Insulin resistance is an independent determinate of ED in young adult men

The Influence of Lifestyle on Male Fertility in the Context of Insulin Resistance-Identification of Factors That Influence Semen Quality

Background: Male fertility is known to have been negatively influenced by the progress of civilization. Another condition whose incidence has been on the increase for the same reason is insulin resistance (IR). In addition, men increasingly often resign from the pursuit of active forms of leisure, preferring more sedentary ones. Considering these trends, this aim of this study was to investigate the relationships between lifestyle factors, insulin resistance, and male fertility in men with and without the condition. A further aim was to select those lifestyle factors that would make it possible to predict the level of male fertility, especially when IR is concerned. Methods: This study was performed in a group of 73 participants, divided into groups based on their insulin resistance status. Their physical activity, diet, perceived stress, sleep quality, libido level, and duration of sexual abstinence were assessed on the basis of a number of parameters, including indices proposed by the authors. In addition, relevant anthropometric measurements were taken and tests related to glucose metabolism and semen quality were carried out. On the basis of these data, statistical tests were performed to establish or disprove relationships between lifestyle choices and semen quality, as measured my sperm motility. Results: The results of this study highlighted the associations between a number of parameters, i.e., micronutrient and vitamin intake, diet quality, body composition, insulin resistance, and the duration of sexual abstinence, and semen quality, as measured by sperm motility. Significantly, the presence or absence of IR was linked to male fertility. A multivariate model was developed, incorporating parameters such as the Matsuda index, vitamin intake, and sexual abstinence duration, to predict motility scores. Conclusions: This study underscores the negative impact of modern civilization's lifestyle choices on male fertility. Notably, vitamin and mineral consumption, especially from antioxidant-rich diets like the Mediterranean diet, emerged as key modifiable factors affecting fertility. Routine diagnostics for insulin resistance in fertility-related interventions is recommended. This study also highlights the importance of considering sexual abstinence duration during semen collection for accurate diagnostic results. Future research should focus on validating the proposed multivariate model and exploring the effects of lifestyle modifications, particularly vitamin supplementation, on fertility outcomes in men, especially in the context of IR.

The potential effect of ambrisentan as monotherapy and combined with tadalafil on diabetic erectile dysfunction in rats

INTRODUCTION

This study investigated the role of ambrisentan; the selective endothelin type-A receptor (ETAR) blocker on experimental diabetic erectile dysfunction in rats.

MATERIALS AND METHODS

Eighty-four adult male Sprague Albino rats were divided randomly into 7 groups. Three control groups received 1 mL saline, 0.2 mg/kg/d ambrisentan and 1.5 mg/kg/d tadalafil, respectively orally for 4 weeks. The remaining four groups were fed high fat diet for 14 days. Diabetes was induced by a single intra-peritoneal injection of 40 mg/kg streptozotocin. After 72 h, diabetes was confirmed by plasma glucose level ⩾250 mg/dL. Diabetic rats were divided randomly into four groups, numbered from 4 to 7. The fourth group was the diabetic-control group, while the fifth and sixth groups received ambrisentan and tadalafil respectively. The seventh group received a combination of both drugs. Treatment continued for 4 weeks then, copulatory, intracavernous pressure measurement, and laboratory tests were conducted.

RESULTS

In diabetic rats, ambrisentan and tadalafil improved fasting glucose, insulin, insulin resistance, testosterone, nitric oxide, and rho kinase (ROCK) values compared to diabetic group with the maximum improvement achieved in ambrisentan/tadalafil group (p < 0.05). Ambrisentan also enhanced ICP and improved latency to erection and number of mounts with a tolerable SBP. Yet, ambrisentan/tadalafil combined therapy resulted in deterioration in SBP with consecutive worsening in ICP and mating indices.

CONCLUSION

Ambrisentan showed significant therapeutic potential to prevent and improve diabetic ED in rats comparable to tadalafil.

Can atherogenic indices and the triglyceride-glucose index be used to predict erectile dysfunction?

Background

Atherosclerosis and insulin resistance play an important role in the development of erectile dysfunction (ED), and few studies have comprehensively evaluated more specific indicators like atherogenic indices and the triglyceride-glucose (TyG) index in the assessment of ED.

