Testosterone/estradiol ratio, is it useful in the diagnosis of erectile dysfunction and low sexual desire?

Mechanisms of erectile dysfunction induced by aging: A comprehensive review

BACKGROUND

With the increasing trend ofpopulation aging, erectile dysfunction (ED) among elderly men has emerged as apressing health concern. Despite extensive research on the relationship betweenED and aging, ongoing discoveries and evidence continue to arise.

OBJECTIVE

Through this comprehensiveanalysis, we aim to provide a more nuanced theoretical framework for thedevelopment of preventive and therapeutic strategies for senile ED, ultimatelyenhancing the quality of life for elderly men.

METHODS

This review delves deeper into thecore mechanisms underlying ED in the context of aging and offers acomprehensive overview of published meta-analyses and systematic reviewspertinent to these conditions.

RESULTS AND CONCLUSION

Our findings revealthat local structural damage to the penis, vascular dysfunction, neuronalinjury, hormonal alterations, other physiological changes, and psychologicalbarriers all play pivotal roles in the pathogenesis of aging-related ED.Furthermore, more than 20 diseases closely associated with aging have beenimplicated in the occurrence of ED, further compounding the complexity of thisissue.

A Review on Testosterone: Estradiol Ratio-Does It Matter, How Do You Measure It, and Can You Optimize It?

There is a natural balance between the major sex steroids, testosterone and estradiol, controlled by gonadal secretion and peripheral conversion by aromatase. This balance is impacted by a variety of inborn and acquired conditions, and, more recently, by a growing use of exogenous testosterone therapy and off-label aromatase use under the guise of "men's health." We summarize reported testosterone:estradiol ratios, both naturally occurring and with pharmacologic manipulation and consider the ramifications of significant changes in these ratios. However, significant limitations exist in terms of steroid separation and measurement techniques, timing of samples, and lack of consistency from one assay to another, as well as definition of normative data. Limited data on the testosterone:estradiol ratio in men exists, particularly due to the scan data on concurrent estradiol values in men receiving testosterone therapy or aromatase inhibitors. Nonetheless, there seems to be a range of apparently beneficial values of the testosterone: estradiol radio at between 10 and 30, calculated as: testosterone in ng/dL/estradiol in pg/mL. Higher values appear to be associated with improved spermatogenesis and reduced bone density while lower values are associated with thyroid dysfunction. While there is growing awareness of the significance of the testosterone:estradiol ratio, and a sense of a desired range, the optimal value has not yet been determined. Further work is needed to clarify the measurement strategies and clearly-defined outcome measures related to the testosterone:estradiol ratio.

The indicative effects of apolipoproteins on organic erectile dysfunction: bridging Mendelian randomization and case-control study

The existing research on the association between apolipoproteins (Apos) and erectile dysfunction (ED) primarily relies on observational studies and does not distinguish between organic and psychogenic causes when diagnosing ED. It is difficult to believe that Apos play a role in psychogenic ED. To address these issues, our study explored the causal relationship between lipoproteins and ED using Mendelian randomization (MR) analysis and differentiate between organic and psychogenic ED through the use of nocturnal penile tumescence and rigidity (NPTR) monitoring. Multivariate MR analysis revealed significant causal associations between high-density lipoprotein (HDL), Apo A1, and Apo B/A1 with ED (OR and 95% CI were 0.33 (0.14-0.78), 3.58 (1.52-8.43), and 0.30 (0.13-0.66)). we conducted statistical and analytical analyses on the data of 212 patients using multivariate analyses and receiver operating characteristic (ROC) curves. Patients with organic ED had significantly lower levels of HDL, Apo A1 and Apo A1/B, whereas patients with organic ED had considerably higher levels of Apo B and low-density lipoprotein (LDL). The diagnostic value of Apos in predicting the risk of organic ED was evaluated using ROC curves. The results indicated that Apo A1 and Apo A1/B demonstrated good predictive value. HDL, Apo A1, and Apo A1/B have been identified as risk factors for ED in our study. Furthermore, our research highlights the significance of Apo A1 and Apo A1/Apo B in the development of organic ED and suggests their potential use as indicators to assess the risks associated with organic ED.

