Erectile dysfunction may be the first clinical sign of insulin resistance and endothelial dysfunction in young men

Association between different insulin resistance surrogates and erectile dysfunction in non-diabetic men: a large population-based study

BACKGROUND

Although it is widely recognized that insulin resistance (IR) plays a critical role in the development of erectile dysfunction (ED), the specific relationship between IR and ED among non-diabetics has been little studied, and no relevant large-scale studies have been conducted. The purpose of this study is to examine the association between different IR surrogates and the risk of ED in non-diabetic populations.

METHODS

National Health and Nutrition Examination Survey (NHANES) 2001-2004 data were used for this cross-sectional analysis. Weighted multivariable logistic regression and restricted cubic spline curves (RCS) were performed to evaluate the relationship between homeostasis model assessment (HOMA-IR), triglyceride glucose (TyG), TyG with body mass index (TyG-BMI), TyG with waist circumference (TyG-WC) and TyG with waist-to-height ratio (TyG-WHtR), and ED risk. When segmenting effects were detected, recursive algorithms were used to determine potential inflection points. Then log-likelihood ratio test and weighted segmented regression were carried out. In the sensitivity analysis, stratified and interaction analyses were performed.

RESULTS

A total of 1569 (weighted: 76450963) individuals eventually were enrolled in the study. After adjusting for all confounders, the TyG did not correlate with ED (P > 0.05), whereas the other IR surrogates, HOMA-IR, TyG-BMI, TyG-WC, and TyG-WHtR, remained positively correlated with ED [ORs (95% CIs) were 1.02 (0.95, 1.10), 1.01 (1.00, 1.02), 1.00 (1.00, 1.01), 1.17 (0.84, 1.63), respectively; all P < 0.05]. Furthermore, we found the risk of ED was significantly higher when TyG-BMI > 328.94 or TyG-WC > 1128.25 or TyG-WHtR > 6.42 [the ORs (95% CIs) were 1.05 (1.02, 1.08), 1.02 (1.01, 1.03) and 51.30 (4.46, 453.64), respectively]. No interactions were found between these IR surrogates and the stratification variables.

CONCLUSIONS

In the non-diabetic population, ED risk was positively associated with elevated HOMA-IR, TyG-BMI, TyG-WC, and TyG-WHtR.

Association of insulin resistance surrogate indices and erectile dysfunction: a systematic review and meta-analysis

BACKGROUND

Erectile dysfunction (ED) has been linked to insulin resistance (IR), with various surrogate indices being used to assess this association. This systematic review and meta-analysis aimed to evaluate the relationship between IR indices and the incidence and severity of ED.

METHODS

A comprehensive search across PubMed, Embase, Web of Science, and Scopus was carried out. Required data were extracted and meta-analyzed. The Newcastle-Ottawa Scale (NOS) was employed to evaluate the studies' risk of bias. Sensitivity analyses and meta-regressions were conducted to explore heterogeneity and the impact of confounding variables.

RESULTS

Seventeen studies with a total of 3810 patients with ED and 8252 without ED were included. Meta-analysis revealed that males with ED had significantly higher levels of Homeostasis Model Assessment of Insulin Resistance (HOMA-IR) (SMD = 0.59, 95% CI [0.15, 1.03], I2 = 82%, P < 0.01), Triglyceride-Glucose Index (TyG) (SMD = 0.53, 95% CI [0.31, 0.75], I2 = 69%, P < 0.01), and Visceral Adiposity Index (VAI) (SMD = 0.45, 95% CI [0.25, 0.64], I2 = 76%, P < 0.01) compared to those without ED. However, there was no significant correlation between a one-unit increase in HOMA-IR (OR = 0.63, 95% CI [0.03, 13.69], I2 = 91%, P = 0.77) or TyG (OR = 0.53, 95% CI [0.02, 11.53], I2 = 88%, P = 0.68) and the odds of ED. Additionally, a one-unit increase in VAI was associated with more severe ED (SMD = 0.34, 95% CI [0.03, 0.64], I2 = 16%, P = 0.03). The diagnostic accuracy of these indices varied.

CONCLUSIONS

The results indicate a significant connection between insulin resistance and erectile dysfunction, as shown by HOMA-IR, TyG, and VAI. Yet, their usefulness in predicting ED is restricted because of significant differences and inconsistencies in diagnostic precision. More research is required to determine the clinical importance of these indices in treating ED.

The Association between the Gut Microbiota and Erectile Dysfunction

PURPOSE

Explore the causal relationship between the gut microbiota and erectile dysfunction (ED) at phylum, class, order, family, and genus levels, and identify specific pathogenic bacteria that may be associated with the onset and progression of ED.

MATERIALS AND METHODS

The genetic variation data of 196 human gut microbiota incorporated in our study came from the human gut microbiome Genome Wide Association Studies (GWAS) dataset released by the MiBioGen Consortium. The GWAS statistics for ED were extracted from one study by Bovijn et al., which included 223,805 participants of European ancestry, of whom 6,175 were diagnosed with ED. Subsequently, Mendelian randomization (MR) analysis was carried out to explore whether a causal relationship exists between the gut microbiota and ED. Additionally, bidirectional MR analysis was performed to examine the directionality of the causal relationship.

