Folate: a possible role in erectile dysfunction?

Mendelian Randomization Reveals Serum Copper as a Micronutrient is a Risk Factor for Erectile Dysfunction

The cause and effect between serum micronutrients and erectile dysfunction (ED) is not clear. The purpose of this study was to evaluate the causal relationship between micronutrients and ED by Mendelian randomization (MR) analysis. We used the published genome-wide association study (GWAS) data for two-sample MR analysis. This study utilized inverse variance weighted (IVW), MR egger, weighted median, simple mode, and weighted mode method to assess the causal relationship between serum micronutrients and ED. IVW is considered the standard method for MR analysis. We used Cochran's Q tests to evaluate the heterogeneity. To investigate horizontal pleiotropy, this study employed the MR Egger method. Additionally, leave-one-out analysis was used to evaluate the influence of individual genetic loci on the results. The results showed that there was a causal relationship between serum copper and ED, and it was positively correlated with ED (OR = 1.115, CI = 1.00-1.24, p = 0.014). There was no significant correlation between other micronutrients and ED. Sensitivity analysis results indicated that our findings exhibit no heterogeneity or pleiotropy, thereby strengthening our conclusions. Serum copper is a risk factor for ED, which provides a new idea for the diagnosis and treatment of ED in the future. However, further experiments are needed to elucidate the underlying mechanisms.

Correlation between erectile dysfunction and serum B12 levels: a 136-case cross-sectional analysis

BACKGROUND

Erectile dysfunction (ED) involves the inability to initiate or sustain penile erection with sufficient hardness to ensure satisfying sexual relations. Many causes are blamed in the etiology.

OBJECTIVES

In this study, the correlation between serum vitamin B12 (vit B12) levels with ED was researched in a homogeneous case group after exclusion of all other predisposing conditions causing ED.

METHODS

The study included male patients attending the urology clinic from 2015 to 2022. Patients were prospectively registered to the study. Cases were divided into two groups as low and normal according to vit B12 levels. In the study, vit B12 levels ≤200 mg/dL were accepted as low. The Sexual Health Inventory for Men-5 (SHIM-5) was used to assess the erectile function. The SHIM-5 scores for the groups were compared. All patients with comorbid diseases, medication use, or previous surgical history predisposing toward ED and organic and/or psychogenic causes for ED were excluded from the study.

RESULTS

The study included 136 patients abiding by the study criteria among 957 patients. The mean age of cases was 63.35 ± 7.83 years. Mean vit B12 value was 320.74 ± 184.74 mg/dL and 32 cases (23.5%) had inadequate vit B12 (< 200 mg/dL). The mean SHIM-5 value in the group was 15.48 ± 6.71. In the inadequate vit B12 and normal vit B12 groups, the mean SHIM-5 values were 15.30 ± 6.85 and 16.06 ± 6.28, respectively, with no significant difference between the two groups (t = 0.562, p = 0.575). Vit B12 deficiency was identified in 26.7% of patients with sexual desire disorder (SDD) (n = 90) and 17.4% of those without SDD (X2 = 1.46, p = 0.228).

DISCUSSION

Contrary to the general trend in the literature, we found no significant correlation between vit B12 levels and ED.

CONCLUSION

There is a need for prospective randomized controlled studies for detailed analysis of the correlation between erectile dysfunction and vit B12.

Effect of folic acid on the sexual function of postmenopausal women: a triple-blind randomized controlled trial

BACKGROUND

There are reports of sexual dysfunction in postmenopausal women, and several treatment recommendations are available.

AIM

To investigate the effect of folic acid on postmenopausal women's sexual function.

METHODS

This triple-blind randomized controlled trial was conducted in Tehran, Iran, in 2020. A sample of 100 postmenopausal women was recruited from comprehensive health centers affiliated with the Shahid Beheshti University of Medical Sciences. Eligible women were randomly assigned to receive folic acid (5 mg) or placebo on an empty stomach every day for 8 weeks. Women were assessed at 3 time points: baseline and 4 and 8 weeks after the intervention.

OUTCOME

Sexual function was the main outcome, as measured by the Female Sexual Function Index.

