Lifestyle, Environment, and Male Reproductive Health

Current global status of male reproductive health

BACKGROUND

The widespread interest in male reproductive health (MRH), fueled by emerging evidence, such as the global decline in sperm counts, has intensified concerns about the status of MRH. Consequently, there is a pressing requirement for a strategic, systematic approach to identifying critical questions, collecting pertinent information, and utilizing these data to develop evidence-based strategies. The methods for addressing these questions and the pathways toward their answers will inevitably vary based on the variations in cultural, geopolitical, and health-related contexts. To address these issues, a conjoint ESHRE and Male Reproductive Health Initiative (MRHI) Campus workshop was convened.

OBJECTIVE AND RATIONALE

The three objectives were: first, to assess the current state of MRH around the world; second, to identify some of the key gaps in knowledge; and, third, to examine how MRH stakeholders can collaboratively generate intelligent and effective paths forward.

SEARCH METHODS

Each expert reviewed and summarized the current literature that was subsequently used to provide a comprehensive overview of challenges related to MRH.

OUTCOMES

This narrative report is an overview of the data, opinions, and arguments presented during the workshop. A number of outcomes are presented and can be summarized by the following overarching themes: MRH is a serious global issue and there is a plethora of gaps in our understanding; there is a need for widespread international collaborative networks to undertake multidisciplinary research into fundamental issues, such as lifestyle/environmental exposure studies, and high-quality clinical trials; and there is an urgent requirement for effective strategies to educate young people and the general public to safeguard and improve MRH across diverse population demographics and resources.

LIMITATIONS REASONS FOR CAUTION

This was a workshop where worldwide leading experts from a wide range of disciplines presented and discussed the evidence regarding challenges related to MRH. While each expert summarized the current literature and placed it in context, the data in a number of areas are limited and/or sparse. Equally, important areas for consideration may have been missed. Moreover, there are clear gaps in our knowledge base, which makes some conclusions necessarily speculative and warranting of further study.

WIDER IMPLICATIONS

Poor MRH is a global issue that suffers from low awareness among the public, patients, and heathcare professionals. Addressing this will require a coordinated multidisciplinary approach. Addressing the significant number of knowledge gaps will require policy makers prioritizing MRH and its funding.

STUDY FUNDING/COMPETING INTERESTS

The authors would like to extend their gratitude to ESHRE for providing financial support for the Budapest Campus Workshop, as well as to Microptic S.L. (Barcelona) for kindly sponsoring the workshop. P.B. is the Director of the not-for-profit organization Global Action on Men's Health and receives fees and expenses for his work, (which includes the preparation of this manuscript). Conflicts of interest: C.J.D.J., C.L.R.B., R.A.A., P.B., M.P.C., M.L.E., N.G., N.J., C.K., AAP, M.K.O., S.R.-H., M.H.V.-L.: ESHRE Campus Workshop 2022 (Travel support-personal). C.J.D.J.: Cambridge University Press (book royalties-personal). ESHRE Annual Meeting 2022 and Yale University Panel Meeting 2023 (Travel support-personal). C.L.R.B.: Ferring and IBSA (Lecture), RBMO editor (Honorarium to support travel, etc.), ExSeed and ExScentia (University of Dundee), Bill & Melinda Gates Foundation (for research on contraception). M.P.C.: Previously received funding from pharmaceutical companies for health economic research. The funding was not in relation to this work and had no bearing on the contents of this work. No funding from other sources has been provided in relation to this work (funding was provided to his company Global Market Access Solutions). M.L.E.: Advisor to Ro, Doveras, Next, Hannah, Sandstone. C.K.: European Academy of Andrology (Past president UNPAID), S.K.: CEO of His Turn, a male fertility Diagnostic and Therapeutic company (No payments or profits to date). R.I.M.: www.healthymale.org.au (Australian Government funded not for profit in men's health sector (Employed as Medical Director 0.2 FET), Monash IVF Pty Ltd (Equity holder)). N.J.: Merck (consulting fees), Gedeon Richter (honoraria). S.R.-H.: ESHRE (Travel reimbursements). C.N.: LLC (Nursing educator); COMMIT (Core Outcomes Measures for Infertility Trials) Advisor, meeting attendee, and co-author; COMMA (Core Outcomes in Menopause) Meeting attendee, and co-author; International Federation of Gynecology and Obstetrics (FIGO) Delegate Letters and Sciences; ReproNovo, Advisory board; American Board of Urology Examiner; American Urological Association Journal subsection editor, committee member, guidelines co-author Ferring Scientific trial NexHand Chief Technology Officer, stock ownership Posterity Health Board member, stock ownership. A.P.: Economic and Social Research Council (A collaborator on research grant number ES/W001381/1). Member of an advisory committee for Merck Serono (November 2022), Member of an advisory board for Exceed Health, Speaker fees for educational events organized by Mealis Group; Chairman of the Cryos External Scientific Advisory Committee: All fees associated with this are paid to his former employer The University of Sheffield. Trustee of the Progress Educational Trust (Unpaid). M.K.O.: National Health and Medical Research Council and Australian Research Council (Funding for research of the topic of male fertility), Bill and Melinda Gates Foundation (Funding aimed at the development of male gamete-based contraception), Medical Research Future Fund (Funding aimed at defining the long-term consequences of male infertility). M.H.V.-L.: Department of Sexual and Reproductive Health and Research (SRH)/Human Reproduction Programme (HRP) Research Project Panel RP2/WHO Review Member; MRHI (Core Group Member), COMMIT (member), EGOI (Member); Human Reproduction (Associate Editor), Fertility and Sterility (Editor), AndroLATAM (Founder and Coordinator).