RESULTS

Through MR analysis, we found that family Lachnospiraceae (odds ratio [OR]: 1.27, 95% confidence interval [CI]: 1.05-1.52, p=0.01) and its subclass genus LachnospiraceaeNC2004 group (OR: 1.17, 95% CI: 1.01-1.37, p=0.04) are associated with a higher risk of ED. In addition, genus Oscillibacter (OR: 1.17, 95% CI: 1.02-1.35, p=0.03), genus Senegalimassilia (OR: 1.32, 95% CI: 1.06-1.64, p=0.01) and genus Tyzzerella3 (OR: 1.14, 95% CI: 1.02-1.27, p=0.02) also increase the risk of ED. In contrast, the inverse variance weighted estimate of genus RuminococcaceaeUCG013 (OR: 0.77, 95% CI: 0.61-0.96, p=0.02) suggests that it has a protective effect against the occurrence of ED.

CONCLUSIONS

This study preliminarily identified 6 bacterial taxa that may have a causal relationship with ED, including family Lachnospiraceae, genus Lachnospiraceae NC2004 group, Oscillibacter, Senegalimassilia, Tyzzerella 3 and Ruminococcaceae UCG013. These identified important bacterial taxa may serve as candidates for microbiome intervention in future ED clinical trials.

Associations between Erectile Dysfunction and Vascular Parameters: A Systematic Review and Meta-Analysis

PURPOSE

Erectile dysfunction (ED) is associated with several vascular disorders, but the associations between ED and vascular parameters are still unclear.

MATERIALS AND METHODS

We analyzed and synthesized a comprehensive range of studies from PubMed, Web of Science, and Scopus regarding the associations between ED and the following measures: ankle-brachial index (ABI), pulse wave velocity (PWV), intima-media thickness (IMT), nitrate-mediated dilation (NMD), flow-mediated dilation (FMD), augmentation index (AI), endothelial progenitor cells (EPCs) and other vascular parameters. Subgroup analysis was conducted according to specific types of parameters. Study quality was assessed by using the Newcastle-Ottawa Scale. Sensitivity analysis was conducted to confirm the robustness of the pooled results.

RESULTS

Fifty-seven studies with 7,312 individuals were included. Twenty-eight studies were considered to be high-quality. ED patients had a 0.11 mm higher IMT (95% confidence interval [CI]: 0.07, 0.15), a 2.86% lower FMD (95% CI: -3.56, -2.17), a 2.34% lower NMD (95% CI: -3.37, -1.31), a 2.83% higher AI (95% CI: 0.02, 5.63), a 1.11 m/s higher PWV (95% CI: 0.01, 2.21), and a 0.72% lower percentage of EPCs (95% CI: -1.19, -0.24) compared to those without ED. However, ABI was similar between ED patients and non-ED individuals. According to sensitivity analysis, the pooled results were robust.

CONCLUSIONS

Our study confirmed the associations between ED and several vascular parameters and highlighted the importance of prevention and management of vascular and endothelial dysfunction in ED patients.

Pharmacokinetics and Bioequivalence of Vardenafil Hydrochloride in Healthy Chinese Volunteers

Vardenafil hydrochloride tablet is an inhibitor of phosphodiesterase type 5, primarily for the treatment of erectile dysfunction. This postprandial study evaluated the pharmacokinetics and bioequivalence of the test and reference formulations of vardenafil hydrochloride tablets in healthy Chinese volunteers. An open, randomized, single-center, single-dose, 2-period, 2-sequence bioequivalence test was conducted on 66 healthy subjects under fed conditions. Subjects were randomly assigned to a 20-mg test or reference formulation with a 7-day washout period. Venous blood samples (4 mL) were collected from each subject 25 times spanning predose (0 hour) to 24 hours after dosing. The plasma concentration of vardenafil was determined by high-performance liquid chromatography-tandem mass spectrometry. Sixty-two volunteers completed the study. Under fed conditions, the maximum plasma concentration was 29.1 ng/mL, the area under the concentration-time curve (AUC) from time 0 to the time of the last measurable concentration was 85.3 ng•h/mL, and AUC from time 0 to infinity was 87.1 ng•h/mL. The 90% confidence intervals of the geometric mean ratio of AUC time 0 to the time of the last measurable concentration and AUC from time 0 to infinity were within the bioequivalence acceptance range of 0.80-1.25. The test formulation was a bioequivalent alternative to the reference formulation when taken under fed conditions in healthy Chinese subjects.

Association between the C-reactive protein-triglyceride glucose index and erectile dysfunction in US males: results from NHANES 2001-2004

The C-reactive protein-triglyceride glucose index (CTI) is emerging as a novel indicator for comprehensively assessing the severity of both inflammation and insulin resistance. However, the association between CTI and erectile dysfunction (ED) remains largely unexplored. Participant data for this study were sourced from NHANES 2001-2004, with exclusion criteria applied to those lacking information on clinical variables. The CTI was defined as 0.412*Ln (CRP) + ln [T.G. (mg/dL) × FPG (mg/dL)/2]. Weighted univariable and multivariable logistic regression models were utilized to examine the correlation between the CTI and ED, assessing the CTI as both a continuous and categorical variable (quartile). Moreover, subgroup analyses were conducted to pinpoint sensitive populations, and interaction analysis was performed to validate the findings. A total of 1502 participants were included in the final analysis, encompassing 302 with ED and 1200 without ED. After adjusting for potential confounders, the CTI was positively associated with ED incidence (OR = 1.56, 95% CI: 1.27-1.90, P = 0.002). The fourth quartile of the CTI significantly increased the incidence of ED (OR = 2.69, 95% CI: 1.07-6.74, P = 0.04), and the lowest quartile of CTI was used as the reference. The dose-response curve revealed a positive linear relationship between the CTI and the incidence of ED. Subgroup analysis confirmed the consistent positive relationship between the CTI and ED. The interaction test indicated no significant impact on this association. Finally, a sensitivity analysis was performed to verify the significant positive correlation between the CTI and severe ED (OR = 1.44, 95% CI: 1.19-1.76, P = 0.004). Our national data indicate that a greater CTI is positively linked to an increased risk of ED in US men, suggesting its potential for use in clinical practice for ED prevention or early intervention. Additional large-scale prospective studies are warranted to substantiate the causative relationship between CTI and ED.

