Sexual dysfunction and male infertility

Sexual health and function in liver disease

Sex is a central aspect of human life and is significantly impacted by chronic illness. Cirrhosis, due to its unique pathophysiology and the side effects of common therapies, serves as a paradigmatic example, being associated with very high rates of sexual dysfunction in both men and women. Liver transplantation can modify certain hormonal and pathophysiological aspects related to sexual dysfunction, but complete recovery occurs in only a relatively small percentage of patients. This review examines the pathophysiology, epidemiology, and management of sexual and reproductive dysfunction in patients with cirrhosis and those undergoing liver transplantation. It provides a framework for understanding the sources of dysfunction, tools for identifying it in clinical settings, and interventions to improve sexual health and functioning in these patients.

Erectile Dysfunction and Oxidative Stress: A Narrative Review

Erectile dysfunction (ED) is a prevalent condition affecting male sexual health, characterized by the inability to achieve or maintain satisfactory erections. ED has a multifactorial pathogenesis in which psychological, hormonal, neurologic, cardiovascular, and lifestyle factors all contribute to a progressive decline of erectile function. A critical underlying mechanism involves oxidative stress (OS), an imbalance between reactive oxygen species (ROS) production and antioxidant defenses, which disrupts endothelial function, reduces nitric oxide (NO) bioavailability, and contributes to vascular dysfunction. This narrative review explores the interplay between OS and ED, focusing on the roles of ROS sources such as NADPH oxidase, xanthine oxidase, uncoupled nitric oxide synthase, and mitochondrial dysfunction. It examines the impact of OS on chronic conditions like hypertension, diabetes mellitus, hyperlipidemia, hypogonadism, and lifestyle factors like smoking and obesity, which exacerbate ED through endothelial and systemic effects. Emerging research underscores the potential of antioxidant therapies and lifestyle interventions to restore redox balance, improve endothelial function, and mitigate ED's progression. This review also highlights gaps in understanding the molecular pathways linking ROS to ED, emphasizing the need for further research to develop targeted therapeutic strategies.

Normozoospermic men in infertile couples: Potential benefit of early medical diagnostic procedures

INTRODUCTION

Infertility, defined as the inability to achieve pregnancy despite regular, unprotected sexual intercourse for 1 year, affects approximately 15% of couples. Male factors contribute to 50% of these cases. The necessity of andrological evaluations for male partners of infertile couples with normozoospermia is currently under consideration.

METHODS

From 2010 to 2020, our center evaluated 997 patients presenting with infertility and normozoospermia. All patients underwent comprehensive assessments, including physical examinations, testicular sonography, blood tests, follice-stimulating hormone beta (FSHB) c.-211 variants, and semen analyses. For comparative purposes, we established two control groups: one comprising healthy men participating in the FAMe study (n = 201) and another consisting of men seeking fertility restoration following vasectomy (n = 75). Within the infertile male group, we further stratified patients into those with primary or secondary infertility.

RESULTS

Analysis of patient histories revealed a significantly elevated prevalence of genital malformations (e.g., hypospadias (p = 0.024) and undescended testes during childhood (p < 0.001) in our infertile group relative to the control group. By anamnesis we could find significant more patients with erectile dysfunction (p < 0.001) in our infertile men. The physical examination showed significant more patients with obesity in our infertility group (p < 0.001). Regarding hormonal profiles, a notably higher proportion of patients in the infertility group exhibited hypogonadism (p < 0.001), while compensated hypogonadism was more common in the control group. Reduced serum follicle-stimulating hormone (FSH) concentrations in men with the FSHB c.-211 GT/TT polymorphism versus the GG wildtype were only present in the infertile but not the fertile cohort (p < 0.001). Evaluation of ejaculate samples indicated a significant increase in round cells (p < 0.001) and leukocytes (p = 0.013) in our infertile patients compared to the healthy subjects.

DISCUSSION

The assessment of men presenting with infertility and normozoospermia unveiled a marked prevalence of physical and genetic findings. This underscores the critical need for andrological evaluations to prevent potential long-term consequences.

CONCLUSION

The andrological examination of normozoospermic and infertile men promises better health outcomes for the patients as well as it aids in refining fertility treatment options for their female counterparts.

Circulating microRNAs in Body Fluid: "Fingerprint" RNA Snippets Deeply Impact Reproductive Biology

Circulating miRNAs (C-miRNAs) occuring in a cell-free form within body fluids and other extracellular environments have garnered attention in recent times. They offer deeper insight into various physiological and pathological processes which include reproductive health. This review delves into their diagnostic potential across a spectrum of reproductive disorders, including conditions affecting ovarian function, male infertility and post pregnancy issues. Through analysis of C-miRNA profiles in bodily fluids, researchers uncover crucial markers indicative of reproductive challenges. Dysregulated C-miRNAs emerge as important players in the progression of several reproductive disorders which is the main focus of this review. Advancements in technology, facilitate precise detection and quantification of C-miRNAs, paving the way for innovative diagnostic approaches. Challenges in studying C-miRNAs, such as their low abundance and variability in expression levels, underscore the need for standardized protocols and rigorous validation methods. Despite these challenges, ongoing research endeavors aim to unravel the complex regulatory roles of C-miRNAs in reproductive biology, with potential implications for clinical practice and therapeutic interventions.

Sexual and reproductive health in overweight and obesity: Aims and visions for integrated research approaches

Overweight and obesity increasingly affect women in their reproductive phase, during family planning, pregnancy, breastfeeding and the postpartum period. Overweight and obesity are associated with impaired sexual and reproductive health, including increased rates of infertility, pregnancy complications, and reduced breastfeeding rates. Furthermore, maternal overweight and obesity are associated with long-term negative health consequences for the child, such as an increased risk for respiratory and metabolic disease. With the Junior Research Center for Reproduction: Sexual and Reproductive Health in Overweight and Obesity (SRHOO Center), we aim to address the effects of overweight and obesity on sexual and reproductive health in an interdisciplinary approach, combining the areas of obstetrics and midwifery, sexual health research, basic research in feto-maternal medicine and glycoimmunology, pediatrics, as well as endocrinology, metabolism and bariatric surgery. Combining these areas of expertise, we seek (1) to understand the effects of overweight and obesity on sexual and reproductive health in different patient groups, focusing on their specific needs in order to provide appropriate counselling and access to healthcare; (2) to improve reproductive health in different groups of overweight and obese patients; and (3) to create interdisciplinary, comprehensive scientific and clinical training regarding sexual and reproductive health in overweight and obese patients. In this short introduction to the SRHOO Center, we provide information on its structure, aims and individual projects as well as its presumed long-term implications for clinical care and public health.

Causal inference of inflammatory proteins in infertility: a Mendelian randomization study

Background

Infertility affects 8-12% of couples globally, manifesting as a complex reproductive disorder with varied causes, negatively impacting emotional, physical, and social well-being. Inflammation is implicated in many diseases, including male and female infertility.

Methods

This study employed Mendelian randomization (MR) with two-sample, bidirectional, and mediation approaches to explore the relationship between circulating inflammatory proteins and infertility. Causal analysis was conducted using inverse variance-weighted (IVW) and MR-Egger regression, supplemented by enrichment analysis, protein-protein interaction (PPI) network exploration, and drug signature analysis.

Results

Our findings identified a significant positive correlation between C-X-C motif chemokine 6 (CXCL6) and male infertility, positioning CXCL6 as a potential therapeutic target or biomarker. No causal links were detected between circulating inflammatory proteins and female infertility post-FDR adjustment. Minor mediation effects were observed for metabolites such as androstenediol monosulfate, arachidonoylcholine, and serum phosphate to glycerol ratio. Cytokine-related pathways emerged as significant in both male and female infertility. Gene-drug interaction analysis highlighted the need for further investigation of pioglitazone in treating female infertility.

Conclusion

This study establishes a potentially causal relationship between CXCL6 and male infertility, suggesting its potential as a drug target or molecular biomarker. The integrative approach combining causal inference with molecular pathway and drug interaction analysis opens new avenues for understanding and treating infertility.

Effect of ovarian reserve on pregnancy outcomes in patients undergoing IVF treatment due to azoospermia

PURPOSE

Infertility is an increasingly common condition that has demographic, psychological, economic, and medical consequences for society. Although many studies have examined azoospermia (AZO) and diminished ovarian reserve (DOR), few have investigated these two groups together. In this study, we aimed to contribute to the literature by comparing these conditions, which can be challenging for physicians and patients.

METHODS

The study included couples with AZO and/or DOR who underwent intracytoplasmic sperm injection (ICSI) at Tepecik Training and Research Hospital Gynecology and Obstetrics Clinic In Vitro Fertilization (IVF) Center between 01 January 2017 and 30 June 2023. A total of 100 couples meeting the inclusion criteria were divided into 3 groups according to treatment indication: AZO (n = 34), DOR (n = 34), and AZO + DOR (n = 32). The women's ages, basal hormone levels (follicle-stimulating hormone, estradiol, progesterone, anti-Müllerian hormone), treatment indications, day of embryo transfer, and clinical pregnancy outcomes were documented.

RESULTS

Clinical pregnancy rates were 64.7% in the AZO group, 50% in the DOR group, and 34.4% in the DOR + AZO group. In pairwise comparisons, the clinical pregnancy rate was significantly higher in the AZO group than in the DOR + AZO group (p = 0.014). The live birth rate was also significantly lower in the DOR + AZO group than in the AZO group (p = 0.022). In the DOR group, 70.6% of achieved pregnancies resulted in live birth and 29.4% in missed abortion.

