Erectile Dysfunction as a Cardiovascular Risk Factor: Time to Step Up?

Advances in stem cell therapy for erectile dysfunction: preclinical evidence and emerging therapeutic approaches

The inability to get or sustain an erection strong enough for fulfilling sexual performance is the hallmark of the common disorder known as erectile dysfunction (ED). It mostly affects a significant percentage of men worldwide, particularly those aged 40 to 70. Even though phosphodiesterase type 5 inhibitors (PDEi) and other conventional therapies have demonstrated efficacy, they frequently prove insufficient for patients with underlying medical disorders such as diabetes, Peyronie's disease, or post-prostatectomy. This review delves into the therapeutic capacity of stem cells for ED, emphasizing the latest clinical and preclinical studies that showcase their efficacy across various models. The review examines diverse sources of stem cells, including adipose-derived stem cells (ADSCs), bone marrow-derived stem cells (BMSCs), and other emerging sources such as urine-derived stem cells (UDSCs). Critical studies are highlighted, particularly those demonstrating the benefits of MSCs in ED models induced by cavernous nerve injury (CNI), diabetes, and other conditions. The review also explores the role of paracrine signaling, with a focus on factors like vascular endothelial growth factor (VEGF), and brain-derived neurotrophic factor (BDNF), which are involved in the regenerative process. Additionally, the capacity of stem cells with genetic modifications and the integration of stem cell therapy with adjunctive treatments such as platelet-rich plasma (PRP) and shock wave therapy are discussed. Overall, this review underscores significant progress in both clinical and preclinical studies on cell therapy for ED, paving the way for future clinical applications and innovative treatment strategies.

Associated Factors for Erectile Dysfunction Occurrence in Patients with Coronary Artery Disease: A Cross-sectional Study

Background

Erectile dysfunction (ED) is associated with cardiovascular events, and a significant proportion of men with coronary artery disease (CAD) exhibit early signs of ED. Moreover, both of these disorders shared common risk factors in previous studies. This study was conducted to determine which risk factors and conditions in CAD patients might contribute to the occurrence of ED.

Methods

This analytical cross-sectional study was conducted in the North of Iran from October 2016 to September 2017. 316 patients with coronary artery disease were enrolled. Demographic information were collected using a checklist, and the International Index of Erectile Function (IIEF-15) questionnaire was used to determine the participant's ED status. Univariate and multivariate logistic regression were used to investigate associated factors.

Results

The mean age of the participants was 56.51±9.88 years. About 55.1% of the patients had ED. Moreover, the severity of CAD was independently associated with an increased risk of ED (OR=4.11, 95%CI=1.69-9.97), with patients having more than one involved coronary artery and greater coronary artery stenosis had a higher risk of developing ED occurrence (OR=3.74, 95%CI=1.72-8.09). Besides, age (OR=1.23, 95%CI=1.18-1.29) and BMI (OR=1.26, 95%CI=1.13-1.41) were independent predictors of ED occurrence in CAD patients.

Conclusion

Higher CAD severity, older age, and higher BMI were all independent predictors of ED occurrence in CAD patients. While, diabetes mellitus, dyslipidemia, and smoking were not independent risk factors, they could contribute to the development of ED when combined with other risk factors.

Reassessing cardiovascular risk stratification in men with erectile dysfunction

BACKGROUND AND OBJECTIVES

Erectile dysfunction (ED) is an independent and strong marker of cardiovascular disease (CVD) risk. The Princeton Consensus aimed to evaluate and manage cardiovascular risk in men with ED and no known cardiovascular disease, focusing on identifying those requiring additional cardiologic work-up. It has recently been updated to the American population demographics, but European recommendations are needed.

METHODS

It was developed a cross-sectional investigation including erectile dysfunction patients. Data were collected from hospital registries. Two risk stratification models were employed and compared: Princeton Consensus Criteria (PC) and European Society of Cardiology (ESC) CVD Risk Criteria. The objective was to stress the importance of the changes in IV Princeton Consensus recommendations in stratifying CVD risk in men with erectile dysfunction using a model validated in European men.