Effect of laparoscopic sleeve gastrectomy on male reproductive function in Chinese men with obesity: a prospective cohort study

BACKGROUND

Obesity is a widely recognized global public health issue, and bariatric surgery has emerged as an effective intervention for alleviating obesity associated health complications. However, the impact of bariatric surgery on male reproductive function remains inconclusive in the literature. The current understanding of the impact of laparoscopic sleeve gastrectomy (LSG) on male reproductive function remains ambiguous, despite its status as the most commonly performed bariatric surgery. This prospective cohort study aimed to investigate the impact of LSG on erectile function and semen quality.

PATIENTS AND METHODS

A total of 34 obese patients were enrolled in this study and underwent LSG. Prior to the operation and at 3, 6, and 12 months postoperation, all participants were required to complete the International Index of Erectile Function-5 (IIEF-5) questionnaire and undergo a nocturnal erectile function test and semen quality analysis.

RESULTS

Within 12 months postoperation, BMI, blood lipids, and insulin resistance showed significant improvement. The IIEF-5 score increased significantly (18.88±5.97 vs. 23.78±3.19, P <0.05), and the frequency and duration of erections significantly improved compared to baseline. Sperm concentration, total motility, survival rate, and sperm morphology parameters exhibited a significant decline at 3 months but demonstrated a significant improvement at 6 and 12 months postoperation. At 12 months, sperm concentration was shown to be correlated with changes in zinc (r=0.25, P =0.033) as well as changes in testosterone (r=0.43, P =0.013).

CONCLUSIONS

LSG has beneficial effects on erectile function, despite a transient decline in semen quality at 3 months postoperatively, followed by a significant improvement at 12 months.

A higher TyG index is related with a higher prevalence of erectile dysfunction in males between the ages 20-70 in the United States, according to a cross-sectional research

Objective

This study aims to investigate the relationship between triglyceride glucose index (TyG) and erectile dysfunction (ED) among United States (US) adult males.

Methods

A logistic regression analysis, subgroup analysis, and the computation of the dose-response curve were used to investigate the relationship between TyG index and ED prevalence among participants from the 2001-2004 National Health and Nutrition Examination Survey (NHANES) database.

Results

After adjusting for all confounders, each unit increase in TyR index was associated with a 25 percent increase in ED prevalence (OR=1.25, 95%CI:1.03, 1.52), and stratified analysis showed that elevated TyG index was associated with increased ED prevalence in the 50-year old group (OR=1.35, 95% CI:1.05, 1.74), the Mexican-American group (OR=1.50, 95% CI:1.00, 2.23) and BMI 25-29.9 kg/m2 (OR=1.48, 95% CI:1.08, 2.01). The dose-response curve demonstrated a positive linear connection between the TyG index and the risk of ED.

Conclusion

It has been shown that a higher TyG index is associated with a higher prevalence of erectile dysfunction. Although the causal relationship is not clear, it still deserves clinical attention.

Novel predictive risk factor for erectile dysfunction: Serum high-sensitivity C-reactive protein

BACKGROUND

C-reactive protein (CRP), as a marker of inflammation, may be closely related to erectile dysfunction (ED), however, there is no meta-analysis exists for it.

OBJECTIVES

We aimed to verify the relationship between CRP and erectile dysfunction and to explore the changes of CRP levels in ED patients after first-line treatment.

MATERIALS AND METHODS

We searched databases including the Cochrane Library, PubMed, and MEDLINE to identify studies up to January 1, 2022. We performed a comprehensive analysis of the included studies by STATA software and calculated standardized mean differences (SMDs) and their corresponding 95% confidence intervals.

RESULTS

A total of 12 studies were included and the analysis showed that CRP levels were higher significantly in patients with erectile dysfunction than the healthy controls (P < 0.001) and decreased by a mean of 0.38 mg/L after first-line PDE5i drug treatment (P = 0.001).

DISCUSSION AND CONCLUSION

This novel meta-analysis suggests that CRP is statistically significantly associated with erectile dysfunction and may be a predictor or risk factor for the assessment of ED. However, further original studies with large sample sizes are needed to validate this. This article is protected by copyright. All rights reserved.

