Circulating Monocyte Oxidative Activity is Increased in Patients With Type 2 Diabetes and Erectile Dysfunction

The management of erectile dysfunction in men with diabetes mellitus unresponsive to phosphodiesterase type 5 inhibitors

INTRODUCTION

Erectile dysfunction is associated with diabetes mellitus with an estimated prevalence of 52.5% in the diabetic population. The first-line therapy for erectile dysfunction is phosphodiesterase type 5 inhibitors, but data suggest that diabetic men may be less responsive than non-diabetic men. Thus, other treatments, including intracavernosal injections, intraurethral prostaglandin, vacuum erection devices and penile prosthetic surgery, should be considered in management of diabetic men with erectile dysfunction refractory to phosphodiesterase type 5 inhibitors. Furthermore, combination therapy of phosphodiesterase type 5 inhibitors and other oral treatments such as arginine or l-carnitine may have synergistic effects resulting in better outcomes. In addition, there are novel therapies such as low-intensity shockwave therapy and stem-cell therapy, which may also be effective in targeted treatment modalities. Furthermore, studies suggest that erectile dysfunction can be improved by targeting concurrent comorbidities or metabolic diseases such as depression, hypertension, hypogonadism, and dyslipidaemia. We present an evidence-based narrative review focusing on the management of erectile dysfunction in diabetic men who have not responded to phosphodiesterase type 5 inhibitors.

CONCLUSIONS

Both clinicians and patients should be aware of the different management options in diabetic patients who have not responded to phosphodiesterase type 5 inhibitors.

Macrophage, a potential targeted therapeutic immune cell for cardiomyopathy

Cardiomyopathy is a major cause of heart failure, leading to systolic and diastolic dysfunction and promoting adverse cardiac remodeling. Macrophages, as key immune cells of the heart, play a crucial role in inflammation and fibrosis. Moreover, exogenous and cardiac resident macrophages are functionally and phenotypically different during cardiac injury. Although experimental evidence has shown that macrophage-targeted therapy is promising in cardiomyopathy, clinical translation remains challenging. In this article, the molecular mechanism of macrophages in cardiomyopathy has been discussed in detail based on existing literature. The issues and considerations of clinical treatment strategies for myocardial fibrosis has also been analyzed.

Autologous Immune Cell-Based Regenerative Therapies to Treat Vasculogenic Erectile Dysfunction: Is the Immuno-Centric Revolution Ready for the Prime Time?

About 35% of patients affected by erectile dysfunction (ED) do not respond to oral phosphodiesterase-5 inhibitors (PDE5i) and more severe vasculogenic refractory ED affects diabetic patients. Innovative approaches, such as regenerative therapies, including stem cell therapy (SCT) and platelet-rich plasma (PRP), are currently under investigation. Recent data point out that the regenerative capacity of stem cells is strongly influenced by local immune responses, with macrophages playing a pivotal role in the injury response and as a coordinator of tissue regeneration, suggesting that control of the immune response could be an appealing approach in regenerative medicine. A new generation of autologous cell therapy based on immune cells instead of stem cells, which could change regenerative medicine for good, is discussed. Increasing safety and efficacy data are coming from clinical trials using peripheral blood mononuclear cells to treat no-option critical limb ischemia and diabetic foot. In this review, ongoing phase 1/phase 2 stem cell clinical trials are discussed. In addition, we examine the mechanism of action and rationale, as well as propose a new generation of regenerative therapies, evolving from typical stem cell or growth factor to immune cell-based medicine, based on autologous peripheral blood mononuclear cells (PBMNC) concentrates for the treatment of ED.

Sexual Dysfunction in Men and Women with Diabetes: A Reflection of their Complications?

BACKGROUND

Diabetes mellitus (DM), one of the worldwide leading causes of death, is associated with a plethora of micro- and macro-vascular complications which should be carefully investigated and, in case, treated in order to improve quality of life and reduce the risk of premature mortality.

OBJECTIVE

The study aimed to investigate and report current evidence with regard to the association between sexual dysfunction and diabetes.

METHODS

A detailed analysis of current literature has been performed on PubMed and Scholar in order to retrieve the most relevant findings pertaining to the study topic.

