Prevalence, lifestyle, and risk factors of erectile dysfunction, premature ejaculation, and low libido in middle‐aged men: first results of the Bavarian Men's Health‐Study

Erectile dysfunction (ED), premature ejaculation (PE), and low libido (LL) are reported as the most common male sexual dysfunctions.


INTRODUCTION
[3] ED is defined as the inability to achieve or maintain an erection sufficient for satisfactory sexual performance. 4[6] The most often used diagnostic tool is the International Index of Erectile Function-Erectile Function (IIEF-EF) domain. 7However, the IIEF-EF domain does not capture men without sexual intercourse, few sexual attempts or non-heterosexual orientation identity.Therefore, a considerable number of men are not captured by this tool.To capture all men independent of their sexual orientation identity and sexual activity further additional tools such as the Erection Hardness Score (EHS) 8 could be used.
PE is a three-dimensional condition that includes (I) short intravaginal ejaculation latency time (IELT) within about one minute (lifelong PE) or within about 3 min (acquired PE), (II) inability to delay ejaculation, and (III) personal distress and/or avoidance of sexual intimacy. 9[12] LL is defined as a "deficiency or absence of sexual fantasies or desire for sexual activity" and additionally requires "marked distress or interpersonal difficulty". 13A Danish population-based study published in 2007 revealed that the range of men reporting LL varied, depending on age, between 2.3% and 7.7%. 14A large German population-based survey showed similar results with a prevalence rate between 0.5% and 4.2% in men aged 41−50 years. 2 The causes of the aforementioned three male sexual dysfunctions are physical, psychological, or a combination of these factors.
They occur most often due to comorbidities (diabetes, hypertension, endocrine alterations, urogenital tumors, urinary infections, incontinence, and surgical damage to nerves and organs), psychological problems (depression and anxiety), and psychoactive and antihypertensive drug use. 15Lifestyle (smoking, alcohol abuse, inactivity, and obesity) and sociodemographic factors (age, income, education, and employment status) may also be associated with male sexual dysfunction. 16,17Sexual dysfunction can impact the quality of life of affected men and their partners. 18Given the frequent concomitant occurrence of ED, PE, and LL and their burden on affected men, it is important to detect their prevalence and associations with potential modifiable lifestyle risk factors and comorbidities in middle-aged men.
While there is some evidence regarding the interplay between ED and PE, 3 little is known about interactions between all these three aforementioned and most common sexual dysfunctions, especially in population-based samples of middle-aged men.
Thus, the objectives of this analysis were first, to investigate the prevalence of ED, PE, and LL in a large community-based sample of 50-year-old men, and secondly, to determine the association between these sexual dysfunctions and lifestyle, comorbidities, and other potentially modifiable risk factors.

Bavarian Men's Health Study
The

Sociodemographic, lifestyle, and psychosocial factors, comorbidities, and sexual behavior
A self-report sheet was used to assess sociodemographic variables, including being in a partnership, duration of the partnership, living with the partner, having children, level of education, employment status, and self-perceived economic situation.Lifestyle factors included among others, smoking, alcohol consumption, physical activity, and waist circumference (in cm, measured by an instructed study physician).Lower urinary tract symptoms (LUTS) were assessed with the validated German version of the International Prostate Symptom Score (IPSS). 19All further comorbidities (hypertension, diabetes mellitus, dyslipidemia, depression, etc.) and current medication were assessed in the clinical interview.Self-rated health was measured with the first question of the Short Form-36 Health Survey. 20Anxiety and depression were assessed using the German version of the two-question screening tool Generalized Anxiety Disorder-2 and the Patient Health Questionnaire-2. 21Both measures are rated on a 4-point Likert scale (0-3).A summary score ≥3 indicates clinical levels of anxiety and depression, respectively.These measures have proven reliable and valid in previous studies. 21Sexual behavior included among others, the six items: sexual orientation identity, partnered sexual activity/solo masturbation within the past 3 months, the importance of sexuality, sexual satisfaction, and number of lifetime sexual partners.Details of group categorizations are provided in Table 1.

Erectile dysfunction
The presence of ED was assessed using the German version of the IIEF-EF 7 and the Erection Hardness Score (EHS). 8 attempts, or non-heterosexual orientation identity are not suitable to be evaluated by the IIEF-EF domain the EHS was additionally asked. 22e EHS is a validated single-item patient-reported outcome (PRO) on the hardness of erection ranging from 0 (penis does not enlarge) to 4 (completely hard and fully rigid).The presence of ED was defined as an IIEF-EF score ≤25 or an EHS score ≤3. 7,8(I) "Some men cannot control their sexual excitement so that they cum (ejaculate) before or shortly (within approximately 2 min) after penetration.Has this happened to you during the last 6 months?"Response options were "no sexual activity"; "never/almost never"; "rarely"; "sometimes"; "often"; "almost all the time/almost always".

PE and delayed ejaculation
(II) "Has this been a personal problem for you?" Here, response options were "not at all a problem"; "a very small problem"; "some problem"; "a considerable problem"; "a very great problem".