The Association Between FGF21 and Diabetic Erectile Dysfunction: Evidence from Clinical and Animal Studies

Erectile dysfunction (ED), a complication of diabetes mellitus (DM), affects 50-75% of men with diabetes. Fibroblast growth factor 21 (FGF21) is a liver-derived metabolic regulator which plays a role in insulin-independent glucose uptake in adipocytes. We designed a clinical study and an animal experiment to investigate the relationship between FGF21 and DM-induced ED. The clinical study enrolled 93 participants aged > 18 years (61 patients with type 2 DM and 32 healthy controls) from Taian City Central Hospital (TCCH) in Shandong Province, China, amongst whom the association between serum FGF21 and diabetic ED was analyzed. To further validate this association, we developed animal model of diabetic ED using Sprague-Dawley (SD) rats. Serum FGF21 concentration and FGF21 mRNA expression in penile samples of the rats were determined with Western blotting and quantitative real-time PCR. Among the 93 participants, the level of serum FGF21 was negatively correlated with the IIEF-5 score (r = -0.74, P < 0.001). The analysis on the performance of FGF21 for ED diagnosis showed that the area under the receiver operating characteristic (ROC) curve was 0.875 (95% confidence interval [CI]: 0.803 to 0.946). In the animal experiment, the levels of serum FGF21, 2-Δ Δ Ct values of FGF21 mRNA expression, and relative levels of FGF21 in penile samples were higher in the ED group compared to the DM and control groups. Our findings demonstrated an association between the FGF21 level and diabetic ED, indicating the potential of this cytokine in predicting diabetic ED.

Erectile Dysfunction in Individuals with Type 1 Diabetes is Associated with Long-term Metabolic Control and Diabetic Complications: A Cross-Sectional Study

Background  Erectile dysfunction (ED) affects approximately 38% of individuals with type 1 diabetes (T1DM). Skin autofluorescence (AF) reflects skin advanced glycation end product (AGE) deposits and is a marker of long-term glycemia control. Objective  The study investigates the relationship between ED and diabetes control in patients with T1DM. Methods  Adult patients with T1DM visiting the Diabetology Department were cross-sectionally investigated. Medical history, anthropometric features, and laboratory findings were collected. All individuals filled the International Index of Erectile Function (IIEF-5). IIEF-5 total score < 22 represented the presence of ED. AF was measured on the volar aspect of the forearm using AGE Reader. Insulin resistance (IR) was assessed by the estimated glucose disposal rate. Descriptive statistics and multivariate logistic regression analyses were performed. The adjusted covariates were general risk factors of ED. Results  Of a total of n  = 70 patients, n  = 30 (42.9%) suffered from ED. The presence of ED was associated with higher glycated hemoglobin level (OR, 95% CI; 1.62, 1.02-2.60; p  = 0.043), presence of at least one diabetic complication (3.49, 1.10-11.03; p  = 0.03), and skin AF (9.20, 1.60-52.94; p  = 0.01), but not with IR (0.78, 0.57-2.60; p  = 0.12). Skin AF values ≥ 2.2 indicates presence of ED with a sensitivity of 70.0% and a specificity of 77.5%. Area under the curve was equal to 0.72 (95% CI: 0.60-0.85). Conclusions  The presence of ED in individuals with T1DM is associated with HbA1c, the presence of at least one diabetic complication, and skin AF.

Prevalence of and risk factors for erectile dysfunction in young nondiabetic obese men: results from a regional study

Erectile dysfunction (ED), a condition closely related to cardiovascular morbidity and mortality, is frequently associated with obesity. In this study, we aimed to determine the prevalence of ED and evaluate the associated risk factors in a cohort of 254 young (18-49 years) nondiabetic obese (body mass index [BMI] ≥ 30 kg m^-2) men from primary care. Erectile function (International Index of Erectile Function [IIEF-5] questionnaire), quality of life (Aging Males' Symptoms [AMS scale]), and body composition analysis (Tanita MC-180MA) were determined. Total testosterone was determined using high-performance liquid chromatography-mass spectrometry. Multivariate logistic regression analysis was used to study the factors associated with ED. ED prevalence was 42.1%. Subjects with ED presented higher BMI, waist circumference, number of components of the metabolic syndrome, AMS score, insulin resistance, and a more unfavorable body composition than those without ED. Multivariate logistic regression analysis showed that a pathological AMS score (odds ratio [OR]: 4.238, P < 0.001), degree of obesity (BMI ≥ 40 kg m^-2, OR: 2.602, P = 0.005, compared with BMI 30-34.9 kg m^-2), high-density lipoprotein (HDL)-cholesterol levels (OR: 0.956, P = 0.004), and age (OR: 1.047, P = 0.016) were factors independently associated with ED. In conclusion, we demonstrate that, in a primary care-based cohort of nondiabetic young obese men, ED affected >40% of subjects. A pathological AMS score, the degree of obesity, and age were positively associated with ED, while elevated HDL-cholesterol levels were inversely associated with the odds of presenting ED. Further prospective studies are needed to evaluate the long-term consequences of ED in this population.

What is the best biological parameter to predict erectile dysfunction in men aged >55 years with type 2 diabetes?

To date, there is no evidence regarding the best biological marker to predict erectile dysfunction (ED) in men aged >55 years with type 2 diabetes. This prospective study included data from men aged >55 years with type 2 diabetes. ED was assessed by the International Index of Erectile Function 15-item survey. Total testosterone (TT) levels and bioavailable testosterone were measured; the free testosterone index was calculated. Data from 155 men (aged 64 ± 7 years) were explored. The prevalence of ED and testosterone deficiency was 78.7% and 34.8%, respectively. After univariate analysis, TT and bioavailable testosterone were associated with ED (P = 0.01). After multivariate analysis, and adjustment for age, body mass index, tobacco, alcohol, duration of diabetes, TT, bioavailable testosterone, vitamin D and high-sensitivity C-reactive protein, we found that only high-sensitivity C-reactive protein was significantly predictive of ED. TT could predict ED, but it lacks specificity. We found a potential role of high-sensitivity C-reactive protein as a predictive marker of ED in this targeted population.