RESULTS

The mean ± SD age of participants in the folic acid and placebo groups was 53.2 ± 3.84 and 54.4 ± 4.05 years, respectively (P = .609). The results obtained from mixed effects analysis of variance revealed a statistically significant difference between baseline and posttreatment scores and the interaction between time and group for desire, orgasm, satisfaction, arousal, pain, and total sexual function score, with the folic acid group improving more than control group. Lubrication was the only domain that showed no significant difference for the interaction between time and group.

CLINICAL IMPLICATIONS

Folic acid may beneficially affect sexual function in postmenopausal women.

STRENGTHS AND LIMITATIONS

Strengths include the novelty of the subject, the triple-blind design, the block randomization, the administration of a standard scale for sexual function (Female Sexual Function Index), and the affordability and availability of folic acid. This study was conducted with a small sample size and short follow-up time; therefore, interpretation of the results requires great caution.

CONCLUSION

The findings suggest that folic acid possibly improves sexual function in postmenopausal women. Larger studies are needed to confirm the findings.

TRIAL REGISTRATION

IRCT20150128020854N8; August 2, 2020. Iranian Registry of Clinical Trials; https://en.irct.ir/user/trial/48920/view.

Serum folic acid: an effective indicator for arteriogenic erectile dysfunction

Background

The present study is the first to explore the correlation between serum folic acid (FA) level and penile arterial peak systolic velocity (PSV) as measured via penile color Doppler ultrasonography (PDU), which directly reflects endothelial function in the penile artery.

Materials and methods

A total of 244 consecutive erectile dysfunction (ED) patients and 72 healthy controls, recruited from the Andrology department and the Healthy Physical Examination Center of our hospital, respectively, from June 2020 to April 2022, were included in the study. Serum FA was measured in ED patients and healthy controls, and PDU examinations were conducted for all eligible ED patients. The Pearson method was used to evaluate the correlation between FA levels and PDU parameters in ED patients. A receiver operating characteristic (ROC) curve analysis was also performed to calculate the sensitivity and specificity of these parameters for prediction of arteriogenic ED.

Results

After the PDU test, the average serum FA level among patients diagnosed with arteriogenic ED was 8.08 ± 2.64 ng/ml, lower than the average of 10.78 ± 2.87 ng/ml among healthy controls. There were no statistically significant inter-group differences on any basic parameters, including age, body mass index, fasting blood glucose, total cholesterol, and triglyceride. For further analysis, we divided the arteriogenic ED group into three subgroups by PSV range to compare serum FA levels among these subgroups. The mean FA levels in each of these groups were 5.97 ± 1.51ng/ml, and 8.21 ± 2.37ng/ml, and 10.55 ± 2.56ng/ml, while the corresponding PSV values were 15.75 ± 2.39cm/s, 23.53 ± 2.19cm/s, and 32.72 ± 1.64cm/s. Overall, a positive correlation between PSV and FA level was found among patients with arteriogenic ED (r=0.605, P<0.001). Furthermore, when FA level was used, with a cut-off value of 10.045 ng/ml, as a criterion to distinguish patients with arteriogenic ED from healthy controls, the area under the curve (AUC) was 0.772 (95% confidential interval: [0.696, 0.848]), for a sensitivity of 0.611 and specificity of 0.824.

Conclusion

Serum FA level is positively correlated with PSV in ED patients, and has the ability to distinguish patients with arteriogenic ED from healthy controls. Taking these findings together, FA deficiency should be regarded as an independent risk factor for arteriogenic ED.

Homocysteine levels correlate with velocimetric parameters in patients with erectile dysfunction undergoing penile duplex ultrasound

INTRODUCTION

Hyperhomocysteinemia may contribute to the development of endothelial dysfunction and, consequently, atherosclerosis, a systemic disease involving the vessels that may affect the cavernous arteries leading to vasculogenic erectile dysfunction. Our study aims therefore to explore the relationship between homocysteine levels and velocimetric parameters detected by basal penile duplex ultrasound such as peak systolic velocity and flaccid penile acceleration in patients with erectile dysfunction.

METHODS

A cross-sectional study was conducted collecting clinical, metabolic, hormonal, and instrumental (basal penile duplex ultrasound) data in patients affected by vasculogenic erectile dysfunction.

