation of ED prevalence estimates based on studies published after 2000.6 Higher prevalence estimates were reported in Southeast Asia (22e28%) and East Asia (27%) than in Europe, Central and South America, and the Middle East (8e15%).7e9 Wong et al10 reported the highest overall prevalence estimate of ED (88%) in a Chinese survey, in which severe ED was as high as 77%. However, the subjects in that survey were limited to the Hong Kong district of China. Another Chinese study involved 1,472 subjects from a region in northern China.11 The ED prevalence was reported to be 78%, and prevalences of 55.3%, 88.2%, and 91.8% were found for men 40 to 49, 50 to 59, and 60 to 69 years old, respectively. Differences between the prevalence estimates of ED and the limits of these surveys imply the lack of true national prevalence estimates of ED in the non-institutionalized Chinese male population. Because of its population (1.4 billion) and use of global health care resources, it is very important to obtain the true prevalence of ED in China. This first nationwide and population-based study was designed to attain the representative prevalence estimate of ED in Chinese men at least 40 years old and to analyze risk factors associated with ED under different demographics, socioeconomic conditions, and medical comorbidities from Western countries. The data are essential not only to understand the current status of the epidemiology of ED in China and to develop adequate measurements, education programs, prevention, and treatment of ED, but also to provide future direction for studies on the etiology of ED.
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autonomies, Qinghai Province, Tibet, and Hong Kong. The study was approved by the medical ethic committee of the Peking Union Medical College Hospital (Beijing, China).
Assessment of ED and Other Sexual Dysfunctions Having been recognized as a valuable tool for diagnostics and epidemiologic studies of ED, the five-item International Index of Erectile Function (IIEF-5) questionnaire combined with interview in-person was used for the study. An IIEF-5 score no higher than 21 identifies ED.12 Subjects with IIEF-5 scores no higher than 21 were interviewed further by urologists and andrologists for information about their sexual activities. This information included intercourse within a 1-month period (yes or no, frequency), erectile rigidity (from grade IV to I), ejaculation (weakened, difficult, or none), amount of semen (decreased or none), climax (yes or no), libido (high, average, low, or no), impulsive erection (yes or no), and specific reason for stopping sexual activities. The questionnaires were collected from 6,338 subjects.
Assessment of Demographic, Socioeconomic Factors, and Medical Comorbidities Information on age, sex, ethnicity, marital status, couples’ relationship, sexual partners, sexual activity, smoking, drinking habits, education levels, personal incomes, and medical histories of cardiovascular and/or cerebrovascular problems, diabetes, and lower urinary tract symptoms (LUTS) from benign prostatic hyperplasia (BPH) were collected. Weight and waist and hip circumferences were measured and body mass index (BMI) and waist-to-hip ratio were calculated.13 The information was subjected to prevalence estimates and risk analysis of innate, socioeconomic, and medical conditions associated with ED.
METHODS Study Population, Participant Selection, and Sample Distribution This cross-sectional survey was directed to noninstitutionalized Chinese men at least 40 years of age who inhabited the mainland of China from 2010 to 2013. The study was community based. Urologists, andrologists, physicians in general practice, nurses, and social workers from 76 local hospitals and communities across the nation were involved with the study. A series of public lectures on men’s health were given. Male audience members were asked whether they are willing to take part in the survey. Men who agreed to be involved were selected and their medical histories were obtained. Those who had had severe diseases such as prostate cancer, heart diseases, or stroke and those who required assisted living were excluded from the study. Detailed instruction was given to discretionary participants before the survey questionnaire was completed. Questions relating to sexual activities were explained by the urologists and andrologists who administered the survey. All subjects consented by signing the informed consent form. The survey covered 30 provinces and autonomies except for Xinjiang
Statistical Analysis All statistical analyses were performed using SPSS 13.0 (SPSS, Inc, Chicago, IL, USA). The prevalence estimates of ED and its variations in different age groups were calculated. The raw and age-adjusted prevalences of ED by demographic, socioeconomic, and medical conditions were analyzed using c2 test. Age- and multivariable-adjusted odds ratios (ORs) and their 95% CIs were analyzed using multiple logistic regressions. A statistical significance level was set at a P value less than 0.05.
