Type 2 diabetes mellitus increases risk of erectile dysfunction independent of obesity and dyslipidemia: A Mendelian randomization study

Comprehensive analysis of biological landscape of oxidative stress-related genes in diabetic erectile dysfunction

Oxidative stress plays a pivotal role in the pathogenesis of diabetic erectile dysfunction, while specific mechanisms have not been illuminated. The study aims to reveal the genetic expression patterns of oxidative stress in diabetic erectile dysfunction. Transcriptome data of diabetic erectile dysfunction and oxidative stress-related genes (OSRGs) in the Gene Expression Omnibus database were downloaded and analyzed based on differential expression. Functional enrichment analyses were conducted to clarify the biological functions. A protein interaction framework was established, and significant gene profiles were validated in the cavernous endothelial cells, clinical patients, and rat models. A miRNA-OSRGs network was predicted and validated. The results were analyzed using Student's t-test. The analysis screened 203 differentially expressed OSRGs (p < 0.05), which had a close association with oxidoreductase activities, glutathione metabolism, and autophagy. A four-gene signature comprised of EPS8L2 (p = 0.044), GSTA3 (p = 0.015), LOX (p < 0.001) and MGST1 (p = 0.002) was well validated and regarded as the hub OSRGs. Compared with the control group, notable increases and decreases were observed in the expressions of GSTA3 (3.683 ± 0.636 vs. 0.416 ± 0.507) and LOX (2.104 ± 1.895 vs. 18.804 ± 2.751) in the validated diabetic erectile dysfunction group. The hub OSRGs-related miRNAs participated in smooth muscle cell proliferation. Besides, miR-125a-3p (p = 0.034) and miR-138-2-3p (p = 0.012) were validated as promising oxidative stress-related miRNA biomarkers. Our findings revealed the genetic alternations of oxidative stress in diabetic erectile dysfunction. These results will be instructive to explore the molecular landscape and the potential treatment for diabetic erectile dysfunction.

Uncovering the Potential Mechanisms and Effects of Hyperuricemia and its Associated Diseases on Male Reproduction

Male fertility and metabolic disorders, including obesity and diabetes, are closely connected. Since hyperuricemia and metabolic syndrome are strongly related, male fertility and hyperuricemia may, to some degree, be associated. According to recent studies, hyperuricemia imposes various effects on sex hormones, semen quality, and male erectile dysfunction. Some researchers claim that uric acid worsens male semen and raises the risk of erectile dysfunction (ED), while others state that it safeguards both penile erection and male semen. Additionally, it has been shown that gout and metabolic syndrome also raise the risk of ED. To clarify this controversy, the influence and potential mechanisms of hyperuricemia on ED, semen quality, sex hormone levels, and the effects of hyperuricemia-related disorders on ED will be comprehensively summarized.

Insights into modifiable risk factors of erectile dysfunction, a wide-angled Mendelian Randomization study

INTRODUCTION

The causal association between modifiable risk factors and erectile dysfunction (ED) remains unclear, which hinders the early identification and intervention of patients with ED. The present study aimed to clarify the causal association between 42 predominant risk factors and ED.

METHODS

Univariate Mendelian Randomization (MR), multivariate MR, and mediation MR analyses were used to investigate the causal association between 42 modifiable risk factors and ED. Combined results were pooled from two independent ED genome-wide association studies to verify the findings.

RESULTS

Genetically predicted body mass index (BMI), waist circumference, trunk fat mass, whole body fat mass, poor overall health rating, type 2 diabetes, basal metabolic rate, adiponectin, cigarette consumption, insomnia, snoring, hypertension, stroke, ischemic stroke, coronary heart disease, myocardial infarction, heart failure, and major depressive disorder were found to increase the risk of ED (all P < 0.05). Additionally, genetic liability to higher body fat percentage and alcohol consumption were suggestively associated with an increased risk of ED (P < 0.05 and adjusted P > 0.05). Genetic predisposition to higher sex hormone-binding globulin (SHBG) levels could decrease the risk of ED (P < 0.05). No significant association was detected between lipid levels and ED. Multivariate MR identified type 2 diabetes, basal metabolic rate, cigarette consumption, hypertension, and coronary heart disease as risk factors for ED. The combined results confirmed that waist circumference, whole body fat mass, poor overall health rating, type 2 diabetes, basal metabolic rate, adiponectin, cigarette consumption, snoring, hypertension, ischemic stroke, coronary heart disease, myocardial infarction, heart failure, and major depressive disorder could increase the risk of ED (all P < 0.05), while higher SHBG decreased the risk of ED (P = 0.004). There were suggestive significances of BMI, insomnia, and stroke on ED (P < 0.05 and adjusted P > 0.05).