RESULTS

Data of 126 subjects affected by erectile dysfunction were collected. Mean age was 52.1 ± 12.6 years, whereas mean body mass index was 25.6 ± 4.0 kg/m² . Basal penile duplex ultrasound showed peak systolic velocity values of 13.1 ± 2.9 cm/s and mean flaccid penile acceleration of 2.28 ± 0.70 m/s² , with a strong correlation among these two parameters (r = 0.690; p < 0.001). Frankly pathological values of peak systolic velocity and flaccid penile acceleration were detected in 39.7% and 4.8% of the subjects examined, respectively. Mean homocysteine levels were 14.9 ± 9.5 μmol/l. Homocysteine values >15 μmol/l were found in 26% of the subjects with erectile dysfunction. Peak systolic velocity values and homocysteine levels showed an inverse correlation (r = -0.213; p = 0.03). Similarly, flaccid penile acceleration values were inversely correlated to homocysteine levels (r = -0.199; p = 0.05). In addition, an inverse correlation was found between both peak systolic velocity and flaccid penile acceleration and body mass index, atherogenic lipid pattern, and age. Homocysteine and metabolic parameters showed no significant correlations.

CONCLUSION

Hyperhomocysteinemia is highly prevalent in erectile dysfunction patients. The results of our study show that homocysteine levels correlate with velocimetric parameters assessed by basal penile duplex ultrasound, confirming the role of hyperhomocysteinemia in the genesis of erectile dysfunction of arterial origin.

Association between folic acid, homocysteine, vitamin B12 and erectile dysfunction-A cross-sectional study

To evaluate the relationship between serum levels of folic acid (FA), homocysteine (HCY), vitamin B12 (B12) and erectile dysfunction (ED) and to explore their internal relationships. The study included 134 ED patients and 50 healthy controls. ED was assessed using IIEF-5 scores. ED group had lower median FA (6.08 versus 10.21; p < .001) and B12 (256.0 versus 337.5; p < .001) levels, and higher median HCY (11.4 versus 7.95; p < .001) levels, and these differences seemed to be more pronounced in the younger participants (age < 35 yr). FA decreased with the severity of ED (7.52 versus 6.15 versus 5.49 versus 3.97; p < .001), while HCY increased (10.35 versus 11.8 versus 12.9 versus 15; p < .001). Smoking and shift work were associated with lower FA levels. Multivariate analysis showed that serum FA and HCY revealed significant relation with ED. ROC analysis showed that FA ≤ 8.84 and HCY ≥ 10.35 were the best cut-off values for ED diagnosis. Both FA (r = -0.703, p < .001) and B12 (r = -0.576, p < .001) were negatively correlated with HCY. In conclusion, low FA levels and high HCY levels might be independent risk factors for ED. Low serum FA and B12 levels might co-cause high HCY levels and lead to ED.

Folate Deficiency Triggers the Abnormal Segregation of a Region With Large Cluster of CG-Rich Trinucleotide Repeats on Human Chromosome 2

Folate deficiency is associated with a broad range of human disorders, including anemia, fetal neural tube defects, age-associated dementia and several types of cancer. It is well established that a subgroup of rare fragile sites (RFSs) containing expanded CGG trinucleotide repeat (TNR) sequences display instability when cells are deprived of folate. However, given that folate sensitive RFSs exist in a very small percentage of the population, they are unlikely to be the cause of the widespread health problems associated with folate deficiency. We hypothesized that folate deficiency could specifically affect DNA replication at regions containing CG-rich repeat sequences. For this, we identified a region on human chromosome 2 (Chr2) comprising more than 300 CG-rich TNRs (termed “FOLD1”) by examining the human genome database. Via the analysis of chromosome shape and segregation in mitosis, we demonstrate that, when human cells are cultured under folate stress conditions, Chr2 is prone to display a “kink” or “bending” at FOLD1 in metaphase and nondisjunction in anaphase. Furthermore, long-term folate deprivation causes Chr2 aneuploidy. Our results provide new evidence on the abnormalities folate deficiency could cause in human cells. This could facilitate future studies on the deleterious health conditions associated with folate deficiency.

Serum Folic Acid and Erectile Dysfunction: A Systematic Review and Meta-Analysis

Introduction

The association between folic acid (FA) and erectile dysfunction (ED) was contradictory in the published original articles, and no meta-analysis was conducted to pool these data.