RESULTS

A total of 137 patients with ED, with a mean age of 57.1 years old, were included. According to the PC criteria, 39.7% of the patients were "Low Risk". When using ESC criteria, the proportion of "Low Risk" patients were significantly lower (12%, p < 0.05). Among "Low Risk" patients according to the PC, 52.5% and 20% were classified as High and Very high risk according to ESC criteria, respectively. One myocardial infarction was reported. The patient was classified as "Low Risk" according to the PC, but the ESC criteria categorized him as "high risk".

CONCLUSIONS

PC is less sensitive than ESC recommendations detecting CVD. It raises concerns that Urologists could be overlooking patients with undiagnosed CVD, consequently missing out on opportunities for prevention of major cardiovascular events (MACEs) and premature deaths.

Exploring the bidirectional link between erectile dysfunction and 10-year cardiovascular risk in men with diabetes and hypertension

Erectile dysfunction (ED) shares common risk factors with cardiovascular (CV) disease, such as a sedentary lifestyle, obesity, and metabolic syndrome. However, the relationship between ED and CV risk in Vietnam remains unknown. To investigate this, we conducted a multi-center observational study, randomly selecting 2,936 men aged 40 to 69 years in Vietnam, with 385 participants included after exclusions. The study evaluated the 10-year CV risk using the Systematic Coronary Risk Evaluation 2-Diabetes (SCORE2-Diabetes) score and assessed ED using the International Index of Erectile Function (IIEF-5) score. Results showed that men with diabetes mellitus and hypertension had significantly lower IIEF-5 scores compared to healthy individuals (18 [15-22] vs. 23 [20-24], p < 0.001). Additionally, the IIEF-5 score proved effective in identifying patients at very high CV risk, with an area under the curve (AUC) of 0.747, a cutoff point of 18.5, sensitivity of 69.6%, and specificity of 69.9%. Furthermore, we found a significant inverse correlation between SCORE2-Diabetes and IIEF-5 (ρ = -0.45 and p < 0.001). These findings establish a significant connection between ED and CV risk in men with diabetes, underscoring the need for integrated screening and management strategies to address both conditions concurrently.

Global prevalence of sexual dysfunction in cardiovascular patients: a systematic review and meta-analysis

BACKGROUND

Sexual dysfunction poses a significant challenge for patients with cardiac conditions. Concerning the prevalence of sexual disorders in cardiovascular patients, several seminal studies conducted in various regions of the world have provided diverse facts and figures pertaining to sexual dysfunction among cardiovascular patients. Therefore, the present study aimed to analyze, summarize, and integrate the findings of seminal studies on the effect of underlying factors and estimate the global rate of sexual disorders in cardiovascular patients.

METHODS

The present systematic review and meta-analysis included studies conducted in 2003-2023. To find the relevant published academic papers, SID, MagIran, PubMed, Scopus, Web of Science (WOS), and Google Scholar databases were searched for keywords using MeSH/Emtree until January 14, 2023. The GRADEpro software was used to evaluate the quality of evidence. The heterogeneity of studies was checked using the I2 index.

RESULTS

An initial number of 2122 studies were found in the first search. Following a precise screening process based on predefined inclusion criteria, a total of 17 studies were deemed suitable for inclusion in the meta-analysis. The global prevalence of sexual disorders in cardiovascular patients was estimated at 62.6% (95% CI: 49.8-73.8%). As the results of the meta-regression showed that as the sample size increased, there was a significant decrease in the overall prevalence of sexual disorders among cardiovascular patients. Additionally, as the study years progressed, both age and JBI score exhibited an upward trend.

CONCLUSION

The present findings showed a high prevalence of sexual disorders among cardiovascular patients. Therefore, it is recommended that experts and health policymakers enhance their focus on effectively preventing and controlling these disorders. Besides the evidence achieved very low certainty, it is important for the treatment team to prioritize the sexual relations of cardiovascular patients and focus on improving their sexual function. This should be seen as an essential aspect of their overall recovery process.

Novel erectile analyses revealed augmentable penile Lyve-1, the lymphatic marker, expression

Purpose

The pathophysiology of penis extends to erectile dysfunction (ED) to conditions including sexually transmitted diseases (STDs) and cancer. To date, there has been little research evaluating vascular drainage from the penis. We aimed to evaluate penile blood flow in vivo and analyze its possible relationship with the lymphatic maker.

