The Effect of Antioxidant Supplementation on Operated or Non-Operated Varicocele-Associated Infertility: A Systematic Review and Meta-Analysis

COVID-19 and Male Infertility: Is There a Role for Antioxidants?

Coronavirus disease 19 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), jeopardizes male fertility because of the vulnerability of the male reproductive system, especially the testes. This study evaluates the effects of the virus on testicular function and examines the potential role of antioxidants in mitigating the damage caused by oxidative stress (OS). A comprehensive PubMed search examined exocrine and endocrine testicular function alteration, the interplay between OS and COVID-19-induced defects, and the potential benefit of antioxidants. Although the virus is rarely directly detectable in sperm and testicular tissue, semen quality and hormonal balance are affected in patients, with some changes persisting throughout a spermatogenesis cycle. Testicular pathology in deceased patients shows defects in spermatogenesis, vascular changes, and inflammation. Acute primary hypogonadism is observed mainly in severely infected cases. Elevated OS and sperm DNA fragmentation markers suggest redox imbalance as a possible mechanism behind the fertility changes. COVID-19 vaccines appear to be safe for male fertility, but the efficacy of antioxidants to improve sperm quality after infection remains unproven due to limited research. Given the limited and inconclusive evidence, careful evaluation of men recovering from COVID-19 seeking fertility improvement is strongly recommended.

Oxidative versus reductive stress: a delicate balance for sperm integrity

Despite the long-standing notion of "oxidative stress," as the main mediator of many diseases including male infertility induced by increased reactive oxygen species (ROS), recent evidence suggests that ROS levels are also increased by "reductive stress," due to over-accumulation of reductants. Damaging mechanisms, like guanidine oxidation followed by DNA fragmentation, could be observed following reductive stress. Excessive accumulation of the reductants may arise from excess dietary supplementation over driving the one-carbon cycle and transsulfuration pathway, overproduction of NADPH through the pentose phosphate pathway (PPP), elevated levels of GSH leading to impaired mitochondrial oxidation, or as a result NADH accumulation. In addition, lower availability of oxidized reductants like NAD⁺, oxidized glutathione (GSSG), and oxidized thioredoxins (Trx-S2) induce electron leakage leading to the formation of hydrogen peroxide (H₂O₂). In addition, a lower level of NAD⁺ impairs poly (ADP-ribose) polymerase (PARP)-regulated DNA repair essential for proper chromatin integrity of sperm. Because of the limited studies regarding the possible involvement of reductive stress, antioxidant therapy remains a central approach in the treatment of male infertility. This review put forward the concept of reductive stress and highlights the potential role played by reductive vs oxidative stress at pre-and post-testicular levels and considering dietary supplementation.

Effects of alpha-lipoic acid on sperm quality in patients with varicocele-related male infertility: study protocol for a randomized controlled clinical trial

BACKGROUND

Varicocele is a high incidence and is considered to be the most common and correctable cause of male infertility. Oxidative stress (OS) plays a central role in the pathogenesis of varicocele-related male infertility. In addition to varicocelectomy, antioxidant supplementation seems to be an effective scheme for the treatment of varicocele-related male infertility, but it is still controversial. The purpose of this study is to determine the effects of alpha-lipoic acid (ALA) supplementation on sperm quality in patients with varicocele-related male infertility.

METHODS

In this randomized controlled clinical trial, we will randomize 80 patients with varicocele-related male infertility from Guilin People's Hospital. The non-surgical observation group (n = 20) will receive ALA, the non-surgical control group (n = 20) will receive vitamin E, the surgical observation group (n = 20) will receive ALA after the operation, and the surgical control group (n = 20) will receive vitamin E after the operation. The course of treatment will be 3 months. The results will compare the changes in semen parameters, sex hormones, testicular volume, sperm DNA fragment index (DFI), seminal plasma malondialdehyde (MDA), and total antioxidant capacity (TAC) between the groups at baseline and after 3 months of antioxidant supplementation.

DISCUSSION

Whether it is necessary to use antioxidants in varicocele-related male infertility, how potent antioxidants should be used, postoperative application or non-surgical independent application still needs to be explored. This study attempts to compare the effects of two antioxidants (ALA and vitamin E) on sperm quality in patients with varicocele-related male infertility (surgical or non-surgical) and attempted to answer the above questions.