Aim

To verify the role of FA in the pathology of ED and explore the treatment efficacy of FA for ED patients.

Methods

An extensive search was performed on PubMed, Cochrane Library, and Web of Science to obtain all relevant studies published up to October 31, 2020. Studies comparing the serum FA level between ED patients and healthy controls, or comparing the score of the IIEF-5, or IIEF before and after folic acid therapy alone or combination in ED patient were eligible for our meta-analysis. The Newcastle-Ottawa Scales (NOS) was used to qualify included studies.

Main Outcome Measures

The standardized mean differences (SMD) and their corresponding 95% confidence intervals (95% CIs) were calculated to pool our data.

Results

Nine studies were eligible for our meta-analysis to verify the association between FA and ED, and to explore the treatment efficacy of FA for ED patients. The pooled SMD of the FA level difference between ED patients and healthy subjects was -0.94 (95% CI: -1.59, -0.30, P = .004). Moreover, the level of folic acid in healthy subjects, Mild ED patients, Moderate ED patients and Severe ED patients was 11.847 (95%CI = 9.671, 14.022), 9.496 (95%CI = 8.425, 10.567), 6.597 (95%CI = 5.187, 8.007) and 5.623 (95%CI = 3.535, 7.711) respectively. The SMD of changes in score of IIEF-5 was 1.89 with 95%CI (1.60, 2.17) after FA administration in ED patients. Our analysis also showed that combination therapy of FA plus tadalafil changed the score of IIEF with 0.90 (95%CI = 0.44, 1.36) comparing to combination of placebo plus tadalafil.

Conclusion

This novel meta-analysis demonstrated that FA was an independent risk factor for ED and FA supplement may have potentially positive effects in the treatment of ED patients.

Zhang Y, Zhang W, Dai Y, et al. Serum Folic Acid and Erectile Dysfunction: A Systematic Review and Meta-Analysis. Sex Med 2021;9:100356.

Serum folic acid levels and erectile dysfunction: A meta-analysis and systematic review

The aim of this study was to assess the relationship between serum folic acid (FA) levels and erectile dysfunction (ED) through a meta-analysis. A research was conducted in MEDLINE via PubMed, Cochrane Library, EMBASE and Web of Science up to 22 November 2020 to identify studies related to FA and ED. Two authors independently screened the literature, evaluated methodological quality and extracted the data. We used RevMan5.3 and STATA 14.0 for meta-analysis. A total of six studies including 1,842 participants were included, and the results showed that the FA levels in the non-ED group were significantly higher than those in the ED group (MD = 3.37, 95% CI 1.49-5.52, p = 0.004). Subgroup analysis indicated that with the increase in ED severity, the difference in FA levels between groups was more obvious (MD: 1.99 vs. 4.63 vs. 5.63). The differences in FA levels between groups seem more significant in the younger group (MD = 4.87, 95% CI 2.58-6.89, p < 0.001) than in the older group (MD = 3.15, 95% CI 2.21-4.08, p < 0.001). In conclusion, FA deficiency is closely related to ED, and the degree of FA deficiency may reflect the severity of ED. In addition, the association seems to be more pronounced in the younger group.

Addressing male sexual and reproductive health in the wake of COVID-19 outbreak

PURPOSE

The COVID-19 pandemic, caused by the SARS-CoV-2, represents an unprecedented challenge for healthcare. COVID-19 features a state of hyperinflammation resulting in a "cytokine storm", which leads to severe complications, such as the development of micro-thrombosis and disseminated intravascular coagulation (DIC). Despite isolation measures, the number of affected patients is growing daily: as of June 12th, over 7.5 million cases have been confirmed worldwide, with more than 420,000 global deaths. Over 3.5 million patients have recovered from COVID-19; although this number is increasing by the day, great attention should be directed towards the possible long-term outcomes of the disease. Despite being a trivial matter for patients in intensive care units (ICUs), erectile dysfunction (ED) is a likely consequence of COVID-19 for survivors, and considering the high transmissibility of the infection and the higher contagion rates among elderly men, a worrying phenomenon for a large part of affected patients.