CONCLUSION

This comprehensive MR study supported the causal role of obesity, type 2 diabetes, basal metabolic rate, poor self-health rating, cigarette and alcohol consumption, insomnia and snoring, depression, hypertension, stroke, ischemic stroke, coronary heart disease, myocardial infarction, heart failure, SHBG, and adiponectin in the onset and development of ED.

UPLC-Q-TOF-MS profiling of Viola stocksii Boiss. and evaluation of aphrodisiac potential and risk factors associated with erectile dysfunction

ETHNOPHARMACOLOGICAL RELEVANCE

Viola stocksii Boiss. locally known as makhni or makhanr booti, is an important medicinal food plant with multiple therapeutic applications, including erectile dysfunction (ED). It is mixed with butter and used for boosting energy and sexual health in the subcontinent.

AIMS OF THE STUDY

This study was designed to evaluate the chemical composition, aphrodisiac potential and effect of V. stocksii on the risk factors associated with ED.

METHODOLOGY

The hydroethanolic extract of V. stocksii (HEEVS) was prepared through the microwave-assisted extraction (MAE) technique. The chemical composition was evaluated using preliminary phytochemical screening and UPLC-Q-TOF-MS analysis. Metals and minerals analysis was performed by an atomic absorption spectrophotometer. The aphrodisiac activity of HEEVS was evaluated using an in vivo aphrodisiac model established in male albino rats and the effect on various sexual parameters such as mount, intromission, ejaculation frequencies and mount, intromission, ejaculation latencies, postejaculatory interval, penile reflexes and serum hormone concentration were analyzed. The effect of HEEVS on various risk factors associated with ED, including prostate cancer (PC), bacterial infections, diabetes and obesity, was evaluated using various in vitro assays. Moreover, four compounds were selected from the UPLC-Q-TOF-MS profile and evaluated for in silico computational analysis against phosphodiesterase-5 (PDE-5) for possible interaction.

FINDINGS

The phytochemical screening revealed the presence of various secondary metabolites in HEEVS, while 58 compounds were tentatively identified in the UPLC-Q-TOF-MS analysis. Various important minerals and metals such as zinc, calcium, cadmium and magnesium were detected in the atomic absorption spectrometry analysis. The in vivo aphrodisiac evaluation showed a significant (p < 0.05) increase in the mount, intromission and ejaculation frequencies and a decrease in the mount, intromission latencies and post-ejaculatory intervals at a dose of 300 mg/kg. A marked (p < 0.05) increase was observed in the concentration of serum testosterone and luteinizing hormones in HEEVS treated animals with a significant increase in total penile reflexes. The extract displayed significant anti-prostate cancer activity and a potential antibacterial spectrum against E. coli and S. aureus, with MIC50 values of 215.72 μg/mL and 139.05 μg/mL, respectively. Similarly, HEEVS was found active towards pancreatic lipase (67.34 ± 1.03%), α-glucosidase (3.87 ± 0.54 mmol ACAE/g d.w.) and α-amylase (6.98 ± 1.63 mmol ACAE/g d.w.). The in silico docking study presented a potential interaction between the selected compounds and residues of the active site of PDE-5.

CONCLUSION

This report highlights the aphrodisiac potential of V. stocksii and provides experimental support for its traditional use in ED with an attenuative effect on the risk factors associated with ED. Moreover, the chemical composition displayed the presence of functional phytoconstituents and minerals in HEEVS and paves the way for the isolation of compounds with potent aphrodisiac activity.

Effects of obesity-related anthropometric indices and body composition on erectile dysfunction mediated by coronary artery disease: A Mendelian randomization study

BACKGROUND

The causal relationship between obesity-related anthropometric indicators/body composition and erectile dysfunction has not been established in previous observational studies.