Aim

This study aimed to reveal the role of atherogenic indices (atherogenic index of plasma [AIP], Castelli risk index-1/2 [CRI-1/2], and atherogenic coefficient [AC]) based on plasma lipid ratios, which have been used as more sensitive indicators of atherosclerosis in recent years, and the TyG index, a practical indicator of insulin resistance, in predicting vasculogenic ED.

Methods

The study included a total of 199 patients who met the inclusion criteria and a total of 51 control subjects without ED complaints according to the International Index of Erectile Function (IIEF-5) scores (>21) between May 2021 and October 2022. For all participants, the demographic and biochemical parameters were evaluated, and atherogenic indices, namely CRI-1 (total cholesterol/high-density lipoprotein [HDL]), CRI-2 (LDL/HDL) AIP [log10(triglycerides/HDL)], and AC (non-HDL/HDL), as well as the TyG index [Ln {fasting triglycerides (mg/dL) × fasting glucose (mg/dL)/2}] were calculated.

Outcomes

The TyG index, which is an indicator of insulin resistance, and atherogenic indices such as CRI-1, AIP, and AC were significantly associated with ED, and especially AIP and the TyG index seem to be more important in the evaluation of ED.

Results

According to the univariate analysis, the patient group had significantly higher CRI-1 (5.3 ± 1.4 vs 4.7 ± 1.3; P = .005), AIP (0.31 ± 0.26 vs 0.13 ± 0.2; P < .001), AC (4.1 ± 1.4 vs 3.70 ± 1.2; P = .026), and TyG (9.16 ± 0.71 vs 8.77 ± 0.52; P < .001) values compared with the control group. In the correlation analysis, a significant negative correlation was found between the AIP and TyG index and the IIEF-5 scores (r2 = 0.120, P < .001 between AIP and IIEF-5; r2 = 0.091, P < .001 between TyG index and IIEF-5). The multivariate analysis revealed AIP and the TyG index as independent predictive factors for ED.

Clinical Implications

The use of atherogenic indices and TyG index in daily urology practice can help physicians in the diagnosis and follow-up of ED.

Strengths and Limitations

The lack of sex hormone-binding globulin and free testosterone levels represents a limitation of our study. Another limitation is that the severity of ED was determined using the IIEF-5 scores, rather than a more objective method, such as penile artery ultrasound.

Conclusion

Atherogenic indices and the TyG index can be used as inexpensive and practical markers to predict the severity of arteriogenic ED.

Chronic liver diseases and erectile dysfunction

Chronic liver diseases (CLDs) are characterized by progressive necrosis of hepatocytes, which leads to liver fibrosis and cirrhosis, and ultimately liver dysfunction. The statistics of 2020 shows that the number of patients with CLDs, including chronic hepatitis, fatty liver, and cirrhosis, may exceed 447 million in China. The liver is a crucial organ for the metabolism of various substances, including sex hormones and lipids. CLDs frequently result in abnormalities in the metabolism of sex hormones, glucose, and lipids, as well as mental and psychological illnesses, all of which are significant risk factors for erectile dysfunction (ED). It has been reported that the prevalence of ED in male patients with CLDs ranges from 24.6 to 85.0%. According to a survey of Caucasians, liver transplantation may improve the erectile function of CLDs patients with ED. This finding supports the link between CLDs and ED. In addition, ED is often a precursor to a variety of chronic diseases. Given this correlation and the significant prevalence of CLDs, it is important to evaluate the epidemiology, risk factors, etiology, and treatment outcomes of ED in male patients with CLDs, expecting to attract widespread attention.

The role of microRNAs in erectile dysfunction: From pathogenesis to therapeutic potential

Erectile dysfunction (ED) is a common male sexual dysfunction disease, and it was predicted that the number of ED patients worldwide will reach 322 million by 2025. However, the pathogenesis of ED is complex and the current treatment options are still limited, so it is urgent to explore new treatment strategies. Recent studies have shown that microRNAs (miRNAs) play an important role in ED, and these single-stranded non-coding small RNA molecules are involved in key pathophysiological processes in the occurrence and development of ED. Therefore, miRNAs have remarkable potential as therapeutic targets in ED. Here, this review introduces the physiological basis of erectile function and the pathophysiological changes in ED and summarizes the current knowledge on the expression, biological functions, and molecular mechanisms of miRNAs in ED, especially the potential of miRNA-targeted therapies to improve ED. This review will provide a comprehensive view of the role of miRNAs in the pathogenesis of ED and the potential value of miRNAs in the treatment of ED.