Prevalence and predictors of unrecognised low sexual desire/interest in men with new onset erectile dysfunction: findings from a cross-sectional, real-life study

The interrelationship between male sexual desire and erectile dysfunction (ED) has been scantly investigated. Thus, we aimed at investigating the prevalence of and the predictors of unrecognised low sexual desire/interest (uLSD/I) in a cohort of men with new onset ED. Complete data from 1587 men seeking for first medical help for ED between 2010 and 2021 were analysed. Comorbidities were scored with the Charlson Comorbidity Index (CCI). At entrance, all patients were asked to self-report low sexual desire/interest and completed the International Index of Erectile Function (IIEF) and the Beck Depression Inventory (BDI) (depressive symptoms scored as BDI ≥ 11). The IIEF-erectile function (IIEF-EF) domain was categorised according to Cappelleri's criteria. The median value of the IIEF-sexual desire domain (IIEF-SD) was used to dichotomise men with uLSD/I along with ED (IIEF-SD < 7) vs. ED-only (IIEF-SD ≥ 7). Circulating hormones were measured in every patient. Hypogonadism was defined as total testosterone (tT) <3.0 ng/mL. Descriptive statistics and logistic regression models tested the association between clinical variables and uLSD/I. Of 1197 patients not self-reporting LSD/I, 369 (30.8%) had IIEF-SD < 7. Patients with ED + uLSD/I were older [median (IQR) 54(41-63) vs. 49(36-59) years], had lower IIEF-EF [10.5(5-22) vs. 22(11-28)] but higher BDI [6(3-12) vs. 4(1-8)] and lower tT [4.3(3.2-5.7) vs. 4.8(3.2-6.3) ng/mL] compared to ED-only men (all p < 0.05). Overall, ED + uLSD/I men had higher rate of severe ED (49.9% vs. 23.9%), and of BDI ≥ 11 (30.6% vs. 18.2%) (all p < 0.05). At multivariable logistic regression analysis, lower tT (OR: 0.82), lower IIEF-EF scores (OR:0.95) and BDI ≥ 11 (OR:2.51) were independently associated with ED + uLSD/I, after accounting for age (all p < 0.05). Almost 30% of men seeking first medical help for ED-only had also uLSD/I. Men with both conditions were older, had higher rates of severe ED and more depressive symptoms. A detailed investigation of sexual desire should be always included in men self-complaining only of ED.

Role of testosterone to estradiol ratio in predicting the efficacy of recombinant human chorionic gonadotropin and testosterone treatment in male hypogonadism

OBJECTIVE

We aimed to investigate the role of testosterone to estradiol ratio in predicting the effectiveness of human chorionic gonadotropin and testosterone treatments in male hypogonadism.

METHODS

Thirty-six male patients with hypogonadotropic hypogonadism were included in the study. Seventeen (47.2%) patients received weekly recombinant human choriogonadotropin alpha (hCG) treatment (group-1) and 19 (52.8%) received testosterone replacement therapy (T treatment) every 21 days (group-2). Under these treatments, adequate frequency of morning erection (≥3/week), testosterone to estradiol ratio (T/E), and testicular volume changes were analyzed.

RESULTS

The mean age of the patients was 28.5 ± 8.7 years. When the frequency of morning erection (≥3/week) was specified as adequate, the cut-off value for effective T/E ratio was found to be 12.0 (sensitivity 93.8%, specificity 90.0%). There was no significant difference between the treatment groups in terms of total testosterone levels, T/E ratio, or frequency of morning erections (≥3/week) (p > 0.05). However, there was a statistically significant difference between the groups in terms of median left-right testicular volume in favor of group-1 (p < 0,05).