METHOD

We screened single nucleotide polymorphisms significantly associated with exposure from genome-wide association studies as instrumental variables (p < 5.0 × 10-8 ). The summary statistics for erectile dysfunction were collected from a genome-wide association study with a sample size of 223,805. Exposure and outcome populations included are of European ancestry. We used univariate and multivariate Mendelian randomization (i) to investigate the causal relationship between genetically predicted obesity-related anthropometric indicators/body composition and erectile dysfunction and (ii) to examine the mediating role of coronary artery disease. Mendelian randomization analysis was conducted using an inverse variance weighted method. A series of sensitivity analyses validated the results of the Mendelian randomization analysis. Causal estimates are expressed as odds ratios with 95% confidence intervals.

RESULTS

Obesity-related anthropometric indicators/body composition were associated with an increased risk of erectile dysfunction in univariate Mendelian randomization analyses. For the 1-SD increase in body mass index, the odds ratio was 1.841 (95% confidence interval: 1.049-1.355, p = 0.006). For the 1-SD increase in waist circumference and hip circumference, the odds ratios were 1.275 (95% confidence interval: 1.101-1.478, p = 0.001) and 1.156 (95% confidence interval: 1.015-1.317, p = 0.009), respectively. The odds ratio for the 1-SD increase in whole body fat mass was 1.221 (95% confidence interval: 1.047-1.388, p = 0.002). For the 1-SD increase in leg fat percentage (left and right), the odds ratios were 1.256 (95% confidence interval: 1.006-1.567, p = 0.044) and 1.285 (95% confidence interval: 1.027-1.608, p = 0.028), respectively. For the 1-SD increase in leg fat mass (left and right), the odds ratios were 1.308 (95% confidence interval: 1.108-1.544, p = 0.001) and 1.290 (95% confidence interval: 1.091-1.524, p = 0.003), respectively. For the 1-SD increase in arm fat mass (left and right), the odds ratios were 1.269 (95% confidence interval: 1.113-1.447, p < 0.001) and 1.254, respectively. Multivariate Mendelian randomization analysis showed that after adjusting for coronary artery disease, some genetic predispositions to obesity-related anthropometric indicators and body composition were still associated with an increased risk of erectile dysfunction. Significant associations were found for waist circumference-erectile dysfunction (odds ratio: 1.218, 95% confidence interval: 1.036-1.432), leg fat percentage (left)-erectile dysfunction (odds ratio: 1.245, 95% confidence interval: 1.035-1.497), leg fat mass (left)-erectile dysfunction (odds ratio: 1.264, 95% confidence interval: 1.051-1.521), arm fat mass (right)-erectile dysfunction (odds ratio: 1.186, 95% confidence interval: 1.024-1.373), and arm fat mass (left)-erectile dysfunction (odds ratio: 1.17, 95% confidence interval: 1.018-1.360). Meanwhile, coronary artery disease mediated the effects of fat on erectile dysfunction, and the proportion of coronary artery disease-mediated cases ranged from 10% to 22%.

CONCLUSION

There is a potential causal relationship between obesity-related anthropometric indicators/body composition and erectile dysfunction. Higher waist circumference, leg fat percentage, and arm fat mass may increase the risk of erectile dysfunction, and coronary artery disease partly mediates this overall effect. Understanding the causal relationship between obesity and erectile dysfunction and the mediating role of coronary artery disease may provide more information for erectile dysfunction intervention and prevention strategies.

Causal association of cardiovascular disease with erectile dysfunction: a two-sample bidirectional Mendelian randomization analysis

BACKGROUND

The association between cardiovascular diseases (CVD), including ischemic stroke (IS), heart failure (HF), myocardial infarction (MI), and coronary heart disease (CHD), and erectile dysfunction (ED) remains unclear from observational studies.

OBJECTIVES

We explored the potential bidirectional association between CVD and ED by Mendelian randomization (MR).

METHODS

Data from genome-wide association studies for CVD in individuals with European ancestry were obtained from several databases, with 1,711,875-977,323 participants, while that for ED included 223,805 participants. We conducted univariate MR (UVMR), inverse variance-weighting (IVW), weighted median, MR-Egger, and multivariate MR (MVMR) analyses to explore the bidirectional causal effects between CVD and ED.