Erectile dysfunction is associated with subclinical carotid vascular disease in young men lacking widely-known risk factors

This study aimed to gain insight into the underlying pathogenesis of erectile dysfunction in young men under the age of 40 years without widely-known risk factors. Compared with normal controls, patients with erectile dysfunction had increased carotid intima–media thickness, fasting levels of blood glucose and insulin, and homeostatic model assessment index, as well as lower flow-mediated vasodilation and testosterone levels (P < 0.05), though all of these values were within their respective normal range. Multivariate logistic regression analysis identified carotid intima–media thickness, flow-mediated vasodilation, insulin level, and homeostatic model assessment index as significant predictors of erectile dysfunction. Young men with flow-mediated vasodilation <10.65% were 11.645 times more likely to have erectile dysfunction, young men with carotid intima–media thickness >0.623 mm had a 4.16-fold, and young men with homeostatic model assessment index >1.614 had a 5.993-fold greater risk of having erectile dysfunction. In conclusions, in young men with normal results from general clinical screening, an increased carotid intima–media thickness and homeostatic model assessment index and reduced flow-mediated vasodilation were associated with a higher incidence of erectile dysfunction. Erectile dysfunction may appear before the detection of traditional cardiovascular risk factors and may be the earliest clinical sign of subclinical cardiovascular disease.

Lower urinary tract symptoms/benign prostatic hyperplasia and erectile dysfunction: from physiology to clinical aspects

Erectile dysfunction, prostatic hyperplasia and lower urinary tract symptoms hare important pathogenetic links. Endothelial dysfunction and hormonal alterations represent the main aspects. The present article examines the anatomical, physiological, and pathophysiological characteristics of this association, finalizing the text to an interpretation of the clinical management of these patients based on these functional considerations.

The relationship of erectile dysfunction and subclinical cardiovascular disease: A systematic review and meta-analysis

Erectile dysfunction (ED) is associated with cardiovascular disease (CVD) and CVD mortality. However, the relationship between ED and subclinical CVD is less clear. We synthesized the available data on the association of ED and measures of subclinical CVD. We searched multiple databases for published literature on studies examining the association of ED and measures of subclinical CVD across four domains: endothelial dysfunction measured by flow-mediated dilation (FMD), carotid intima–media thickness (cIMT), coronary artery calcification (CAC), and other measures of vascular function such as the ankle–brachial index, toe–brachial index, and pulse wave velocity. We conducted random effects meta-analysis and meta-regression on studies that examined an ED relationship with FMD (15 studies; 2025 participants) and cIMT (12 studies; 1264 participants). ED was associated with a 2.64 percentage-point reduction in FMD compared to those without ED (95% CI: –3.12, −2.15). Persons with ED also had a 0.09-mm (95% CI: 0.06, 0.12) higher cIMT than those without ED. In subgroup meta-analyses, the mean age of the study population, study quality, ED assessment questionnaire (IIEF-5 or IIEF-15), or the publication date did not significantly affect the relationship between ED and cIMT or between ED and FMD. The results for the association of ED and CAC were inconclusive. In conclusion, this study confirms an association between ED and subclinical CVD and may shed additional light on the shared mechanisms between ED and CVD, underscoring the importance of aggressive CVD risk assessment and management in persons with ED.

Relation of Erectile Dysfunction to Subclinical Myocardial Injury

The circulating concentration of cardiac troponin I (cTnI) is an index of subclinical myocardial injury in several patient populations and in the general population. Erectile dysfunction is associated with greater risk for cardiovascular events, but the association with subclinical myocardial injury is not known. We aimed to test the hypothesis that the presence and severity of erectile dysfunction is associated with greater concentrations of cTnI in the general population. The presence and severity of erectile dysfunction was assessed by administering the International Index of Erectile Function 5 (IIEF-5) questionnaire to 260 men aged 30 to 65 years recruited from a population-based study. Concentrations of cTnI were determined by a high-sensitivity (hs) assay. Hs-cTnI levels were significantly higher in subjects with than in those without erectile dysfunction (median 2.9 vs 1.6 ng/l; p <0.001). Men with erectile dysfunction (i.e., IIEF-5 sum score <22) were also significantly older; had a higher systolic blood pressure, lower estimated glomerular filtration rate, higher augmentation index and N-terminal pro-B-type natriuretic peptide; and had a higher prevalence of hypertension, diabetes mellitus, and previous coronary artery disease than subjects without erectile dysfunction. These covariates were adjusted for in a multivariate linear regression model, yet the IIEF-5 sum score remained significantly negatively associated with the hs-cTnI concentration (standardized β -0.206; p <0.001). In conclusion, the presence and severity of erectile dysfunction is associated with circulating concentrations of hs-cTnI, indicating subclinical myocardial injury independently of cardiovascular risk factors, endothelial dysfunction and heart failure biomarkers.

Hyperinsulinemia and Insulin Resistance: Scope of the Problem

No abstract available.