RESULTS

Female and male sexual dysfunction often occurs in diabetes; while cardiovascular complications are clearly involved, psychosexological factors, endocrine complications, and endothelial dysfunction all contribute to the pathogenesis of sexual dysfunctions. Psychological symptoms are seldom investigated, yet they should not be overlooked by the clinician; in fact, an interplay between sexual dysfunctions and depressive symptoms has been reported, and beneficial effects in both conditions might be obtained by adequate psychological support. Sexual dysfunctions can also act as early biomarkers of cardiovascular disease, a phenomenon frequently reported in men, in which erectile dysfunction predicts the development of coronary artery disease. Additionally, drug therapies can act in both directions, with treatments for diabetes possibly improving male sexual function and exerting beneficial effects for cardiovascular health being reported for pro-erectile drugs.

CONCLUSION

Sexual dysfunctions often occur in men and women with diabetes. Investigating micro- and macro-vascular complications might not be enough to prevent the development or worsening of any sexual dysfunction; endocrine and psychological assessments are therefore needed to provide the best chances for adequate treatment.

People smoke for nicotine, but lose sexual and reproductive health for tar: a narrative review on the effect of cigarette smoking on male sexuality and reproduction

PURPOSE

To systematically review the impact of smoking habits on cardiovascular (CV) as well as on male sexual and reproductive function and to provide updated evidence on the role of electronic cigarettes (e-Cig) on the same topics.

METHODS

A comprehensive Medline, Embase, and Cochrane search was performed including the following words: smoking, CV system, CV risk, erectile dysfunction (ED), and male fertility. Publications from January 1, 1969 up to February 29, 2020 were included.

RESULTS

Smoking has a tremendous negative impact on CV mortality and morbidity. Current smoking behavior is also negatively associated with erectile dysfunction (ED) and impaired sperm parameters. E-Cig can release significantly lower concentrations of harmful substances when compared to regular combustible cigarettes. Whether or not the latter can result in positive CV, sexual, and fertility outcomes is still under study. Preliminary studies showed that exposure to e-Cig leads to lower vascular damage when compared to the traditional cigarette use. However, data on the long-term effects of e-Cig are lacking. Similarly, preliminary data, obtained in animal models, have suggested a milder effect of e-Cig on erectile function and sperm parameters.

CONCLUSION

Available evidence showed that e-Cig are much less dangerous when compared to the traditional tobacco use. However, it should be recognized that the risk related to e-Cig is still higher when compared to that observed in non-smoking patients. Hence, e-Cig should be considered as a potential tool, in the logic of harm reduction, to reduce the CV, sexual and fertility risk in patients refractory to the fundamental, healthy choice to definitively quit smoking.

Potential activity of Aframomum daniellii (Zingiberaceae) dry seeds: A case study of its action mechanism on the Wistar rat strain with testicular deficiency

This work was undertaken to evaluate the biological activity of the aqueous extract of the dry seeds of Aframomum daniellii seeds on the copulatory performance of rats with testicular deficiency. Hypogonadal adult male rats (30) were divided into 6 groups: group I received distilled water (10 ml/kg), group II received sildenafil citrate (5 mg/kg), group III received intramuscular injections of testosterone enanthate (3. 6 mg/kg), group IV, V, and VI received the aqueous extract of A. daniellii at the respective doses of 100, 200, and 400 mg/kg/po/day for 14 days. The copulatory performance of the animals were assessed on days 1, 7 and 14 through the following copulation parameters: Mount, intromission, and ejaculation latency (ML, IL, and EL) and frequency (MF, IF and EF), average interval of copulation (AIC) and post-ejaculatory interval (PEI)). We noticed a significant decrease of ML (p < 0.05), IL (p < 0.01), EL (p < 0.001) and the increase of MF, IF and EF (p < 0.01) particularly at doses of 100 and 400 mg/kg when compared to group I and II. In addition, we noticed a significant increase of AIC from day 7 (p < 0.05) to day 14 (p < 0.001) at the same two doses while the PEI significantly decreased from the 1st (p < 0.01) to the 14th day (p < 0.001) when compared to group I and II. These findings demonstrated that A. daniellii aqueous extract of seeds enhanced pro-sexual potential and pro-sexual desire in male rats with testicular deficiency.

The phosphodiesterase 5 inhibitor sildenafil decreases the proinflammatory chemokine IL-8 in diabetic cardiomyopathy: in vivo and in vitro evidence

PURPOSE

Interleukin (IL)-8 is a proinflammatory C-X-C chemokine involved in inflammation underling cardiac diseases, primary or in comorbid condition, such diabetic cardiomyopathy (DCM). The phosphodiesterase type 5 inhibitor sildenafil can ameliorate cardiac conditions by counteracting inflammation. The study aim is to evaluate the effect of sildenafil on serum IL-8 in DCM subjects vs. placebo, and on IL-8 release in human endothelial cells (Hfaec) and peripheral blood mononuclear cells (PBMC) under inflammatory stimuli.