Differences in the prevalence of erectile dysfunction between novel subgroups of recent-onset diabetes

AIMS/HYPOTHESIS

In men with diabetes, the prevalence of erectile dysfunction increases with advanced age and longer diabetes duration and is substantially higher in men with type 2 diabetes than those with type 1 diabetes. This study aimed to evaluate the prevalence of erectile dysfunction among the five novel subgroups of recent-onset diabetes and determine the strength of associations between diabetes subgroups and erectile dysfunction.

METHODS

A total of 351 men with recent-onset diabetes (<1 year) from the German Diabetes Study baseline cohort and 124 men without diabetes were included in this cross-sectional study. Erectile dysfunction was assessed with the International Index of Erectile Function (IIEF) questionnaire. Poisson regression models were used to estimate associations between diabetes subgroups (each subgroup tested against the four other subgroups as reference) and erectile dysfunction (dependent binary variable), adjusting for variables used to define diabetes subgroups, high-sensitivity C-reactive protein and depression.

RESULTS

The prevalence of erectile dysfunction was markedly higher in men with diabetes than in men without diabetes (23% vs 11%, p = 0.004). Among men with diabetes, the prevalence of erectile dysfunction was highest in men with severe insulin-resistant diabetes (SIRD) (52%), lowest in men with severe autoimmune diabetes (SAID) (7%), and intermediate in men with severe insulin-deficient diabetes (SIDD), mild obesity-related diabetes (MOD) and mild age-related diabetes (MARD) (31%, 18% and 29%, respectively). Men with SIRD had an adjusted RR of 1.93 (95% CI 1.04, 3.58) for prevalent erectile dysfunction (p = 0.038). Similarly, men with SIDD had an adjusted RR of 3.27 (95% CI 1.18, 9.10) (p = 0.023). In contrast, men with SAID and those with MARD had unadjusted RRs of 0.26 (95% CI 0.11, 0.58) (p = 0.001) and 1.52 (95% CI 1.04, 2.22) (p = 0.027), respectively. However, these associations did not remain statistically significant after adjustment.

CONCLUSIONS/INTERPRETATION

The high RRs for erectile dysfunction in men with recent-onset SIRD and SIDD point to both insulin resistance and insulin deficiency as major contributing factors to this complication, suggesting different mechanisms underlying erectile dysfunction in these subgroups.

Triglycerides/Glucose Index is Associated with Sperm Parameters and Sperm DNA Fragmentation in Primary Infertile Men: A Cross-Sectional Study

Study question: we aimed to investigate the relationship between the tyg index and both semen and hormonal characteristics in a cohort of primary infertile men. Summary answer: almost one in two primary infertile men presented with a triglycerides/glucose index (tyg) suggestive of insulin resistance (ir). overall, patients with tyg suggestive of ir showed worse clinical, hormonal, and semen parameters. What is already known: male factor infertility (MFI) is often associated with metabolic disorders such as diabetes mellitus and metabolic syndrome, where insulin resistance (IR) plays a relevant pathological role. Recently, TyG has been suggested as a user-friendly IR marker. Study Design: serum hormones and the sperm DNA fragmentation index (SDF) were measured in every patient. The semen analysis was based on 2010 WHO reference criteria. Glucose and insulin levels were measured for every man after a 12-h overnight fast, and the homeostatic model assessment index (HOMA-IR) was then calculated and categorized using a 2.6 threshold. Similarly, fasting glucose and triglycerides levels were measured and the TyG index was calculated and categorized using an 8.1 threshold. Descriptive statistics and logistic regression models tested the association between the TyG and semen and hormonal characteristics. Participants: complete demographic, clinical, and laboratory data from 726 consecutive white European primary infertile men were considered for this analysis. Main results and the role of chance: the median (IQR) age was 39 (35–43) years. A TyG and HOMA suggestive for IR was found in 339 (46.6%) and 154 (21.2%) men, respectively. During the Spearman’s test, the TyG index was highly correlated with HOMA-IR (rho = 0.46, p < 0.001). Compared to men with a normal TyG, men with TyG > 8.1 were older, had greater BMI and CCI scores, and lower total testosterone and sperm concentration, but higher DFI, and presented a greater proportion of NOA (all p < 0.01). The multivariable logistic regression analysis showed that men with TyG > 8.1 were at higher risk of SDF > 30 (OR 1.92 (CI: 1.2–2.9)) and NOA (OR 1.78 (CI: 1.1–2.8)). Wider implications of the findings: the Tyng index may act as a reliable marker of IR in the clinical work-up of primary infertile men in real-life settings.

