Functional characterization of platelets in patients with arterial erectile dysfunction

Mean platelet volume as a predictive marker of erectile dysfunction: a meta-analysis

Erectile dysfunction (ED) is a global health problem that commonly occurs due to multiple factors, particularly by a vascular abnormality with the activation of platelet (PLT). Mean platelet volume (MPV), a PLT activity marker, has been hypothesized to be associated with ED. The present meta-analysis aims to evaluate the MPV and its contribution to ED diagnosis. A systematic searching to summarize the association of MPV as a predictive marker for ED was conducted on two databases, including MEDLINE (PubMed) and CINAHL (EBSCOhost). We included all English studies that measured MPV levels in ED and non-ED subjects. A total of 168 publications were initially retrieved and screened systematically. 12 studies with 1643 subjects were included for both qualitative and quantitative analysis. The MPV mean difference between ED patients and healthy subjects; vasculogenic and non-vasculogenic ED showed significant differences. Our findings show PLT is associated with the development of ED. Higher MPV level was found in the ED subjects compared to the healthy controls. Nevertheless, the evidence is still limited due to the small number of studies and further investigations are required to support the utilization of MPV for ED diagnosis.

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 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.

Effect of the icariin on endothelial microparticles, endothelial progenitor cells, platelets, and erectile function in spontaneously hypertensive rats

OBJECTIVES

To investigate the effect of icariin on endothelial microparticles, endothelial progenitor cells, platelets, and erectile function in spontaneously hypertensive rats.

MATERIALS AND METHODS

Twelve 8-week-old healthy male Wistar-Kyoto rats and 12 spontaneously hypertensive rats were randomly divided into four following groups: Wistar-Kyoto control group (normal saline 1 ml/d given by gavage), Wistar-Kyoto + icariin group (icariin 10 mg/kg × d dissolved in 1 ml normal saline and given by gavage), spontaneously hypertensive rats control group (normal saline 1 ml/d given by gavage), and spontaneously hypertensive rats + icariin group (icariin 10 mg/kg × d dissolved in 1 ml normal saline and given by gavage). Four weeks later, the maximum intracavernous pressure/mean arterial pressure, platelet count, mean platelet volume, platelet distribution width, endothelial microparticles, endothelial progenitor cells, and vitronectin receptor were measured in each group.

RESULTS

Under 3 or 5 V electrical stimulation, the maximum intracavernous pressure/mean arterial pressure in the spontaneously hypertensive rats + icariin group (0.23 ± 0.03, 0.38 ± 0.02) was significantly higher compared to the spontaneously hypertensive rats control group (0.12 ± 0.02, 0.20 ± 0.02) (p<0.05). Platelet count, mean platelet volume, and platelet distribution width in the spontaneously hypertensive rats + icariin group (1103.67 ± 107.70 × 10⁹ /L, 9.08 ± 0.50 fl, 11.87 ± 0.45%) were significantly lower than those in the spontaneously hypertensive rats control group (1298.00 ± 89.54 × 10⁹ /L, 9.72 ± 0.44 fl, 13.03 ± 0.59%) (all p < 0.05). Endothelial microparticles, endothelial progenitor cells, and vitronectin receptor in the spontaneously hypertensive rats + icariin group (1.01 ± 0.28%, 1.53 ± 0.65%, 2.13 ± 0.53%) were significantly lower than those in the spontaneously hypertensive rats control group (1.58 ± 0.19%, 2.71 ± 0.64%, 3.76 ± 0.52%) (all p < 0.05). Moreover, maximum intracavernous pressure/mean arterial pressure was strongly negatively correlated with platelet distribution width and vitronectin receptor (r > 0.7), and maximum intracavernous pressure/mean arterial pressure was moderately negatively correlated with mean platelet volume, endothelial microparticles, and endothelial progenitor cells (0.5 < r<0.7).

CONCLUSION

Icariin may improve erectile function in spontaneously hypertensive rats by reducing the content of endothelial microparticles in blood and inhibiting the activation of the platelets. Endothelial microparticles, endothelial progenitor cells, and platelet activation-related (mean platelet volume, platelet distribution width, and vitronectin receptor) can be used as indicators for icariin to improve erectile function in spontaneously hypertensive rats.

The penile duplex ultrasound: How and when to perform it?

BACKGROUND

Because it is a superficial structure, the penis is ideally suited to ultrasound imaging. A number of disease processes, including Peyronie's disease, penile fractures and tumors, are clearly visualized with ultrasound. Baseline and dynamic assessment of cavernosal arterial changes after pharmaco-stimulation with alprostadil allows standardized diagnosis of arterial and venogenic causes of erectile dysfunction (ED).

OBJECTIVE

To illustrate how to correctly perform flaccid and dynamic penile duplex ultrasound (D-PDU) and in which patients to recommend it.