METHODS

IL-8 was quantified: in sera of (30) DCM subjects before (baseline) and after sildenafil (100 mg/day, 3-months) vs. (16) placebo and (15) healthy subjects, by multiplatform array; in supernatants from inflammation-challenged cells after sildenafil (1 µM), by ELISA.

RESULTS

Baseline IL-8 was higher in DCM vs. healthy subjects (149.14 ± 46.89 vs. 16.17 ± 5.38 pg/ml, p < 0.01). Sildenafil, not placebo, significantly reduced serum IL-8 (23.7 ± 5.9 pg/ml, p < 0.05 vs. baseline). Receiver operating characteristic (ROC) curve for IL-8 was 0.945 (95% confidence interval of 0.772 to 1.0, p < 0.01), showing good capacity of discriminating the response in terms of drug-induced IL-8 decrease (sensitivity of 0.93, specificity of 0.90). Sildenafil significantly decreased IL-8 protein release by inflammation-induced Hfaec and PBMC and downregulated IL-8 mRNA in PBMC, without affecting cell number or PDE5 expression.

CONCLUSION

Sildenafil might be suggested as potential novel pharmacological tool to control DCM progression through IL-8 targeting at systemic and cellular level.

Biochemical and genetic markers of erectile dysfunction

Erectile dysfunction (ED) is a very common pathology, affecting over 150 million men worldwide. The pathogenesis is typically multifactorial, involving a kaleidoscope of organic, endocrine, and psychogenic factors. In general, ED is divided into organic and psychogenic impotence, but most men with organic etiologies have an associated psychogenic component. Given the high frequency of this pathology, the identification of biochemical and genetic correlates and/or markers is of pivotal interest not only for treating preciously these patients and preventing serious psychological consequences but also for the high risk for occult cardiovascular disease (CVD) that often accompanies or follows this pathology. A variety of cardiovascular risk factors have been associated with both the onset and the severity of ED, including markers of endothelial function, thrombosis, and especially dyslipidemia, so that their measurement should now be considered as an important part of the increased global cardiometabolic risk profile in patients with ED. While nitric oxide (NO), asymmetric dimethylarginine (ADMA), and endothelin (ET) hold some promises as biochemical markers of both CVD and ED, there are several technical and clinical drawbacks that make their measurement overall meaningless in the clinical practice. As regards genetic polymorphisms, controversial results have been provided so far. Although some genetic markers were consistently associated with ED, other studies failed to demonstrate significant associations, highlighting a substantial bias in standardization of methodologies and patient enrolment. Nevertheless, further research in this area should be encouraged, since the first promising evidence that gene therapy might be effective to restore the decline in ED has been provided in the animal model.

Comparison of sildenafil with strontium fructose diphosphate in improving erectile dysfunction against upregulated cavernosal NADPH oxidase, protein kinase Cε, and endothelin system in diabetic rats

Objectives

Phosphodiesterase type 5 inhibitors are potent in relieving erectile dysfunction (ED), however, they are less satisfactory in diabetic patients, probably due to the pro-inflammatory biomarkers caused by diabetes. Therefore, it was interesting to compare the effects of sildenafil with strontium fructose 1,6-diphosphate (FDP-Sr) on cavernosal vascular activity and expressions of pro-inflammatory biomarkers in diabetic rats.

Methods

Male Sprague-Dawley rats were injected with streptozocin (60 mg/kg, i.p.) to develop diabetes. The animals were diabetic for eight weeks with sildenafil (12 mg/kg per day) or FDP-Sr (200 mg/kg per day) being administered for the last four of those eight weeks.

Key findings

Sildenafil was more effective in relieving reduced vascular dilatation (relevant to ED), but less in attenuating over-expressions of NADPH oxidase p22, p47 and p67 subunits, and ETA/BR (endothelin receptor type A and type B) in the diabetic cavernosum. In contrast, FDP-Sr was less effective in improving ED, but more effective in normalizing the abnormal NADPH oxidase and ETA/BR.

Conclusions

The activated NADPH oxidase and upregulated ETAR and ETBR due to diabetic lesions played a minor or moderate role in ED. By offering extra ATP, FPD-Sr suppressed these abnormalities, however, sildenafil did not. A combined therapy of sildenafil with FDP-Sr may be more effective in relieving ED in diabetic patients through normalizing pro-inflammatory cytokines and improving the nitric oxide/cGMP pathway in the cavernosum.