Materials and Methods

We established an in vivo system designed to assess the dynamic blood outflow from the corpus cavernosum (CC) by dye injection. To analyze lymphatic characteristics in the CC, the expression of Lyve-1, the key lymphatic endothelium marker, was examined by the in vitro system and lipopolysaccharide (LPS) injection to mimic the inflammatory conditions.

Results

A novel cavernography methods enable high-resolution morphological and functional blood drainage analysis. The expression of Lyve-1 was detected along the sinusoids. Furthermore, its prominent expression was also observed after penile LPS injection and in the erectile condition.

Conclusions

The current in vivo system will potentially contribute to the assessment of penile pathology from a novel viewpoint. In addition, current analyses revealed inducible Lyve-1 expression for LPS injection and the erection state, which requires further analyses on penile lymphatic system.

Genetically predicted cardiovascular diseases could increase the risk of erectile dysfunction: a bidirectional Mendelian randomization

PURPOSE

Erectile dysfunction (ED) often appears concomitantly with cardiovascular diseases (CVDs). However, the causal relationship between ED and CVDs is still unclear. This study aimed to investigate the causal effects between CVDs and ED using bidirectional Mendelian randomization (MR).

METHODS

ED data (6175 cases and 217,630 controls) were obtained from the IEU OpenGWAS project. Seven types of CVDs were acquired in our study, including stroke (Sample size = 440,328), myocardial infection (Sample size = 184,305), coronary heart disease (Sample size = 86,995), hypertension (Sample size = 36,683), heart failure (Sample size = 208,178), atrial fibrillation (Sample size = 1,030,836), and coronary artery disease (Sample size = 141,217). Inverse variance weighted (IVW) was selected as the primary method for MR analysis.

RESULTS

IVW results indicated that stroke (OR = 1.14, 95% CI = 1.02-1.29, P = 0.025), coronary artery disease (OR = 1.09, 95% CI = 1.02-1.16, P = 0.013), coronary heart disease (OR = 1.07, 95% CI = 1.01-1.13, P = 0.017), myocardial infection (OR = 1.09, 95% CI = 1.02-1.17, P = 0.011), and atrial fibrillation (OR = 1.06, 95% CI = 1.00-1.12, P = 0.04) were causally associated with ED. The reverse MR analysis suggested that ED did not influence the prevalence of CVDs.

CONCLUSION

These findings highlighted CVDs as causal risk factors for ED, but ED did not directly result in the development of CVDs. Regular monitoring of the erectile function of individuals with CVDs, along with implementing appropriate preventive measures, might help reduce the incidence of ED and enhance the sexual well-being of patients with CVDs.

Comparison of Risk Factors for Erectile Dysfunction (ED) in Type 2 Diabetics and Nondiabetics: A Retrospective Observational Study

BACKGROUND AND AIMS

We aim to compare the various risk factors for erectile dysfunction (ED) in type 2 diabetes mellitus (DM) and nondiabetic patients.

MATERIALS AND METHODS

We retrospectively collected and evaluated the data of 175 OPD patients with ED. We included 138 patients of ED from endocrinology and urology OPD after exclusion. ED was assessed by using a questionnaire adapted from the abridged five-item version of the International Index of Erectile Function (IIEF-5) score.

RESULTS

A total of 96 (69.56%) were diabetic, and 42 (30.43%) were nondiabetic. The majority of patients (62.31 %) were in the age group of 40-60 years. Thirty-nine (28.26%) were alcoholics, and 55 (40%) were smokers. The average duration of diabetes was 6.6±1.5 years. Hypertension was present in 49 (35.5%). Diabetic patients were significantly older (47.9±8.2 vs. 40.2±7.6 years, p=0.0001) and obese (BMI (kg/m2), 27.3±5.4 vs. 24.6±3.9, p=0.004). Waist circumference in diabetics was 95.3±10.9, as compared to nondiabetics, which was 89.6±9.2 cm (p=0.0037). The IIEF-5 score was significantly lower in diabetic subjects in comparison to nondiabetics (9.4±3.2 vs. 12.1±3.6 p=0.0001). Moderate-to-severe ED was more common in diabetic patients (76%) in comparison to nondiabetics (59.5%). The prevalence of mild and mild-to-moderate ED was 11.45 % and 12.5 % in diabetic patients in comparison to 16.7% and 23.5% in nondiabetics, respectively. The prevalence of hypertension and coronary artery was higher in diabetics in comparison with nondiabetics. Hypertension was significantly higher in diabetic patients with ED (42.7% vs. 19.04%, p=0.0075), but coronary artery disease was not statistically significant (8.3% vs. 2.3%, p=0.1925). LH (2.6±0.7 vs. 3.5±0, p=0.0001) and testosterone (312.1±110.7 vs. 367.8±115.1, p=0.0081) were significantly lower in diabetics in comparison to nondiabetics.

