Vascular risk factors and erectile dysfunction in a cohort of healthy men

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.

Erectile dysfunction and diabetes: A melting pot of circumstances and treatments

Diabetes mellitus (DM), a chronic metabolic disease characterised by elevated levels of blood glucose, is among the most common chronic diseases. The incidence and prevalence of DM have been increasing over the years. The complications of DM represent a serious health problem. The long-term complications include macroangiopathy, microangiopathy and neuropathy as well as sexual dysfunction (SD) in both men and women. Erectile dysfunction (ED) has been considered the most important SD in men with DM. The prevalence of ED is approximately 3.5-fold higher in men with DM than in those without DM. Common risk factors for the development of DM and its complications include sedentary lifestyle, overweight/obesity and increased caloric consumption. Although lifestyle changes may help improve sexual function, specific treatments are often needed. This study aims to review the definition and prevalence of ED in DM, the impact of DM complications and DM treatment on ED and, finally, the current and emerging therapies for ED in patients with DM.

Relationship between the risk factors of cardiovascular disease by testing biochemical markers and young men with erectile dysfunction: a case-control study

Background

Erectile dysfunction (ED) shares common risk factors with cardiovascular disease (CVD), such as diabetes mellitus (DM) and dyslipidemia, but the relationship between the risk factors of CVD in biochemical markers and young men with ED age 20–40 years is not fully clarified.

Methods

A total of 289 ED outpatients (20–40 years old) were allocated under ED group, based on patients’ complaints and physical examinations. According to the frequency matching ratio of 1:4, 1,155 male individuals (20–40 years old) without ED were set as control group. All participants were tested for lipid profiles including total cholesterol (TC), triglyceride (TG), high density lipoprotein (HDL), low density lipoprotein (LDL), blood glucose (BG), homocysteine (HCY), liver function including alanine aminotransferase (ALT) and aspartate aminotransferase (AST), and renal function including uric acid (UA) and creatinine (CR). The study was designed to compare the two groups using an established binary logistic regression analysis model. The ED group was then subdivided into a younger ED group (20–30 years old) and an older ED group (31–40 years old) for further comparisons.

Results

After comparison, no obvious differences were found in medians of age, TC, TG, HDL, HCY, UA, and ALT in the two groups. Median LDL, BG, and CR were significantly higher and AST was much lower in the ED group (P<0.01). In binary logistic regression analysis, odds ratios (OR) for LDL, BG, CR, and AST were 1.279, 1.237, 1.026, and 0.978, respectively. The sensitivity value and specificity value were 43.25% and 72.56%, respectively. The medians of LDL, TG, and TC were higher and HDL was much lower in the older ED group, as compared with the younger group (P<0.05). No significant differences were displayed in medians of other biochemical markers in the above comparisons.

Conclusions

Elevated LDL, BG, and CR were related factors of ED in young men. Lipid profile was significantly different between young men with ED aged 20–30 and 31–40 years.

Impact of metabolic syndrome and its components on kidney stone in aging Taiwanese males

OBJECTIVES

Metabolic syndrome (MtS) and kidney stone are two common aging diseases with male dominant. This is the first study regarding the potential impact of MtS and its components on kidney stone in aging Chinese population.

METHODS

A total of 694 males with a mean age of 55.6 years were enrolled. The definition of MtS was according to the modified criteria developed by the Bureau of Health Promotion in Taiwan. Subjects were classified as having a disease of kidney stones according to diagnosis by a physician with available medical records or evidence from ultrasonography judged by an investigator of urologist.

RESULTS

Using age-adjusted multivariate logistic regression analysis, our results showed that subjects with kidney stone had significantly higher prevalence of MtS (p = 0.04, OR = 1.74, 95% CI: 1.0 1-3.00). The presence of MtS had significant correlation with kidney stone (p = 0.01, OR = 1.83, 95% CI: 1.1 4-2.93), which were associated with the increment of MtS components (p < 0.01). After adjusting for age and testosterone level, abnormal blood pressure (BP) was the most significantly independent component of MtS for kidney stone among the MtS components (p < 0.01, OR = 2.81, 95% CI: 1.46-5.39).

