Predictors of Erectile Function Normalization in Men With Erectile Dysfunction Treated With Placebo

Effect of Antioxidants Supplementation on Erectile Dysfunction: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

INTRODUCTION

In Erectile dysfunction (ED) patients, phosphodiesterase type 5 (PDE5) inhibitors are considered as the first-line therapy. However, 30-50% of ED patients fail to follow this therapeutic option because of adverse events, lack of efficacy, or drug costs. Antioxidant supplementation is widely applied in clinical practice and viewed as a potential therapeutic option for ED. Therefore, it is attractive to assess the effect of antioxidants supplementation on ED patients.

OBJECTIVES

To evaluate the effects of antioxidants supplementation on ED.

METHODS

Published randomized controlled trials of antioxidants in ED were searched in the PubMed, Embase, and Cochrane Library databases from inception to October 3, 2021. Meta-analyses were carried out using a random-effects model. The results were presented as standard mean differences (SMDs) with their 95% confidence intervals (CIs).

RESULTS

Eighteen studies with 1,331 ED patients were included in the study. Compared with placebo, antioxidants alone treatment showed a statistical increase in International Index of Erectile Function (IIEF) score (SMD = 1.93; 95% CI: 0.15, 3.72; P = .034). Compared with placebo, antioxidants compound treatment elicited a significant increase in IIEF score (SMD = 2.74; 95% CI: 1.67, 3.81; P < .001) as well as sexual satisfaction score (SMD = 1.61; 95% CI: 0.63, 2.59; P = .001). Compared with the PDE5 inhibitors alone, combination of PDE5 inhibitors and antioxidants showed a significant increase in IIEF score (SMD = 1.1; 95% CI: 0.51, 1.68; P < .001) and sexual satisfaction score (SMD = 1.28; 95% CI: 0.06, 2.51; P = .04).

CONCLUSION

This study found that the effect of antioxidant alone treatment on ED may be limited. However, antioxidant compound treatment, as well as combination of PDE5 inhibitors and antioxidants, were associated with improved ED, and can be considered as an accessary therapeutic option for ED. Su L, Yang Z, Qu H, et al. Effect of Antioxidants Supplementation on Erectile Dysfunction: A Systematic Review and Meta-Analysis of Randomized Controlled Trials. Sex Med Rev 2021;XX:XXX-XXX.

The placebo and nocebo effects in functional urology

A placebo is an inert substance normally used in clinical trials for comparison with an active substance. However, a placebo has been shown to have an effect on its own; commonly known as the placebo effect. A placebo is an essential component in the design of conclusive clinical trials but has itself become the focus of intense research. The placebo effect is partly the result of positive expectations of the recipient on the state of health. Conversely, a nocebo effect is when negative expectations from a substance lead to poor treatment outcomes and/or adverse events. Randomized controlled trials in functional urology have demonstrated the importance of the placebo and nocebo effects across different diseases such as overactive bladder, urinary incontinence, lower urinary tract symptoms and interstitial cystitis/painful bladder syndrome, as well as male and female sexual dysfunction. Understanding the true nature of the placebo-nocebo complex and the scope of its effect in functional urology could help urologists to maximize the positive effects of this phenomenon while minimizing its potentially negative effects.

Oral Testofen, L-Citrulline, Resveratrol, and Caffeine Supplement Drink Improves Sexual Function in Men with Phosphodiesterase 5 Inhibitors: Randomized, Double-Blind, Placebo-Controlled Crossover Pilot Study

PURPOSE

Sexuality is very important for men's health. Currently, phosphodiesterase type 5 inhibitors (PDE5i) remain the first-line therapy for erectile dysfunction, and no other oral drugs or drinks are approved and used clinically to treat male libido or orgasm dysfunction. In reference to a pharmaceutical dosage document, growing health consciousness is said to have boosted yearly sales of supplement drinks to more than 170 billion yen (1.58 billion US dollars) in Japan. We have created a supplement drink comprised of testofen, L-citrulline, resveratrol, and caffeine. We hypothesized that our supplement drink would be effective for men with sexual dysfunction, and especially libido dysfunction.

MATERIALS AND METHODS

In this study, men with sexual dysfunction received a placebo drink for 14 days or our supplement drink (testofen, 600 mg/d; L-citrulline, 800 mg/d; resveratrol, 300 mg/d; and caffeine, 40 mg/d) for another 14 days separated by a 7-day washout period. Patients continued on-demand use of PDE5i. The International Index of Erectile Function (IIEF) score and adverse events were assessed.