Eating and arterial endothelial function: a meta-analysis of the acute effects of meal consumption on flow-mediated dilation

Given that endothelial dysfunction precedes atherosclerotic cardiovascular disease, exploring the parameters that modify postprandial flow-mediated dilation (FMD) is important for public health. The objectives of the study are to estimate the population effect of meal ingestion on FMD and to determine how the effect varied based on patient characteristics and modifiable methodological features. Articles published before June 2015 were located using MEDLINE, PubMed and Web of Science. One hundred fifty-four effects were derived from 78 articles involving 2,548 subjects were selected. Included articles required measurement of FMD in adults before and after meal ingestion. Effects were analysed using an unstandardized mean gain random effects model, and significant moderators were analysed using meta-regression. Meal consumption significantly reduced FMD by a heterogeneous mean effect size delta (Δ) of -2.03 (95% CI: [-2.28, -1.77]), an ~2% reduction in FMD. FMD reductions were larger among normal weight individuals, males, those with a cardio-metabolic disorder, those with elevated baseline FMD, and individuals with impaired glucose tolerance at baseline. Macronutrient meal ingestion significantly reduced FMD, an effect that was moderated by body mass index, sex and two-way interactions between disease status and both baseline FMD and baseline blood glucose levels.

Effects of prolonged ingestion of epigallocatechin gallate on diabetes type 1-induced vascular modifications in the erectile tissue of rats

Diabetes Mellitus type 1 is a metabolic disease that predisposes to erectile dysfunction, partly owing to structural and molecular changes in the corpus cavernosum (CC) vessels. The aim of this study was to determine the effects of early treatment with the antioxidant epigallocatechin gallate (EGCG) in cavernous diabetes-induced vascular modifications. Diabetes was induced in two groups of young Wistar rats; one group was treated with EGCG for 10 weeks. A reduction in smooth muscle content was observed in the CC of diabetic rats, which was significantly attenuated with EGCG consumption. No differences were observed among groups, neither in the expression of VEGF assayed by western blotting nor in the immunofluorescent labeling of vascular endothelial growth factor (VEGF) and its receptors (VEGFR1 and VEGFR2). VEGFR2 was restricted to the endothelium, whereas VEGF and VEGFR1 co-localized in the smooth muscle layer. With regard to the Angiopoietin/Tie-2 system, no quantitative differences in Angiopoietin 1 were observed among the experimental groups. Ang1 localization was restricted to the smooth muscle layer, and receptor Tie2 and Angiopoietin 2 were both expressed in the endothelium. In brief, our results suggest that EGCG consumption prevented diabetes-induced loss of cavernous smooth muscle but does not affect vascular growth factor expression in young rats.

Erectile dysfunction

Erectile dysfunction is a multidimensional but common male sexual dysfunction that involves an alteration in any of the components of the erectile response, including organic, relational and psychological. Roles for nonendocrine (neurogenic, vasculogenic and iatrogenic) and endocrine pathways have been proposed. Owing to its strong association with metabolic syndrome and cardiovascular disease, cardiac assessment may be warranted in men with symptoms of erectile dysfunction. Minimally invasive interventions to relieve the symptoms of erectile dysfunction include lifestyle modifications, oral drugs, injected vasodilator agents and vacuum erection devices. Surgical therapies are reserved for the subset of patients who have contraindications to these nonsurgical interventions, those who experience adverse effects from (or are refractory to) medical therapy and those who also have penile fibrosis or penile vascular insufficiency. Erectile dysfunction can have deleterious effects on a man's quality of life; most patients have symptoms of depression and anxiety related to sexual performance. These symptoms, in turn, affect his partner's sexual experience and the couple's quality of life. This Primer highlights numerous aspects of erectile dysfunction, summarizes new treatment targets and ongoing preclinical studies that evaluate new pharmacotherapies, and covers the topic of regenerative medicine, which represents the future of sexual medicine.

Treatment With Metformin Improves Erectile Dysfunction in a Murine Model of Obesity Associated With Insulin Resistance

OBJECTIVE

To evaluate the effects of treatment with metformin on a murine model of obesity-associated erectile dysfunction.

MATERIAL AND METHODS

C57BL/6 male mice were fed for 10 weeks with standard chow or high-fat diet. Lean and obese mice were treated with the insulin sensitizer metformin (300 mg/kg/day, 2 weeks). Intracavernosal pressure (ICP) and in vitro corpus cavernosum (CC) relaxations to both acetylcholine and electrical field stimulation, as well as phenylephrine-induced contractions, were obtained. Levels of cyclic guanosine monophosphate in CC were detected by enzyme immunoassay.

RESULTS

High-fat-fed mice exhibited higher body weight and insulin resistance. Cavernous nerve stimulation caused frequency-dependent ICP increases, which were significantly lower in obese compared with lean mice (P <.05). Two-week therapy with metformin reversed the decreased ICP in obese group. The maximal response to acetylcholine in CC was 35% lower (P <.05) in the obese compared to the lean group, which were restored by metformin treatment. Likewise, the impaired electrical field stimulation-induced CC relaxations in obese mice were also partly restored by metformin. Contractile responses to phenylephrine were significantly greater (P <.05) in obese compared to lean mice, which were fully restored by metformin. Basal and stimulated cyclic guanosine monophosphate productions in the erectile tissues were significantly lower (P <.05) in the obese group, an effect fully restored by metformin.

CONCLUSION

Treatment with metformin restored the erectile function in obese mice, through improvement of in vitro endothelial and nitrergic cavernosal relaxations. Therefore, use of metformin may be a good pharmacologic approach to treat insulin resistance-associated erectile dysfunction.