CONCLUSIONS

In aging Taiwanese males, the presence of MtS and its components are strongly associated with kidney stone. Abnormal BP is the most significant risk component of MtS for kidney stone.

The Associations of Novel Vitamin D3 Metabolic Gene CYP27A1 Polymorphism, Adiponectin/Leptin Ratio, and Metabolic Syndrome in Middle-Aged Taiwanese Males

Metabolic syndrome (MetS) confers increased risks of cardiovascular disease (CVD). Both vitamin D3 and adipocytokines (especially adiponectin and leptin) have a great impact on CVD and MetS. In vitamin D3 metabolism, the vitamin D3 25-hydroxylase (CYP27A1) and 25-hydroxyvitamin D3 1-alpha-hydroxylase (CYP27B1) are two key enzymes. This study aimed to examine the influence of vitamin D3 CYP27 single nucleotide polymorphisms (SNPs) on adipocytokines and MetS. Cross-sectional data and DNA samples were collected from male volunteers (n = 649, age: 55.7 ± 4.7 years). Two tagging SNPs, CYP27A1 rs4674344 and CYP27B1 rs10877012, were selected from the HapMap project. MetS was significantly associated with the CYP27A1 rs4674344 SNP (P = 0.04) and the ratio of adiponectin/leptin (A/L ratio) was most correlated to the CYP27A1 rs4674344 SNP, appearing to be significantly lower in T-carriers than in AA subjects (3.7 ± 4.0 versus 5.1 ± 6.0, P = 0.001) and significantly negatively associated after adjustment. For each MetS component associated with the CYP27A1 rs4674344 SNP, the A/L ratios were significantly negative in preclinical stage (condition not meeting the individual criteria), except the blood pressure. In conclusion, CYP27A1 rs4674344 SNP, A/L ratio, and MetS are significantly associated and T-carriers might have a higher risk of developing MetS due to low A/L ratios in the preclinical stage.

The impact of metabolic syndrome on the responsiveness to α1-blocker in men with BPH/LUTS

AIMS

Increasing evidence has proposed the components of metabolic syndrome (MtS) as risk factors for the development of benign prostate hyperplasia (BPH); therefore, it is thought that MtS may play a role in lower urinary tract symptoms related to BPH (BPH/LUTS) aetiology. Considering the closed relationships between MtS and BPH/LUTS, it is possible that patients with MtS might have different drug responsiveness in men with BPH/LUTS. We prospectively investigated the impact of MtS on responsiveness to α1-blocker in men with BPH/LUTS.

METHODS

We enrolled a total of 109 patients with a mean (SD) age of 59.8 (9.0) years, having a prostate volume of 20 cm(3) or greater with moderate to severe LUTS. All patients received doxazosin GITS (gastrointestinal therapeutic system) 4 mg once daily for a 12-week period of treatment. The efficacy measurement was assessed by the changes from baseline in the total IPSS, maximum urinary flow rate and postvoid residual urine volume. The drug responders were defined as those who had a total IPSS decrease of more than 4 points from baseline after 12 weeks of treatment.

RESULTS

Using multiple logistic regression analysis, our results showed that MtS was an independent factor for drug non-responder (OR = 4.26, p = 0.002). The rate of drug responder and total IPSS improvements in patients with MtS significantly decreased as the number of MtS components increased (p = 0.012 and p = 0.026). Among the MtS components, abnormal fasting blood glucose (FBG) was the most significantly independent factor for drug non-responder (OR = 3.17, p = 0.020).

CONCLUSION

This study suggested that the presence of MtS had a significantly negative impact on the responsiveness to α1-blocker in men with BPH/LUTS. Our results are important for BPH/LUTS patients who did not initially respond to α1-blocker or who strive to reduce these metabolic risk factors.