Markers of erectile dysfunction

With the development and marketing of oral pharmacotherapy that is both noninvasive and successful in treating erectile dysfunction (ED), the quest to identify markers of organic ED lost ground. Indeed, the multi-factorial nature of ED may have led many researchers to conclude that searching for a universal marker of ED was futile. However, the realization that ED is strongly correlated with the overall health of men, and may act as a predictor for the development of cardiovascular disease (CVD) and diabetes, has stimulated interest in identifying genes that can distinguish organic ED. In addition, the potential ability to suggest to the patient that ED is reversible (i.e., psychogenic) with a simple test would be of significance to both the physician and patient, as well as for reimbursement issues for therapy by insurance companies. Such a marker may also act as a non-subjective measure of the degree of ED and the efficacy of treatment. This review discusses the importance of identifying such markers and recent work identifying potential markers in human patients.

Relationship between erectile dysfunction and silent myocardial ischemia in type 2 diabetic patients with no known macrovascular complications

INTRODUCTION

Erectile dysfunction (ED) is associated with cardiovascular disease (CVD) because it is highly prevalent among those with cardiovascular risk factors (CVRFs). Moreover, it precedes the development of CVD and is considered a subrogate marker of subclinical CVD.

AIM

The aim of this study was to evaluate the presence of ED among patients with type 2 diabetes (DM2) without macroangiopathy, and to assess the association between ED and other CVRFs, chronic diabetes complications, silent myocardial ischemia (SMI), and peripheral arterial disease (PAD).

METHODS

One hundred fifty-four male patients with DM2 and without clinical evidence of CVD were included in the study. The presence of ED, PAD, SMI, chronic diabetic complications, and other CVRFs was evaluated in these patients.

MAIN OUTCOME MEASURES

PAD; SMI; ED; 24-hour blood pressure Holter; lipid profile; insulin resistance; testosterone; chronic inflammation; nephropathy; retinopathy; neuropathy.

RESULTS

Prevalence of ED was 68.2%. Patients with ED were older and characterized by DM2, systolic blood pressure (BP), retinopathy, and insulin treatment of longer duration than patients without ED, even when adjusting for age was performed. Adjusting for duration of diabetic condition revealed significant differences in age and systolic BP. Independent factors for ED were age (57.7±7.5 years, relative risks [RR 1.1], P=0.003) and duration of diabetes (9[3-15] years, RR 1.1, P=0.006). SMI was detected in 13.6% of patients (18.1% in patients with ED vs. 4.1% in patients without ED). Asymptomatic PAD was detected in 13.2% of subjects (14.4% in patients with ED vs. 10.4% in patients without).

CONCLUSIONS

ED is highly prevalent in DM2, and is associated with the presence of SMI, higher systolic BP and chronic microvascular diabetic complications.

Imbalanced low-grade inflammation and endothelial activation in patients with type 2 diabetes mellitus and erectile dysfunction

INTRODUCTION

Erectile dysfunction (ED) is highly prevalent among type 2 diabetes mellitus patients (T2DM). Although a link among systemic inflammation, endothelial dysfunction, and ED is described in clinical situations mainly related with coronary heart disease (CHD) risk, evidences of this link in T2DM patients are rather limited.

AIMS

To evaluate the association between endothelial dysfunction and balance of pro-/anti-inflammatory mediators with ED presence and severity in T2DM.

METHODS

We conducted a cross-sectional study of 190 T2DM patients without symptomatic CHD, 150 out of them with ED and 40 without ED. Serum levels of E-selectin, intercellular adhesion molecule-1, tumor necrosis factor-α (TNF-α), and interleukin (IL)-10 were measured using specific enzyme-linked immunosorbent assays (ELISAs). ED presence and severity were tested by the five-item version of the International Index of Erectile Function questionnaire.

MAIN OUTCOME MEASURES

Differences in circulating levels of endothelial dysfunction (ICAM-1, E-selectin) and inflammatory/anti-inflammatory (TNF-α, IL-10, TNF-α : IL-10 ratio) markers between T2DM patients with and without ED, and assessment of biomarkers ED predictive value while adjusting for other known ED risk factors.