TA B L E 1
Baseline characteristics of the study sample (n = 2500).
The numbers indicated are among the completed entries and not always adding up to the total sample size.Percent refers to the observed data and does not include missing data.Participants were classified into two groups according to the ISSM definition of PE: "no PE" and "lifelong/acquired PE".They were identified as having "no PE", if they answered the first question with "never/almost never" and the second question with "not at all a problem".In contrast, participants were identified as having lifelong/acquired PE when answering the first question with "often" or "almost all the time/almost always" and the second question with "some problem", "a considerable problem" or "a very great problem".If participants answered the first question with "never/almost never", "rarely" or "sometimes" and the second question with "some problem", "a considerable problem" or "a very great problem" they were identified as having variable/subjective PE.

Low libido
The presence of LL was assessed with the question "How often have you felt sexual desire during the past 4 weeks?"(very frequently, frequently, occasionally, rarely, very rarely/never), which was adopted from a study of men and women in Germany. 2 The latter two answer options were defined as LL.

Statistical analysis
Descriptive statistics were used to summarize participant characteris-

Study population
Note that, 2500 Bavarian men with a mean age of 50.

DISCUSSION
This cross-sectional study provides a basis for the understanding of men's sexual health and the most common male sexual dysfunctions in a large population-based random sample of middle-aged men.One in three middle-aged men experience some form of sexual dysfunction and risk factors identified in this study underline the multifactorial nature of ED, PE, and LL.Every fifth 50-year-old man reported being affected by ED, defined as both IIEF-EF score ≤25 and EHS ≤3.A previously published US-American study assessing ED in prostate cancer patients before treatment reported a comparable prevalence of 20% in healthy 50-year-old men. 6ED prevalence was higher in other large European studies including more than 3000 and about 2000 German men, respectively, for example, 29.5% in 40-59-year-old men living in a heterosexual, well-established relationship, 25 and among sexually active German men, 17% and 31% in 40-49-year-old men and 50-59-year-old men, respectively, versus among all men, 28% in 40-49-year-old men and 45% in 50-59-year-old men, respectively. 26wever, both studies were hampered by low response rates of 31% and 32%, respectively.Further, when applying the same ED definition (IIEF-EF score ≤25) used in the abovementioned studies, ED prevalence in the cohort of this study is comparable at 37%. 25,26 Notably, the IIEF-EF-domain does not capture men without sexual intercourse, few sexual attempts, or non-heterosexual orientation identity.Adding the EHS in this study captures all men independent of their sexual orientation identity and sexual activity.
The results observed underline the well-known link between ED and PE. 3 However, men complaining of both ED and PE should be considered and treated primarily as men with ED and treatment should be predominantly focused on the erectile problem. 27Men with ED had likewise higher odds of reporting LL, which is in line with previous studies. 28ED leads to low self-confidence and avoidance behavior that might result in LL. 28 From the investigated lifestyle factors and comorbidities only higher waist circumference and LUTS were associated with ED.A waist circumference >102 cm was associated with 2.2-fold increased odds of having ED.Previous studies reported that the relative risk of ED was nearly twice as high (risk ratio: 1.9) in obese men compared with men with normal BMI, 29 and that the prevalence of ED increased from 32.1% to 74.5% with increasing waist circumference. 30The Cologne Male Survey described the relationship of LUTS and ED, 31 and this analysis showed likewise a 1.8-fold increased odds of ED in men with LUTS (IPSS > 7).
Contrary to the results of previous studies, 6,32 ED was not associated with other lifestyle factors and comorbidities.In simple logistic regression, less physical activity, hypertension, diabetes, and depression were associated with ED, but the effect failed to reach significance when controlling for concurrent confounders in the multiple regression analyses.Notably, the aforementioned studies showing an effect of these risk factors investigated mainly older men.Shorter existence and lower severity of symptoms caused by these risk factors might mitigate ED severity, however, with increasing age symptoms of ED might aggravate.The correlation between ED and cardiovascular events is an issue of major interest warranting further studies on older high-risk populations.
In the present analysis, the prevalence of lifelong/acquired PE was 5.2%, and 11% of men had variable/subjective PE.This is consistent with findings from two large observational studies, which also used the ISSM evidence-based definition of PE.In these studies, the prevalence of lifelong/acquired PE was 6.2% and 8.0%, respectively; however, the prevalence of variable/subjective PE was higher in these samples (14% and 18%, respectively). 33,34This underlines the assumption that the higher prevalence of subjective PE might partly be due to cultural reasons, 35 since these samples were from Turkey and China, respectively.
Regarding lifestyle factors, physically active men had lower odds of having PE.This was consistent with previous findings, which reported that engaging in physical exercise is associated with lower levels of PE symptoms. 36Physical activity is attributed to have a regulating effect on the serotonergic neurotransmission, which activates the ejaculatory reflex. 37e prevalence of LL was 7.2% in this analysis which is compara- in men aged 45-66 years was reported. 14terestingly, an association between LL and various lifestyle factors/comorbidities could not be found in the multiple analyses.In fact, when assessing the factors separately, an association of LL with less physical activity, alcohol consumption, depression, and LUTS was found, whereas higher waist circumference, smoking, hypertension, diabetes, and dyslipidemia showed no association.Studies investigating older men showed that age itself, low physical activity, obesity, depression, and diabetes were associated with lower sexual desire. 14,38e findings of this study provide a good generalizability due to the large, population-based, and randomly selected sample of 50year-old men.Additionally, instructed physicians surveyed all men; thus detailed medical history was obtained and a physical examination was conducted.Furthermore, sexual dysfunctions (i.e., ED and PE) were assessed using validated questionnaires, allowing comparison of results.The BMH-Study will also provide longitudinal data in the future, which will enable a more profound understanding of male sexual health and sexual dysfunctions.