METHODS

A literature research on the possible mechanisms involved in the development of ED in COVID-19 survivors was performed.

RESULTS

Endothelial dysfunction, subclinical hypogonadism, psychological distress and impaired pulmonary hemodynamics all contribute to the potential onset of ED. Additionally, COVID-19 might exacerbate cardiovascular conditions; therefore, further increasing the risk of ED. Testicular function in COVID-19 patients requires careful investigation for the unclear association with testosterone deficiency and the possible consequences for reproductive health. Treatment with phosphodiesterase-5 (PDE5) inhibitors might be beneficial for both COVID-19 and ED.

CONCLUSION

COVID-19 survivors might develop sexual and reproductive health issues. Andrological assessment and tailored treatments should be considered in the follow-up.

Hyperhomocysteinemia: Focus on Endothelial Damage as a Cause of Erectile Dysfunction

Erectile Dysfunction (ED) is defined as the inability to maintain and/or achieve a satisfactory erection. This condition can be influenced by the presence of atherosclerosis, a systemic pathology of the vessels that also affects the cavernous arteries and which can cause an alteration of blood flow at penile level. Among the cardiovascular risk factors affecting the genesis of atherosclerosis, hyperhomocysteinemia (HHcys) plays a central role, which is associated with oxidative stress and endothelial dysfunction. This review focuses on the biological processes that lead to homocysteine-induced endothelial damage and discusses the consequences of HHcys on male sexual function

Aging and erectile function

The authors review and discuss numerous factors that influence erectile function and their interactions, based on the published literature. Of critical importance are vascular nitric oxide; nutrition; exercise; weight control and maintaining insulin sensitivity; early treatment of hypertension with attention to effects on erectile function; avoiding sources of oxidative stress such as obesity and smoking; reducing inflammation (e.g. from gingivitis); improving pelvic floor muscle strength; and inhibiting cyclic GMP break-down. The described interventions act on different aspects of erectile biochemistry and physiology. Therefore, combining multiple therapeutic approaches will yield maximum benefits for erectile and vascular and general health.

Novel predictive risk factor for Erectile Dysfunction: Serum folic acid

The purpose of this study was to compare the serum Folic Acid (FA) levels in patients with Erectile Dysfunction (ED) and healthy controls and whether levels vary with its severity. The study was carried out on 77 sexually active individuals, out of which 41 complained of ED and 36 were apparently normal. Patients were excluded if they had any diseases known to cause ED. The severity was further categorised based on IIEF-5 scores. Blood serum levels of testosterone, lipid profile, random blood sugar, liver function test, renal function test and FA levels were obtained in each patient. Independent-samples t test of significance was used when comparing between two means. Pearson's correlation coefficient (r) test was used for correlating data. All clinical and biochemical parameters except FA were comparable in both the groups. FA levels were significantly decreased in ED group (5.29 vs. 10.8; p value = .004). Smoking habits were comparable between the groups, and FA levels did not vary among smokers and nonsmokers (p value = .46). Serum FA levels significantly declined with increasing severity of ED (8.28 vs. 5.56 vs. 4.37 vs. 3.5; p value < .001). Thus, decreased FA might possibly be one of the novel risk factors for ED.

Melatonin Treatment Ameliorates Hyperhomocysteinemia-Induced Impairment of Erectile Function in a Rat Model

BACKGROUND

Hyperhomocysteinemia (HHcy) has been reported to be strongly correlated with the occurrence of erectile dysfunction (ED), but the mechanisms are not fully understood. Moreover, whether melatonin could be a potential treatment of HHcy-induced ED needs to be elucidated.

AIM

The aim of this study was to investigate the effects of melatonin on HHcy-induced ED and the potential mechanisms via modulating oxidative stress and apoptosis.

METHODS

The Sprague-Dawley (SD) rat model of HHcy was induced by 7% methionine (Met)-rich diets. 36 male SD rats were randomly distributed into 3 groups (n = 12 per group): control group, 7% Met group, and 7% Met + melatonin (Mel; 10 mg/kg, intraperitoneal injection) treatment group. After 4 weeks, the erectile function of all rats was evaluated by electrical stimulation of the cavernous nerve. Histologic and molecular alterations of the corpus cavernosum were also analyzed by immunofluorescence, immunohistochemistry, enzyme-linked immunosorbent assay, Western blotting, and polymerase chain reaction.