RESULTS Prevalence Estimates of ED The 5,210 completed questionnaires were counted as valid responses. The response rate was 82.2%. Of 5,210 Chinese men, 2,113 had IIEF-5 scores no higher than 21. Thus, the prevalence estimate of ED was 40.56% in the general Chinese male population at least 40 years old. The prevalence of ED increased steadily in relation to age (Table 1). There was a significant difference in ED prevalence among different age groups (P < .04 J Sex Med 2017;-:1e8
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Prevalence and Risk Factors for ED in Chinese Men
Table 1. Prevalence estimates of ED in 5,210 surveyed Chinese men and variations of ED in different age groups Age (y), range (average ± SD)
Subjects, n
Age distribution of all subjects, %
ED cases, n
Prevalence, %*
40e49 (43.9 ± 4.1) 50e59 (55.7 ± 2.4) 60e69 (65.2 ± 3.4) 70 (74.6 ± 2.6) Total
1,167 1,078 1,348 1,617 5,210
22.40 20.69 25.87 31.04 100
211 254 652 996 2,113
18.08 23.56 48.37 81.60 40.56
ED ¼ erectile dysfunction. *Prevalence estimates of ED were not adjusted by age.
by c2 test). The most remarkable increase in ED prevalence per decade was observed in groups 60 to 69 and at least 70 years old (33.2%) and then in groups 50 to 59 and 60 to 69 years old (24.9%). Prevalence estimates of ED by demographic characteristics, socioeconomic conditions, and medical comorbidities are listed in Table 2. The age-adjusted prevalence of ED in men smoking more than 30 cigarettes daily was significantly higher than in men smoking fewer cigarettes or men who did not smoke. A high prevalence of ED was observed for men who had estranged relationships with their spouses. There also was a significant difference of ED prevalence in men with vs without diabetes and BPH-related LUTS. When BMI was at least 30 kg/m2, the prevalence of ED increased. However, age-adjusted prevalence of ED did not show a significant difference. Personal income seemed to affect ED prevalence inversely, that is, a higher prevalence of ED was seen in men with lower income. Statistically there was no significant difference of ED prevalence for different marital statuses, waist-to-hip ratios, education levels, or area of residence, and for the absence vs presence of cardiovascular and cerebrovascular diseases. Interestingly, a very low prevalence of ED was observed in subjects from two minorities, Zhuang and Muslim. However, the numbers of subjects in these ethnic groups were relatively small.
Risk Factors Associated With ED by Demographics, Socioeconomic Conditions, and Medical Comorbidities Table 3 presents age- and multivariable-adjusted ORs associated with ED prevalence by demographics, socioeconomic status, and medical histories. Age- and multivariable-adjusted ORs were significantly higher for heavy smokers or those with BPH-related LUTS compared with ORs for other demographic, socioeconomic, and medical conditions. A high multivariable-adjusted OR was observed when BMI was at least 30 kg/m2 and diabetes was present as the comorbidity. An estranged relationship with a partner also seemed to be a significant risk factor for ED by age-adjusted OR. Stable or erratic sexual partnerships, personal incomes, alcohol consumption, and cardiovascular and cerebrovascular diseases were not risk factors associated with ED prevalence in the study. J Sex Med 2017;-:1e8
Other Sexual Dysfunctions in Surveyed Subjects Of 5,210 subjects, 4,269 self-reported having regular sex (81.9%), whereas 941 reported no sex (18.1%). Erectile rigidity was assessed for men with regular sex by the question, “How would you describe your ability to keep an adequate erection for satisfactory intercourse?” To this question, 1,855 answered “always or almost always” (grade IV; 43.5%), 1,829 answered “usually able to insert but not rigid enough” (grade III; 42.9%), 299 answered “sometimes able to but unable to insert” (grade II; 7.0%), and 286 answered “not able to” (grade I; 6.7%). In addition, 2,224 self-reported a noticeable decrease of semen (52.1%), 1,097 reported weakened ejaculation (25.7%), 551 reported difficult ejaculation (12.9%), and 397 reported no ejaculation (9.3%); of those who reported no ejaculation, 128 reported climaxing and 269 reported no climax. Of 941 subjects without partnered sexual activity, high, average, and low to no libido were self-reported by 111 (11.8%), 541 (57.5%), and 289 (30.7%), respectively. Moreover, 556 men reported having a spontaneous erection (59.1%), whereas 385 reported no spontaneous erection (40.9%) during the night. For more than half (381 or 54.1%) of the 704 who acknowledged responsibility for not having sex, ED was the cause. One hundred sixty-three (excluding 74 widowers) ascribed the lack of sex to their partners’ problems (17.3%). The latter resulted in 60 divorces or separations (36.8%) and 25 estrangements from spouses (15.3%).