Increased Risk of Dementia in Patients With Erectile Dysfunction: A Population-Based, Propensity Score-Matched, Longitudinal Follow-Up Study

Erectile dysfunction (ED) is a well-known predictor for future cardiovascular and cerebrovascular disease. However, the relationship between ED and dementia has rarely been examined. This study investigates the longitudinal risk for Alzheimer's disease and non-Alzheimer dementia in patients with ED. We collected a random sample of 1,000,000 individuals from Taiwan's National Health Insurance database. From this sample, we identified 4153 patients with newly diagnosed ED between 2000 and 2009 and compared them with a matched cohort of 20,765 patients without ED. All patients were tracked for 7 years from the index date to identify which of them subsequently developed dementia. During the 7-year follow-up period, the incidence rate of dementia in the ED cohort was 35.33 per 10,000 person-years. In the comparison groups, it was 21.67 per 10,000 person-years. After adjustment for patients characteristics and comorbidities, patients with ED were 1.68-times more likely to develop dementia than patients without ED (95% CI = 1.34-2.10, P < 0.0001). In addition, older patients and those with diabetes, hypertension, chronic kidney disease, stroke, depression, and anxiety were found to be at increased risk for dementia. Analyzing the data by dementia type, we found the hazard risk for Alzheimer's disease and non-Alzheimer dementia to be greater in patients with ED (adjusted HR 1.68, 95% CI = 1.31-2.16, P < 0.0001 and 1.63, 95% CI = 1.02-2.62, P = 0.0429, respectively). Log-rank test revealed that patients with ED had significantly higher cumulative incidence rates of dementia than those without (P < 0.0001). Patients with ED are at an increased risk for dementia later in life.

A comprehensive review of metabolic syndrome affecting erectile dysfunction

INTRODUCTION

Metabolic syndrome (MetS) is the most important public health issue threatening the health of men and women all over the world. Its current prevalence (i.e., approximately 30%) is continuously increasing. MetS by itself is considered a risk factor for erectile dysfunction (ED).

AIM

To focus on the definition epidemiology, pathogenesis, and possible mechanistic links between MetS and ED in order to provide guidelines for treating such individuals.

METHODS

The search strategies yielded total records screened from PubMed.

MAIN OUTCOME MEASURES

Regardless of the definition, MetS consists of insulin resistance, hypertension, dyslipidemia, and obesity. MetS is not an end disease but is a disorder of energy utilization and storage.

RESULTS

The prevalence of ED in patients with MetS is almost twice than in those without MetS, and about 40% of patients with ED have MetS. An important mechanism linking MetS and ED is hypogonadism.

CONCLUSIONS

Recognizing through ED, underlying conditions such as hypogonadism, diabetes and MetS might be a useful motivation for men to improve their health-related choices. The clinical management of MetS can be done by therapeutic interventions that include lifestyle modifications, hormone replacement alone or in combination with phosphodiesterase 5 inhibitors, and other pharmacological treatments.

Investigating the role of acute mental stress on endothelial dysfunction: a systematic review and meta-analysis

Chronic stress is a known risk factor for both endothelial dysfunction and cardiovascular disease (CVD), but less is known of how acute mental stress affects the vasculature. In this systematic review and meta-analysis, we analyzed the impact of acute mental stress on flow-mediated dilation (FMD), an indicator of endothelial function. We searched the Medline, Cochrane, EMBASE, and ISI Web of Knowledge databases through May 2014, to identify publications in English-language journals. The primary outcome was the change in FMD from baseline to the time of measurement. We also assessed the risk of bias and the heterogeneity of included studies. Our search identified eight prospective studies, which displayed significant heterogeneity. Four studies measured FMD while the subject was performing the task; six measured FMD after the task had been completed. The total number of participants was 164. The pooled results indicate that FMD did not change significantly while the task was being performed (pooled difference in means: -0.853; 95 % confidence interval (CI), -3.926/2.220; P = 0.586); however, FMD measured after the task was completed was significantly less than baseline (pooled difference in means: -2.450; 95 %CI, -3.925/-0.975; P = 0.001). In conclusions, our findings provide evidence that an acute stressful experience has a delayed, negative impact on the function of the endothelium. Repeated exposure to short-term stress may lead to permanent injury of the vasculature. Therefore, assessment of patients' exposure to both repeated acute mental stress and chronic stress may be useful in determining their risk of developing CVD.

Understanding and targeting the Rho kinase pathway in erectile dysfunction

Erectile dysfunction (ED) is a common disorder that affects a quarter of US men, and has many causes, including endothelial impairment, low testosterone levels, prior surgical manipulation, and/or psychogenic components. Penile erection is a complex process requiring neurally mediated relaxation of arteriolar smooth muscle and engorgement of cavernosal tissues, mediated by nitric oxide (NO). Current medical therapies for ED largely seek to maximize endogenous NO signalling. Certain aetiologies, including diabetes, are difficult to treat with current modalities, emphasizing the need for new molecular targets. Research has demonstrated the importance of RhoA-Rho-associated protein kinase (ROCK) signalling in maintaining a flaccid penile state, and inhibition of RhoA-ROCK signalling potentiates smooth-muscle relaxation in an NO-independent manner. The mechanisms and effects of RhoA-ROCK signalling and inhibition suggest that the RhoA-ROCK pathway could prove to be a new therapeutic target for the treatment of ED.

Carotid artery intima-media thickness and erectile dysfunction in patients with metabolic syndrome

Background

Metabolic syndrome (MS) has become a pandemic in Turkey, as is the case globally. Increase in carotid artery intima-media thickness (CIMT) and erectile dysfunction (ED) may be evident before the clinical signs of cardiovascular disease appear. We aimed to investigate the prevalence of increased CIMT and ED as markers of atherosclerotic disease in patients with MS.