RESULTS

Twenty patients aged 30-7 years old were enrolled in and concluded the study with no adverse events experienced. The IIEF domains of desire frequency, erection frequency, erection firmness, erection confidence, intercourse satisfaction, ejaculation frequency, orgasm frequency, and overall satisfaction were significantly improved with our supplement drink.

CONCLUSIONS

This is the first study to show that our supplement drink may not only be effective for erection but also for libido, orgasm, and ejaculation.

The impact of extracorporeal shock wave therapy for the treatment of young patients with vasculogenic mild erectile dysfunction: A prospective randomized single-blind, sham controlled study

BACKGROUND

Low-intensity extracorporeal shock wave therapy (ESWT) for the treatment of vasculogenic erectile dysfunction (ED) has emerged as a promising method directly targeting the underlying pathophysiology of the disease.

OBJECTIVES

To compare outcomes in ED patients after ESWT and placebo treatment.

MATERIALS AND METHODS

Prospective randomized placebo-controlled single-blinded trial on 66 patients with mild ED. The study comprised a 4-week washout phase, a 4-week treatment phase, and a 48-week follow-up. Inclusion criteria included age between 18 and 75 years and diagnosis of mild ED (IIEF-EF score = 17-25) being made at least six months prior to study inclusion and being confirmed by Penile Doppler ultrasonography (US) at baseline examination. Efficacy endpoints were changes from baseline in patient-reported outcomes of erectile function (International Index of Erectile Function domain scores [IIEF-EF]), as well as erection hardness and duration (Sexual Encounter Profile diary [SEP] and Global Assessment Questions [GAQ]). Safety was assessed throughout the study.

RESULTS

A total of 66 enrolled patients were allocated to ESWT (n = 44) or placebo (n = 22). Mean age of ESWT and placebo group was 42.32 ± 9.88 and 39.86 ± 11.64 (p = 0.374), respectively. Mean baseline IIEF-EF scores of ESWT group and placebo were 20.32 ± 2.32 and 19.68 ± 1.55 respectively (p = 0.34). At 3-months follow-up, mean IIEF-EF scores were significantly higher in ESWT patients than in placebo patients (23.10 ± 2.82 vs. 20.95 ± 2.19, p = 0.003), and IIEF-EF scores of ESWT patients remained high during the 6 months (22.67 ± 3.35 vs. 19.82 ± 1.56) follow-up. The percentage of patients reporting both successful penetration (SEP2) and intercourse (SEP3) in more than 50% of attempts was significantly higher in ESWT-treated patients than in placebo patients (p = 0.001). A minimal clinically important difference between the IIEF = EF baseline and 3-months follow-up was found in 74% of ESWT and 36% of placebo. No serious adverse events were reported.

DISCUSSION AND CONCLUSION

ESWT significantly improved the erectile function of relatively young patients with vasculogenic mild ED when compared to placebo and the beneficial effect of this treatment up to 6 months. These findings suggest that ESWT could be a useful treatment option in vasculogenic ED.

Undiagnosed prediabetes status is associated with a reduced effectiveness of phosphodiesterase type 5 inhibitors in men with erectile dysfunction

The efficacy of phosphodiesterase type 5 inhibitors (PDE5i) in patients with erectile dysfunction (ED) and undiagnosed prediabetes (PreDM) has been scantly analysed. We aimed to assess rates of and predictors of response to oral treatment in a cohort of ED men naïve for PDE5i with either normo-glycaemia or PreDM or diabetes mellitus (DM). Complete data from 466 men were analysed. Comorbidities were scored with the Charlson Comorbidity Index (CCI). Patients completed the International Index of Erectile Function (IIEF) at baseline and after 3 months of PDE5i treatment. Treatment response was evaluated using the minimal clinically important difference (MCID) (mild: +2; moderate: +5; severe: +7 from baseline IIEF-EF). PreDM status was defined as for the American Diabetes Association (2015) criteria. Descriptive statistics and logistic regression models tested the association between clinical predictors and MCID response. Overall, 253 (56.7%), 105 (23.5%) and 88 (19.7%) patients had normo-glycaemia (=controls), PreDM and DM, respectively. Diabetic and PreDM men were older, had higher BMI, higher CCI scores and lower total testosterone (tT) (all p < 0.01) compared to controls. Median baseline IIEF-EF was lower both in PreDM (14.0 vs. 18.0; p < 0.05) and DM patients (10.0 vs. 18.0; p < 0.001) than in controls. IIEF-EF improved in all groups after treatment (all p < 0.001), but scores were higher in controls compared to both PreDM and DM men at 3-mos assessment (26.0 vs. 20.0 vs. 17.5, respectively; all p < 0.001). Controls more frequently achieved significant MCID than both PreDM and DM patients (65.3 vs. 22.9 vs. 11.8%, respectively; p < 0.01). Age (p < 0.001), baseline IIEF-EF (p < 0.001), and DM status (p = 0.02) were independently associated with MCID. In conclusion, patients with undiagnosed PreDM depicted lower rates of response to PDE5i than normoglycemic men. These findings suggest that even milder forms of glucose impairment are associated with a poorer PDE5i effectiveness in men with ED.