RESULTS

Patients with ED were older and had longer duration of diabetes than patients without ED. E-selectin serum levels were significantly increased, while IL-10 were lower in patients with ED; because TNF-α levels tend to be higher, TNF-α : IL-10 ratio was more elevated in ED patients. No significant differences of ICAM-1 levels were observed between study groups. Endothelial activation markers and TNF-α, as well as diabetes duration, were negatively correlated with erectile function. On multivariate analysis including age, duration of diabetes, insulin treatment, hypertension, insulin resistance, fair-to-poor glycemic control, and metabolic syndrome, increments in E-selectin levels and TNF-α : IL-10 ratio predicted independently ED presence, while IL-10 increases were associated with lower risk of ED in T2DM patients.

CONCLUSIONS

ED in T2DM patients without symptomatic CHD is associated with systemic endothelial dysfunction and a predominant, imbalanced low-grade inflammatory response.

Diabetes, obesity and erectile dysfunction: field overview and research priorities

PURPOSE

We provide an overview of basic, clinical and epidemiological research in the field of erectile dysfunction and important research priorities presented at the 2009 National Institute of Diabetes and Digestive and Kidney Diseases symposium on Urological Complications of Diabetes and Obesity.

MATERIALS AND METHODS

Experts in molecular biology, physiology, pharmacology, clinical trials, epidemiology and urological surgery highlighted current knowledge on erectile dysfunction associated with diabetes mellitus and obesity.

RESULTS

Predictable associations between erectile dysfunction, and poor diabetic control and modifiable risk factors, including body mass index, have not yet been translated into randomized trials in the United States. The relationship between erectile dysfunction and metabolic syndrome, and surrogate markers for erectile dysfunction requires further investigation. Basic research aimed at discovering disease mechanisms and therapeutic targets has focused on autonomic neuropathy, vascular dysfunction, smooth muscle contractile function and matrix. However, significant gaps exist in regard to the integration of molecular, cellular and functional data. Animal models of type 2 diabetes and obesity associated erectile dysfunction require investigation because most basic science studies have used rodent models of type 1 diabetes.

CONCLUSIONS

Studies are needed to synthesize a systems biology understanding of erectile function/dysfunction, and characterize and disseminate rodent models of erectile dysfunction associated with type 2 diabetes and obesity. Clinical studies are needed of promising intervention and prevention strategies. Leveraging existing and future cohort phenotypes, and biological samples is needed for risk factor analysis, biomarker discovery and genome wide association studies.

The endothelial-erectile dysfunction connection: an essential update

INTRODUCTION

The endothelial monolayer plays a crucial role in the vasodilation and hemodynamic events involved in erection physiology. Due to its relevant functions, a close link has been established between endothelial integrity and erectile dysfunction (ED). Endothelial dysfunction is induced by the detrimental actions of vascular risk factors (VRFs), identified as common correlates for the development of cardiovascular disease and ED. It is currently recognized that ED is the early harbinger of a more generalized vascular systemic disorder, and, therefore, an evaluation of endothelial health in ED patients should be of prime relevance. Several noninvasive methods for endothelial function assessment have been proposed, including the Penile Nitric Oxide Release Test (PNORT).

AIM

To highlight the most recent gathered knowledge on basic and clinical mechanisms underlying loss of cavernosal endothelial function promoted by VRFs and to discuss local and systemic methods for endothelial function assessment in ED individuals, focusing on the PNORT.

MAIN OUTCOME MEASURES

A complete revision on the novel basic and clinical links between endothelial and ED.

METHODS

A systematic review of the literature regarding the aforementioned issues.

RESULTS

Risk factor-associated cavernosal endothelial dysfunction is mostly induced by unifying mechanisms, including oxidative stress and impaired endothelial nitric oxide functional activities, which present clinically as ED. Several techniques to evaluate endothelial dysfunction were revised, with advantages and limitations debated, focusing on our detailed expertise using the PNORT method.

CONCLUSIONS

The established endothelial-erectile dysfunction connection was thoroughly revised, from basic mechanisms to the clinical importance of endothelial dysfunction assessment as diagnosis for generalized vascular disease. Further studies are required to disclose efficient approaches to repair disabled endothelium and both restore and prevent endothelial dysfunction.

Review type 2 diabetes mellitus and erectile dysfunction

INTRODUCTION

Diabetes mellitus (DM) is a major risk factor for the development of erectile dysfunction (ED). Although most diabetic ED cases are in patients with type 2 diabetes (T2DM), the majority of basic science studies examining mechanisms of diabetic ED have been conducted in animal models of type 1 diabetes.