OUTCOMES

HHcy-induced ED rat models were successfully established, and Mel could preserve erectile function mainly through inhibiting oxidative stress via the Erk1/2/Nrf2/HO-1 signaling pathway and suppression of apoptosis.

RESULTS

Erectile function was significantly reduced in the rats with HHcy compared with that in the control group and was ameliorated in the HHcy rats treated with Mel. Compared with the control group, the rats in the HHcy group showed the following: (1) higher levels of total plasma homocysteine; (2) fewer neuronal nitric oxide synthase-positive cells in the corpus cavernous; (3) higher levels of reactive oxygen species and malondialdehyde, higher expression levels of nicotinamide adenine dinucleotide phosphate oxidase, and lower activities of superoxide dismutase, indicating an overactivated oxidative stress; (4) lower expression levels of Erk1/2/Nrf2/HO-1 signaling pathway components; and (5) higher levels of apoptosis, as determined by the expression levels of Bax, Bcl-2, and caspase 3. Mel treatment improved the erectile response, as well as histologic and molecular alterations.

CLINICAL TRANSLATION

Our study on a rodent model of HHcy provided evidence that Mel could be a potential therapeutic method for HHcy-related ED.

CONCLUSIONS

Mel treatment improves erectile function in rats with HHcy probably by potential antioxidative stress activity. This finding provides evidence for a potential new therapy for HHcy-induced ED. Tang Z, Song J, Yu, Z, et al. Melatonin Treatment Ameliorates Hyperhomocysteinemia-Induced Impairment of Erectile Function in a Rat Model. J Sex Med 2019;16:1506-1517.

Folic acid supplementation improves erectile function in patients with idiopathic vasculogenic erectile dysfunction by lowering peripheral and penile homocysteine plasma levels: a case-control study

BACKGROUND

Erectile dysfunction (ED) has common risk factors with many cardiovascular (CV) impairments. In view of these facts, hyperhomocysteinemia (HHcys) has been postulated for involvement in endothelial dysfunction.

OBJECTIVES

We evaluated peripheral and penile homocysteine (Hcys) plasma levels before and after folic acid supplementation in idiopathic vasculogenic erectile dysfunction (ED) patients.

MATERIALS AND METHODS

This study included 50 consecutive patients and 50 consecutive healthy controls that were recruited from December 2017 to December 2018. The patients received folic acid (FA) daily for 3 months and were evaluated by the abridged 5-item International Index of Erectile Function (IIEF-5) and penile duplex before and after therapy, in addition to plasma Hcys levels.

RESULTS

Our study showed improvement in the severity of ED in our patients as all of them became mild to moderate ED after folic acid administration. Additionally, the median scores of IIEF-5 significantly increased from 6 to 14, respectively (p < 0.001). Furthermore, the median peripheral and penile Hcys plasma levels (μmol/l) significantly decreased after folic acid administration as 39 patients with moderate ED and 11 patients with severe ED were 0.62, 0.34, 5.37, 0.37, respectively, became mild to moderate ED with their median peripheral and penile Hcys plasma levels became 0.19, 0.15, p < 0.001, <0.001, respectively. Peripheral Hcys level correlates significantly with penile Hcys before and after folic acid administration (r: -0.06 p: 0.8, r: 0.9, p < 0.001, respectively).

DISCUSSION AND CONCLUSION

Recently, an emerging body of evidence suggests a role for Hcys and folate in erectile function. Interestingly, our interventional study is one of the first that evaluated the effect of folic acid supplementation on HHcys where it demonstrated a significant decrease in peripheral and penile Hcys plasma levels after folic acid administration. Thus, FA should be prescribed concomitantly with phosphodiesterase type 5 inhibitors in ED patients.

Association between homocysteine, vitamin B 12 , folic acid and erectile dysfunction: a cross-sectional study in China

OBJECTIVES

Erectile dysfunction (ED) affects up to 53.4% of men aged 30-80 years. In this study, we aimed to examine the association between homocysteine (HCY), vitamin B₁₂ (B12), folic acid (FA) and ED.