Erectile Dysfunction in Individuals with Type 1 Diabetes is Associated with Long-term Metabolic Control and Diabetic Complications: A Cross-Sectional Study

Background  Erectile dysfunction (ED) affects approximately 38% of individuals with type 1 diabetes (T1DM). Skin autofluorescence (AF) reflects skin advanced glycation end product (AGE) deposits and is a marker of long-term glycemia control. Objective  The study investigates the relationship between ED and diabetes control in patients with T1DM. Methods  Adult patients with T1DM visiting the Diabetology Department were cross-sectionally investigated. Medical history, anthropometric features, and laboratory findings were collected. All individuals filled the International Index of Erectile Function (IIEF-5). IIEF-5 total score < 22 represented the presence of ED. AF was measured on the volar aspect of the forearm using AGE Reader. Insulin resistance (IR) was assessed by the estimated glucose disposal rate. Descriptive statistics and multivariate logistic regression analyses were performed. The adjusted covariates were general risk factors of ED. Results  Of a total of n  = 70 patients, n  = 30 (42.9%) suffered from ED. The presence of ED was associated with higher glycated hemoglobin level (OR, 95% CI; 1.62, 1.02-2.60; p  = 0.043), presence of at least one diabetic complication (3.49, 1.10-11.03; p  = 0.03), and skin AF (9.20, 1.60-52.94; p  = 0.01), but not with IR (0.78, 0.57-2.60; p  = 0.12). Skin AF values ≥ 2.2 indicates presence of ED with a sensitivity of 70.0% and a specificity of 77.5%. Area under the curve was equal to 0.72 (95% CI: 0.60-0.85). Conclusions  The presence of ED in individuals with T1DM is associated with HbA1c, the presence of at least one diabetic complication, and skin AF.

Triglyceride-Glucose Index (TyG) is associated with erectile dysfunction: A cross-sectional study

BACKGROUND

Erectile dysfunction (ED) is often associated with endocrine metabolic diseases such as metabolic syndrome (MetS) and diabetes mellitus (DM), in which insulin resistance (IR) plays a decisive role in pathology. Triglyceride-glucose index (TyG), a simple, inexpensive and easily accessible IR marker, is calculated by fasting serum glucose and triglyceride values.

OBJECTIVES

We aimed to reveal the relationship between TyG index and ED.

MATERIALS AND METHODS

Of 152 male patients, aged between 24-80 years, admitted to the urology outpatient clinic with complaining erectile insufficiency were evaluated. Liver function tests, complete blood count, fasting serum triglyceride, serum testosterone, fasting glucose, fasting insulin, and hemoglobinA1c (HbA1c) were analyzed. TyG index was calculated. All patients were requested to fill in the validated Turkish version of the 5-item International Index of Erectile Function (IIEF-5) survey.

RESULTS

A total of 142 patients were included the study. ED was detected in 91 (64.1%) of the patients. BMI, fasting insulin level, fasting glucose level, IR, GGT, HDL, HbA1c, Triglyceride, TyG, DM, HT, and MetS status of the patients in ED group were statistically significantly higher compared to non-ED group (all P < .05). It was found that the cutoff value of TyG index for ED was 8.88 (AUC = 0.739, sensitivity 67%, specificity = 68.6%). In multivariate logistic regression analysis, age (OR = 1.07, 95% CI = 1026-1115, P = .002) and TyG index above 8.88 (OR = 3.865, 95% CI = 1686-8859, P = .001) were found as independent predictors of ED after accounting for BMI, serum total T and IR.

CONCLUSION

TyG index might be useful in the diagnosis and follow-up of ED.

The association of quantitative insulin sensitivity indices (HOMA-IR and QUICKI) with anthropometric and cardiometabolic indicators in adolescents

Introduction

Homoeostasis model assessment (HOMA-IR) and the quantitative insulin sensitivity check index (QUICKI) are used to evaluate insulin resistance. The aim of this study was to investigate the association between quantitative insulin sensitivity indices and anthropometric and cardiometabolic indicators in adolescents.

