Serum L-carnitine and vitamin D levels may be low among oral sildenafil citrate non-responders

Is there a relationship between mean platelet volume and response to treatment with daily tadalafil in patients with erectile dysfunction?

Mean platelet volume (MPV) has been related to erectile dysfunction (ED). However, its value in predicting therapeutic response to phosphodiesterase-5 inhibitors is not evaluated. This study aimed to investigate the value of MPV as a marker for the prediction of the response of the tadalafil treatment of ED. A retrospective analysis of patients who were admitted to the andrology outpatient clinic between 2020-2022 were performed. The inclusion criteria were, ≥40 years old male, International Index of Erectile Function-Erectile Function domain score < 26, not received any ED treatment before, have a stable heterosexual relationship, and prescribed 5 mg daily tadalafil for primary treatment of ED. A total of 116 patients were included in the study. The mean age of the patients was 53.7 ± 8.7 years. The response rate to 5 mg tadalafil treatment was 52.6% (Group-1; N = 61). An MPV value ³ 10.05 fL was associated with 66% sensitivity and 75,4% specificity for no response to 5 mg daily tadalafil treatment (Area under curve = 76.9% [95% CI 68.2%-85.6%; p < 0.001]). Initial IIEF-EF score, fasting blood glucose, and MPV level was independently associated with the response to the tadalafil treatment. This is the only study to evaluate the value of MPV level on the therapeutic response of ED to tadalafil. Strict inclusion criteria were applied to the cohort. However, the diagnose of vascular ED has been made by clinical evaluation and retrospective design of the study were the limitations of the study. The results of our study suggest that MPV might be used to predict the result of 5 mg daily tadalafil treatment in selected ED patients as a fast and cost-effective test.

The effect of vitamin D replacement in patients with lower urinary tract complaint/erectile dysfunction resistant to Tadalafil 5 mg treatment: A pilot clinical study

The aim of this study was to evaluate the effect of vitamin D replacement in patients with lower urinary tract symptoms (LUTS)/erectile dysfunction (ED) who did not respond to tadalafil 5 mg treatment. Patients who applied to the Andrology Clinic with LUTS/ED between September 2017 and August 2020 and used 5 mg Tadalafil daily for treatment and did not benefit from treatment for 1 month were included in the study. Vitamin D levels of the patients were analysed and Vitamin D3 100,000 IU/week oral therapy was administered for a month to the patients with low levels of Vitamin D(<20 ng/ml).The values of the patients before and after Vitamin D replacement were compared. A total of 84 patients were included in the study. The mean age was 49.175 ± 11.63(28-70) years and the mean BMI was 25.93 ± 6.82(18.26-37.87). Testosterone levels of the examined patients were 3.45 ± 0.99 ng/ml. After 1 month of Vitamin D replacement + Tadalafil 5 mg/d treatment, the international index of erectile function-erectile function (IIEF-EF) (pre-treatment: 10.73 ± 6.12, post-treatment: 24.18 ± 4.87; p = 0.001) and International Prostate Symptom Score (pre-treatment: 9.12 ± 7.16, post-treatment: 3.11 ± 1.08; p = 0.003) scores of the patients improved significantly. Evaluation of Vitamin D levels is important to improve treatment response, especially in patients who do not respond to PDE-5 inhibitors.

Assessment of the intracavernosal injection platelet-rich plasma in addition to daily oral tadalafil intake in diabetic patients with erectile dysfunction non-responding to on-demand oral PDE5 inhibitors

This study aimed to evaluate the effectiveness of ICI of platelet-rich plasma (PRP) in addition to daily oral tadalafil intake in diabetic erectile dysfunction (ED) patients non-responding to PDE5 inhibitors. Overall, 48 patients complaining of ED non-responding to on-demand PDE5 inhibitors were allocated into 2 equal groups, diabetics and non-diabetics that were given a daily dose of 5 mg tadalafil plus vardenafil 20 mg on demand during the study besides being subjected to 3 doses of ICI of PRP, 4 weeks apart. Responses to on-demand PDE5 inhibitors, International index of erectile function-5 (IIEF-5) score, erection hardness scores (EHS) and pharmaco-dynamic duplex studies were assessed. After PRP injections, 33% and 50% of cases were satisfied with on-demand PDE5 inhibitors, respectively, whereas 41% and 66% of them showed improved EHS response. Compared with baseline scores, the mean IIEF-5 scores were significantly improved after PRP therapy in the diabetic ED group (12.1 vs. 8.04, p = 0.003) as well as in the non-diabetic ED group (14.8 vs. 10.2, p = 0.001) linked to pharmaco-penile duplex readings. Both good and fair diabetic control exhibited significant responses to ICI therapy of PRP compared with bad controlled cases. The significant improvement included; the IIEF-5 score increase (86.7%, 126% vs. 16.1%), improved EHS as well as penile duplex readings. Baseline HbA1C demonstrated a significant negative correlation with IIEF-5 score before (p = 0.019) and after PRP therapy (p = 0.002) respectively. It could be concluded that ICI of PRP could be an effective therapy for treating ED patients non-responding to on-demand oral PDE5 treatment.