Serum lipid profile levels and semen quality: new insights and clinical perspectives for male infertility and men's health

PURPOSE

Several clinical scenarios regulate the final ejaculated semen, which is pivotal to reproductive success. Sperm motility and plasma membrane fusogenic activity primarily rely on the peculiar sperm lipid composition, influenced by the patient's metabolism, genetics, nutritional, environmental status, and concomitant clinical entities such as varicocele. This study aimed to determine the relationship between serum lipid profile and testicular function (semen quality and testosterone levels).

METHODS

This retrospective study uses medical charts of 278 infertile men who attended andrological care between 2000 and 2019. Seminal analysis data, lipid profile, and total serum testosterone were collected. A multiple linear regression analysis was performed to evaluate the influence of the lipid parameters on the seminal variables. Statistical analyses were carried out with p ≤ 0.05 considered statistically significant.

RESULTS

Seminal creatine kinase activity (p = 0.024) is negatively related to HDL (p = 0.032) and triglycerides (p = 0.037), while total testosterone (p < 0.0001) and seminal volume (p = 0.046) appeared both to be negatively related to triglycerides (p = 0.030 and p = 0.033, respectively).

CONCLUSION

Medical advice commonly advocated to prevent endothelial dysfunction and cardiovascular disease and improve HDL-cholesterol and triglyceride levels in dyslipidemic patients should also be given to infertile men. Physicians should give patients a thorough assessment, including the blood lipid profile, hormonal status, and routine seminal examinations. We propose a more comprehensive men´s health check-up for the infertile male population, not limited to a simple evaluation of basic sperm parameters.

Heat stress disrupts spermatogenesis via modulation of sperm-specific calcium channels in rats

Heat is a detrimental environmental stressor that disrupts spermatogenesis and results in male infertility. Previous investigations have shown that heat stress reduces the motility, number, and fertilization ability of living spermatozoa. Sperm hyperactivation, capacitation, acrosomal reaction, and chemotaxis towards the ova are regulated by the cation channel of sperm (CatSper). This sperm-specific ion channel triggers the influx of calcium ions into sperm cells. The aim of this study in rats was to investigate whether heat treatment affected the expression levels of CatSper-1 and -2, together with the sperm parameters, testicular histology and weight. The rats were exposed to heat stress for 6 days and the cauda epididymis and testis were collected 1, 14, and 35 days after heat treatment to measure sperm parameters, gene and protein expression, testicular weight, and histology. Interestingly, we found that heat treatment caused a notable downregulation of CatSper-1 and -2 expression at all three time points. In addition, there were significant reductions in sperm motility and number and an increase in the percentage of abnormal sperm at 1 and 14 days, with cessation of sperm production at 35 days. Furthermore, expression of the steroidogenesis regulator, 3 beta-hydroxysteroid dehydrogenase (3β-HSD) was upregulated in the 1-, 14- and 35-day samples. Heat treatment also upregulated the expression of the apoptosis regulator, BCL2-associated X protein (BAX), decreased testicular weight, and altered testicular histology. Therefore, our data showed for the first time that heat stress downregulated CatSper-1 and -2 in the rat testis, and that this may be a mechanism involved in heat stress-induced impairment of spermatogenesis.