CONCLUSION

Clinical pregnancy and live birth rates were found to be significantly higher in couples with AZO compared to those with both DOR and AZO. This suggests that the woman's ovarian reserve is more decisive than sperm quality in the success of IVF/ICSI.

Biogenesis of stress granules and their role in the regulation of stress-induced male reproduction disorders

Stress granules (SGs) are conserved messenger ribonucleoprotein (mRNP) granules that form through rapid coalescence in the cytoplasm of eukaryotic cells under stressful environments. These dynamic membrane-free organelles can respond to a variety of both intracellular and extracellular stressors. Studies have shown that stress conditions such as heat stress, arsenite exposure, and hypoxic stress can induce SGs formation. The formation of SGs helps mitigates the effects of environmental stimuli on cells, protects them from damage, and promotes cell survival. This paper focuses on the biogenesis of SGs and summarizes the role in regulating environmental stress-induced male reproductive disorders, with the aim of exploring SGs as a potential means of mitigating male reproduction disorders. Numerous studies have demonstrated that the detrimental effects of environmental stress on germ cells can be effectively suppressed by regulating the formation and timely disassembly of SGs. Therefore, regulating the phosphorylation of eIF2α and the assembly and disassembly of SGs could offer a promising therapeutic strategy to alleviate the impacts of environmental stress on male reproduction health.

Which PDE5 inhibitor is the most effective in the treatment of erectile dysfunction in men with spinal cord injury? A systematic review and network meta-analysis

BACKGROUND

Phosphodiesterase 5 inhibitors (PDE5i) are the first-line drugs for erectile dysfunction (ED) but differences among available molecules should drive therapy personalization. Choosing one PDE5i over another is a challenge in men with spinal cord injury (SCI), as the evidence of efficacy for each molecule is derived from few studies and comparative "head-to-head" trials are lacking.

OBJECTIVE

To assess the efficacy of the different PDE5i for SCI-related ED with a network meta-analysis (NMA) approach.

MATERIALS AND METHODS

Databases from PubMed, Web of Science, Scopus, and Cochrane Library were checked for randomized controlled trials (RCTs) comparing any PDE5i to each other or placebo in men with traumatic SCI lasting ≥6 months. Data were incorporated in a random-effect NMA, where treatments' efficacy was ranked using the surface under the cumulative ranking curve (SUCRA).

RESULTS

The 10 RCTs included provided information about 1,492 men with ED due to traumatic SCI. Intervention arms included sildenafil, tadalafil, and/or vardenafil. Overall, at the pairwise meta-analysis, PDE5i were four times more effective than placebo in improving erectile function (risk ratio: 4.13, 95% CI: 2.76, 6.19). The comparative analysis from NMA revealed that tadalafil was associated with the highest SUCRA value (81%), followed by vardenafil (68%) and sildenafil (49%).

DISCUSSION AND CONCLUSION

Within the grading of comparison network, tadalafil appeared to be the best PDE5i in the treatment of SCI-related ED. Further focused studies are warranted to confirm these findings and define optimal doses and duration of therapy.

The role of the radiologist in the evaluation of male infertility: recommendations of the European Society of Urogenital Radiology-Scrotal and Penile Imaging Working Group (ESUR-SPIWG) for scrotal imaging

OBJECTIVES

The Scrotal and Penile Imaging Working Group (SPIWG) of the European Society of Urogenital Radiology (ESUR) aimed to produce recommendations on the role of the radiologist in the evaluation of male infertility focused on scrotal imaging.

METHODS

The authors independently performed an extensive literature Medline search and a review of the clinical practice and consensus opinion of experts in the field.

RESULTS

Scrotal ultrasound (US) is useful in investigating male infertility. US abnormalities related to abnormal sperm parameters (sperm concentration, total count, motility, and morphology) are low testicular volume (TV), testicular inhomogeneity (TI), cryptorchidism, testicular microlithiasis (TML), high-grade varicocele, bilateral absence of vas deferens, bilateral dilation and echotexture abnormalities of the epididymis. The proposed ESUR-SPIWG recommendations for imaging in the evaluation of male infertility are therefore: to measure TV; investigate TI; perform annual (US) follow-ups up to age 55 in men with a history of cryptorchidism/orchidopexy and/or in men with TML plus "additional risk factors" or with "starry sky" TML; perform scrotal/inguinal US in men with nonpalpable testis; perform scrotal US in men with abnormal sperm parameters to investigate lesions suggestive of tumors; evaluate varicocele in a standardized way; evaluate the presence or absence of vas deferens; investigate the epididymis to detect indirect signs suggesting obstruction and/or inflammation.

CONCLUSIONS

The ESUR-SPIWG recommends investigating infertile men with scrotal US focusing on TV, inhomogeneity, localization, varicocele, vas deferens, and epididymal abnormalities. Cryptorchidism, TML, and lesions should be detected in relation to the risk of testicular tumors.

CLINICAL RELEVANCE STATEMENT

The ESUR-SPIWG recommendations on scrotal imaging in the assessment of male infertility are useful to standardize the US examination, focus on US abnormalities most associated with abnormal semen parameters in an evidence-based manner, and provide a standardized report to patients.

KEY POINTS

So far, ESUR-SPIWG recommendations on scrotal imaging in the assessment of male infertility were not available. The ESUR-SPIWG recommends investigating infertile men with scrotal US focusing on testicular volume, inhomogeneity, localization, varicocele, vas deferens and epididymal abnormalities, and assessing cryptorchidism, testicular microlithiasis and lesions in relation to the risk of testicular tumors. The ESUR-SPIWG recommendations on scrotal imaging in the assessment of male infertility are useful to standardize the US examination, focus on US abnormalities most associated with abnormal sperm parameters in an evidence-based manner, and provide a standardized report to patients.

Kidney disease and reproductive health

Understanding the relationship between reproductive health and kidney function is important to provide holistic care for people living with kidney disease. Chronic kidney disease (CKD) has negative impacts on both male and female fertility owing to factors including inflammation, hormonal dysregulation, reduced ovarian reserve, reduced sperm quality and sexual dysfunction. However, pregnancy is achievable for most cisgender women with kidney disease, including kidney transplant recipients and patients on dialysis. CKD in pregnancy is associated with health risks to the mother and child, including increased risk of progression of kidney disease, hypertensive complications of pregnancy, and neonatal complications including fetal growth restriction, preterm birth and stillbirth. However, with appropriate pre-pregnancy counselling, fertility assessment and support, health optimization, and evidence-based antenatal care, the majority of patients will achieve a good outcome. Medication safety should be reviewed before and during pregnancy and lactation, weighing the risk of disease flare against potential adverse effects on the offspring. Important areas for further research include the optimal timing of delivery and the short- and long-term cardiovascular and renal impacts of pregnancy in patients with CKD, as well as long-term kidney and cardiovascular outcomes in their offspring.

Design and Probing of Prism-Based SPR Nano-Biosensor for Human Sperm Detection

Human sperm functioning is crucial for maintaining natural reproduction, but its sterility is enhanced by variations in environmental conditions. Because of these agitating properties, powerful computer-aided devices are required, but their precision is inadequate, particularly when it comes to samples with low sperm concentrations. Therefore, for the first time, this article introduces the sulfide material-based structure for the detection of human sperm samples using the prism-based surface plasmon resonance sensor (SPR) Nano-biosensor. The proposed structure is designed on the basis of a prism-based Kretschmann configuration and includes silver, silicon, a sulfide layer, black phosphorus, and a sensing medium. This work takes advantage of the excitement of surface plasmons and evanescent waves in the metal dielectric region. For the detection process, seven sperm samples are taken, with their concentration, mobility, and refractive index measured by the refractometer. The proposed structure provides a maximum sensitivity of , QF of and a DA of 1.37. The results provide a substantial improvement in comparison to the reported work in the literature.

Vascular health of fathers with history of intracytoplasmic sperm injection

OBJECTIVE

Studies suggest that men who undergo assisted reproductive technologies (ART) may have a higher risk of cardiovascular disease; however, limited data on this matter is available. This observational pilot study aimed to investigate the overall vascular health of fathers with history of intracytoplasmic sperm injection (ICSI) compared to fathers whose partners conceived spontaneously.

METHODS

Diet quality, physical activity, sedentary behavior as well as overall vascular function including the assessment of pulse wave analysis, intima-media thickness (cIMT), arterial stiffness of the common carotid artery (CCA) and blood lipids, were evaluated.

RESULTS

A total of 34 fathers with history of ICSI and 29 controls (48.49 [46.32 - 57.09] years vs. 47.19 [40.62 - 55.18] years, p = 0.061) were included. After adjusting for age, no significantly increased cardiovascular risk was detected regarding vascular function.

CONCLUSIONS

The results suggest an unaltered cardiovascular risk profile in fathers with history of ICSI. In the future, prospective multicenter studies are required to validate these preliminary results.

Collagen-based materials in male genitourinary diseases and tissue regeneration

Male genitourinary dysfunction causes serious physical or mental distress, such as infertility and psychological harm, which leads to impaired quality of life. Current conventional treatments involving drug therapy, surgical repair, and tissue grafting have a limited effect on recovering the function and fertility of the genitourinary organs. To address these limitations, various biomaterials have been explored, with collagen-based materials increasingly gaining attention for reconstructing the male genitourinary system due to their superior biocompatibility, biodegradability, low antigenicity, biomimetic 3D matrix characteristics, hemostatic efficacy, and tissue regeneration capabilities. This review covers the recent biomedical applications of collagen-based materials including treatment of erectile dysfunction, premature ejaculation, penile girth enlargement, prostate cancer, Peyronie's disease, chronic kidney disease, etc. Although there are relatively few clinical trials, the promising results of the existing studies on animal models reveal a bright future for collagen-based materials in the treatment of male genitourinary diseases.