DISCUSSION The high prevalence of ED has become a global health concern as the lifespan of men has increased remarkably from improved living conditions and health care since World War II.14 According to the Sexual Life Survey, the prevalence estimate of ED was 33.7% in American men vs 27% in Taiwanese men.15,16 The prevalence of ED varied in Europe from 6% to 64% in various age subgroups, showing a clear trend of an ageassociated increase.17 Ramezani et al18 reported that the prevalence of ED was 56.1% in middle-age and elderly Iranian men. In this nationwide survey, the overall prevalence of ED was 40.56% in Chinese men, which is much lower than that reported in studies in Hong Kong (88%) and northern China (78%).10,11 Differences of prevalence of ED in these three Chinese studies
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Table 2. Prevalence estimates of ED by demographics, socioeconomic factors, and medical comorbidities in 5,210 non-institutionalized Chinese men Prevalence of ED, % Factors Residence Urban Rural Ethnicity Han Zhuang Mongolian Muslim Others BMI (kg/m2) <18 18e24 25e29 30 WHR <0.9 0.9 Smoking (cigarettes/d) 0 1e9 10e19 20e29 30 Alcohol consumption (g/d) Socially 1e199 200e299 300 Marital status Married Widower Couples’ relationship Good Moderate Estranged Education Less than elementary Middle school At least university Personal income (U/mo) <2,000 2,000e3,999 4,000e5,999 6,000e7,999 8,000 Medical comorbidities Cardiovascular diseases Cerebrovascular diseases Diabetes BPH-related LUTS
Subjects, n
Age (y), average (SD)
ED cases, n
Raw
Age adjusted
3,838 1,272
50.5 (11.5) 51.4 (9.8)
1,608 505
41.90 39.70
40.96 40.02
4,861 83 63 52 151
60.5 50.6 48.6 51.7 47.8
(10.7) (9.1) (9.9) (8.2) (11.2)
2,008 9 21 10 65
41.31 10.84* 33.33 19.23* 43.05
39.88 10.94* 33.35 19.24* 36.54
115 1,578 2,471 1,046
74.1 52.5 59.5 63.6
(6.8) (11.8) (8.2) (6.8)
45 518 1,033 517
39.13 32.83 41.80 49.42
40.06 29.66 40.56 45.12
2,223 2,987
68.4 (5.8) 52.9 (8.8)
962 1,151
43.27 38.53
42.22 40.26
2,246 1,489 624 508 343
64.1 56 59.6 62.1 54.4
(6.4) (9.8) (8.5) (9.4) (7.8)
435 602 239 244 188
19.36* 40.43 38.30 48.03 54.80*
30.48 38.66 42.56 49.24 55.98*
1,365 2,062 510 1,138
64.1 56.5 62.1 53.08
(6.4) (8.0) (9.4) (7.2)
615 554 280 664
45.05 26.87 54.90 58.35
38.46 26.74 48.86 48.88
4,804 406
64.1 (6.4) 56.5 (9.8)
1,970 143
41.00 35.22
36.34 36.22
2,809 1,261 734
62.1 (7.4) 59.7 (8.8) 54.1 (6.9)
1,003 540 425
35.71 42.82 57.90*
36.66 38.46 49.66*
646 2,350 2,214
72.8 (3.9) 67.2 (5.4) 46.7 (8.7)
265 948 1,000
41.02 40.34 38.45
41.44 38.78 39.66
1,193 2,016 1,021 359 621
72.8 67.2 47.7 57.4 43.5