The impact of estradiol and 1,25(OH)2D3 on metabolic syndrome in middle-aged Taiwanese males

In addition to adipocytokines, estradiol (E2) and vitamin D have been reported to affect insulin sensitivity, glucose homeostasis and body weight. However, studies about the impact of E2 and vitamin D on metabolic syndrome (MetS) are still limited. The aim of this study is to clarify the roles of circulating E2 and vitamin D on the risk of MetS in middle-aged Taiwanese males. A total of 655 male volunteers, including 243 subjects with MetS (mean age: 56.7±5.8 years) and 412 normal controls (mean age: 55.1±3.6 years), were evaluated. Subjects with MetS had significantly lower circulating E2, 1,25(OH)₂D₃, and adiponectin, and higher leptin than those without MetS (P<0.001 for all comparisons). E2 and 1,25(OH)₂D₃ were significantly associated with 4 individual components of MetS; more than adiponectin and leptin that were only associated with 3 individual components. In multivariate regression analysis, E2 (beta = −0.216, P<0.001) and 1,25(OH)₂D₃ (beta = 0.067, P = 0.045) were still significant predictors of MetS independent of adiponectin and leptin. Further large studies are needed to confirm our preliminary results and elucidate the possible mechanism.

The effects of the combined use of a PDE5 inhibitor and medications for hypertension, lower urinary tract symptoms and dyslipidemia on corporal tissue tone

ED is closely associated with its comorbidities (hypertension, dyslipidemia and lower urinary tract symptoms (LUTS)). Therefore, several drugs have been prescribed simultaneously with PDE5 inhibitors. If a specific medication for ED comorbidities has enhancing effects on PDE5 inhibitors, it offers alternative combination therapy in nonresponders to monotherapy with PDE5 inhibitors and allows clinicians to treat ED and its comorbidities simultaneously. To establish theoretical basis of choosing an appropriate medication for ED and concomitant disease, we examined the effects combining a PDE5 inhibitor with representative drugs for hypertension, dyslipidemia and LUTS on relaxing the corpus cavernosum of rabbits using the organ-bath technique. The effect of mirodenafil on relaxing phenylephrine-induced cavernosal contractions was significantly enhanced by the presence of 10(-4) M losartan, 10(-6) M nifedipine, 10(-6) M amlodipine, 10(-7) M doxazosin and 10(-9) M tamsulosin (P<0.05). The maximum relaxation effects were 47.2±3.8%, 57.6±2.6%, 64.0±3.7%, 76.1±5.7% and 71.7±5.4%, respectively. Enalapril and simvastatin had no enhancing effects. The relaxation induced by sodium nitroprusside alone (39.0±4.0%) was significantly enhanced in the presence of the 10(-4) M losartan (66.0±6.0%, P<0.05). Tetraethylammonium (1 mM) significantly inhibited the enhancement effects of tamsulosin and doxazosin on mirodenafil-induced relaxation (doxazosin: 76.1±5.7% vs 45.3±2.3%; tamsulosin: 71.7±5.4% vs 48.1±3.5%). On the basis of these findings, losartan seemed to induce synergistic effects through an interaction with nitric oxide. In addition, K(+) channel activation could be one of the mechanisms for the synergistic effect of combining mirodenafil with doxazosin or tamsulosin. We believe that the combination of a PDE5 inhibitor with losartan, nifedipine, amlodipine, doxazosin or tamsulosin could be a pharmacologic strategy for simultaneously treating ED and its comorbidities and increasing response rates to PDE5 inhibitors.

The impact of irritative lower urinary tract symptoms on erectile dysfunction in aging Taiwanese males

OBJECTIVE

This study assessed the possible associations between lower urinary tract symptoms (LUTS) and erectile dysfunction (ED) in aging Taiwanese males and investigated the impact of various aspects of LUTS on ED.