Graphic Abstract

The Intricate Functional Networks of Pre-mRNA Alternative Splicing in Mammalian Spermatogenesis

Spermatogenesis is a highly coordinated process that requires the precise expression of specific subsets of genes in different types of germ cells, controlled both temporally and spatially. Among these genes, those that can exert an indispensable influence in spermatogenesis via participating in alternative splicing make up the overwhelming majority. mRNA alternative-splicing (AS) events can generate various isoforms with distinct functions from a single DNA sequence, based on specific AS codes. In addition to enhancing the finite diversity of the genome, AS can also regulate the transcription and translation of certain genes by directly binding to their cis-elements or by recruiting trans-elements that interact with consensus motifs. The testis, being one of the most complex tissue transcriptomes, undergoes unparalleled transcriptional and translational activity, supporting the dramatic and dynamic transitions that occur during spermatogenesis. Consequently, AS plays a vital role in producing an extensive array of transcripts and coordinating significant changes throughout this process. In this review, we summarize the intricate functional network of alternative splicing in spermatogenesis based on the integration of current research findings.

Male infertile couples: an actor-partner interdependence model of attachment styles and fertility pressure

BACKGROUND

Couples undergoing artificial insemination by donor semen(AID) represent a unique group of infertility patients, the relationship between fertility pressure and attachment styles remains unclear. To investigate the fertility pressure and attachment dimensions in artificial insemination by donor semen(AID) couples, and develop an Actor-Partner Interdependence Model (APIM) for patient care.

METHODS

This study is a cross-sectional study. From June to September 2021, couples who were about to receive AID treatment in our hospital were assessed using the Fertility Problem Inventory, and the Experiences in Close Relationships(ECR). Dyadic analysis applying the APIM was used.

RESULTS

A total of 448 valid questionnaires were recovered, the effective response rate was 94.9%. The average score of men's fertility pressure was higher than that of women's(P = 0.021). The score of male attachment anxiety was higher than that of females(P = 0.038). Attachment avoidance(β = 0.46) and attachment anxiety(β = 0.33) in wives significantly impacted their fertility pressure. Attachment avoidance(β = 0.17) and attachment anxiety(β = 0.52) in husbands significantly impacted their fertility pressure. The attachment avoidance of wives' had a significant impact on the husbands' fertility pressure(β = 0.11).

CONCLUSION

Overall, the study revealed that in the couples who use donor sperm to expect pregnancy, the male has higher fertility pressure. Insecure attachment can cause more severe fertility pressure, fertility pressure is also affected by one's partner.

Direct and Gradual Electrical Testicular Shocks Stimulate Spermatogenesis and Activate Sperms in Infertile Men: A Randomized Controlled Trial

Infertility was reported in approximately 15% of all heterozygous couples, with the male factor accounting for nearly half of the cases. This typically occurs due to low sperm production, sperm dysfunction, and sperm delivery obstruction. In this randomized controlled single-blind clinical trial, 90 infertile male subjects diagnosed with oligospermia, hypospermia, asthenozoospermia, or necrozoospermia were recruited. Semen samples were obtained with the masturbation method and an assessment of semen volume, sperm count, and motility was performed. Five milliamps of electrical shock was delivered to the participants through the fertility improvement device. Semen analysis was collected 4 months post-intervention from all subjects. Data were collected and an analysis of pre- and post-intervention results was performed. There was an improvement in the count, volume, and motility of the patient's sperm after electrical shock treatment compared with the control group. By using the analysis of variance (ANOVA) test, there were statistically significant differences between the first and the second seminal analysis results (<.05). All other results were found to be independently correlated. This study demonstrated that using a painless, convenient at-home device, which is designed to contain all the testis tissue as a cup and then extend to include the scrotal roots reaching the penile root to include the epididymis, could significantly improve sperm motility and count. This device can be utilized to tackle the significant issue of infertility in a cost-effective, safe, and efficacious manner. An ultrasound was done before and after using the device as well as years after with no changes noted.Clinical Trial's Registration Number: NCT04173052.

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.

Influence of Mediterranean Diet on Sexual Function in People with Metabolic Syndrome: A Narrative Review

Metabolic syndrome (MS), a cluster of cardiometabolic disorders, and sexual dysfunction are two conditions that impact a large proportion of the general population. Although they can occur independently, they are frequently linked and significantly affect people's quality of life. In recent years, research has increasingly focused on the importance of diet, particularly the Mediterranean diet (MD), in modulating sexual function due to its anti-inflammatory, antioxidant, and vasodilatory properties. In this narrative review, we examined the relationship between MS and sexual function in both men and women, with a special emphasis on the MD's therapeutic efficacy in improving sexual dysfunction. In men, MD has been shown to ameliorate erectile dysfunction, as well as several sperm parameters, perhaps leading to improved fertility. On the other hand, adherence to MD has been demonstrated to partially recover several sexual dysfunctions in women, such as those related to their menstrual cycle, menopause, endometriosis, and polycystic ovary syndrome. These favorable effects of MD have been demonstrated in both sexes also among people affected by MS. However, more targeted studies are needed to validate these data for different dietary approaches as well.

Plin4 exacerbates cadmium-decreased testosterone level via inducing ferroptosis in testicular Leydig cells

Strong evidence indicates that environmental stressors are the risk factors for male testosterone deficiency (TD). However, the mechanisms of environmental stress-induced TD remain unclear. Based on our all-cause male reproductive cohort, we found that serum ferrous iron (Fe2⁺) levels were elevated in TD donors. Then, we explored the role and mechanism of ferroptosis in environmental stress-reduced testosterone levels through in vivo and in vitro models. Data demonstrated that ferroptosis and lipid droplet deposition were observed in environmental stress-exposed testicular Leydig cells. Pretreatment with ferrostatin-1 (Fer-1), a specific ferroptosis inhibitor, markedly mitigated environmental stress-reduced testosterone levels. Through screening of core genes involved in lipid droplets formation, it was found that environmental stress significantly increased the levels of perilipins 4 (PLIN4) protein and mRNA in testicular Leydig cells. Further experiments showed that Plin4 siRNA reversed environmental stress-induced lipid droplet deposition and ferroptosis in Leydig cells. Additionally, environmental stress increased the levels of METTL3, METTL14, and total RNA m6A in testicular Leydig cells. Mechanistically, S-adenosylhomocysteine, an inhibitor of METTL3 and METTL14 heterodimer activity, restored the abnormal levels of Plin4, Fe2⁺ and testosterone in environmental stress-treated Leydig cells. Collectively, these results suggest that Plin4 exacerbates environmental stress-decreased testosterone level via inducing ferroptosis in testicular Leydig cells.

Long-term outcomes of erectile function in adult orchidopexy patients

Objective

Cryptorchidism affects up to 6% of full-term male infants, and orchidopexy has been shown to reduce impaired spermatogenesis and malignant risks significantly. However, the relationship between orchidopexy and sexual function has not been investigated. Therefore, this study aimed to evaluate sexual function outcomes in adult patients who underwent orchidopexy for unilateral undescended testis in childhood.

Methods

Totally, 58 adult patients who underwent unilateral orchidopexy in childhood were enrolled in the study. Erectile dysfunction (ED) was assessed by the International Index of Erectile Function (IIEF)-15 questionnaire. All participants underwent serum (testosterone and follicular stimulating hormone levels) measurement and semen analysis. Paternity rates were evaluated to assess the patient's fertility. Additionally, anxiety, depression, and stress were measured by the self-rating anxiety scale, self-rating depression scale, and visual analogue scale, respectively.

Results

There was no statistically significant difference between IIEF-15 scores (intercourse satisfaction, orgasmic function, sexual desire, or overall satisfaction) comparing the cryptorchidism group with the control group; however, the ED was significantly higher in the cryptorchidism patients (p=0.000). At the median follow-up of 16.3 years, 15.5% of our patients complained of moderate to severe ED. Most patients were satisfied with their overall relationship and only 34.5% were not satisfied. Anxiety, depression, and stress were more prevalent in cryptorchidism than in healthy men (anxiety: 72.4% vs. 20.7%; depression: 19.0% vs. 5.2%; stress: 60.3% vs. 10.3%; p˂0.05). Additionally, ED was negatively associated with anxiety, depression, and stress symptoms (r=-0.518, p=0.000; r=-0.448, p=0.000; r=-0.591, p=0.000, respectively). Moreover, ED had a significant correlation with advancing age, psychological factors (anxiety, depression, and stress), infertility, and low levels of testosterone (p˂0.05).

Conclusion

Low testosterone, infertility, and psychological burden (anxiety, depression, and stress) are used as factors for predicting ED outcomes after orchidopexy for undescended testis to guide physicians to evaluate the efficacy of testosterone replacement and psychological support in their management.

Prevalence of sexual dysfunction in health care workers: a systematic review and meta-analysis

INTRODUCTION

Health care workers represent a substantial demographic whose welfare and work efficiency are crucial to public health and societal well-being. However, the prevalence of sexual dysfunction within this group is often overlooked, despite its significant occurrence.

OBJECTIVE

To evaluate the worldwide prevalence of sexual dysfunction among health care workers.