Material/Methods

Thirty-two patients with MS and 29 healthy controls were included. Anthropometric and biochemical parameters, along with total testosterone (TT), high sensitive C-reactive protein (hs-CRP), were recorded. Carotid artery intima-media thickness was measured. Erectile dysfunction was assessed with International Index of Erectile Function.

Results

Patients with MS had higher BMI, fasting plasma glucose, post-prandial plasma glucose, insulin, HOMA-IR, total cholesterol, triglycerides, hs-CRP, and CIMT, whereas TT levels were lower (p<0.0001). The prevalence and severity of erectile dysfunction were higher in patients with MS (p<0.0001). Erectile dysfunction scores correlated inversely with CIMT. MS patients with ED were older and had higher CIMT compared to those without ED. Increase in age and HOMA and decrease in TT increased the risk of ED. When KIMT exceeding the 95^th percentile of healthy controls was accepted as a risk factor for CVD, presence of ED was the only determinant for this increase.

Conclusions

Erectile dysfunction was more prevalent and severe in patients with MS and correlated with subclinical endothelial dysfunction. Total testosterone deficiency was prominent among MS patients. Presence of ED points to an increased risk of cardiovascular disease when MS is present.

Insulin resistance is an independent predictor of severe lower urinary tract symptoms and of erectile dysfunction: results from a cross-sectional study

INTRODUCTION

Several studies have linked the association between lower urinary tract symptoms (LUTS), erectile dysfunction (ED), and the presence of insulin resistance (IR) due to an underlined metabolic syndrome (MetS).

AIM

This study aims to determine the relationship between IR, sexual function, and LUTS and to demonstrate the ability of IR in predicting ED and severe LUTS.

METHODS

Between January 2008 to January 2013, 544 consecutive patients with benign prostatic hyperplasia-related LUTS were enrolled. LUTS and sexual function of the patients were evaluated by the International Index of Erectile Function (IIEF) and the International Prostate Symptom Score (IPSS). MetS was defined by the International Diabetes Federation. IR was defined as a homeostasis model assessment (HOMA) index of 3 or greater.

MAIN OUTCOME MEASURES

Uni- and multivariate logistic regression analysis was performed to assess significant predictors of severe LUTS (IPSS ≥ 20) and ED (IIEF-Erectile Function [IIEF-EF] <26), including MetS component, prostate volume, prostate-specific antigen, total testosterone, and HOMA index.

RESULTS

IR patients resulted in higher values of IPSS (19.0 vs. 15.0; P<0.01), IPSS-storage (6.0 vs. 5.0; P<0.01), IPSS-voiding (12.0 vs. 9.0; P<0.01), total prostate volume (54.8 vs. 36.5; P<0.01), and lower values of IIEF-EF (17.0 vs. 20.0; P<0.01), IIEF-Intercourse Satisfaction (3.0 vs. 10.0; P<0.01), IIEF-Orgasmic Function (8.0 vs. 9.0; P<0.01), IIEF-Overall Satisfaction (6.0 vs. 8.0; P<0.01), and total testosterone (3.83 vs. 4.44; P<0.01). IR was demonstrated to be a strong predictor of ED (IIEF-EF <26) (odds ratio [OR] =6.20, P<0.01) after adjusting for confounding factors. Finally, IR was also an independent predictor of severe LUTS (IPSS ≥ 20) (OR=2.0, P<0.01) after adjusting for confounding factors.

CONCLUSIONS

IR patients are at high risk of having severe LUTS and contemporary sexual dysfunctions. We strongly suggest to prevent LUTS and ED by reducing insulin resistance.

Erectile dysfunction, metabolic syndrome and arterial disease. Clinical-pathological relation by carotid ultrasonography

INTRODUCTION

Different studies have shown the relationship between erectile dysfunction, metabolic syndrome and cardiovascular disease. The objective of this study was to evaluate the presence of arteriopathy performing carotid ultrasound in patients with and without erectile dysfunction.

MATERIAL AND METHODS

We conducted a case-control study with 44 patients consulting for erectile dysfunction and 20 controls. All subjects completed the IIEF-5 test and we studied the criteria for metabolic syndrome, and a carotid ultrasound to study the intima-media thickness and the presence of atherosclerotic plaques was performed.

RESULTS

Mean intima-media thickness was .71mm±.21 for the right and of .71±.17 for the left carotid in patients with erectile dysfunction. In the control group, the means were .54±0.11 and 0.59±0.15mm respectively, statistically significant differences (P=.02 and P=.05 respectively). No plaque was found in any control, but in 25% of both carotid arteries of patients with erectile dysfunction (P=.01). As metabolic syndrome, according to the American Heart Association, were diagnosed 52.8% of patients with erectile dysfunction, and 16.7% of controls, and according to the International Diabetes Federation, 52.3% of patients with erectile dysfunction and 25% of controls met diagnostic criteria. In both cases there were significant differences (P<.01 and P=.02 respectively). We found a positive linear correlation between waist circumference and the intima-media thickness in both carotid (P<.05).

CONCLUSIONS

Patients with erectile dysfunction may be at increased risk of cardiovascular disease, as determined by the presence of arterial disease in the carotid arteries, which indicates that we should made a more thorough and comprehensive study of patients with erectile dysfunction.