DESIGN

Cross-sectional study.

SETTING

Guangxi, China.

PARTICIPANTS

A total of 1381 participants who completed questionnaires were included, between September 2009 and December 2009.

MEASURES

ED was evaluated by the International Index of Erectile Function scores. Also, the values of HCY, B12 and FA were acquired. Then, regression and between-group analyses were performed.

RESULTS

No association between FA and ED was found. Significant correlations between HCY and ED were found-the relationships between these two parameters were most notable in men aged over 60 years and in men living alone (bachelors or bachelorhood). B12 levels were higher in men with ED (718.53±234.37 pg/mL vs 688.74±229.68, p=0.015). Using multinomial logistic regression analyses, B12 levels were related to mild ED (multivariate adjusted analysis: OR 1.620, 95% CI 1.141 to 2.300, p=0.007), especially among men aged 40-49 years (OR 2.907, 95% CI 1.402 to 6.026, p=0.004).

CONCLUSIONS

We report, for the first time, a relationship between B12 levels and ED. We also found specific cohorts of men for whom the relationship between HCY levels and ED is most prominent. Further studies are required to elucidate the mechanisms underlying these relationships-these may ultimately result in new therapies for ED.

Low serum folic acid can be a potential independent risk factor for erectile dysfunction: a prospective case-control study

PURPOSE

The purpose of the study was to compare serum level of folic acid (FA) in patients with erectile dysfunction (ED) versus healthy controls and to assess its correlation with other well-known confounders for ED.

METHODS

Our prospective study compared FA in 60 patients with ED versus 30 healthy controls. Patients were excluded if they had any hormonal disorders, Peyronie's disease, or decompensated systemic illnesses. ED was evaluated by the validated Arabic version of the abbreviated five-item form of the International Index Of Erectile Function and confirmed by penile duplex. Serum FA level was assayed using ELIZA. Mann-Whitney, Kruskal-Wallis, and Chi-square tests and Spearman correlation were used as appropriate and confirmed by logistic regression model.

RESULTS

Our study revealed that the median FA of the cases and the controls were 7.1 ng/mL and 13.4 ng/mL, respectively, and this difference was of high statistical significance (p < 0.001). Moreover, our study demonstrated significant relations between serum FA with DM, HTN, smoking, age, and cholesterol (p 0.01, 0.03, 0.014, 0.001, and 0.015, respectively). Our study showed that the best cut-off point of serum FA to detect patients with ED was found to be ≤ 9.42 with sensitivity of 80.00%, specificity of 93.33% and area under curve (AUC) of 91.3%.

CONCLUSION

Serum FA level decreased as the severity of ED increased even after adjustment of age, serum testosterone, DM, HTN, and smoking. FA deficiency might be an independent risk factor of ED.

Serum Homocysteine Levels in Men with and without Erectile Dysfunction: A Systematic Review and Meta-Analysis

OBJECTIVES

Elevated levels of serum homocysteine (Hcy) have been associated with cardiovascular diseases and endothelial dysfunction, conditions closely associated with erectile dysfunction (ED). This meta-analysis was aimed to assess serum Hcy levels in subjects with ED compared to controls in order to clarify the role of Hcy in the pathogenesis of ED.

METHODS

Medline, Embase, and the Cochrane Library were searched for publications investigating the possible association between ED and Hcy. Results were restricted by language, but no time restriction was applied. Standardized mean difference (SMD) was obtained by random effect models.

RESULTS

A total of 9 studies were included in the analysis with a total of 1320 subjects (489 subjects with ED; 831 subjects without ED). Pooled estimate was in favor of increased Hcy in subjects with ED with a SMD of 1.00, 95% CI 0.65-1.35, p < 0.0001. Subgroup analysis based on prevalence of diabetes showed significantly higher SMD in subjects without diabetes (1.34 (95% CI 1.08-1.60)) compared to subjects with diabetes (0.68 (95% CI 0.39-0.97), p < 0.0025 versus subgroup w/o diabetes).

CONCLUSIONS

Results from our meta-analysis suggest that increased levels of serum Hcy are more often observed in subjects with ED; however, increase in Hcy is less evident in diabetic compared to nondiabetic subjects. This study is registered with Prospero registration number CRD42018087558.