METHODS

A comprehensive systematic review and meta-analysis of observational studies ranging from 2003 to 2023 were performed to compile prevalence estimates of sexual dysfunction among health care workers. A random effects model was implemented to amalgamate the prevalence analysis. Study heterogeneity was discerned by I2 and χ2 statistics. To assess potential publication bias, an Egger's test and a funnel plot were employed.

RESULTS

This meta-analysis incorporated 39 studies from 16 countries, encompassing 44 017 health care workers. The pooled prevalence of sexual dysfunction among health care workers was 46.79% (95% CI, 38.09%-55.68%), with a slightly higher prevalence of 49.57% (95% CI, 38.18%-61.01%) among clinical health care workers. The most prevalent forms of sexual dysfunction identified were loss of libido (51.26%), erectile dysfunction (36.99%), sexual dissatisfaction (36.90%), pain during intercourse (28.23%), orgasmic disorders (25.13%), low sexual arousal (23.54%), and lubrication disorders (22.62%). Among various health care professions, nurses exhibited the highest prevalence of sexual dysfunction (56.29%), followed by doctors (37.63%) and other health care workers (24.96%). Additionally, female health care workers experienced a higher prevalence of sexual dysfunction (47.61%) as compared with their male counterparts (32.01%).

CONCLUSION

This study indicates that nearly half of health care professionals report experiencing sexual dysfunction, with loss of libido being the most common manifestation. Addressing this issue requires a multistakeholder approach.

Clomiphene Citrate Treatment as an Alternative Therapeutic Approach for Male Hypogonadism: Mechanisms and Clinical Implications

Male hypogonadism, which is characterized by low testosterone levels, has a significant impact on male sexual function, overall health, and fertility. Testosterone replacement therapy (TRT) is the conventional treatment for this condition, but it has potential adverse effects and is not suitable for men seeking to conceive. Testosterone plays an essential role in male sexual function, metabolism, mood, and overall well-being. Clomiphene citrate, a drug originally developed for female infertility, has recently gained attention as an off-label treatment for male hypogonadism. By blocking the negative feedback of estrogen on the hypothalamus and pituitary glands, clomiphene stimulates gonadotropin secretion, leading to increased endogenous testosterone production, which, in turn, improves sperm parameters and fertility and alleviates the symptoms of hypogonadism. Regarding the safety profile of clomiphene compared with TRT, clomiphene appears to confer a lower risk than TRT, which is associated with adverse effects such as polycythemia. Furthermore, combination therapy with clomiphene and anastrozole or human chorionic gonadotropin has been investigated as a potential approach to enhancing the effectiveness of treatments for improving hypogonadism symptoms. In conclusion, clomiphene citrate may offer a promising alternative to TRT for men with hypogonadism, particularly those desiring fertility preservations. However, its long-term efficacy and safety remain inadequately understood. Future research should focus on exploring the benefits of combination therapies and personalized treatment strategies based on individual patient characteristics.

Poweromin X Ten, a polyherbal formulation improves male sexual function: In vivo and network pharmacology study

Introduction

Poweromin X Ten (PXT) is a polyherbal formulation, traditionally used to enhance male sexual function. However, the safety and benefits of PXT have not been scientifically evaluated. Therefore, the present study investigated the toxicity and aphrodisiac potential of PXT in male rats and explored its principal mechanisms of action.

Methods

Male Wistar rats were orally administered PXT (50 or 100 mg/kg) for 28 days, and sexual activity parameters, including latency and frequency of mounting and intromissions, were studied. The reproductive toxicity and spermatogenic potential were also examined. Furthermore, dopamine and serotonin levels in brain regions associated with sexual activity were assessed. Network analysis was used to identify the key bioactive compounds and their core targets involved in their beneficial actions.

Results

Treatment with PXT improved sexual activity in male rats, as evidenced by reduced mounting and intromission latency and a significant increase in mount frequency. Moreover, PXT exhibited spermatogenic potential and did not induce reproductive toxicity. Notably, treatment with 50 mg/kg PXT elevated dopamine levels in median preoptic area and hypothalamus. Pathway analysis indicated that PXT primarily modulated the PI3K-Akt, calcium, and MAPK signalling pathways to enhance male sexual function. Network analysis identified macelignan, β-estradiol, testosterone, and paniculatine as key bioactive components of PXT, which likely act through core targets, such as androgen receptor (AR), Mitogen-activated protein kinase 3 (MAPK3), epidermal growth factor receptor (EGFR), estrogen receptor 1 (ESR1), and vascular endothelial growth factor (VEGF) to facilitate the improvement of male sexual function.

Conclusion

Study results suggest that PXT is a safer alternative with aphrodisiac and spermatogenic potential. These effects are partly attributed to the enhanced dopamine levels in the brain. Furthermore, this study provides insights into the specific signalling pathways and bioactive compounds that underlie the improvements in male sexual function associated with PXT.

Symptom burden in chronic liver disease

Chronic liver disease (CLD) is a significant contributor to global mortality. For people who are living with CLD, however, there is a substantial and often overlooked burden of physical and psychological symptoms that significantly affect health-related quality of life. CLD frequently presents with a multitude of interrelated and intricate symptoms, including fatigue, pruritus, muscle cramps, sexual dysfunction, and falls. Increasingly, there is interest in studying and developing interventional strategies to provide a more global approach to managing these complex patients. Moreover, in addition to established guidelines for the management of conventional complications, such as ascites and hepatic encephalopathy, there have been efforts in developing evidence-based guidance for the treatment of the more subjective yet still problematic elements. This review will address the management of these less "classical" but nonetheless important symptoms.

Management of Male Infertility with Coexisting Sexual Dysfunction: A Consensus Statement and Clinical Recommendations from the Asia-Pacific Society of Sexual Medicine (APSSM) and the Asian Society of Men's Health and Aging (ASMHA)

Male infertility (MI) and male sexual dysfunction (MSD) can often coexist together due to various interplay factors such as psychosexual, sociocultural and relationship dynamics. The presence of each form of MSD can adversely impact male reproduction and treatment strategies will need to be individualized based on patients' factors, local expertise, and geographical socioeconomic status. The Asia Pacific Society of Sexual Medicine (APSSM) and the Asian Society of Men's Health and Aging (ASMHA) aim to provide a consensus statement and practical set of clinical recommendations based on current evidence to guide clinicians in the management of MI and MSD within the Asia-Pacific (AP) region. A comprehensive, narrative review of the literature was performed to identify the various forms of MSD and their association with MI. MEDLINE and EMBASE databases were searched for the following English language articles under the following terms: "low libido", "erectile dysfunction", "ejaculatory dysfunction", "premature ejaculation", "retrograde ejaculation", "delayed ejaculation", "anejaculation", and "orgasmic dysfunction" between January 2001 to June 2022 with emphasis on published guidelines endorsed by various organizations. This APSSM consensus committee panel evaluated and provided evidence-based recommendations on MI and clinically relevant MSD areas using a modified Delphi method by the panel and specific emphasis on locoregional socio-economic-cultural issues relevant to the AP region. While variations exist in treatment strategies for managing MI and MSD due to geographical expertise, locoregional resources, and sociocultural factors, the panel agreed that comprehensive fertility evaluation with a multidisciplinary management approach to each MSD domain is recommended. It is important to address individual MI issues with an emphasis on improving spermatogenesis and facilitating reproductive avenues while at the same time, managing various MSD conditions with evidence-based treatments. All therapeutic options should be discussed and implemented based on the patient's individual needs, beliefs and preferences while incorporating locoregional expertise and available resources.

A hemizygous loss-of-function variant in BCORL1 is associated with male infertility and oligoasthenoteratozoospermia

Oligoasthenoteratozoospermia (OAT) is a common type of male infertility; however, its genetic causes remain largely unknown. Some of the genetic determinants of OAT are gene defects affecting spermatogenesis. BCORL1 (BCL6 corepressor like 1) is a transcriptional corepressor that exhibits the OAT phenotype in a knockout mouse model. A hemizygous missense variant of BCORL1 (c.2615T > G:p.Val872Gly) was reported in an infertile male patient with non-obstructive azoospermia (NOA). Nevertheless, the correlation between BCORL1 variants and OAT in humans remains unknown. In this study, we used whole-exome sequencing to identify a novel hemizygous nonsense variant of BCORL1 (c.1564G > T:p.Glu522*) in a male patient with OAT from a Han Chinese family. Functional analysis showed that the variant produced a truncated protein with altered cellular localization and a dysfunctional interaction with SKP1 (S-phase kinase-associated protein 1). Further population screening identified four BCORL1 missense variants in subjects with both OAT (1 of 325, 0.31%) and NOA (4 of 355, 1.13%), but no pathogenic BCORL1 variants among 362 fertile subjects. In conclusion, our findings indicate that BCORL1 is a potential candidate gene in the pathogenesis of OAT and NOA, expanded its disease spectrum and suggested that BCORL1 may play a role in spermatogenesis by interacting with SKP1.

Can semen analysis be utilized as a screening tool for overall health in young men?