MATERIALS/METHODS

An extensive search of the literature was carried out on Pubmed with the insertion of the following Medical Subjects Headings (MeSH) terms and keywords "penile color Doppler ultrasound" "peak systolic velocity" "end-diastolic velocity", "acceleration time", "resistance index".

EVIDENCE

In our experience, arterial erectile dysfunction is identified after standardized intracavernous injection (ICI) of alprostadil (10 mcg) when values of peak systolic velocity (PSV) are <35 cm/s and, in the most severe forms, for values <25 cm/s. Arterial insufficiency can also be identified by increased acceleration time (AT) values (>110 ms) and/or by a lack of visualization of helicine arteries at power Doppler mode along with incomplete achievement of penile rigidity. The veno-occlusive incompetence is determined when end-diastolic velocity (EDV) values are >4.5-5 cm/s or in the case of resistance index (RI) values <0.75. The assessment of additional surrogate markers of endothelial dysfunction, that is, intima-media thickness, mean platelet volume (MPV), endothelial progenitor cells (EPC), endothelial cell specific molecule-1(endocan) are also useful in assessing the patient's cardiovascular risk but are still considered investigational in the interpretation of D-PDU results.

CONCLUSION

D-PDU scan after ICI with vasoactive drugs is a safe procedure and represents the gold standard for the diagnostics of penile pathologies and should be performed in men with ED not responding to oral conventional therapies and/or in those requiring accurate stratification of cardiovascular risk.

The relationship between erectile dysfunction severity, mean platelet volume and vitamin D levels

Background: The aim of this study was to evaluate the relationship between mean platelet volume (MPV) and vitamin D levels according to ED severity.Methods: Between October 2015 and September 2017, patients who applied to the andrology outpatient clinic with an ED complaint were retrospectively reviewed. Patients with diabetes, hypertension, hyperlipidemia, malignancy, late-onset hypogonadism and smokers were not included in the study. The International Erectile Function Index-Erectile Function (IIEF-EF) questionnaire was used to assess the levels of erectile function. According to this scoring system, patients were divided into two groups. IIEF score: between 17 and 25 = mild ED (Group 1) and IIEF score between 16 and 0 = moderate-severe ED (Group 2). Blood samples of the patients were taken from antecubital vein and MPV and 25-hydroxyvitamin D [25(OH)D] levels were evaluated.Results: Ninety patients were included in the study (Group 1: n = 41, Group 2: n = 49). The mean age of the patients was 41.07 ± 8.56 and the mean body mass index (BMI) was 27.59 ± 3.91. 25(OH)D levels were found to be statistically lower in Group 2 (18.85 ± 6.09; 13.98 ± 7.10; p = .001). MPV levels were found to be statistically higher in Group 2 (10.05 ± 0.81; 10.78 ± 1.16; p = .001). Correlation between IIEF-EF scores and 25(OH)D levels was positive (p = .03, r = 0.22). There was negative correlation between IIEF-EF scores and MPV and between 25(OH)D levels and MPV levels [p = .003 for IIEF-EF/MPV, p = .04, r = -0.23 for 25(OH)D/MPV].Conclusion: There is a significant positive correlation between ED severity and 25(OH)D levels and there is a significant negative correlation between ED severity and MPV levels.

Mean Platelet Volume as a Marker of Vasculogenic Erectile Dysfunction and Future Cardiovascular Risk

Cardiovascular diseases are the main cause of mortality in the Western population, so the attempt to find a marker capable of predicting their early onset is not surprising. It is known that arteriogenic erectile dysfunction (ED) precedes the onset of a major coronary event by several years. However, a marker that is able to early identify those patients who should undergo further diagnostic investigations is, to date, missing. Recent research on this topic has focused on the role of the mean platelet volume (MPV), a marker of platelet activity that is high in most vascular diseases, such as coronary artery disease (CAD), stroke, peripheral artery disease (PAD), and ED. The basic pathophysiological mechanism of all these clinical conditions is atherosclerosis. Platelets play a central role in amplifying this process both indirectly by stimulating endothelial cells to produce inflammatory cytokines and chemokines, and directly through the expression of membrane receptors and the release of molecules that contribute to the formation of atherosclerotic plaque. The objective of this review is to critically analyze the evidence on the role of MPV in predicting the diagnosis and severity of vasculogenic ED and the possibility of using this simple marker as a first step to start a diagnostic process aimed at assessing the cardiovascular risk in these patients.

Is There a Role for Levo-Thyroxine for the Treatment of Arterial Erectile Dysfunction? The Clinical Relevance of the Mean Platelet Volume

BACKGROUND

Arterial erectile dysfunction (ED) is an early sign of vascular damage. Rare evidence has been published so far as to whether subclinical hypothyroidism (SCH) affects arterial erectile function. Therefore, the objective of this study was to fill this gap.