CONCLUSIONS

The IIEF-5 score was lower in diabetic cases as compared to those without diabetes. The factors that significantly contributed to ED in type 2 DM patients, as compared to nondiabetic patients, were age, BMI, waist circumference, hypertension, poor glycemic control, LH, and testosterone levels.

A visualization system for erectile vascular dynamics

Erection is an essential process which requires the male penis for copulation. This copulatory process depends on the vascular dynamic regulation of the penis. The corpus cavernosum (CC) in the upper (dorsal) part of the penis plays a major role in regulating blood flow inside the penis. When the CC is filled with blood, the sinusoids, including micro-vessels, dilate during erection. The CC is an androgen-dependent organ, and various genital abnormalities including erectile dysfunction (ED) are widely known. Previous studies have shown that androgen deprivation by castration results in significantly decreased smooth muscles of the CC. Experimental works in erectile biology have previously measured intracavernosal penile pressure and mechanical tension. Such reports analyze limited features without assessing the dynamic aspects of the erectile process. In the current study, we established a novel explant system enabling direct visual imaging of the sinusoidal lumen to evaluate the dynamic movement of the cavernous space. To analyze the alternation of sinusoidal spaces, micro-dissected CC explants by patent blue dye injection were incubated and examined for their structural alternations during relaxation/contraction. The dynamic process of relaxation/contraction was analyzed with various external factors administered to the CC. The system enabled the imaging of relaxation/contraction of the lumens of the sinusoids and the collagen-containing tissues. Histological analysis on the explant system also showed the relaxation/contraction. Thus, the system mimics the regulatory process of dynamic relaxation/contraction in the erectile response. The current system also enabled evaluating the erectile pathophysiology. In the current study, the lumen of sinusoids relaxed/contracted in castrated mice similarly with normal mice. These results suggested that the dynamic erectile relaxation/contraction process was similarly retained in castrated mice. However, the system also revealed decreased duration time of erection in castrated mice. The current study is expected to promote further understanding of the pathophysiology of ED, which will be useful for new treatments in the future. Hence, the current system provides unique information to investigate the novel regulations of erectile function, which can provide tools for analyzing the pathology of ED.

Cardiovascular/Stroke Risk Assessment in Patients with Erectile Dysfunction-A Role of Carotid Wall Arterial Imaging and Plaque Tissue Characterization Using Artificial Intelligence Paradigm: A Narrative Review

PURPOSE

The role of erectile dysfunction (ED) has recently shown an association with the risk of stroke and coronary heart disease (CHD) via the atherosclerotic pathway. Cardiovascular disease (CVD)/stroke risk has been widely understood with the help of carotid artery disease (CTAD), a surrogate biomarker for CHD. The proposed study emphasizes artificial intelligence-based frameworks such as machine learning (ML) and deep learning (DL) that can accurately predict the severity of CVD/stroke risk using carotid wall arterial imaging in ED patients.

METHODS

Using the PRISMA model, 231 of the best studies were selected. The proposed study mainly consists of two components: (i) the pathophysiology of ED and its link with coronary artery disease (COAD) and CHD in the ED framework and (ii) the ultrasonic-image morphological changes in the carotid arterial walls by quantifying the wall parameters and the characterization of the wall tissue by adapting the ML/DL-based methods, both for the prediction of the severity of CVD risk. The proposed study analyzes the hypothesis that ML/DL can lead to an accurate and early diagnosis of the CVD/stroke risk in ED patients. Our finding suggests that the routine ED patient practice can be amended for ML/DL-based CVD/stroke risk assessment using carotid wall arterial imaging leading to fast, reliable, and accurate CVD/stroke risk stratification.

SUMMARY

We conclude that ML and DL methods are very powerful tools for the characterization of CVD/stroke in patients with varying ED conditions. We anticipate a rapid growth of these tools for early and better CVD/stroke risk management in ED patients.