METHODS

A free health screening for aging males (> or =40 years old) was conducted in Kaohsiung Medical University Hospital. All the subjects had completed clinical data and answered questionnaires. ED and LUTS were assessed by validated symptom scales: the International Index of Erectile Function-5 (IIEF-5) and the International Prostate Symptom Score (IPSS).

RESULTS

A total of 339 eligible patients enrolled in this study with a mean age of 60.1 years old. In multiple logistic regression analysis, age and IPSS (p < 0.001 and p = 0.013, respectively) were significantly associated with ED after controlling other comorbidities. In a further age-adjusted multiple regression analysis, our results showed that irritative symptoms (p = 0.042) have a more significant association with ED than the obstructive symptoms (p = 0.101).

CONCLUSIONS

Our results indicate that age and LUTS are the two most independent risk factors for ED. Aging Taiwanese males with LUTS are at increasing risk for ED, especially for those with significant irritative symptoms.

Vardenafil improves erectile function in men with erectile dysfunction and associated underlying conditions, irrespective of the use of concomitant medications

INTRODUCTION

Men with erectile dysfunction (ED) are also likely to have associated underlying conditions.

AIM

This retrospective analysis evaluated the efficacy and safety of vardenafil in men with ED and underlying conditions, including those taking concomitant medications.

METHODS

A total of 13 randomized, double-blind, placebo-controlled clinical studies were included. Vardenafil was administered at a starting dose of 10 mg, adjustable to 5 or 20 mg after 4 weeks. Efficacy analyses were performed on the intent-to-treat (ITT) population, using a last observation carried forward approach. Efficacy was assessed for subgroups of patients with diabetes, hypertension, dyslipidemia, or metabolic syndrome (as defined by International Diabetes Federation criteria). Incidence rates of treatment-emergent adverse events were analyzed overall and by subgroup for patients in the safety population.

MAIN OUTCOME MEASURES

Primary efficacy measures were the erectile function domain of the International Index of Erectile Function (IIEF-EF), and Sexual Encounter Profile questions 2 and 3 (SEP2, SEP3).

RESULTS

In total, 4,326 patients were randomized to treatment; the ITT population included 4,143 patients, with 4,266 patients valid for safety. At 12 weeks, vardenafil therapy was associated with statistically significant improvements from baseline in IIEF-EF scores, and SEP2 and SEP3 success rates, including patients with ED and diabetes, hypertension, dyslipidemia, or metabolic syndrome. These improvements were irrespective of level of glycemic control, or use of concomitant medications for the treatment of diabetes, hypertension, or dyslipidemia. Across all subgroups, the number and type of treatment-emergent adverse events were consistent with results from previous studies of phosphodiesterase type 5 inhibitors in men with ED and underlying conditions.

CONCLUSIONS

Vardenafil demonstrated favorable efficacy and tolerability in this large pool of patients with ED and underlying conditions. Importantly, the use of concomitant medications was not associated with any noteworthy changes in the efficacy or safety profile of vardenafil.

The associations among eNOS G894T gene polymorphism, erectile dysfunction, and benign prostate hyperplasia-related lower urinary tract symptoms

INTRODUCTION

A number of literature has now identified the role of impaired nitric oxide synthase/nitric oxide pathway in the endothelium as the central to the development of erectile dysfunction (ED) and benign prostate hyperplasia-related lower urinary tract symptoms (BPH/LUTS). Recently a few studies have reported the associations between endothelial nitric oxide synthase (eNOS) G894T gene polymorphisms and ED. However, there has been no report investigating the eNOS G894T genetic susceptibility factor for both ED and BPH/LUTS.

AIM

To investigate the possible associations among eNOS G894T polymorphism, ED, and BPH/LUTS in a Taiwanese population.

MAIN OUTCOME MEASURES

Patients with ED were defined as those having a 5-item International Index of Erectile Function-5 <21.