(3.5) (5.7) (8.7) (9.7) (5.7)
580 923 355 146 109
48.62* 45.78 34.77 40.67 17.55*
42.26 43.42 40.12 41.88 38.04
921 1,067 948 1,980
59.6 64.5 52.7 60.2
(6.9) (8.6) (6.8) (9.4)
465 488 503 965
50.49 45.74 53.06* 48.74
45.34 42.16 52.68* 49.26*
BMI ¼ body mass index; BPH ¼ benign prostatic hyperplasia; ED ¼ erectile dysfunction; LUTS ¼ lower urinary tract symptoms; WHR ¼ waist-to-hip ratio. *Statistically significant (P < .05 by c2 test). J Sex Med 2017;-:1e8
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Prevalence and Risk Factors for ED in Chinese Men
Table 3. Age- and multivariable-adjusted ORs (95% CIs) for erectile dysfunction by demographics and chronic diseases in Chinese men at least 40 years old (N ¼ 5,210) Age-adjusted OR (95% CI)
Multivariable-adjusted OR* (95% CI)
0.886 1.00 0.934 1.114
0.986 1.00 0.884 1.174
2
Body mass index (kg/m ) <18 18e24 25e29 30 Waist-to-hip ratio <0.9 0.9 Smoking status (cigarettes/d) Never 1e9 10e19 20e29 30 Alcohol consumption (g/d) Socially 1e199 200e299 300 Sexual partners Stable Erratic Couples’ relationship Good Moderate Estranged Personal income (U/mo) <2,000 2,000e3,999 4,000e5,999 6,000e7,999 8,000 Cardiovascular disease No Yes Cerebrovascular disease No Yes Diabetes No Yes BPH-related LUTS No Yes
(0.775e1.005) (ref) (0.862e1.119) (0.996e1.221)
(0.895e1.015) (ref) (0.852e1.192) (1.028e1.221)†
1.00 (ref) 0.957 (0.868e1.214)
1.00 (ref) 0.978 (0.886e1.333)
1.00 0.891 0.995 1.110 1.221
(ref) (0.789e1.208) (0.891e1.196) (0.981e1.156) (1.175e1.278)†
1.00 0.882 0.955 1.172 1.312
(ref) (0.799e1.258) (0.863e1.296) (0.984e1.212) (1.166e1.348)†
1.00 0.892 1.006 1.083
(ref) (0.877e1.101) (0.864e1.291) (0.886e1.095)
1.00 0.892 1.036 1.185
(ref) (0.877e1.000)† (0.846e1.266) (0.986e1.198)
1.00 (ref) 0.778 (0.719e1.118)
1.00 (ref) 0.978 (0.829e1.105)
1.00 (ref) 1.074 (0.963e1.201) 1.133 (1.071e1.357)†
1.00 (ref) 1.094 (0.903e1.261) 1.243 (0.996e1.257)
1.132 1.00 0.974 0.868 0.994
(0.817e1.161) (ref) (0.587e1.124) (0.801e1.113) (0.971e1.114)
1.262 1.00 0.953 0.879 1.006
(0.816e1.281) (ref) (0.767e1.225) (0.832e1.213) (0.998e1.114)
1.00 (ref) 0.886 (0.813e1.266)
1.00 (ref) 0.998 (0.713e1.116)
1.00 (ref) 0.863 (0.697e1.113)
1.00 (ref) 0.892 (0.747e1.091)
1.00 (ref) 1.376 (0.982e1.395)
1.00 (ref) 1.269 (1.007e1.364)†
1.00 (ref) 1.386 (1.114e1.515)†
1.00 (ref) 1.332 (1.284e1.521)†
BPH ¼ benign prostatic hyperplasia; LUTS ¼ lower urinary tract symptoms; OR ¼ odds ratio; ref ¼ reference. *Multivariable analysis includes age, ethnicity, marital status, couple’s relationship, sexual partners, smoking, drinking, education levels, personal incomes, and medical history. † P < .05.