TRIAL REGISTRATION

Chinese Clinical Trial Registry (ChiCTR) ChiCTR2100054958. Registered on 29 December 2021.

Improvement in sperm quality by oral antioxidant supplementation in infertile men with varicocele who have not undergone surgical repair: Systematic review and meta-analysis

The aim of this systematic review and meta-analysis was to assess whether oral antioxidant supplementation improves sperm quality in men with infertility and varicocele (VCL) who have not undergone surgical repair. In men with infertility and VCL who had not undergone surgical repair oral antioxidant supplementation significantly increased sperm concentration (WMD +5.86 × 10⁶ /ml 95% CI: +1.47 to +10.24, p < 0.01; random effects model, six studies, 213 patients), total motility (WMD + 3.76%, 95% CI: +0.18 to +7.34, p = 0.04; random effects model, three studies, 93 patients), progressive motility (WMD + 6.38%, 95% CI: +3.04 to +9.71, p < 0.01; random effects model, three studies, 84 patients) and seminal volume (WMD +0.55 ml, 95%CI: +0.06 to +1.04, p = 0.03; random effects model, four studies, 120 patients). On the other hand, no significance difference was observed in sperm morphology (WMD +3.89%, 95% CI: -0.14 to +7.92, p = 0.06; random effects model, five studies, 187 patients). In conclusion, limited evidence suggests that the use of oral antioxidants in men with infertility and VCL, who have not undergone surgical repair improves their seminal volume, sperm concentration, total and progressive motility.

Antioxidants and Male Infertility

Oxidative stress has been associated with decreased sperm quality and male infertility [...].

Comprehensive Analysis of Global Research on Human Varicocele: A Scientometric Approach

Purpose

This study provides a comprehensive analysis of research trends on the etiology, mechanisms, potential risk factors, diagnosis, prognosis, surgical and non-surgical treatment of varicocele, and clinical outcomes before and after varicocele repair.

Materials and Methods

Varicocele studies published between 1988 and 2020 were retrieved from the Scopus database on April 5, 2021. Original studies on human varicocele were included, irrespective of language. Retrieved articles were manually screened for inclusion in various sub-categories. Bibliometric data was subjected to scientometric analysis using descriptive statistics. Network, heat and geographic mapping were generated using relevant software.

Results

In total, 1,943 original human studies on varicocele were published. These were predominantly from the northern hemisphere and developed countries, and published in journals from the United States and Germany. Network map analysis for countries showed several interconnected nodal points, with the USA being the largest, and Agarwal A. from Cleveland Clinic, USA, being a center point of worldwide varicocele research collaborations. Studies of adolescents were underrepresented compared with studies of adults. Studies on diagnostic and prognostic aspects of varicocele were more numerous than studies on varicocele prevalence, mechanistic studies and studies focusing on etiological and risk factors. Varicocele surgery was more investigated than non-surgical approaches. To evaluate the impact of varicocele and its treatment, researchers mainly analyzed basic semen parameters, although markers of seminal oxidative stress are being increasingly investigated in the last decade, while reproductive outcomes such as live birth rate were under-reported in the literature.

Conclusions

This study analyzes the publication trends in original research on human varicocele spanning over the last three decades. Our analysis emphasizes areas for further exploration to better understand varicocele’s impact on men’s health and male fertility.

Diagnostic and therapeutic workup of male infertility: results from a Delphi consensus panel

Male factor infertility (MFI) is a rising issue worldwide with significant socioeconomic costs and negative psychological consequences for the couple. Current guidelines provide recommendations for its diagnosis and treatment but several gaps in the management of MFI are encountered in clinical practice due to the lack of available evidence in published literature. Uncertainty in the management of MFI cases leads to a high degree of variability in therapeutic approaches. We planned a Delphi consensus method to provide insights and help bridge the gaps that separate clinical guidelines from real-world practice. The Advisory Board collected 41 statements on debated topics in the management of MFI, each including multiple items designed as a 5-point Likert scale. The questionnaire was sent by e-mail to a panel of Italian experts for a first round of voting; members of the panel were later invited to a second round of voting, preceded by discussion of the "hot topics" identified in the first round. At both rounds of the Delphi consensus 68 experts participated to the voting process. After the first round 25 statements were identified as hot topics, and these underwent the second round of voting. Consensus was reached on many, but not all cases, leaving vagueness on few debated topics where decisions are unsupported by clinical studies or driven by controversial results. In conclusion, indications emerging from this large panel of experts may help guide the management of male factor infertility in clinical practice. Studies are needed to address unanswered questions left by cases for whom no consensus was reached.