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.

L-carnitine extenuates endocrine disruption, inflammatory burst and oxidative stress in carbendazim-challenged male rats via upregulation of testicular StAR and FABP9, and downregulation of P38-MAPK pathways

We have addressed in the current study the potential of L-carnitine (LC) to extenuate the reproductive toxic insults of carbendazim (CBZ) in male rats, and the molecular mechanisms whereby carnitine would modify the spermatogenic and steroidogenic derangements invoked by the endocrine disruptor. Herein, animals received daily doses of carbendazim (100 mg/kg) by gavage for 8 weeks. Another CBZ-challenged group was co-supplemented with LC (500 mg/kg, IP) twice weekly for 8 weeks. Sperm quantity and quality (morphology, motility and viability), serum testosterone and gonadotropins, and thyroid hormone levels were assessed. Serum tumor necrosis factor alpha (TNF-α), interleukin-6 (IL-6) and interleukin-10 (IL-10) concentrations were determined by ELISA. Oxidant/antioxidant status in rat testis was investigated via measuring testicular contents of malondialdehyde (MDA) and reduced glutathione (GSH), as well as the activities of superoxide dismutase (SOD) and glutathione peroxidase (GPx). Immunohistochemical localizations of the junctional protein; occludin, and inflammatory markers; inducible nitric oxide synthase (iNOS) and nuclear factor kappa beta (NF-κB) were further analyzed. A host of transduction genes that regulate spermatogenic and steroidogenic pathways, and their encoded proteins namely, Steroidogenic Acute Regulatory Protein (StAR), Fatty acid binding protein 9 (FABP9) and P38-mitogen activated protein kinase (P38-MAPK) were assessed by real time quantitative (RT-qPCR) and Western blot. LC improved rat spermiogram, testicular histological alterations and endocrine perturbances, and modulated genes' expressions and their respective proteins. In conclusion, LC effects appear to reside for the most part on its endocrine-preserving, anti-oxidant and anti-inflammatory properties through a myriad of interlaced signal transductions that ultimately recapitulated its beneficial effects on spermatogenesis and steroidogenesis.

Whether Adding Vitamin D to Tadalafil 5 mg Treatment Is Useful in Patients with Erectile Dysfunction and Vitamin D Deficiency?

INTRODUCTION

Numerous factors such as endothelial disease and hormonal disorder cause the development of erectile dysfunction (ED). However, the relationship between vitamin D deficiency (VDD) and ED is unclear. Moreover, the benefit of vitamin D replacement on ED patients with VDD is uncertain. As far as we know, there is no study yet in the literature regarding the addition of vitamin D to phosphodiesterase type 5 inhibitors in the treatment of ED patients with VDD. In this study, we investigated whether adding vitamin D to daily tadalafil treatment would be beneficial in ED patients with VDD.

METHODS

A total of 111 patients with VDD accompanying ED were retrospectively evaluated between January 2016 and December 2019. Patients were divided into 2 groups according to the treatment they received. Group 1 (n = 58) was treated with daily oral tadalafil 5 mg, while group 2 (n = 53) received oral tadalafil 5 mg and 4,000 IU vitamin D3. Total International Index of Erectile Function-15 (IIEF-15) scores and vitamin D levels of the groups were compared at the end of the study.

RESULTS

The mean vitamin D level was increased statistically significant in group 2, but no difference was seen in group 1 (p < 0.001 and p > 0.05, respectively). There was a significant increase in median erectile function, orgasmic function, sexual desire, sexual satisfaction, and overall satisfaction scores in both groups (p < 0.001). However, the increase in median erectile function and sexual desire scores was significantly higher in group 2 compared to group 1 at the end of the study (p = 0.01 and p < 0.001, respectively).