RESULTS

UVMR indicated that IS (odds ratios [OR] = 1.34, 95% confidence interval [CI]: 1.08-1.21, P = 0.007), HF (OR = 1.36, 95% CI 1.07-1.74, P = 0.013), and CHD (OR = 1.15, 95% CI 1.09-1.18, P = 0.022) were associated with ED. By MVMR, IS estimates remained significant after accounting for combining single nucleotide polymorphisms from CVDs (OR = 1.42, 95%CI: 1.13-1.79, P = 0.002). Moreover, the effect of a genetic susceptibility to IS on ED was not mediated by type 2 diabetes or triglycerides; that of HF was not mediated by type 2 diabetes, and that of CHD was not mediated by body mass index. Bidirectional analyses showed that genetic susceptibility to ED did not confer any increased CVD risk.

CONCLUSIONS

Our results, based on MR, indicated that genetic susceptibility to IS, HF, and CHD was causally associated with ED. These findings can inform prevention and intervention strategies for ED in IS, HF, and CHD patients.

Mendelian randomization study reveals the effect of idiopathic pulmonary fibrosis on the risk of erectile dysfunction

Background

Several studies have found that erectile dysfunction (ED) is associated with interstitial lung disease. However, the causal relationship between idiopathic pulmonary fibrosis (IPF) and ED risk remains unclear. The present two-sample Mendelian randomization (MR) study aimed to reveal the causal effect of IPF on ED risk.

Methods

This study included two GWAS summary statistics of IPF (1,028 cases and 196,986 controls) and ED (6,175 cases and 217,630 controls) of European ancestry. The inverse-variance weighted (IVW) was applied as the primary method, and MR-Egger, weighted median, weighted mode, and simple mode were applied as complementary methods to estimate the causal impact of IPF on ED risk. The MR-PRESSO global test and MR-Egger regression were applied to evaluate the pleiotropy. The Cochran's Q test was applied to examine heterogeneity. The leave-one-out analysis ensured the robustness and reliability of the results.

Results

Twenty-one genetic variants were obtained as IPF instrumental variables without pleiotropy and heterogeneity. MR analysis using the IVW showed a potential causal relationship between IPF and increased ED risk (OR_IVW = 1.046, 95% CI: 1.020-1.073, p = 0.001), and consistent results were obtained with MR-Egger, weighted median, and weighted mode. The leave-one-out analysis showed that no instrumental variables unduly influenced the results.

Conclusion

This study suggested that IPF may increase the ED risk of the European population.

A Novel Risk Calculator to Predict Erectile Dysfunction in HIV-Positive Men

HIV infection is considered to be a lifelong medical condition, requiring follow-up and treatment for decades. HIV-positive men are reported to have erectile dysfunction more often than age-matched healthy controls, and improving sexuality is known to potentially improve overall health-related quality of life. The aim of this paper is to evaluate the presence of ED in HIV-positive men and the associated contributing factors and to create a statistical model to assess the risk to develop ED in this population. In a prospective study, we analyzed a group of HIV-positive men in a cross-sectional manner, looking at demographics, blood test results, and smoking habits. Data were statistically analyzed using the Kruskal-Wallis test. In our series, the overall incidence of ED was 48.5%, increasing with age. Our analysis showed no correlation with blood sugar level, but a very strong correlation with total serum lipids. We were able to develop and validate a risk calculator for ED in HIV-positive men.

STIM/Orai Inhibition as a Strategy for Alleviating Diabetic Erectile Dysfunction Through Modulation of Rat and Human Penile Tissue Contractility and in vivo Potentiation of Erectile Responses

BACKGROUND

Stromal interaction molecule (STIM)/Orai calcium entry system appears to have a role in erectile dysfunction (ED) pathophysiology but its specific contribution to diabetic ED was not elucidated.

AIM

To evaluate STIM/Orai inhibition on functional alterations associated with diabetic ED in rat and human penile tissues and on in vivo erectile responses in diabetic rats.

METHODS

Rat corpus cavernosum (RCC) strips from nondiabetic (No DM) and streptozotocin-induced diabetic (DM) rats and human penile resistance arteries (HPRA) and corpus cavernosum (HCC) from ED patients undergoing penile prosthesis insertion were functionally evaluated in organ chambers and wire myographs. Erectile function in vivo in rats was assessed by intracavernosal pressure (ICP) responses to cavernous nerve electrical stimulation (CNES). Expression of STIM/Orai elements in HCC was determined by immunofluorescence and immunoblot.