Material and methods

This descriptive-analytic cross-sectional study was conducted on 80 adolescents aged 12 to 13 years in Isfahan, Iran. Anthropometric, cardiometabolic and QUICKI and HOMA-IR indicators were measured. In the results analysis, Pearson correlation coefficient and regression analysis were used.

Results

There was a significant positive correlation between most of the anthropometric indicators and the HOMA-IR index and a significant negative correlation with QUICKI (all p < 0.0001). Moreover, serum triglyceride level had a significant negative correlation with QUICKI index (R = –0.33, p = 0.002) and systolic blood pressure (R = 0.44, p < 0.0001), and triglyceride level (R = 0.66, p < 0.0001) had a significant positive correlation with HOMA index. The results of these two indices were highly correlated in most of the anthropometric and biochemical indices, except for the waist circumference to the neck circumference ratio and systolic blood pressure, which had a significant positive association with HOMA-IR, but did not show a significant association with QUICKI index.

Conclusions

A significant correlation between anthropometric and cardiometabolic indicators with insulin resistance indices (HOMA-IR and QUICKI) was found. Moreover, the results of these two indices were highly correlated in most of the anthropometric and biochemical indices, except for the waist circumference to the neck circumference ratio and systolic blood pressure.

Free testosterone correlated with erectile dysfunction severity among young men with normal total testosterone

Erectile dysfunction (ED) due to androgen deficiency is rare in the young population. We retrospectively evaluated in this study men aged 18-40 years presenting with ED from 2015 to 2017. The International Index of Erectile Function-5 (IIEF-5) and Erection Hardness Grade Scores (EHGS) were used to assess erectile function. Total testosterone (TT), sex hormone-binding globulin (SHBG), lipid profile, and glycometabolic indicators were tested in fasting blood sample. TT and SHBG were detected by electrochemiluminescence immunoassay, and free (FT) and bio-available testosterone (BT) were calculated from a validated formula. Linear regression was used to analyze the data. In total, 140 cases (30.56 ± 4.81 years) with a mean TT levels of 6.15 ± 2.17 ng/ml were enrolled. Decreased levels of FT were associated with lower IIEF-5 scores(β = 0.176, P = 0.048) and EHGS (β = 0.198, P = 0.026) after adjustment for age, body mass index (BMI), smoking, comorbidities, high-sensitive C-reactive protein (hsCRP), uric acid, fructosamine, and quantitative insulin sensitivity check index (QUICKI). TT was only associated with EHGS in the crude model (β = 0.177, P = 0.037) and some single factor adjustment models, whereas BT and SHBG were not related with erectile function in any model. Low FT level, even in the presence of normal TT, is associated with ED severity in young men. FT levels should be screened in ED patient even with normal total testosterone.

Obesity and Erectile Dysfunction: From Bench to Clinical Implication

Obesity is a major public health issue worldwide and is frequently associated with erectile dysfunction (ED). Both conditions may share an internal pathologic environment, also known as common soil. Their main pathophysiologic processes are oxidative stress, inflammation, and resultant insulin and leptin resistance. Moreover, the severity of ED is correlated with comorbid medical conditions, including obesity. Therefore, amelioration of these comorbidities may increase the efficacy of ED treatment with phosphodiesterase 5 inhibitors, the first-line medication for patients with ED. Although metformin was originally developed as an insulin sensitizer six decades ago, it has also been shown to improve leptin resistance. In addition, metformin has been reported to reduce oxidative stress, inflammatory response, and body weight, as well as improve ED, in animal and human studies. Moreover, administration of a combination of metformin and phosphodiesterase 5 inhibitors improves erectile function in patients with ED who have a poor response to sildenafil and are insulin resistant. Thus, concomitant treatment of metabolic derangements associated with obesity in patients with ED who are obese would improve the efficacy and reduce the refractory response to penile vasodilators. In this review, we discuss the connecting factors between obesity and ED and the possible combined treatment modalities.

Phosphorus as predictive factor for erectile dysfunction in middle aged men: A cross sectional study in Korea

PURPOSE

High serum inorganic phosphorus level is related with atherosclerosis and an elevated risk of cardiovascular disease. At the same time, the association of phosphorus with erectile dysfunction (ED) is not well reported. We studied the effect of serum phosphorus on ED and the relationship with other clinical variables.