METHODS

Patients with arterial ED and SCH were consecutive enrolled and randomly divided into Group A (n = 20) and Group B (n = 20). Group A was treated with levo-thyroxine (LT4) at the dose of 1 µg/kg/day for six months, whereas patients of the group B did not receive any treatment. Thyroid stimulating hormone (TSH), free-thyroxine (FT4), peak systolic velocity (PSV), International Index of Erectile Function 5-item version (IIEF-5) score, mean platelet volume (MPV), and total cholesterol were evaluated at enrollment (T0) and after six months (T1). Patients without hypertension, diabetes mellitus, dyslipidemia, not on drugs, and with normal total testosterone (TT) values were included in this study.

RESULTS

Group A and B did not differ for age (61.2 ± 4.8 vs. 60.3 ± 5.6 years), body-mass index (28.7 ± 2.5 vs. 28.3 ± 2.6 Kg/m²), and serum TT levels (481.2 ± 54.0 vs. 492.1 ± 59.7 ng/dL). At T0, serum TSH levels (6.5 ± 1.2 vs. 6.0 ± 1.0 µIU/mL), FT4 (8.8 ± 0.6 vs. 8.8 ± 0.6 pmol/L), PSV (26.5 ± 1.4 vs. 25.8 ± 2.1 cm/s), IIEF-5 score (8.2 ± 1.7 vs. 9.0±1.7), and total cholesterol (167.8 ± 21.7 vs. 171.6 ± 21.3 mg/dL) did not significantly differ in patients of Group A vs. those of Group B. MPV was significantly higher in Group A than in Group B (12.3 ± 0.3 vs. 11.8±0.7 fL). At T1, Group A showed significantly lower TSH (2.26 ± 0.5 µIU/mL), MPV (9.5 ± 0.3 fL), and total cholesterol (137.8 ± 29.2 mg/dL) and significantly higher FT4 (9.3 ± 0.4 pmol/L), PSV (40.0 ± 2.6 cm/s), and IIEF-5 score (20.2 ± 3.6) compared to pre-treatment values. None of these endpoints showed significant change at T1 compared to T0 in patients of group B.

CONCLUSIONS

Lt4 therapy is associated with an improvement of the erectile function at the vascular level, a decrease in MPV and total cholesterol. LT4 therapy should be considered in patients with arterial ED and SCH.

Efficacy and safety of combination of tadalafil and aspirin versus tadalafil or aspirin alone in patients with vascular erectile dysfunction: a comparative randomized prospective study

PURPOSE

We aimed to investigate the efficacy and safety of tadalafil, aspirin, and tadalafil + aspirin combination therapy in vascular erectile dysfunction (VED).

METHODS

A total of 336 patients were randomly divided into four groups (group 1, aspirin 100 mg/day, 126 patients; group 2, tadalafil 5 mg/day, 72 patients; group 3, tadalafil 5 mg + aspirin 100 mg, 72 patients; group 4, placebo, 66 patients). In all groups, the changes from baseline to end point in erectile function scores on the International Index of Erectile Function (IIEF-EF) and the number of patients who answered "yes" to questions 2 and 3 of the sexual encounter profile(SEP) were compared statistically.

RESULTS

The changes in IIEF-EF scores after treatment were 7.2 ± 4.4, 7.3 ± 4.3, 7.5 ± 4.4, and 2.0 ± 4.6 for group 1 (p < 0.0001), group 2 (p < 0.0001), group 3 (p < 0.0001), and group 4 (p = 0.0204), respectively. The change in SEP-2 ratios after treatment were 36.6%, 36.9%, 41.7%, and 9.4% for group 1 (p < 0.0001), group 2 (p < 0.0001), group 3 (p < 0.0001), and group 4 (p = 0.2925), respectively. The change in SEP-3 ratios after treatment was 46.6%, 49.2%, 53.7%, and 12.5% for group 1 (p < 0.0001), group 2 (p < 0.0001), group 3 (p < 0.0001), and group 4 (p = 0.1456), respectively. In group 2, both the number of patients who reported side effects (p < 0.0001) and stopped using the drug due to side effects (p < 0.05) were significantly higher than the control and others groups.

CONCLUSIONS

Successful results were obtained by tadalafil and aspirin monotherapy and tadalafil + aspirin combination therapy in patients with VED. However, the least side effect was observed in the tadalafil + aspirin group. Aspirin can be used alone in the treatment of patients with VED, or combined with tadalafil to reduce side effects and increase success.