METHODS

In all, 372 Taiwanese men underwent a free health screening were enrolled. All the men had complete clinical data and questionnaires taken. The eNOS G894T polymorphisms were determined using the polymerase chain reaction-restriction fragment length polymorphism method.

RESULTS

Three hundred seventy-two men had a mean (standard deviation) age of 60.2 (8.8) years. With multivariate analysis, our data identified that aging, diabetes mellitus (DM), and eNOS G894T gene polymorphism were three independent common risk factors for both ED and BPH/LUTS (P < 0.001, P = 0.036, and P = 0.039 for ED; P = 0.034, P = 0.004, and P = 0.016 for BPH/LUTS, respectively). The eNOS 894T allele carriers had significantly higher prevalence of ED (77.9% vs. 60.4%, P = 0.012) and higher International Prostate Symptom score (IPSS) (13.3 +/- 10.7 vs. 9.3 +/- 7.8, P = 0.001) than G allele carriers.

CONCLUSIONS

Our results showed that aging, DM, and eNOS 894T allele carrier gene polymorphism were the three independently common risk factors for both ED and BPH/LUTS in the Taiwanese population. The eNOS 894T allele carriers had significantly higher frequencies of ED and higher IPSS, suggesting that eNOS G894T gene polymorphisms may play an implication as a genetic susceptibility factor for both ED and BPH/LUTS.

Erectile dysfunction and cardiovascular disease: efficacy and safety of phosphodiesterase type 5 inhibitors in men with both conditions

Risk factors for cardiovascular disease and erectile dysfunction (ED) are similar, as might be expected given their shared etiologic and pathophysiologic origins. It is now generally accepted that most cases of ED result from a vascular disturbance of the endothelium. Recent epidemiological studies have documented a strong association between ED and comorbid conditions such as hypertension, diabetes mellitus, and dyslipidemia. Phosphodiesterase type 5 (PDE5) inhibitors are recommended as first-line therapy for erection problems of all etiologies and severities. The efficacy and safety of PDE5 inhibitors in the general ED population is well documented and has been extensively reviewed. To examine the association between ED and vascular disorders in the context of current knowledge regarding PDE5 inhibitors, an electronic search was performed of articles published from January 2002 through April 2008 using the PubMed, EMBASE, and MEDLINE databases. Although preference was given to randomized, blinded, controlled clinical trials, data from retrospective studies were also reviewed when appropriate. This analysis revealed that the clinical evidence linking ED to future cardiovascular events is compelling, presenting physicians with a unique interventional opportunity to address underlying cardiovascular health concerns in men presenting with ED. In most studies, PDE5 inhibitors were shown to effectively and safely improve erectile function regardless of cause, severity, or presence of comorbid conditions, including hypertension, diabetes mellitus, and dyslipidemia.

Erectile dysfunction and cardiovascular disease: efficacy and safety of phosphodiesterase type 5 inhibitors in men with both conditions

Risk factors for cardiovascular disease and erectile dysfunction (ED) are similar, as might be expected given their shared etiologic and pathophysiologic origins. It is now generally accepted that most cases of ED result from a vascular disturbance of the endothelium. Recent epidemiological studies have documented a strong association between ED and comorbid conditions such as hypertension, diabetes mellitus, and dyslipidemia. Phosphodiesterase type 5 (PDE5) inhibitors are recommended as first-line therapy for erection problems of all etiologies and severities. The efficacy and safety of PDE5 inhibitors in the general ED population is well documented and has been extensively reviewed. To examine the association between ED and vascular disorders in the context of current knowledge regarding PDE5 inhibitors, an electronic search was performed of articles published from January 2002 through April 2008 using the PubMed, EMBASE, and MEDLINE databases. Although preference was given to randomized, blinded, controlled clinical trials, data from retrospective studies were also reviewed when appropriate. This analysis revealed that the clinical evidence linking ED to future cardiovascular events is compelling, presenting physicians with a unique interventional opportunity to address underlying cardiovascular health concerns in men presenting with ED. In most studies, PDE5 inhibitors were shown to effectively and safely improve erectile function regardless of cause, severity, or presence of comorbid conditions, including hypertension, diabetes mellitus, and dyslipidemia.