MATERIALS AND METHODS

From March to September 2013, 1,899 police men aged 40 to 59 years who entered in a prostate health screening were targeted. All subjects underwent a clinical checking using the International Index of Erectile Function-5 (IIEF-5) questionnaire translated into Korean. Serum prostate-specific antigen (PSA), testosterone, inorganic phosphorus, body mass index, metabolic syndrome (MetS), and prostate ultrasound were also examined.

RESULTS

Serum inorganic phosphorus (r=-0.108, p<0.001) had the highest correlation coefficient with IIEF-5 score other than age, followed by prostate volume (PV) (r=-0.065, P<0.001). Using logistic regression analysis, age, phosphorus, and MetS were predictive factors for moderate to severe ED in univariate analysis. PSA, testosterone, body mass index, and PV could not predict ED. Age, MetS, and phosphorus were independent predictive factors of moderate to severe ED (p<0.001; odds ratio [OR], 1.119; 95% confidence interval [CI] 1.086-1.153; p=0.048; OR, 1.283; 95% CI, 1.003-1.641; and p=0.048; OR, 1.101; 95% CI, 1.076-1.131) in the multivariate analysis.

CONCLUSIONS

In our study, phosphorus level is related with ED. Phosphorus is a significant predictor of ED and a strong factor that can be modified in the middle-age. Controlling phosphorus in men may have a particular meaning of preventing the occurrence of ED.

The Association of Erectile Dysfunction and Cardiovascular Disease: A Systematic Critical Review

Despite strong association between erectile dysfunction (ED) and cardiovascular disease (CVD), there is a paucity of clear clinical guidelines detailing when and how to evaluate for ED in patients with known CVD, or vice versa. This systematic review discuss the role of cardiologists and urologists in the characterization of risk and management of CVD in the setting of ED, as well as contrasting the current evaluation of CVD and ED from the standpoint of published consensus statements. A comprehensive literature review utilizing MEDLINE®, the Cochrane Library® Central Search, and the Web of Science was performed to identify all published peer-reviewed articles in the English language describing ED and CVD across various disciplines. There is strong consensus that men with ED should be considered at high risk of CVD. Available risk assessment tools should be used to stratify the coronary risk score in each patient. The 2012 Princeton III Consensus Conference expanded on existing cardiovascular recommendations, proposing an approach to the evaluation and management of cardiovascular risk in men with ED and no known CVD. This systematic review highlights the similarities and differences of the existing clinical guidelines and recommendations regarding assessment and management of ED and CVD, as well as the pathophysiological linkage between ED and CVD, which may permit physicians, including urologists, to perform opportunistic screening and initiate secondary prophylaxis with regard to cardiovascular risk factors, particularly in young, nondiabetic men with ED.

Protective role of dairy and its constituents on vascular function independent of blood pressure-lowering activities

Greater intakes of dairy are frequently associated with reduced risk of cardiovascular disease. These observational studies have served as the basis for controlled interventions aimed at defining the cardioprotective mechanisms of dairy. Understanding these relationships is of public health importance because most of the US population fails to meet dietary recommendations for dairy, suggesting that many individuals could lower their cardiovascular disease risk by relatively simple dietary modification. Clinical studies investigating the acute ingestion of dairy or its constituents, including short-term (≤2 week) supplementation studies or those assessing postprandial responses, have largely shown benefits on vascular function without concomitant improvements in blood pressure. Chronic interventions have been less conclusive, with some showing benefits and others indicating a lack of improvement in vascular function regardless of blood pressure changes. Vasoprotective activities of dairy are likely mediated through improvements in nitric oxide bioavailability, oxidative stress, inflammation, and insulin resistance. Future controlled studies are needed to determine if these health benefits are mediated directly by dairy or indirectly by displacing other dietary components that otherwise impair vascular health.

Treatment With Metformin Improves Erectile Dysfunction in a Murine Model of Obesity Associated With Insulin Resistance

OBJECTIVE

To evaluate the effects of treatment with metformin on a murine model of obesity-associated erectile dysfunction.

MATERIAL AND METHODS

C57BL/6 male mice were fed for 10 weeks with standard chow or high-fat diet. Lean and obese mice were treated with the insulin sensitizer metformin (300 mg/kg/day, 2 weeks). Intracavernosal pressure (ICP) and in vitro corpus cavernosum (CC) relaxations to both acetylcholine and electrical field stimulation, as well as phenylephrine-induced contractions, were obtained. Levels of cyclic guanosine monophosphate in CC were detected by enzyme immunoassay.