reflect some bias derived from the numbers of subjects, assessment methods, and organizational issues of surveys rather than from the ethnic groups involved. This study covered 30 provinces and territories with a large sample and a wide range of age J Sex Med 2017;-:1e8
groups of non-institutionalized men. Therefore, the prevalence estimate of ED obtained is representative of the national prevalence of ED in the Chinese male population. The results demonstrate that the prevalence of ED in Chinese men is higher
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than the ED prevalence in Taiwan and Europe,16,17 lower than the prevalence in Iran,18 and equivalent to the prevalence reported from a large sample in New York State (46.3%).19 The common consensus is that prevalence of ED increases with age. Stranne et al20 investigated 10,845 older men in Sweden and followed the change of ED prevalence for 11 years. The prevalence of ED increased from 68.7% in 1992 to 74.2% in 2003. The most significant increase of ED prevalence per decade (33.2%) was observed at 60 and 70 years in our study. Therefore, the prevalence estimates of ED are affected greatly by the ages of participants in different epidemiologic surveys. This could explain the great variations of ED prevalence observed in published studies. Medical comorbidities commonly seen in older men have been presumed to be contributing factors to increased ED prevalence. However, there is still a lack of direct evidence on any correlation between medical comorbidities and ED occurrence in elderly men. Psychological problems and couples’ relationships were considered predisposition factors in one third of middle-age and elderly men with clinically symptomatic ED.21 Among demographic, socioeconomic, and medical conditions, heavy smoking, obesity, diabetes, and BPH-related LUTS were found to be significant risk factors associated with ED in Chinese middle-age and elderly men. The effect of smoking on ED has been documented in several studies.22e25 Smoking is considered to adversely alter the response of arterial blood vessels to vasodilation stimulants that are an essential component of erection. Nicotine could damage arterial and sinus endothelia of the corpus cavernosum and affect its veno-occlusive function.26 Our results support the assumption that harmful components from cigarettes in the circulation have a detrimental effect on ED.27 BMI higher than 30 kg/m2 was shown to be a significant risk factor associated with the prevalence of ED, although 80% of subjects had BMI below 30 in this study.28 People with a high BMI are more susceptible to diabetes and dyslipidemia, which are risk factors associated with ED prevalence.29,30 Drinking alcohol was not a risk factor associated with ED.31 ED seemed slightly higher in the low-income groups. Attenuation of the ageand multivariable-adjusted ORs suggests that the association of low income with ED was likely mediated in part by age and other factors because most elderly men were included in the lowincome groups. Multivariable logistic regression analysis showed that the risk ratio for ED was high in Chinese men with diabetes. The same conclusion has been drawn from different epidemiologic studies on ED using the IIEF-5 and other questionnaires.29,30,32 BPHrelated LUTS also was a significant risk factor associated with the prevalence of ED. A high comorbidity of ED with BPH-related LUTS was observed in an epidemiologic survey on ED in Germany.32 Martinez-Salamanca et al33 summarized relevant epidemiologic studies of the association between LUTS and ED and provided ORs of LUTS for ED from 2.3 to 3.4 in Denmark to 3.7 to 7.6 in the United States and six European countries. Pathophysiologic hypotheses regarding the common basis of