Traditionally, semen analysis has been viewed solely as a tool for assessing male fertility. However, emerging research suggests that abnormal semen parameters may serve as indicators of broader health issues beyond reproductive function. Studies have revealed significant associations between abnormal semen parameters and an increased risk of chronic diseases such as prostate cancer, diabetes, ischemic heart disease, and metabolic disorders. These findings challenge the conventional understanding and position semen analysis as a potential screening tool for overall male health. The correlation between abnormal semen parameters and conditions like erectile dysfunction further underscores the multifaceted implications of semen quality. This suggests that abnormal semen parameters may be a risk factor for poorer overall health and a higher likelihood of developing comorbidities over time. Given these compelling associations, there is a growing call to integrate semen analysis into routine health assessments for young men, particularly in conjunction with established general health screenings. This proactive approach aligns with a preventative healthcare paradigm, facilitating early detection of underlying health concerns and timely interventions. However, overcoming cultural, logistical, and cost-related barriers is crucial for the successful implementation of this shift in reproductive health.

pH Homeodynamics and Male Fertility: A Coordinated Regulation of Acid-Based Balance during Sperm Journey to Fertilization

pH homeostasis is crucial for spermatogenesis, sperm maturation, sperm physiological function, and fertilization in mammals. HCO3- and H+ are the most significant factors involved in regulating pH homeostasis in the male reproductive system. Multiple pH-regulating transporters and ion channels localize in the testis, epididymis, and spermatozoa, such as HCO3- transporters (solute carrier family 4 and solute carrier family 26 transporters), carbonic anhydrases, and H+-transport channels and enzymes (e.g., Na+-H+ exchangers, monocarboxylate transporters, H+-ATPases, and voltage-gated proton channels). Hormone-mediated signals impose an influence on the production of some HCO3- or H+ transporters, such as NBCe1, SLC4A2, MCT4, etc. Additionally, ion channels including sperm-specific cationic channels for Ca2+ (CatSper) and K+ (SLO3) are directly or indirectly regulated by pH, exerting specific actions on spermatozoa. The slightly alkaline testicular pH is conducive to spermatogenesis, whereas the epididymis's low HCO3- concentration and acidic lumen are favorable for sperm maturation and storage. Spermatozoa pH increases substantially after being fused with seminal fluid to enhance motility. In the female reproductive tract, sperm are subjected to increasing concentrations of HCO3- in the uterine and fallopian tube, causing a rise in the intracellular pH (pHi) of spermatozoa, leading to hyperpolarization of sperm plasma membranes, capacitation, hyperactivation, acrosome reaction, and ultimately fertilization. The physiological regulation initiated by SLC26A3, SLC26A8, NHA1, sNHE, and CFTR localized in sperm is proven for certain to be involved in male fertility. This review intends to present the key factors and characteristics of pHi regulation in the testes, efferent duct, epididymis, seminal fluid, and female reproductive tract, as well as the associated mechanisms during the sperm journey to fertilization, proposing insights into outstanding subjects and future research trends.

Gene-deficient mouse model established by CRISPR/Cas9 system reveals 15 reproductive organ-enriched genes dispensable for male fertility

Since the advent of gene-targeting technology in embryonic stem cells, mice have become a primary model organism for investigating human gene function due to the striking genomic similarities between the two species. With the introduction of the CRISPR/Cas9 system for genome editing in mice, the pace of loss-of-function analysis has accelerated significantly. This has led to the identification of numerous genes that play crucial roles in male reproductive processes, including meiosis, chromatin condensation, flagellum formation in the testis, sperm maturation in the epididymis, and fertilization in the oviduct. Despite the advancements, the functions of many genes, particularly those enriched in male reproductive tissues, remain largely unknown. In our study, we focused on 15 genes and generated 13 gene-deficient mice [4933411K16Rik, Adam triple (Adam20, Adam25, and Adam39), BC048671, Cfap68, Gm4846, Gm4984, Gm13570, Nt5c1b, Ppp1r42, Saxo4, Sh3d21, Spz1, and Tektl1] to elucidate their roles in male fertility. Surprisingly, all 13 gene-deficient mice exhibited normal fertility in natural breeding experiments, indicating that these genes are not essential for male fertility. These findings have important implications as they may help prevent other research laboratories from duplicating efforts to generate knockout mice for genes that do not demonstrate an apparent phenotype related to male fertility. By shedding light on the dispensability of these genes, our study contributes to a more efficient allocation of research resources in the exploration of male reproductive biology.

Integration of transcriptomics and metabolomics reveals toxicological mechanisms of ZhuRiHeng drop pill in the 180-day repeated oral toxicity study

Background: ZhuRiHeng Drop Pill (ZRH) is a traditional Mongolian medicinal preparation. Despite its long history of use for the treatment of coronary heart disease, there have been few toxicological studies of the safety profile of ZRH. Purpose: In order to comprehensively elucidate the underlying mechanisms behind the observed toxicity of ZRH on rat livers in the 180-day repeated oral toxicity study, we conducted a comprehensive analysis by integrating transcriptomic and metabolomic data. Methods: High-resolution mass spectrometry was conducted to evaluate the constituents of ZRH. For the acute oral toxicity study, mice were administered a dose of 32 g/(kg·d) of ZRH, while rats were instead orally administered 0.934, 1.868, or 3.736 g/(kg·d) of ZRH over a 180-day period in a 180-day repeated oral toxicity study. Conventional index and organ weights/histology were then monitored to detect any potential ZRH treatment-related toxicity. To identify key genes and metabolites involved in ZRH toxicological processes, we performed transcriptomic and metabolomic analyses of liver tissue upon ZRH treatment using RNA-seq techniques, qPCR and liquid chromatography-mass spectrometry analyses. Results: A total of 60 compounds in ZRH were identified and speculated in positive and negative ion modes. Mice in the acute toxicity study exhibited no signs of ZRH-related toxicity. In a protracted oral toxicity investigation spanning 180 days, discernible elevations in liver ratios were noted in both male and female rats across all three dose cohorts, relative to the control group (p < 0.05 or p < 0.01). Upon subjecting to ZRH treatment, our transcriptomic and qPCR analyses unveiled notable upregulation of crucial genes, exemplified by Abcb1b and Cyp2b2, known for theirs involvement in liver drug transport and metabolism function. Furthermore, our untargeted metabolomic analysis provided supplementary insights, revealing significant regulation in pyrimidine metabolism, as well as alanine, aspartate, and glutamate metabolism pathways. Conclusion: Our study unveils a panoramic understanding of the temporal, dosage-specific, and gene dimensions surrounding the metabolic and transcriptional shifts induced by ZRH exposure. As we peer into the future, recommendations emerge for further exploration, encompassing aspects such as time dynamics, dosage considerations, and gene-centric avenues to enhance therapeutic efficacy.

Causal relationship between genetically predicted type 2 diabetes mellitus and male infertility

Background

Diabetes mellitus (DM) stands as the most prevalent endocrine abnormality affecting the physiological systems and organs and impairing the male reproductive functions. Type 2 Diabetes Mellitus (T2DM), accounting for about 90-95% of DM, is closely associated with male infertility. However, the magnitude of the causal relationships between T2DM and male infertility remains unclear. The current investigation was to explore the causal relationship between T2DM and male infertility utilizing the Mendelian Randomization (MR) analysis.

Methods

A two-sample MR (2SMR) analysis was conducted to investigate the causal relationship between T2DM and male infertility in the European population from the genome-wide association study (GWAS) summary data that was publicly accessible. GWAS for T2DM and male infertility were extracted from the IEU Open GWAS Project database, with the resulting data encompassing 680 cases and 72,799 controls as the outcome data. Five MR methods were employed for the 2SMR analyses, namely the MR-Egger, weighted median estimation (WME), weighted mode (WM), inverse-variance weighted (IVW), and simple mode. The primary analytical technique utilized in this study was the IVW method, and a multivariate MR analysis was executed to examine the potential mediating influences of T2DM on male infertility.

Results

Following were the odds ratios (ORs) and associated 95% CIs derived from IVW (fixed effects), MR-Egger, WM, WME, and simple mode approaches: 0.824 (95% CI 0.703-0.966), 0.726 (95% CI 0.527-1.001), 0.827 (95% CI 0.596-1.150), 0.841 (95% CI 0.654-1.082), and 0.875 (95% CI 0.544-1.405), respectively. The outcomes of the heterogeneity tests were P=0.378 and P=0.384, respectively, implying no heterogeneity. Egger-intercept outcomes were P=0.374, highlighting the absence of pleiotropy. The stability of the results was affirmed through the leave-one-out analysis. Notably, all F-values surpassed 10, indicating the absence of weak bias attributed to instrument variables(IVs).

Conclusions

This research furnishes evidence supporting a causal association between T2DM and male infertility. These insights offer a foundation for future investigations aiming to establish the association between genetically predicted T2DM and male infertility. These outcomes suggest the significance of active monitoring and proactive measures for preventing infertility in male individuals with T2DM. Furthermore, careful consideration is required for individuals of reproductive age to prevent and treat T2DM.

Investigation of Vitamin D Levels in Men with Suspected Infertility

Male infertility may be caused by an impaired sperm functionality, with insufficient vitamin D levels affecting the quantity and development of motile sperm. Given the influence of vitamin D on vital aspects of male infertility, this study aimed to investigate the correlation between vitamin D levels and male infertility, along with exploring the possible mechanism of action. A total of 306 male participants were included. Semen samples were collected and analyzed for semen parameters with demographic features. Patients were classified into two groups based on vitamin D levels of <20 ng/mL (low) and ≥20 ng/mL (high). The Super-PRED, Swiss TargetPrediction, GeneCards, and DisGeNET databases were utilized to retrieve potential molecular targets associated with both vitamin D and male infertility, while the STRING database was employed for constructing protein-protein interaction (PPI) networks and conducting a functional enrichment analysis. A total of 146 patients (47.71%) showed low vitamin D levels and 160 patients (52.29%) had high vitamin D levels. Vitamin D was not strongly influenced by demographic parameters. Vitamin D demonstrated significant positive correlations with type A and B sperm motility. Conversely, it exhibited significant negative correlations with type C and D sperm motility. Hormones (thyroid-stimulating hormone, follicle-stimulating hormone, prolactin, luteinizing hormone, estradiol) were not significantly associated with vitamin D; however, testosterone was significantly positive correlated with vitamin D. Notably, no significant correlation was found between vitamin D levels and iron, ferritin, hemoglobin, hematocrit, calcium, magnesium, and phosphorus levels. The functional annotations of potential vitamin D targets associated with male infertility primarily indicated involvement in regulating infection, the immune response, forkhead box O (FOXO) and hypoxia-inducible factor 1 (HIF1) signals in male infertility. Adequate vitamin D levels are associated with an improved reproductive health, evidenced by positive correlations with hormone levels and sperm motility. Specifically, the FOXO and HIF-1 signaling pathways may be effective in the potential molecular mechanisms underlying the impact of vitamin D on male infertility and/or in the significant correlations identified.