RESULTS

High-fat-fed mice exhibited higher body weight and insulin resistance. Cavernous nerve stimulation caused frequency-dependent ICP increases, which were significantly lower in obese compared with lean mice (P <.05). Two-week therapy with metformin reversed the decreased ICP in obese group. The maximal response to acetylcholine in CC was 35% lower (P <.05) in the obese compared to the lean group, which were restored by metformin treatment. Likewise, the impaired electrical field stimulation-induced CC relaxations in obese mice were also partly restored by metformin. Contractile responses to phenylephrine were significantly greater (P <.05) in obese compared to lean mice, which were fully restored by metformin. Basal and stimulated cyclic guanosine monophosphate productions in the erectile tissues were significantly lower (P <.05) in the obese group, an effect fully restored by metformin.

CONCLUSION

Treatment with metformin restored the erectile function in obese mice, through improvement of in vitro endothelial and nitrergic cavernosal relaxations. Therefore, use of metformin may be a good pharmacologic approach to treat insulin resistance-associated erectile dysfunction.

Association of erectile dysfunction with depression in patients with chronic viral hepatitis

AIM: To investigate the prevalence of erectile dysfunction (ED) and its association with depression in patients with chronic viral hepatitis.

METHODS: This single center cross-sectional study was conducted from August 2013 through January 2014. All outpatients with chronic viral hepatitis in our liver clinic between 18 and 80 years of age were considered eligible for this study. The exclusion criteria included well-established causes of ED, such as diabetes, hypertension, hyperlipidemia, alcohol abuse, liver cirrhosis, ischemic heart disease, renal disease, neurologic disease, and malignancy. We also excluded the patients who had incompletely answered the questionnaires. ED was assessed using the validated Korean version of the International Index of Erectile Function (IIEF-5) scale. The Korean version of the self-administered Beck Depression Inventory (BDI) scale was used to assess depression in the patients. Demographic and medical data were obtained from the patients’ medical records. Current or past history of psychiatric diagnosis and drug history including the use of an antiviral agent and an antidepressant were also recorded.

RESULTS: A total of 727 patients met the initial eligibility criteria. Six hundred seventeen patients were excluded because their medical records contained one or more of the previously determined exclusion criteria. The remaining 110 patients were assessed based on the BDI and IIEF-5 questionnaires. Based on the IIEF-5 scale, the prevalence of ED among patients with chronic viral hepatitis was 40%. Compared with the non-ED group, patients in the ED group were older. The proportion of patients in the ED group who had a job or who were naïve peg-interferon users was lower than that in patients in the non-ED group. Patients with ED had significantly lower scores on the IIEF-5 scale than patients without ED (11.75 ± 4.88 vs 21.33 ± 1.86, P = 0.000). Patients with ED rated significantly higher scores on the BDI scale compared with patients without ED (12.59 ± 7.08 vs 5.30 ± 4.00, P = 0.000). Also, the IIEF-5 scores were negatively correlated with age, employment, and BDI scores. In the multiple logistic regression analysis, age and depression were independently associated with erectile dysfunction (P = 0.019 and 0.000, respectively).

CONCLUSION: Patients with chronic viral hepatitis have a high prevalence of ED. Age and depression are independent factors for ED in male patients with chronic viral hepatitis.

Short hairpin ribonucleic acid constructs targeting insulin-like growth factor binding protein-3 rehabilitated dyslipidaemia in diabetic rats

It was investigated whether short hairpin ribonucleic acid constructs targeting insulin-like growth factor binding protein-3 (IGFBP-3 shRNA) can rehabilitate dyslipidaemia in streptozotocin-induced diabetic rats. After 12 weeks of intracavernous administration of IGFBP-3 shRNA, intracavernous pressure responses to electrical stimulation of cavernous nerves were evaluated. The concentrations of serum low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, triglyceride and cavernous cyclic guanosine monophosphate were all detected by enzyme-linked immunosorbent assay. The per cent of smooth muscle in corpus cavernous tissue was also evaluated. It was found that the cavernosal pressure was significantly increased in the IGFBP-3 shRNA treatment group compared to the diabetic control group after 12 weeks of intracavernous administration of IGFBP-3 shRNA (P < 0.01). The concentrations of serum low-density lipoprotein cholesterol and triglyceride were significantly decreased in the IGFBP-3 shRNA treatment group compared to the diabetic control group, while no significant changes of serum high-density lipoprotein cholesterol concentration were found (P < 0.01). At the same time, cavernous cyclic guanosine monophosphate concentrations and the percentage of cavernosal smooth muscle were both significantly increased in the IGFBP-3 shRNA treatment group compared to the diabetic control group (P < 0.01). This study indicated that IGFBP-3 shRNA might rehabilitate erectile function via a decrease in concentrations of serum low-density lipoprotein and triglyceride, an increase in the percentage of cavernosal smooth muscle and an improvement in the nitric oxide-cyclic guanosine monophosphate signalling activities in streptozotocin-induced diabetic rats.