MAIN OUTCOME MEASURES

Functional responses in RCC, HCC and HPRA and STIM/Orai protein expression in HCC. In vivo erectile responses to CNES.

RESULTS

Inhibition of Orai channels with YM-58483 (20 µM) significantly reduced adrenergic contractions in RCC but more effectively in DM. Thromboxane-induced and neurogenic contractions were reduced by STIM/Orai inhibition while defective endothelial, neurogenic and PDE5 inhibitor-induced relaxations were enhanced by YM-58483 (10 µM) in RCC from DM rats. In vivo, YM-58483 caused erections and attenuated diabetes-related impairment of erectile responses. YM-58483 potentiated the effects of PDE5 inhibition. In human tissues, STIM/Orai inhibition depressed adrenergic and thromboxane-induced contractions in ED patients more effectively in those with type 2 diabetes. Diabetes was associated with increased expression of Orai1 and Orai3 in ED patients.

CLINICAL TRANSLATION

Targeting STIM/Orai to alleviate diabetes-related functional alterations of penile vascular tissue could improve erectile function and potentiate therapeutic effects of PDE5 inhibitors in diabetic ED.

STRENGTHS AND LIMITATIONS

Improving effects of STIM/Orai inhibition on diabetes-related functional impairment was evidenced in vitro and in vivo in an animal model and validated in human tissues from ED patients. Functional findings were complemented with expression results. Main limitation was low numbers of human experiments due to limited human tissue availability.

CONCLUSIONS

STIM/Orai inhibition alleviated alterations of functional responses in vitro and improved erectile responses in vivo in diabetic rats, potentiating the effects of PDE5 inhibition. STIM/Orai inhibition was validated as a target to modulate functional alterations of human penile vascular tissue in diabetic ED where Orai1 and Orai3 channels were upregulated. STIM/Orai inhibition could be a potential therapeutic strategy to overcome poor response to conventional ED therapy in diabetic patients. Sevilleja-Ortiz A, El Assar M, García-Gómez B, et al. STIM/Orai Inhibition as a Strategy for Alleviating Diabetic Erectile Dysfunction Through Modulation of Rat and Human Penile Tissue Contractility and in vivo Potentiation of Erectile Responses. J Sex Med 2022;19:1733-1749.

Erectile dysfunction as a marker of endocrine and glycemic disorders

PURPOSE

The aim of this study was to evaluate in a population of patients with erectile dysfunction (ED): (a) the prevalence of a previously unknown endocrine/glycemic disorders; (b) the correlation between ED severity and endocrine/glycemic disorders.

METHODS

1332 patients referred for ED from 2013 to 2020 were included. The ED diagnosis was made using the International-Erectile-Function-Index-5 questionnaire. ED severity was considered according to presence/absence of spontaneous erections, maintenance/achievement deficiency. All patients were subjected to search for sociodemographic and clinical characteristics: age, ethnicity, marital status, previous use of PDE5i, previous prostatectomy, diabetes mellitus (DM), prediabetes, endocrine dysfunctions.

RESULTS

The mean ± SD age was 54.3 ± 13.7 years. The 19.1% (255/1332) of patients were already in treatment for prediabetes/diabetes or endocrine dysfunctions. Among the remaining 1077, the prevalence of previously unknown endocrine and glycemic disorders was 30% (323/1077). Among them, 190/323 subjects (58.8%) were affected by hypogonadism, with high estradiol level observed in 8/190 (4.2%). The prevalence of new glycemic alterations was 17.3% (56/323) [specifically, 32/56 (57.1%) DM, and 24/56 (42.9%) prediabetes]. A thyroid dysfunction was observed in 40/323 subjects (12.3%) and hyperprolactinemia in 37/323 (11.5%). Patients with new diagnosis of DM showed more severe form of ED compared to the total group {difficulty in the achievement of erection: 46/56 [82.2%, vs 265/1332 (19.9%), p < 0.05]; absence of spontaneous erection 23/56 [41.1%, vs 321/1332 (24.1%), p < 0.05]}.