KLF2 controls proliferation and apoptosis of human spermatogonial stem cells via targeting GJA1

Human spermatogonial stem cells (SSCs) are essential for spermatogenesis and male fertility. However, molecular mechanisms regulating fate determinations of human SSCs remain elusive. In this study, we revealed that KLF2 decreased the proliferation, DNA synthesis, and colonization of human SSCs as well as increased apoptosis of these cells. We identified and demonstrated that GJA1 was a target gene for KLF2 in human SSCs. Notably, KLF2 overexpression rescued the reduction of proliferation of human SSCs caused by GJA1 silencing as well as the enhancement of apoptosis of human SSCs. Abnormalities in the higher level of KLF2 and/or KIF2 mutations might lead to male infertility. Collectively, these results implicate that KLF2 inhibits proliferation of human SSCs and enhances their apoptosis by targeting GJA1. This study thus provides novel genetic mechanisms underlying human spermatogenesis and azoospermia, and it offers new endogenous targets for treating male infertility.

Asperosaponin VI protects against spermatogenic dysfunction in mice by regulating testicular cell proliferation and sex hormone disruption

ETHNOPHARMACOLOGICAL RELEVANCE

Studies have found that the causes of male infertility are complex, and spermatogenic dysfunction accounts for 30%-65% of male infertility causes, which is the main cause of male infertility. Asperosaponin VI (ASVI) is a saponin extracted from the traditional Chinese herb Dipsacus asperoides C.Y.Cheng & T.M.Ai. However, the precise protective impact and underlying mechanism of ASVI in the therapy of spermatogenic dysfunction remain unknown.

AIM OF THE STUDY

To investigate the impact of ASVI on the spermatogenic dysfunction induced by cytoxan (CTX) in mice, as well as explore any potential mechanisms.

MATERIALS AND METHODS

Potential ASVI targets were screened using the Pharmapper and Uniprot databases, while genes related to spermatogenic dysfunction were collected from the GeneCards database. The String and Cytoscape databases were then used for PPI analysis for the common targets of ASVI and spermatogenic dysfunction. Meanwhile, the Metascape database was used for KEGG and GO analysis. In vivo experiments, spermatogenic dysfunction was induced in male mice by intraperitoneal administration of CTX (80 mg/kg). To demonstrate the possible protective effects of ASVI on reproductive organs, CTX-induced spermatogenic dysfunction mice with different dosages of ASVI (0.8, 4, 20 mg/kg per day) treatment were collected and gonad weight was detected. The testis and epididymis were detected again by H&E. To assess the impact of ASVI on fertility in male mice, we analyzed sperm quality, serum hormones, sexual behavior, and fertility. The mechanism was investigated using WB, IF, IHC, and Co-IP technology.

RESULTS

The ASVI exhibited interactions with 239 associated targets. Furthermore, 1555 targets associated with spermatogenic dysfunction were predicted, and further PPI analysis identified 6 key targets. Among them, the EGFR gene exhibited the highest degree of connection and was at the core of the network. Based on the GO and KEGG enrichment analysis, ASVI may affect spermatogenic dysfunction through the EGFR pathway. In vivo experiments, ASVI significantly improved CTX-induced damage to male fertility and reproductive organs, increasing sperm quality. At the same time, ASVI can resist CTX-induced testicular cell damage by increasing p-EGFR, p-ERK, PCNA, and p-Rb in the testis and by promoting the interaction of CyclinD1 with CDK4. In addition, ASVI can also regulate sex hormone disorders and protect male fertility.

CONCLUSIONS

ASVI improves CTX-induced spermatogenesis dysfunction by activating the EGFR signaling pathway and regulating sex hormone homeostasis, which may be a new potential protective agent for male spermatogenic dysfunction.

Investigating the prevalence of erectile dysfunction among men exposed to organophosphate insecticides

INTRODUCTION

Erectile dysfunction (ED) poses a significant disease morbidity and contributor to male infertility, where an estimated 20-40% of men are affected annually. While several risk factors have been identified in the etiology of ED (e.g., aging, heart disease, diabetes, and obesity), the complete pathogenesis remains to be elucidated. Over the last few decades, the contribution of environmental exposures to the pathogenesis of ED has gained some attention, though population studies are limited and results are mixed. Among environmental contaminants, organophosphate (OP) insecticides represent one of the largest chemical classes, and chlorpyrifos is the most commonly used OP in the U.S. OP exposure has been implicated in driving biological processes, including inflammation, reactive oxygen species production, and endocrine and metabolism disruption, which have been demonstrated to adversely affect the hypothalamus and testes and may contribute to ED. Currently, studies evaluating the association between OPs and ED within the U.S. general population are sparse.

METHODS

Data were leveraged from the National Health and Nutrition Examination Survey (NHANES), which is an annually conducted, population-based cross-sectional study. Urinary levels of 3,5,6-trichloro-2-pyridinol (TCPy), a specific metabolite of the most pervasive OP insecticide chlorpyrifos, were quantified as measures of OP exposure. ED was defined by responses to questionnaire data, where individuals who replied "sometimes able" or "never able" to achieve an erection were classified as ED. Chi-square, analysis of variance (ANOVA), and multivariable, weighted linear and logistic regression analyses were used to compare sociodemographic variables between quartiles of TCPy exposure, identify risk factors for TCPy exposure and ED, and to analyze the relationship between TCPy and ED.

RESULTS

A total of 671 adult men were included in final analyses, representing 28,949,379 adults after survey weighting. Approximately 37% of our cohort had ED. Smoking, diabetes, aging, Mexican-American self-identification, and physical inactivity were associated with higher ED prevalence. Analysis of TCPy modeled as a continuous variable revealed nonsignificant associations with ED (OR = 1.02 95% CI [0.95, 1.09]). Stratification of total TCPy into quartiles revealed increased odds of ED among adults in the second and fourth quartiles, using the first quartile as the reference (OR = 2.04 95% CI [1.11, 3.72], OR = 1.51 95% CI [0.58, 3.93], OR = 2.62 95% CI [1.18, 5.79], for quartiles 2, 3, and 4, respectively).

CONCLUSIONS

The results of our study suggest a potential role for chlorpyrifos and other OPs the pathogenesis of ED. Future studies are warranted to validate these findings, determine clinical significance, and to investigate potential mechanisms underlying these associations.

Hypogonadism and sexual function in men affected by adrenocortical carcinoma under mitotane therapy

Purpose

Adrenocortical carcinoma (ACC) is a rare and aggressive tumor. ACC male patients under adjuvant mitotane therapy (AMT) frequently develop hypogonadism, however sexual function has never been assessed in this setting. The aim of this retrospective study was to evaluate in AMT treated ACC patients the changes in Luteinizing hormone (LH), Sex Hormone Binding Globulin (SHBG), total testosterone (TT) and calculated free testosterone (cFT), the prevalence and type of hypogonadism and sexual function, the latter before and after androgen replacement therapy (ART).

Methods

LH, SHBG, TT and cFT were assessed in ten ACC patients at baseline (T0) and six (T1), twelve (T2), and eighteen (T3) months after AMT. At T3, ART was initiated in eight hypogonadal patients, and LH, SHBG, TT and cFT levels were evaluated after six months (T4). In six patients, sexual function was evaluated before (T3) and after (T4) ART using the International Index of Erectile Function-15 (IIEF-15) questionnaire.

Results

Under AMT we observed higher SHBG and LH and lower cFT levels at T1-T3 compared to T0 (all p<0.05). At T3, hypergonadotropic hypogonadism and erectile dysfunction (ED) were detected in 80% and 83.3% of cases. At T4, we observed a significant cFT increase in men treated with T gel, and a significant improvement in IIEF-15 total and subdomains scores and ED prevalence (16.7%) in men under ART.

Conclusion

AMT was associated with hypergonatropic hypogonadism and ED, while ART led to a significant improvement of cFT levels and sexual function in the hypogonadal ACC patients. Therefore, we suggest to evaluate LH, SHBG, TT and cFT and sexual function during AMT, and start ART in the hypogonadal ACC patients with sexual dysfunction.

Long-term impact of commonly performed operations in pediatric urology on reproductive and sexual health

Introduction

Sexual dysfunction is highly prevalent among men of reproductive age. Clinical practice guidelines have been established to assist providers in identification and education of patients who are at increased risk for infertility and sexual dysfunction with certain congenital and acquired urogenital disorders. The authors sought to review the reproductive and sexual health implications of treating common childhood urological conditions with commonly performed surgical procedures.