Testosterone replacement alters the cell size in visceral fat but not in subcutaneous fat in hypogonadal aged male rats as a late-onset hypogonadism animal model

Background

Patients with late-onset hypogonadism (LOH) benefit from testosterone replacement by improvement in the parameters of the metabolic syndrome, but fat cell morphology in these patients is still unclear. This study aims to determine the effect of testosterone replacement on the morphology of fat cells in subcutaneous and visceral adipose tissue and on erectile function in hypogonadal aged male rats as a model of LOH.

Methods

Ten male Sprague-Dawley rats aged 20–22 months were randomly allocated to two groups, ie, aged male controls (control group, n=5) and aged males treated with testosterone replacement therapy (TRT group, n=5). Testosterone enanthate 25 mg was injected subcutaneously every 2 weeks for 6 weeks. At 6 weeks, the intracavernous pressure (ICP) and mean arterial blood pressure (MAP) ratio was assessed. Visceral and subcutaneous adipose tissue specimens were collected and analyzed using Image-J software.

Results

Body weight at 2, 4, and 6 weeks after TRT was 800.0±35.4 g, 767.5±46.3 g, and 780±40.4 g, respectively (not statistically significant). The ICP/MAP ratio was 0.341±0.015 in the TRT group and 0.274±0.049 in the control group (not statistically significant). The median subcutaneous fat cell size was 4.85×10³ (range 0.85–12.53×10³) μm² in the control group and 4.93×10³ (range 6.42–19.7×10³) μm² in the TRT group (not statistically significant). In contrast, median visceral fat cell size was significantly smaller in the TRT group (4.93×10³ μm² [range 0.51–14.88×10³]) than in the control group (6.08×10³ μm² [0.77–19.97×10³]; P<0.001, Mann-Whitney U test).

Conclusion

This is the first study clearly indicating that TRT can decrease visceral fat cell size, which is a key modulator in the metabolic syndrome. However, a short course of TRT could not improve the ICP response in hypogonadal aged male rats. Further investigation is necessary to clarify the exact rationale of TRT on the visceral fat cell.

Erectile dysfunction as a marker for cardiovascular disease diagnosis and intervention: a cost analysis

INTRODUCTION

Erectile dysfunction (ED) is a risk factor for cardiovascular disease (CVD). We examine the costs of screening men with ED for CVD risk factors and the cost savings of treating these at risk men.

AIM

This study aims to evaluate the effect of screening men presenting with ED for CVD risk factors and to determine the cost effectiveness of this screening protocol.

METHODS

The known incidence and prevalence of ED and CVD, the rate of undiagnosed CVD, and the effects of CVD treatment were used to model the change in prevalence of acute CVD events and ED as a function of the number of men with ED and CVD. The cost savings associated with reduction in acute cardiovascular (CV) events and ED prevalence was estimated over 20 years.

MAIN OUTCOME MEASURES

Acute CVD event rate reduction and associated cost savings were modeled over 20 years.

RESULTS

The relative risk of ED in men with CVD is 1.47 and the coprevalence of both ED and CVD was estimated at 1,991,520 men. Approximately 44% of men with CVD risk factors are unaware of their risk. If all men presenting with ED were screened for CVD, 5.8 million men with previously unknown CVD risk factors would be identified over 20 years, costing $2.7 billion to screen. Assuming a 20% decrease in CV events as a result of screening and treatment, 1.1 million cardiovascular events would be avoided, saving $21.3 billion over 20 years. Similarly, 1.1 million cases of ED would be treated, saving $9.7 billion. Together, the reduction in acute CVD and ED treatment cost would save $28.5 billion over 20 years.

CONCLUSIONS

Screening for CVD in men presenting with ED can be a cost-effective intervention for secondary prevention of both CVD and, over the longer term, ED.