AIM

Recently, however, clinical and laboratory-based studies have uncovered some key underlying factors of T2DM-associated ED, which we have compiled in this review of T2DM ED.

MAIN OUTCOME MEASURES

The outcomes discussed in this review include major mechanisms underlying T2DM, discussing both clinical and basic science studies.

METHODS

We conducted an extensive search of pertinent clinical and basic science literature using PUBMED.

RESULTS

Mechanisms causing ED in T2DM are multifactorial and often lead to resistance to current therapy. Systemic effects of hyperglycemia and hypogonadism contribute to the development of impaired vasodilatory signaling, smooth muscle cell hypercontractility, and veno-occlusive disorder in T2DM ED.

CONCLUSIONS

Understanding the different causes for ED in T2DM patients may allow targeted therapy for improved erectile function.

NADPH oxidase: recent evidence for its role in erectile dysfunction

Important roles for reactive oxygen species (ROS) in physiology and pathophysiology have been increasingly recognized. Under normal conditions, ROS serve as signaling molecules in the regulation of cellular functions. However, enhanced ROS production as a result of the activation of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase contributes significantly to the pathogeneses of vascular diseases. Although it has become evident that increased ROS is associated with erectile dysfunction (ED), the sources of ROS in the penis remain largely unknown. In recent years, emergent evidence suggests the possible role of NADPH oxidase in inducing ED. In this review, we examine the relationship between ROS and ED in different disease models and discuss the current evidence basis for NADPH oxidase-derived ROS in ED.

Antioxidant Treatment Associated with Sildenafil Reduces Monocyte Activation and Markers of Endothelial Damage in Patients with Diabetic Erectile Dysfunction: A Double-Blind, Placebo-Controlled Study

OBJECTIVE

To investigate the synergic effect of propionyl L-carnitine (PLC) plus sildenafil in reducing monocyte oxidative activity and endothelial dysfunction markers in diabetic patients with erectile dysfunction (ED).

METHODS

Thirty-two type 2 diabetic patients with ED (according to the International Index of Erectile Function-5 [IIEF-5]) were randomized to receive PLC (2 g/d) alone (n=8) or combined with sildenafil (50 mg/d twice weekly) (n=8), sildenafil alone (50 mg/d twice weekly) (n=8), or placebo (n=8) in a double-blind, fixed-dose study. Monocyte oxidative activity (stimulation index [SI]), intercellular adhesion molecule-1 [ICAM-1], P-selectin, advanced glycation end product (AGE) levels, Doppler sonography (recording peak systolic velocity [PSV]; end diastolic velocity [EDV]; systolic wave time [SWT]; resistive index [RI]), and IIEF score were evaluated before and after 12 wk of treatment; IIEF-5 was evaluated again 4 wk posttreatment.

RESULTS

SI was reduced by treatment with PLC alone or combined with sildenafil (p<0.05). In patients treated with PLC plus sildenafil, a decrease in ICAM-1, P-selectin, and EDV values was observed compared with patients treated with sildenafil alone (p<0.05, p<0.01, p<0.001, respectively). IIEF-5 improved in all patients treated with PLC plus sildenafil or sildenafil alone (p<0.03, p<0.05, respectively). Four weeks posttreatment, patients treated with PLC plus sildenafil maintained the improvement of the IIEF-5 compared with patients on sildenafil alone (p=0.05). In patients on PLC treatment (with or without sildenafil), SI was correlated with IIEF-5 (p<0.001), glycemia with STW (p<0.03), and AGEs with IIEF-5 (p<0.01).

CONCLUSION

PLC plus sildenafil was more effective in reducing SI and endothelial dysfunction markers in patients with type 2 diabetes and ED.

Chronic sildenafil in men with diabetes and erectile dysfunction

Erectile dysfunction frequently represents a neurovascular complication of diabetes mellitus, and it has been calculated that almost 50% of diabetic men will have erectile dysfunction within 6 years after diagnosis. Penile endothelial and smooth muscle cell dysfunction are due to molecular pathway abnormalities (i.e., activation of PKC, increased oxidative stress and overproduction of advanced-glycosylation end products). The response rate to oral drug therapies, such as sildenafil, is lower than in most other groups. Because therapeutic alternatives (i.e., intracavernous injections with vasoactive agents) are not curative, clinical trials aimed to demonstrate rehabilitative effects with daily phosphodiesterase type-5 inhibitors are ongoing. If this approach proves successful, it will determine many advantages over the intracavernosal treatment and potentially induce sexual rehabilitation.