Recovery of erectile function in aging hypertensive and normotensive rats using exercise and caloric restriction

INTRODUCTION

Using aging spontaneously hypertensive rats (SHR), we established that antihypertensive drugs can improve erections and penile vascular structure, and lower arterial pressure. Using kidney cross-transplantations, our findings revealed that the benefit of this treatment resulted from drug-induced changes specific to the penile circulation, and not to the kidney-mediated lowering of pressure.

AIM

The objective of the present study was to determine whether increased exercise and/or caloric restriction (CR) can reverse the decline in sexual responses in aging hypertensive and normotensive rats.

METHODS

From 30 to 40 weeks, food intake was restricted (10-40%), and SHR, Wistar, and Sprague-Dawley rats ran on treadmills (30 minutes/day, 5 days/week). Exercise was withdrawn at 40 weeks, and CR was stopped at 50 weeks. Using a separate group of older Wistars (56 weeks) and Sprague-Dawley rats (67 weeks), the effects of 10% CR or exercise plus 10-40% CR on erectile function were determined.

MAIN OUTCOME MEASURE

Apomorphine-induced erectile responses and body weight were monitored weekly.

RESULTS

An age-related decline in erections was seen from 15 to 29 weeks of age in all strains. This decline paralleled increases in body weight, particularly in the normotensive strains. Exercise and CR induced a 10% weight loss in normotensive rats and improved erections in all animals. In SHR, increased erections occurred without decreasing body weight. Body weight and erectile responses were maintained by CR alone after exercise was withdrawn, but erectile function rapidly declined soon after CR was stopped and paralleled increases in body weight. In aged Wistar and Sprague-Dawley rats treated with exercise and CR, erectile function was also significantly improved.

CONCLUSIONS

Similar to previous studies, erectile function progressively decreased with age in both hypertensive and normotensive rats. Erectile responses were found to be substantially improved by an intervention involving exercise and CR, but not necessarily involving weight loss.

The associations among eNOS G894T gene polymorphism, erectile dysfunction and related risk factors

OBJECTIVE

To investigate the possible correlations among eNOS G894T polymorphism, erectile dysfunction (ED) and related risk factors in a Taiwanese population.

MATERIALS AND METHODS

In all, 151 patients with ED and 77 healthy controls were enrolled. All the men had a complete clinical history taken and laboratory data was collected. To assess erectile conditions the five-item version of the International Index of Erectile Function (IIEF-5) was used. The eNOS G894T polymorphisms were determined using the polymerase chain reaction-restriction fragment length polymorphism method.

RESULTS

In all, 228 men were enrolled with a mean (sd) age of 58.6 (9.7) years. In a univariate analysis, age, serum testosterone level, and the prevalence of diabetes mellitus (DM) and hypertension were significantly different between patients with ED and the healthy controls (P < 0.01). In the multiple logistic regression analysis, DM, age and hypogonadism were three independent risk factors for ED (P = 0.018, P = 0.046 and P = 0.016, respectively). The prevalence of ED in T allele carriers (GT/TT) was significantly greater than in G allele carriers (GG; 80.0% vs 63.3%, P = 0.04). Also the eNOS 894T allele carriers had significantly lower IIEF-5 scores than the eNOS 894G allele carriers, at 13.2 (5.3) vs 15.7 (6.1) (P = 0.01) and it was associated with increment of T allele number (11.0 (5.6) vs 13.6 (5.2) vs 15.7 (6.1); P = 0.03).

CONCLUSION

Our results indicate that DM, age and hypoganadism are three significant independent risk factors for ED. Also, in the Taiwanese population, the eNOS 894T allele carriers are at greater risk of ED, both in prevalence and severity, and this might be a factor of genetic susceptibility.