CONCLUSION

In patients with hypogonadism who are under treatment, elevated estradiol-induced erectile dysfunction symptoms may persist even if serum testosterone levels are normal. Testosterone to estradiol ratio can be used as a predictive value in the effective treatment of hypogonadotropic hypogonadism with hCG and T.

Estradiol is an independent risk factor for organic erectile dysfunction in eugonadal young men

Erectile dysfunction attributable to testosterone deficiency is less common in young males, and the effect of estradiol on erectile function in eugonadal young males is unclear. We analyzed data from 195 male participants, including 143 eugonadal patients with erectile dysfunction and 52 healthy men. To distinguish psychogenic and organic erectile dysfunction, penile rigidity was measured using the nocturnal penile tumescence rigidity test. Serum levels of sexual hormones were quantified by electrochemiluminescence, and penile vascular status was assessed by penile color Doppler ultrasound. Both serum estradiol levels and the ratio of estradiol to testosterone were higher in patients with organic erectile dysfunction than in patients with psychogenic erectile dysfunction or healthy controls. Organic erectile dysfunction was negatively associated with estradiol levels and the ratio of estradiol to testosterone, and estradiol was the only significant risk factor for organic erectile dysfunction (odds ratio: 1.094; 95% confidence interval: 1.042–1.149, P = 0.000). Moreover, serum estradiol levels were negatively correlated with penile rigidity. Serum estradiol levels were higher and penile rigidity was lower in patients with venous erectile dysfunction than in patients with nonvascular erectile dysfunction. We conclude that elevated serum estradiol levels may impair erectile function and may be involved in the pathogenesis of organic erectile dysfunction in eugonadal young men.

Estradiol correlates with erectile dysfunction and its severity in type 2 diabetic patients

AIMS

Erectile dysfunction (ED) is a frequent microvascular complication of type 2 diabetes mellitus (T2DM). Hormonal derangements such as hypogonadism and hyperestrogenism are common in T2DM. Our aim was to investigate the relationship between estrogens and ED in diabetic patients.

METHODS

We performed a retrospective study on 57 patients with T2DM suffering from ED. ED was assessed with the International Index of Erectile Function questionnaire (IIEF-5) and penile color-doppler ultrasound (PCDU). Blood tests included glycated hemoglobin, lipid profile, total testosterone (T), and estradiol (E2).

RESULTS

E2 was negatively correlated with IIEF-5 score after correction for age, diabetes duration, BMI, HbA1c, LDL- and HDL-cholesterol, T and PSA (r = -0.457, p < 0.01). Patients in the higher E2 quartile, had statistically higher probability of severe ED (61.5%). In the same patients, the PCDU demonstrated a statistically longer Acceleration Time (120.0 ± 24.5, p = 0.048) indicating an impaired arterial flow.

CONCLUSIONS

In diabetic patients, higher E2 is associated with worse erectile function and impaired cavernous arterial flow. Diabetic patients with high E2 are more prone to severe ED. It could be suggested to include estradiol measurement in the hormonal assessment of ED in patients with T2DM.

Comparison of hormone profile and systemic inflammation in patients presenting with sexual dysfunction: Which is important?

INTRODUCTION

Erectile dysfunction (ED) is the inability to achieve or maintain erection sufficient for satisfactory sexual performance. Although the definition is well known, there are controversial issues about the effects of hormones and inflammation on ED.

OBJECTIVES

We aimed to compare the clinical value of the hormonal and inflammation parameters in sexual dysfunction.

MATERIALS AND METHODS

A total of 152 patients diagnosed with erectile dysfunction between September 2018 and March 2019 and 101 healthy males were included in this prospective study as case group and control group, respectively. The 152 patients were divided into three groups based on their total International Index of Erectile Function (IIEF) scores: (I) severe ED, (II) mild-moderate ED and (III) mild ED. All groups were compared in terms of neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR) and total testosterone (TT), estradiol, prolactin, testosterone-to-estradiol ratio and 25 (OH) vitamin D.