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LUTS and ED have been discussed in the literature.34 The underlying mechanisms of the impact of LUTS on ED remain largely unknown. However, we observed that successful management of LUTS clinically alleviates LUTS and ED.35 The survey showed that impairment of a couple’s relationship was a significant risk factor associated with ED (age-adjusted only). A previous study showed that deterioration of a couple’s relationship led to a decreased frequency of intercourse and low penile blood flow in patients with ED.36 The relational factors assessed by the Structured Interview on Erectile Dysfunction Scale 2 not only caused erectile difficulty and delayed ejaculation but also showed significant correlations with increased extramarital affairs and depressive symptoms.37 Boddi et al38 reported an association of a high prevalence of conflicts within couples (21.2%) with a high risk of ED as determined subjectively (selfreported) and objectively (systolic velocity at penile color-duplex ultrasound). To our knowledge, this study is one of few studies to explore the relational risk factors associated with ED. Other sexual dysfunctions are commonly present in surveyed Chinese men. Most men (more than two thirds) who had regular sex could not achieve climax. Of men without sexual activity, lack of libido was self-reported in a relatively large percentage and only half had ED. With the increasing lifespan in China, elderly men still have the desire and ability for sexual activity. However, a knowledge gap on sexual dysfunction, sexual activities, aging, and sexual partners’ issues exists between urologists, andrologists, and physicians in practice and the general population. An educational program is duly required for physicians and the public in China to promote their understanding of sexual dysfunction and the availability of pharmacotherapy for ED. Education should include awareness that lifestyle modification such as smoking cessation, improvement of couples’ relationships, and relief of psychological stress is an important component for the prevention and treatment of ED.25,39 This study has some limitations, such as lack of data on the influence of psychological conditions on ED and the analysis of ED prevalence without further categorizing ED as minor, moderate, or severe. The cross-sectional nature of this study did not permit us to draw a conclusion of direction and causation of significantly associated risk factors observed but did provide clues for future study on ED etiology.
CONCLUSION This nationwide survey provides representative prevalence estimates of ED (40.56%) in non-institutionalized Chinese men. Heavy smoking, deteriorated couple relationships, diabetes, and BPH-related LUTS were risk factors associated with the prevalence of ED.
ACKNOWLEDGMENTS The authors acknowledge the following individuals for their contributions to this study (names are listed in analphabetic J Sex Med 2017;-:1e8
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Prevalence and Risk Factors for ED in Chinese Men
order of family name): Fubao Chen, Liting Gao, Lijun Guan, Weidong Huang, Baofang Jin, Fengshuo Jin, Tong Li, Xiangru Li, Xijun Liu, Jinxing Lv, Baoguang Shi, Yanxin Song, Yan Tan, Yuxin Tang, Huiyu Wang, Jiahui Wang, Rui Wang, Yijue Wang, Zhiping Wang, Junping Xing, Guogen Xiong, Jixiu Xu, Peng Xu, Changhai Yang, Guosheng Yang, Shuwen Yang, Wentao Yang, Dongxu Yi, Ning Yu, Bin Zhang, Rui Zhang, Xiansheng Zhang, Xinrong Zhang, and Lianwen Zheng. The authors also express their sincere thanks to Dr Tiejun Gao (Department of Laboratory Medicine and Pathology, the Faculty of Medicine and Dentistry, University of Alberta, Canada) for scientific discussion and English editing. They are grateful to Gayle Simonson, MA, for her tireless editing of the English and examining the context of this report. Corresponding Author: Hongjun Li, MD, PhD, Department of Urology, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing 100730, China; E-mail: [email protected] Conflicts of Interest: The authors report no conflicts of interest. Funding: This work was supported by the National Family Planning Committee of China (grant 2009GJKJS05) and the National Natural Science Foundation of China (grants 81370698 and 81671448). The funding sources had no influence on the design and conduct of the study; collection, analysis and interpretation of data; the writing of the report; and the decision to submit the article for publication.
STATEMENT OF AUTHORSHIP Category 1 (a) Conception and Design Xinyu Zhang; Ni Li; Hongjun Li (b) Acquisition of Data Xinyu Zhang; Bin Yang; Hongjun Li (c) Analysis and Interpretation of Data Xinyu Zhang; Bin Yang; Ni Li; Hongjun Li Category 2 (a) Drafting the Article Xinyu Zhang; Hongjun Li (b) Revising It for Intellectual Content Xinyu Zhang; Hongjun Li Category 3 (a) Final Approval of the Completed Article Ni Li; Hongjun Li
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