Current guideline recommendations and analysis of evidence quality on low-intensity shockwave therapy for erectile dysfunction

Erectile dysfunction (ED) is defined as the inability to attain and maintain erection of the penis sufficient to permit satisfactory sexual activity. ED most commonly affects men from 40 years of age with a clear age-associated increase in prevalence. The condition may have significant negative impact on quality of life for both the patients and their partners. Over recent years, low-intensity shockwave therapy (LIST) has gained popularity in the treatment of ED, based on the assumption that LIST application may result in neoangiogenesis and thus increased blood flow to the corpora cavernosa. The increasing usage of LIST is contrasting with current guidelines, with the EAU guideline on ED stating that LIST can be used in mild organic ED patients or poor responders to PDE5I's, but with a weak strength of recommendation. In the AUA guideline on ED, the panel makes a conditional recommendation of grade C that LIST should be considered investigational. In this review, we will briefly review practice patterns, and critically discuss the evidence based on which these guideline statements have been made.

An update on the diagnosis and treatment of diabetic somatic and autonomic neuropathy

Diabetic peripheral neuropathy (DPN) is the most common chronic complication of diabetes. It poses a significant challenge for clinicians as it is often diagnosed late when patients present with advanced consequences such as foot ulceration. Autonomic neuropathy (AN) is also a frequent and under-diagnosed complication unless it is overtly symptomatic. Both somatic and autonomic neuropathy are associated with increased mortality. Multiple clinical trials have failed because of limited efficacy in advanced disease, inadequate trial duration, lack of effective surrogate end-points and a lack of deterioration in the placebo arm in clinical trials of DPN. Multifactorial risk factor reduction, targeting glycaemia, blood pressure and lipids can reduce the progression of DPN and AN. Treatment of painful DPN reduces painful symptoms by about 50% at best, but there is limited efficacy with any single agent. This reflects the complex aetiology of painful DPN and argues for improved clinical phenotyping with the use of targeted therapy, taking into account co-morbid conditions such as anxiety, depression and sleep disturbance.

Endothelial Dysfunction in Patients With Erectile Dysfunction: A Double-Blind, Randomized-Control Trial Using Tadalafil

Objective

To assess whether tadalafil improves endothelial dysfunction(EnD) in a placebo-controlled randomized-control trial.

Methods

Erectile dysfunction and EnD were assessed by the International Index of Erectile Function (IIEF-5) and flow-mediated dilation (FMD) of the brachial artery respectively, at baseline and 4 weeks by blinded observer. Patients with FMD of < 15% were randomized in 1:1 ratio to receive either placebo or tadalafil. Both placebo and tadalafil in similar-appearing capsules but coded separately, were dispensed by a blinded co-investigator. Compliance and drug-related events were recorded. The randomization codes were then decoded and appropriate statistical tests applied.

Results

89 patients were randomized and 82 completed the study. Both groups were comparable. Posttreatment, there were significant improvements in IIEF-5 score (pre- vs posttreatment; tadalafil: 11.432 vs 15.937, P < .001 and placebo 11.232 vs 14.935, P < .00) and FMD% pre- vs posttreatment; tadalafil: 11.222 vs 13.827, P < .001 and placebo: 11.617 vs 14.027, P < .001). Intergroup comparison did not show any significant difference in IIEF scores (mean change in tadalafil vs placebo group: 3.719 vs 4.433, P = .223) and FMD% (mean change tadalafil vs placebo group: 2.426 and 2.829, P = .528). The adverse events were significantly more in the tadalafil group (tadalafil vs placebo 14 adverse reactions [ADR] vs 5 ADR, P < .001).

Conclusion

The response of low-dose tadalafil on IIEF and FMD is largely similar to placebo; however, the utility of FMD% in young patients and placebo effect needs to be studied further.

Pattanaik S, Kaundal P, Mavuduru RS, et al. Endothelial Dysfunction in Patients With Erectile Dysfunction: A Double-Blind, Randomized-Control Trial Using Tadalafil. Sex Med 2019;7:41–47.