RESULTS

Patient and control groups differed significantly in term of NLR, PLR, prolactin and vitamin D (p<0.001, p=0.004, p=0.002, p<0.001, p<0.001, respectively). NLR was more significant in determining the severity of ED (p<0.001). It was observed that libido score (the total score of IIEF items #11 and #12) was negatively associated with prolactin and NLR (p<0.001, p=0.023, respectively), was positively associated with vitamin D and TT (p<0.001, p=0.02, respectively), and was lower in severe ED patients.

CONCLUSIONS

Although more clinical studies are needed, we think that our findings may be useful on these controversial issues of ED.

Lipotoxicity, neuroinflammation, glial cells and oestrogenic compounds

The high concentrations of free fatty acids as a consequence of obesity and being overweight have become risk factors for the development of different diseases, including neurodegenerative ailments. Free fatty acids are strongly related to inflammatory events, causing cellular and tissue alterations in the brain, including cell death, deficits in neurogenesis and gliogenesis, and cognitive decline. It has been reported that people with a high body mass index have a higher risk of suffering from Alzheimer's disease. Hormones such as oestradiol not only have beneficial effects on brain tissue, but also exert some adverse effects on peripheral tissues, including the ovary and breast. For this reason, some studies have evaluated the protective effect of oestrogen receptor (ER) agonists with more specific tissue activities, such as the neuroactive steroid tibolone. Activation of ERs positively affects the expression of pro-survival factors and cell signalling pathways, thus promoting cell survival. This review aims to discuss the relationship between lipotoxicity and the development of neurodegenerative diseases. We also elaborate on the cellular and molecular mechanisms involved in neuroprotection induced by oestrogens.

The association between elevated serum oestradiol levels and clinically significant erectile dysfunction in men presenting for andrological evaluation

The goal of this study was to investigate the association between serum oestradiol levels and clinically significant erectile dysfunction in a cohort of men presenting for andrological evaluation. Retrospective review was conducted of patients that presented to a urologist with practice in andrology over an 18-month period. Patients completed the Male Sexual Health Questionnaire and had serum total testosterone and oestradiol measurements prior to 10:30 a.m. via immunoassay. t Tests, chi-square tests and multivariate logistic regression were used to compare clinical characteristics between those with adequate erectile function (erection scale score > 2) vs. clinically significant erectile dysfunction (erection scale score ≤ 2). Among 256 patients, average age was 49 years (SD 15), average serum oestradiol was 22.3 pg/ml (SD 10.6), and average serum total testosterone was 465.9 pg/ml (SD 206.3). On multivariate logistic regression, serum oestradiol was associated with clinically significant erectile dysfunction (OR 1.52 per SD increase, 95% CI 1.11-2.09, p = 0.009) when controlling for serum total testosterone, age, body mass index and smoking status. These results warrant future studies on the utility of measuring serum oestradiol in patients with erectile dysfunction and the use of aromatase inhibitors in patients with erectile dysfunction and elevated serum oestradiol.

Molecular basis of androgen action on human sexual desire

Reproduction is a fundamental process for the species maintenance and the propagation of genetic information. The energy expenditure for mating is overtaken by motivational stimuli, such as orgasm, finely regulated by steroid hormones, gonadotropins, neurotransmitters and molecules acting in the brain and peripheral organs. These functions are often investigated using animal models and translated to humans, where the androgens action is mediated by nuclear and membrane receptors converging in the regulation of both long-term genomic and rapid non-genomic signals. In both sexes, testosterone is a central player of this game and is involved in the regulation of sexual desire and arousal, and, finally, in reproduction through cognitive and peripheral physiological mechanisms which may decline with aging and circadian disruption. Finally, genetic variations impact on reproductive behaviours, resulting in sex-specific effect and different reproductive strategies. In this review, androgen actions on sexual desire are evaluated, focusing on the molecular levels of interaction.