Methods

To ensure the inclusion of influential and highly regarded research, we prioritized citations from the most-frequently cited articles on our respective review topics. Our inclusion criteria considered studies with substantial sample sizes and rigorously designed methodologies. Several topics were reviewed, including penile chordee, hypospadias, posterior urethral valves, varicoceles, undescended testicles, and testicular torsion.

Results

For chordee, surgical plication or corporal grafting may be employed. Erectile function remains unaltered post-surgery, while penile length may decrease after repair, which may be avoided using dermal grafts. Hypospadias repair hinges on severity and availability of the urethral plate. Those who underwent hypospadias repair report decreased penile length, but sexual satisfaction, libido, and semen quality are comparable to controls. Posterior urethral valves are usually treated with valve ablation. While valve ablation and bladder neck incision have not been found to affect ejaculatory function, high degree of concurrent renal dysfunction related to nephrogenic and bladder dysfunction may impact semen parameters and erectile function. Regarding varicocele, earlier management has been associated with better long-term fertility outcomes, and surgical intervention is advisable if there is observable testicular atrophy. Earlier repair of undescended testicle with orchiopexy has been found to improve fertility rates as well as decrease malignancy rates. Unilateral orchiectomy for testicular torsion without the ability for salvage has been shown to have decreased semen parameters but unaffected fertility rates.

Conclusion

Infertility and sexual dysfunction are multivariable entities, with etiologies both congenital and acquired. At the same time, many common pediatric urology surgeries are performed to correct anatomic pathology that may lead to reproductive dysfunction in adulthood. This review highlights the need for diagnosis and management of pediatric urologic conditions as these conditions may impact long-term sexual function post-operatively.

Association between MTHFR c.677C>T variant and erectile dysfunction among males attending fertility clinic

Genetic risk factors have been shown to contribute to the development of sexual dysfunction. However, the role of methylenetetrahydrofolate reductase ( MTHFR ) gene variants in the risk of erectile dysfunction (ED) remains unclear. In this study, we recruited 1254 participants who underwent ED assessed by the International Index of Erectile Function-5. The MTHFR c.677C>T variant was also measured by fluorescence polymerase chain reaction (PCR). No significant difference in the genotypic frequency of the MTHFR C677T polymorphism (CC, CT, and TT) was observed between men from the ED and non-ED groups. In addition, on binary logistic regression analysis, both crude and adjusted models showed that the risk of ED was not significantly associated with the C677T polymorphism. Interestingly, a significantly higher frequency of the 677TT polymorphism was found in severe and moderate ED (P = 0.02). The positive correlation between the MTHFR 677TT polymorphism and severe ED was confirmed by logistic regression analysis, even after adjusting for potential confounders (odds ratio [OR] = 2.46, 95% confidence interval [CI] 1.15-5.50, P = 0.02). These findings suggest a positive correlation between the MTHFR 677TT polymorphism and the risk of severe ED. Identification of MTHFR gene polymorphisms may provide complementary information for ED patients during routine clinical diagnosis.

Hyperbaric oxygen therapy as a treatment for erectile dysfunction: a meta-analysis

INTRODUCTION

Hyperbaric oxygen therapy (HBOT) is a medical treatment in which the patient is exposed to 100% oxygen at a higher than atmospheric pressure. Over the past few decades, HBOT has been used to treat a variety of medical conditions. In recent times, there has been a rising curiosity regarding the potential therapeutic benefits of HBOT in the treatment of erectile dysfunction (ED).

AIMS

The study sought to review and meta-analyze available data regarding the use of HBOT for ED, including its potential mechanisms of action and effectiveness.

METHODS

We included only articles that evaluated the impact of HBOT on ED symptoms using the International Index of Erectile Function score. Prospective nonrandomized studies or randomized controlled clinical trials were included. Data extraction was performed in duplicate. Data analysis was conducted using Review Manager 5.41, and the presence of heterogeneity between studies was evaluated. The results were presented as the mean difference (MD) with 95% confidence interval (CI).

RESULTS

A total of 5 studies that reported outcomes using the International Index of Erectile Function scores were included in this analysis. In patients with post-robotic-assisted laparoscopic prostatectomy-induced ED, the analysis showed a significant MD of -4.13 (95% CI, -6.08 to -2.18; P < .0001) in favor of the control group. Conversely, patients who received HBOT for reasons other than ED exhibited an MD of 4.58 (95% CI, 2.63 to 6.52; P < .00001). In the group that received HBOT for pure vasculogenic ED, the MD was 10.50 (95% CI, 9.92 to 11.08) in favor of HBOT. A meta-analysis of these data revealed a nonsignificant difference in erectile function scores, with an MD of 3.86 (95% CI, -2.13 to 9.86; P = .21).

CONCLUSION

The use of HBOT in the treatment of ED appears to be a promising approach. While further research is needed to establish the efficacy and long-term effects of this treatment, preliminary studies have shown encouraging results in terms of improving erectile function in men with vasculogenic ED.

Quality of sexual life in Mexican men after spinal cord injury

OBJECTIVE

To evaluate the quality of sexual life in men with spinal cord injury.

DESIGN

Cross-sectional analytical study.

PATIENTS

Males with a history of spinal cord injury who attended an outpatient rehabilitation service.

METHODS

An analytical study examined adult male patients with complete spinal cord injury in rehabilitation. A modified Sexual Life Quality Questionnaire (SLQQ) examined quality of sexual life, with scores below 50 suggesting significant sexual dysfunction and dissatisfaction. The assessment evaluated age, occupation, marital status, comorbidities, and treatment methods.

RESULTS

A total of 80 patients were included; 33 (41%) had a thoracic spinal cord injury, and 47 (59%) had a lumbar spinal cord injury. Thirty-seven patients (46%) were dissatisfied with the quality of their sexual life; 29 patients (88%) with thoracic spinal cord injury and 8 patients (17%) with lumbar spinal cord injury were dissatisfied with the quality of their sexual life (p = 0.001). Patients with higher education level experienced less sexual dissatisfaction (p = 0.03).

CONCLUSION

Human sexuality involves numerous interconnected elements that impact on general health. Sexual pleasure, self-esteem, and personal relationships are crucial for patients with spinal cord injury to identify rehabilitation needs. These results indicate the importance of supporting sexual well-being in recovery. Further studies of sexual enjoyment and quality of life for patients with spinal cord injury are needed, using larger and more diverse populations.

Deafening Silence of Male Infertility

Think about 6 loved ones of reproductive age in your life. Now imagine that 1 of these 6 individuals is suffering from infertility. Perhaps they feel alone and isolated, unable to discuss their heartbreak with their closest friends, family, and support network. Suffering in silence. In this editorial, we discuss the infertility journey through the lens of the patients, the providers, and the scientists who struggle with infertility each and every day. Our goal is to open a dialogue surrounding infertility, with an emphasis on dismantling the longstanding societal barriers to acknowledging male infertility as a disease. Through education, communication, compassion, and advocacy, together we can all begin to break the deafening silence of male infertility.

Assessment of sexual function before medically assisted procreation: A mixed-methods study among a sample of infertile women and men cared for in a fertility center

A mixed-methods study was conducted to investigate sexual function among infertile patients undergoing medically assisted procreation for the first time. The study employed an interview and content analysis approach, involving 45 infertile patients prior to their medically assisted procreation procedures. The findings revealed that infertile patients are a group at risk for sexual distress. Furthermore, patients with sexual dysfunctions exhibited lower levels of sexual activity, potentially diminishing their chances of achieving pregnancy. Participants faced challenges in openly discussing their sexual problems and demonstrated limited knowledge of sexual functioning. Among infertile women with sexual dysfunctions, the most frequently reported issues were sexual interest/arousal disorders, with a majority also experiencing pain during sexual activity and associated genital-pelvic pain disorders. In contrast, delayed ejaculation and erectile disorder seem to be more common in infertile men, while sexual desire and excitement disorders and premature ejaculation disorders appeared to be as common as in the general population. While the relationship between infertility and sexuality is complex, our study suggests that sexual dysfunctions or the absence of sexual activity may explain infertility. Therefore, it is imperative for clinicians to evaluate the sexual functioning of both men and women undergoing medically assisted procreation treatment, to increase their chances of procreation and offer them sexological support if needed. Future studies should expand their scope to include a larger sample size and delve into the potential etiological factors associated with sexual dysfunctions.

Comparing the clinical and singleton neonatal outcomes in male infertility patients with Oligoasthenospermia, OA, or NOA following fresh ICSI-ET using different sources of sperm

Objective

To investigate clinical and singleton newborn outcomes in fresh cycles of embryo transfer after intracytoplasmic sperm injection (ICSI-ET) with diverse sperm sources (ejaculate, epididymis, and testis) in patients with Oligoasthenospermia, obstructive azoospermia (OA) or non-obstructive azoospermia (NOA).

Methods

Patients who received fresh ICSI-ET for the first time at the First Affiliated Hospital of Zhengzhou University Reproductive Medicine Center between June 2011 and June 2021 were selected for this 10-year retrospective cohort analysis. After propensity score matching, only 1630 cycles were included in the investigation of ICS-ET clinical and singleton newborn outcomes in patients with Oligoasthenospermia, OA, and NOA using sperm from diverse sperm sources.

Results

After propensity score matching, our data revealed a negligible difference in baseline and cycle parameters among groups. In patients with Oligoasthenospermia and OA, different sperm sources do not appear to influence clinical pregnancy rates and live birth rates, nor do they influence newborn outcomes, such as newborn weight, premature birth rate, and neonatal sex ratio in singleton births, except for OA patients who use epididymal sperm having higher low birth weight (LBW) rates in singleton pregnancies than those who use testicular sperm. In addition, clinical pregnancy rates, live birth rates, singleton gestation birth weights, premature birth rates, and neonatal sex ratios were similar between patients with Oligoasthenospermia, OA, and NOA using testicular sperm.