Platelet indices and erectile dysfunction: A systematic review and meta-analysis

Elevated platelet levels have been postulated to be associated with cardiovascular diseases, conditions closely linked to erectile dysfunction (ED). The current systematic review and meta-analysis was performed to assess the platelet indices, which including platelet count (PLT), mean platelet volume (MPV) and platelet distribution width (PDW) in subjects with ED compared to controls in an attempt to clarify the possible role of platelet indices in the pathogenesis of ED. We initially screened the candidate studies observing the possible association between platelet indices and ED following literature search of database Cochrane Library, PubMed, EMBASE and MEDLINE and therefore included the studies based on the pre-defined inclusion and exclusion criteria. Two independent investigators extracted the related information on article data and outcome measures from the qualified studies, and a meta-analysis was therefore performed using Stata 12.0 software. Subgroup analyses were conducted by the different ED aetiology obtained from the eligible studies. The standard mean difference (SMD) and the corresponding 95% confidence intervals (95% CIs) were applied to estimate the outcome measures. A total of 14 articles were qualified in our meta-analysis with a total of 1595 cases and 987 controls included. Pooled estimate was in favour of increased MPV levels in subjects with ED with a SMD of 0.651 fl, 95% CI 0.567-0.735, p = 0.000. Subgroup analysis showed that vasculogenic ED had a higher MPV levels than controls as well (SMD [95% CI] = 1.026 [0.823-1.228], p = 0.000). However, pooled analysis based on PLT and PDW levels has produced inconsistent results and not strong evidence on platelet level and ED correlation. In conclusion, vasculogenic ED patients had a higher MPV level in our study. However, the results need further interpretation with caution and more high-quality studies are warranted.

Antiplatelet (aspirin) therapy as a new option in the treatment of vasculogenic erectile dysfunction: a prospective randomized double-blind placebo-controlled study

PURPOSE

To investigate the efficiency of antiplatelet (aspirin) therapy in vasculogenic erectile dysfunction (VED) patients with a high mean platelet volume.

METHODS

A total of 184 patients diagnosed with VED between the ages of 18 and 76 were randomly divided into two groups and treated for 6 weeks [group 1: 120 patients (mean age 48.3), aspirin 100 mg/day; group 2: 64 patients (mean age 47.7), placebo 100 mg/day]. The changes from baseline to end point in erectile function scores on the International Index of Erectile Function (IIEF-EF) and the number of patients who answered "yes" to questions 2 and 3 of the sexual encounter profile (SEP) were compared statistically.

RESULTS

The mean baseline IIEF-EF scores in groups 1 and 2 were 14.1 ± 4.9 and 14.3 ± 5.2, respectively (p = 0.7966), the number of patients who answered "yes" to SEP-2 was 62 (51.6%) in group 1 and 32 (50%) in group 2 (p = 0.8366), and the number of patients who answered "yes" to SEP-3 was 38 (31.6%) in group 1 and 20 (31.2%) in group 2 (p = 0.9557). In the aspirin group, the changes from baseline to end point in the IIEF-EF, SEP-2, and SEP-3 scores were 7.2, 36.6, and 46.6%, respectively. In the placebo group, these changes were 2.0, 9.4, and 12.5%, respectively. When compared with the placebo group, aspirin-treated subjects showed a significant improvement in all three efficacy measures (p < 0.0001).

CONCLUSIONS

100 mg of aspirin administered once a day significantly improved EF in men with VED.

Mean Platelet Volume is Reduced in Acute Appendicitis

Objectives

Acute appendicitis (AA) is the most common indication for emergency abdominal surgery, although it remains difficult to diagnose. In this study, we investigated the the clinical utility of mean platelet volume in the diagnosis of acute appendicitis.

Methods

The medical records of 241 patients who had undergone appendectomy between June 2013 and March 2014 were investigated retrospectively. Sixty patients who had undergone at least one complete blood count during preoperative hospital admission and who had no other active inflammatory conditions at the time the sample was taken were included in the study. Mean platelet volume and leukocyte count values were determined in each patient at hospital admission and during active acute appendicitis. Age, sex, mean platelet volume and leukocyte counts were recorded for each patient.

Results

The mean age of patients was 33.15±10.94 years and the male to female ratio was 1.5:1. The mean leukocyte count prior to acute appendicitis was 7.42±2.12×10³/mm³. Mean leukocyte count was significantly higher (13.14±2.99×10³/mm³) in acute appendicitis. The optimal leukocyte count cutoff point for the diagnosis of acute appendicitis was 10.10×10³/mm³, with sensitivity of 94% and a specificity of 75%. The mean platelet volume prior to acute appendicitis was 7.58±1.11 fL. Mean platelet volume was significantly lower (7.03±0.8 fL) in acute appendicitis. The optimal mean platelet volume cutoff point for the diagnosis of AA was 6.10 fL, with a sensitivity of 83% and a specificity of 42%. Area under the curve for leukocyte count diagnosis was 0.67 and 0.69 for the diagnosis of AA by mean platelet volume.

Conclusions

Mean platelet volume was significantly decreased in acute appendicitis. Mean platelet volume can be used as a supportive diagnostic parameter in the diagnosis of acute appendicitis.