Redox Balance in Male Infertility: Excellence through Moderation-"Μέτρον ἄριστον"

Male infertility, a relatively common and multifactorial medical condition, affects approximately 15% of couples globally. Based on WHO estimates, a staggering 190 million people struggle with this health condition, and male factor is the sole or contributing factor in roughly 20–50% of these cases. Nowadays, urologists are confronted with a wide spectrum of conditions ranging from the typical infertile male to more complex cases of either unexplained or idiopathic male infertility, requiring a specific patient-tailored diagnostic approach and management. Strikingly enough, no identifiable cause in routine workup can be found in 30% to 50% of infertile males. The medical term male oxidative stress infertility (MOSI) was recently coined to describe infertile men with abnormal sperm parameters and oxidative stress (OS), including those previously classified as having idiopathic infertility. OS is a critical component of male infertility, entailing an imbalance between reactive oxygen species (ROS) and antioxidants. ROS abundance has been implicated in sperm abnormalities, while the exact impact on fertilization and pregnancy has long been a subject of considerable debate. In an attempt to counteract the deleterious effects of OS, urologists resorted to antioxidant supplementation. Mounting evidence indicates that indiscriminate consumption of antioxidants has led in some cases to sperm cell damage through a reductive-stress-induced state. The “antioxidant paradox”, one of the biggest andrological challenges, remains a lurking danger that needs to be carefully avoided and thoroughly investigated. For that reason, oxidation-reduction potential (ORP) emerged as a viable ancillary tool to basic semen analysis, measuring the overall balance between oxidants and antioxidants (reductants). A novel biomarker, the Male infertility Oxidative System (MiOXSYS^®), is a paradigm shift towards that goal, offering a quantification of OS via a quick, reliable, and reproducible measurement of the ORP. Moderation or “Μέτρον” according to the ancient Greeks is the key to successfully safeguarding redox balance, with MiOXSYS^® earnestly claiming its position as a guarantor of homeostasis in the intracellular redox milieu. In the present paper, we aim to offer a narrative summary of evidence relevant to redox regulation in male reproduction, analyze the impact of OS and reductive stress on sperm function, and shed light on the “antioxidant paradox” phenomenon. Finally, we examine the most up-to-date scientific literature regarding ORP and its measurement by the recently developed MiOXSYS^® assay.

Using Data Mining to Assist in Predicting Reproductive Outcomes Following Varicocele Embolization

We carried out a retrospective analysis of infertile couple data using several methodologies and data analysis techniques, including the application of a novel data mining approach for analyzing varicocele treatment outcomes. The aim of this work was to characterize embolized varicocele patients by ascertaining the improvement of some of their clinical features, predicting the success of treatment via pregnancy outcomes, and identifying data patterns that can contribute to both ongoing varicocele research and the more effective management of patients treated for varicocele. We retrospectively surveyed the data of 293 consenting couples undergoing infertility treatment with male varicocele embolization over a 10-year period, and sperm samples were collected before and at 3, 6, and 12 months after varicocele embolization treatment and analyzed with World Health Organization parameters—varicocele severity grades were assessed with medical assessment and scrotal ultrasound, patient personal information (e.g., age, lifestyle, and embolization complications) was collected with clinical inquiries, and varicocele embolization success was measured through pregnancy outcomes. Varicocele embolization significantly improved sperm concentration, motility, and morphology mean values, as well as sperm chromatin integrity. Following this study, we can predict that a male patient without a high varicocele severity grade (with grade I or II) has a 70.83% chance of conceiving after embolization treatment if his partners’ age is between 24 and 33 with an accuracy of 70.59%. Furthermore, male patients successful in achieving pregnancy following embolization are mostly characterized by having a normal sperm progressive motility before treatment, a normal sperm concentration after treatment, a moderate to low varicocele severity grade, and not working in a putatively hazardous environment.