Conclusions

Regardless of the type of male infertility (Oligoasthenospermia, OA, NOA) or sperm sources (ejaculate, epididymis, testis), a successful ICSI-ET procedure can result in similar clinical and neonatal outcomes, such as clinical pregnancy rate, live birth rate, abortion rate, neonatal birth weight and sex ratio of singleton pregnancies.

Mitigating Lower Urinary Tract Symptoms Secondary to Benign Prostatic Hyperplasia: Ameliorating Sexual Function and Psychological Well-Being in Older Men

This study aimed to investigate the prevalence of lower urinary tract symptoms (LUTS) in older men (N= 3056) with benign prostatic hyperplasia (BPH) and its effects on their sexual function and mental health. Descriptive, correlation, and regression analyses were used to explore the relationships between prostate and lower urinary tract health and psychological well-being. Better prostate and lower urinary tract health positively affected psychological well-being, and sexual function also had a positive influence. LUTS have an adverse impact on sexual function and mental health. Early intervention is crucial for mitigating the negative impact of LUTS on the quality of life in older men. Addressing prostate and lower urinary tract health issues through appropriate interventions may improve psychological well-being. Health care professionals must consider the adverse effects of BPH and LUTS on sexual function and mental health, and implement interventions to enhance the overall quality of life in older men.

Identification of a missense variant of MND1 in meiotic arrest and non-obstructive azoospermia

Meiotic arrest is a common pathologic phenotype of non-obstructive azoospermia (NOA), yet its genetic causes require further investigation. Meiotic nuclear divisions 1 (MND1) has been proved to be indispensable for meiotic recombination in many species. To date, only one variant of MND1 has been reported associated with primary ovarian insufficiency (POI), yet there has been no report of variants in MND1 associated with NOA. Herein, we identified a rare homozygous missense variant (NM_032117:c.G507C:p.W169C) of MND1 in two NOA-affected patients from one Chinese family. Histological analysis and immunohistochemistry demonstrated meiotic arrest at zygotene-like stage in prophase I and lack of spermatozoa in the proband's seminiferous tubules. In silico modeling demonstrated that this variant might cause possible conformational change in the leucine zippers 3 with capping helices (LZ3wCH) domain of MND1-HOP2 complex. Altogether, our study demonstrated that the MND1 variant (c.G507C) is likely responsible for human meiotic arrest and NOA. And our study provides new insights into the genetic etiology of NOA and mechanisms of homologous recombination repair in male meiosis.

[The urologist's role in assisted reproductive technology (ART)]

BACKGROUND

Following on from the Rapport vers une stratégie nationale de lutte contre l'infertilité (Report on a national strategy to combat infertility) submitted to the French Minister of Health in 2022, whose objective 13 is: to better identify and diagnose male infertility, we wanted to clarify with reproductive specialists what role the urologist should play in the management of the infertile couple.

METHODS

An expert consensus was reached with the Pedagogical Committee and pilots of the Transversal Specialized Training in Reproductive Medicine and Biology - Andrology, and with the presidents, board and scientific council of the French Federation for Reproductive Study (FFER).

RESULTS

In the case of infertility in a couple, the fertility of both partners should be assessed from the outset, and in the event of abnormality or failure of ART, the patient should be referred to a uro-andrologist for expert management. The uro-andrologist will set up medical or surgical treatments to improve the prognosis of the man's fertility, in conjunction with the entire ART team. It is also important for the urologist/andrologist to take charge of the man's health before conception, because of the benefits for the patient himself and for his offspring.

CONCLUSION

This expert consensus has shed light on the role of the uro-andrologist in the ART pathway, on the need for training in Andrology and on the medical demography required.

Impact of multiple sclerosis on male sexual and reproductive health

Multiple sclerosis (MS) is a chronic inflammatory and autoimmune neurodegenerative disease characterized by the destruction of myelin in the central nervous system, leading to significant health and quality of life burdens for patients. MS is most prevalent in younger individuals aged 20-40, a critical period when many patients hope to establish relationships and start families. While neurological disability, such as fatigue, sensory dysfunction, spasticity, and cognitive dysfunction, have been greatly improved with the advances in managing MS, physicians are frequently confronted with sexual and reproductive problems among younger male people with MS (PwMS). These issues mainly include erectile dysfunction, ejaculatory disorders, reduced libido, decreased sperm quality, and impaired male fertility. Despite recent studies indicating that MS negatively impacts the sexuality and fertility of male PwMS, these issues have not received sufficient attention. Genetic factors, autoimmunity, chronic inflammation, psychological factors, and the use of drugs may contribute to sexual/reproductive dysfunction in PwMS. However, like the overall understanding of MS pathophysiology, the complete mechanisms of its development remain unclear. In this study, we review the existing literature to summarize the range of sexual and reproductive issues unique to males with MS, explore potential underlying mechanisms, and aim to improve these issues in male PwMS. By shedding light on this overlooked aspect of MS, we hope to enhance the care and well-being of male PwMS facing these challenges.

Testis-specific knockout of Kdm2a reveals nonessential roles in male fertility but partially compromises spermatogenesis

Lysine-specific histone demethylase 2 (Kdm2a) is a regulatory factor of histone modifications that participates in gametogenesis and embryonic development. The mis-regulation of Kdm2a can lead to aberrant gene expression, thereby contributing to abnormal cell proliferation, differentiation, apoptosis, and tumorigenesis. However, due to the potential confounding effects that are secondary to the loss of Kdm2a function from the soma in existing whole-animal mutants, the in vivo function of Kdm2a in spermatogenesis for male fertility remains unknown. Herein, we focus on exploring the spatiotemporal expression profile and biological functions of Kdm2a in the spermatogenesis and fertility of male mice. A testis-specific knockout Kdm2a model (Kdm2a cKO) was established by using the Stra8-Cre/loxP recombinase system to explore the roles of Kdm2a in male fertility. Our results showed that Kdm2a was ubiquitously expressed and dynamically distributed in multiple tissues and cell types in the testis of mice. Surprisingly, Kdm2a-deficient adult males were completely fertile and comparable with their control (Kdm2aflox/flox) counterparts. Despite the significantly reduced total number of sperm and density of seminiferous tubules in Kdm2a cKO testis accompanied by the degeneration of spermatogenesis, the fertilization ability and embryonic developmental competence of the Kdm2a cKO were comparable with those of their control littermates, suggesting that Kdm2a disruption did not markedly affect male fertility, at least during younger ages. Furthermore, Kdm2a homozygous mutants exhibited a lower total number and motility of sperm than the control group and showed notably affected serum 17β-estradiol concentration. Interestingly, the transcriptome sequencing revealed that the loss of Kdm2a remarkably upregulated the expression level of Kdm2b. This effect, in turn, may induce compensative effects in the case of Kdm2a deficiency to maintain normal male reproduction. Together, our results reveal that Kdm2a shows spatiotemporal expression during testicular development and that its loss is insufficient to compromise the production of spermatozoa completely. The homologous Kdm2b gene might compensate for the loss of Kdm2a. Our work provides a novel Kdm2a cKO mouse allowing for the efficient deletion of Kdm2a in a testis-specific manner, and further investigated the biological function of Kdm2a and the compensatory effects of Kdm2b. Our study will advance our understanding of underlying mechanisms in spermatogenesis and male fertility.

Genetic Insights into Intestinal Microbiota and Risk of Infertility: A Mendelian Randomization Study

BACKGROUND

The interaction between intestinal microbiota and infertility is less researched. This study was performed to investigate the causal association between gut microbiota and infertility.

METHODS

In this two-sample Mendelian randomization (MR) study, genetic variants of intestinal microbiota were obtained from the MiBioGen consortium, which included 18,340 individuals. Inverse variance weighting (IVW), MR-Egger, weighted median, maximum likelihood, MR Robust adjusted profile score, MR Pleiotropy residual sum, and outlier (MR-PRESSO) methods were used to explore the causal links between intestinal microbiota and infertility. The MR-Egger intercept term and the global test from the MR-PRESSO estimator were used to assess the horizontal pleiotropy. The Cochran Q test was applied to evaluate the heterogeneity of instrumental variables (IVs).

RESULTS

As indicated by the IVW estimator, significantly protective effects of the Family XIII AD3011 group (OR = 0.87) and Ruminococcaceae NK4A214 group (OR = 0.85) were identified for female fertility, while Betaproteobacteria (OR = 1.18), Burkholderiales (OR = 1.18), Candidatus Soleaferrea (OR = 1.12), and Lentisphaerae (OR = 1.11) showed adverse effects on female fertility. Meanwhile, Bacteroidaceae (OR = 0.57), Bacteroides (OR = 0.57), and Ruminococcaceae NK4A214 group (OR = 0.61) revealed protective effects on male fertility, and a causal association between Anaerotruncus (OR = 1.81) and male infertility was detected. The effect sizes and directions remained consistent in the other five methods except for Candidatus Soleaferrea. No heterogeneity or pleiotropy were identified by Cochran's Q test, MR-Egger, and global test (all p > 0.05).

CONCLUSIONS

This two-sample MR study revealed that genetically proxied intestinal microbiota had potentially causal effects on infertility. In all, the Ruminococcaceae NK4A214 group displayed protective effects against both male and female infertility. Further investigations are needed to establish the biological mechanisms linking gut microbiota and infertility.