CONCLUSION

ED is an early marker of endocrine/glycemic disorder, and a previously unknown dysfunction was found in more than a quarter of patients. A newly diagnosed DM is associated with ED severity, especially in elderly man and in presence of hypertension.

Comparison of characteristics between Chinese diabetes mellitus-induced erectile dysfunction populations and non-diabetes mellitus-induced erectile dysfunction populations: A cross-sectional study

BACKGROUND

Erectile dysfunction (ED) is a common disease in adult men, and diabetes is an independent risk factor for ED. However, there are few reports on the distinction between diabetes mellitus-induced erectile dysfunction (DMED) and non-DMED features, as well as ED features of varying severity in the two groups.

METHODS

A total of 365 ED patients treated at two clinics in China from 2019 to 2022 were included. Questionnaires of the International Index of Erectile Function (IIEF-5), Erectile Hardness Score (EHS), Premature Ejaculation Diagnostic Tool (PEDT), Patient Health Questionnaire-9 (PHQ-9), and Generalized Anxiety Disorder-7 (GAD-7) were administered to the patients. They were divided into three groups according to the IIEF-5 score: 5-7 for severe ED, 8-11 for moderate ED, and 12-21 for mild ED. In addition, the patient's age, weight, height, fasting blood glucose (FBG), total cholesterol (TC), triglycerides (TG), follicle-stimulating hormone (FSH), luteinizing hormone (LH), prolactin (PRL), total testosterone (TT) and other indicators were also collected. Statistical analysis was performed using SPSS 26, comparing all parameters between groups.

RESULTS

Age (P<0.001), height (P=0.009), body mass index (BMI) (P=0.002), PEDT (P<0.001), FBG (P<0.001), FSH (P<0.001), TG (P<0.001), TT (P<0.001) and triglyceride-glucose index (TyG) (P<0.001) were significantly different between diabetic ED and nondiabetic ED subjects. The trend test in the nondiabetic ED population found a negative correlation between the IIEF-5 score and PHQ-9 (P for trend=0.15). Multivariate ordinal logistic regression in the diabetic ED population showed that elevated LH OR=11.37 (95% CI: 0.966, 3.897) and elevated PRL OR=4.10 (95% CI: 0.410, 2.411) were associated with an increased risk of more severe ED.

CONCLUSIONS

The aetiology, demographic parameters, degree of premature ejaculation, and related biochemical tests were significantly different between the DMED and non-DMED populations.

Differences in structural connectivity between diabetic and psychological erectile dysfunction revealed by network-based statistic: A diffusion tensor imaging study

INTRODUCTION

Type 2 diabetes mellitus (T2DM) has been found to be associated with abnormalities of the central and peripheral vascular nervous system, which were considered to be involved in the development of cognitive impairments and erectile dysfunction (ED). In addition, altered brain function and structure were identified in patients with ED, especially psychological ED (pED). However, the similarities and the differences of the central neural mechanisms underlying pED and T2DM with ED (DM-ED) remained unclear.

METHODS

Diffusion tensor imaging data were acquired from 30 T2DM, 32 ED, and 31 DM-ED patients and 47 healthy controls (HCs). Then, whole-brain structural networks were constructed, which were mapped by connectivity matrices (90 × 90) representing the white matter between 90 brain regions parcellated by the anatomical automatic labeling template. Finally, the method of network-based statistic (NBS) was applied to assess the group differences of the structural connectivity.

RESULTS

Our NBS analysis demonstrated three subnetworks with reduced structural connectivity in DM, pED, and DM-ED patients when compared to HCs, which were predominantly located in the prefrontal and subcortical areas. Compared with DM patients, DM-ED patients had an impaired subnetwork with increased structural connectivity, which were primarily located in the parietal regions. Compared with pED patients, an altered subnetwork with increased structural connectivity was identified in DM-ED patients, which were mainly located in the prefrontal and cingulate areas.

CONCLUSION

These findings highlighted that the reduced structural connections in the prefrontal and subcortical areas were similar mechanisms to those associated with pED and DM-ED. However, different connectivity patterns were found between pED and DM-ED, and the increased connectivity in the frontal-parietal network might be due to the compensation mechanisms that were devoted to improving erectile function.

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.