CONCLUSION

We found that adding vitamin D to 5 mg oral daily tadalafil treatment may have an additional positive effect on erectile function and sexual desire in ED patients with VDD.

Effect of Genetic Polymorphism on the Response to PDE5 Inhibitors in Patients With Erectile Dysfunction: A Systematic Review and a Critical Appraisal

INTRODUCTION

Several treatment strategies are nowadays available for erectile dysfunction (ED) patients. Currently, oral phosphodiesterase type 5 inhibitors (PDE5Is) are the first-line therapy for ED. However, they are effective in all treated cases with variable non-responsiveness. Many factors have been listed for this behavior, but the possibility of gene polymorphisms as an underlying cause has not been systematically investigated.

OBJECTIVES

This review aimed to assess the possible involvement of gene polymorphisms affecting the response to PDE5Is in men with ED.

METHODS

A systematic review was conducted based on a search of all relevant articles in various electronic sites such as PubMed, Medline Medical Subject Headings, Cochrane Library, Science Direct, Scopus, Embase, CINAHL, and Egyptian Knowledge Bank databases. Keywords used for relevant associations were sexual health, genes, variants, erectile dysfunction, polymorphisms, PDE5Is, and cavernous tissues.

RESULTS

Several studies have been carried out to determine the contribution of different encoded genes to ascertain the association between different genotypes and ED men who were non-responders for PDE5Is. 11 studies were selected for this review. In these studies, 6 investigated eNOS genetic polymorphism with variable outcomes. Only 1 study was carried out for each of the following genetic polymorphisms: phosphodiestrase 5A, G-protein β3 subunit, angiotensin converting enzyme, dimethylarginine dimethylaminohydrolase, arginase, and vascular endothelial growth factor with variable results.

CONCLUSION

Despite the relative shortage of available studies and the varied methodologies used, most of the research articles demonstrated a significant association between genetic polymorphism and the response to PDE5Is, especially for endothelial nitric oxide synthase polymorphism. The limited number of studies that investigated the possible effect of genetic polymorphism and the response to PDE5Is are challenged by many factors, particularly for the definition of responders and non-responders. This should be a motivating factor for researchers to perform further studies with a standardized methodology to address the influence of genetic variations on the response to PDE5Is. Mostafa T, Hassan A, Alghobary MF, et al. Effect of Genetic Polymorphism on the Response to PDE5 Inhibitors in Patients With Erectile Dysfunction: A Systematic Review and a Critical Appraisal. J Sex Med 2020;8:573-585.

Is There an Association Between Vitamin D Deficiency and Erectile Dysfunction? A Systematic Review and Meta-Analysis

Erectile dysfunction (ED) is found very frequently in the male population, in particular in its arteriogenic form, which also represents an important predictor of cardiovascular diseases (CVDs). Some evidence suggests that vitamin D could play a role in cardiovascular risk prevention thanks to its ability to reduce endothelial damage, oxidative stress, the production of inflammatory cytokines, and dyslipidemia. Since ED and CVDs have pathogenic mechanisms in common, numerous studies have evaluated a possible association between vitamin D deficiency (blood concentrations of 25-hydroxyvitamin D < 20 ng/mL) and ED, but with conflicting results. This meta-analysis was therefore performed to clarify the discrepancy of the data so far published. To achieve this, articles have been searched extensively in the Pubmed, MEDLINE, Cochrane, Academic One Files, Google Scholar, and Scopus databases from the first day they were created until January 2020. The search strategy included pertinent Medical Subjects Headings (MeSH) terms. Of the 431 items retrieved, only eight observational studies were included, resulting in a total sample size of 4055 patients. It was found that 25-hydroxyvitaminD (25(OH)D) levels did not show any significant difference between patients with and without ED. However, when patients with vitamin D deficiency only were taken into account, the international index of erectile function (IIEF) score for erectile dysfunction was significantly worse than in controls. This association remained significant even when eugonadal-only patients were considered. Finally, we found that eugonadal patients with severe ED have lower 25(OH)D₃ levels than patients with mild ED. In conclusion, this meta-analysis suggests an association between vitamin D deficiency and the presence of severe forms of ED, independent of testicular function.