CONCLUSIONS
Results of the current analysis provide a basis for the understanding of men's sexual health and the most common male sexual dysfunctions in a large population-based random sample of middle-aged men.ED measured with both the IIEF-EF domain and the EHS was more precise and independent of men's sexual orientation identity.Factors associated included not only typical risk factors and comorbidities but also other sexual dysfunctions and LUTS, underlining the multifactorial nature of these sexual dysfunctions.Most associated risk factors and comorbidities are modifiable, which should be addressed in patient education as well as in men's health campaigns and men should take active measures to remove the risk posed by these factors.

AUTHOR CONTRIBUTIONS
In addition to being the corresponding author, Kathleen Herkommer's contribution to this manuscript was research design and oversight, acquisition of data analysis and interpretation, and drafting of the manuscript.Valentin Meissner helped with the analysis and interpretation of data and drafted the manuscript.Stefan Schiele helped with the statistical analysis and interpretation of the data.Jürgen Gschwend helped with additional administrative support.All authors revised critically the manuscript for important intellectual content.
Bavarian Men's Health Study (BMH-Study) is an ongoing study that focuses on various aspects of male physical, mental, and sexual health in a large, population-based random sample of 50-year-old Bavarian men concomitantly participating in a prostate cancer screening trial.Men were invited from the local population registers within a radius of 100 km around the study center by using simple random sampling.A short postal inquiry and invitation to participate in the trial were sent.Address information was provided by local registration offices.To obtain a representative overview of the population, we decided to include all participants without applying any exclusion criteria.The study protocol was reviewed and approved by the ethical review committee of the Technical University of Munich.All participants are informed about study procedures and provide written informed consent.At three time-points, comprising study entry, 5 and 10 years afterward, participants visit the clinical center for an interview and brief physical examination, where they complete standardized questionnaires.The report here contains the cross-sectional results of the baseline measures for men enrolled between April 2020 and April 2021.
Severity of ED was classified as mild (IIEF-EF score 22−25), mild to moderate (IIEF-EF score 17−21), moderate (IIEF-EF score 11−16), or severe (IIEF-EF score 6−10).Since men with failed sexual intercourse, few sexual PE and delayed ejaculation (DE) were assessed using the Sexual Complaints Screener for Men (SCS-M),23 an evidence-based screening tool estimating men's sexual complaints during the past 6 months.The SCS-M was developed based on expert opinion to assess sexual problems in a medical practice setting, with its validity and reliability recently established for Turkish men.24 Participants were classified into three groups according to the International Society for Sexual Medicine Ad Hoc Committee for the Definition of Premature Ejaculation 9 (no PE vs. lifelong/acquired PE vs. variable/subjective PE) and into two groups for DE (no DE vs. DE).The screening measure comprised the following two items.
tics and simple logistic regression to explore individual characteristic associations with the outcomes of ED, PE, and LL.Three separate multiple logistic regression models with backward selection were performed for the outcomes ED, PE, and LL to measure associations with lifestyle factors and comorbidities.For each specific outcome modeled, partnership, lifestyle factors, comorbidities, psychosocial factors, and the other two outcomes were included as explanatory variables.Resultswere reported in terms of odds ratios (ORs), along with 95% confidence intervals (CIs).All statistical tests were two-sided, exploratory, and performed at the 0.05 level of significance.Data analyses were conducted using the Statistical Analysis System (SAS), version 9.4 (SAS Institute Inc.).
However, several limitations of the current analysis should be mentioned.Data from the BMH-Study are collected from men who are attending a prostate cancer screening trial and might include more health-concerned men, as well as men who are suffering from prostate symptoms resulting in a recruitment bias.Patients with controlled comorbidities who are under specific therapies were not distinguished from patients with uncontrolled comorbidities without therapy and duration of comorbidities or lifestyle factors were not considered.However, these factors have various severity levels.For instance, the risk of ED is different between men with severe or mild cases of diabetes, and between patients with controlled and uncontrolled diabetes or different length of time.Further limitations include the lack of serum testosterone levels and the use of a single item to assess LL.Therefore, data do not necessarily correspond to a clinical diagnosis.Lastly, outcome measures are subjective and self-reported and are therefore at risk for exaggeration.
Multiple logistic regression analysis of factors associated with low libido.