Cortisol modulates Ca2+ signaling and acrosome reaction in human sperm

BACKGROUND

Stress and elevated cortisol levels have negative effects on fertility, although there is controversy about the effect of cortisol on human sperm. One study reported that hydrocortisone (HC), the synthetic form of cortisol, does not activate CatSper channel but is able to inhibit its activation by progesterone (Pg). However, subsequent reports showed that HC has an agonist effect on CatSper, producing intracellular Ca²⁺ ([Ca²⁺ ]_i ) increases. These studies were performed using only electrophysiological techniques and fluorometric measurements of Ca²⁺ . Therefore, it is important to evaluate the effects of different HC concentrations on human sperm physiology using other approaches and techniques.

OBJECTIVE

To analyze the effects of different HC concentrations on human sperm physiology and to evaluate the association of perceived stress, anxiety and depression with acrosome reaction (AR), and semen quality.

MATERIALS AND METHODS

In capacitated human sperm, we tested the effects of HC on [Ca²⁺ ]_i mobilization and AR. Furthermore, the perceived stress and symptoms of anxiety and depression were evaluated with standardized psychometric tests.

RESULTS

HC induces a low increase in [Ca²⁺ ]_i compared to Pg response while, at higher concentrations, HC inhibits the Pg-induced Ca²⁺ response. Also, low concentrations of HC induce AR and when co-incubating it with Pg, the percentages of AR are decreased. Finally, the anxiety symptoms are negatively correlated with Pg induced AR and semen quality.

DISCUSSION

HC has an agonist effect on [Ca²⁺ ]_i mobilization and AR. However, our data also suggest that HC may compete for the binding site of Pg. Additionally, the association between anxiety and decreased AR could be explained by high cortisol levels.

CONCLUSION

Our data showed that HC interferes with the Pg action. Therefore, the negative correlation between anxiety symptoms and Pg-induced AR is due to the accompanying high cortisol levels of this condition and its competitive action with Pg.

O-GlcNAc transferase plays a non-catalytic role in C. elegans male fertility

Animal behavior is influenced by the competing drives to maintain energy and to reproduce. The balance between these evolutionary pressures and how nutrient signaling pathways intersect with mating remains unclear. The nutrient sensor O-GlcNAc transferase, which post-translationally modifies intracellular proteins with a single monosaccharide, is responsive to cellular nutrient status and regulates diverse biological processes. Though essential in most metazoans, O-GlcNAc transferase (ogt-1) is dispensable in Caenorhabditis elegans, allowing genetic analysis of its physiological roles. Compared to control, ogt-1 males had a four-fold reduction in mean offspring, with nearly two thirds producing zero progeny. Interestingly, we found that ogt-1 males transferred sperm less often, and virgin males had reduced sperm count. ogt-1 males were also less likely to engage in mate-searching and mate-response behaviors. Surprisingly, we found normal fertility for males with hypodermal expression of ogt-1 and for ogt-1 strains with catalytic-dead mutations. This suggests OGT-1 serves a non-catalytic function in the hypodermis impacting male fertility and mating behavior. This study builds upon research on the nutrient sensor O-GlcNAc transferase and demonstrates a role it plays in the interplay between the evolutionary drives for reproduction and survival.

Impact of heavy alcohol consumption and cigarette smoking on sperm DNA integrity

The purposes of the presents study were to investigate the impact of alcohol consumption and cigarette smoking on semen parameters and sperm DNA quality, as well as to determine whether tobacco smoking, or alcohol consumption causes more deterioration of sperm quality. Two hundred and eleven semen samples of men were included in this study. Four groups were studied: heavy smokers (N = 48), heavy drinkers (N = 52), non-smokers (n = 70), and non-drinkers (n = 41). Semen parameters were determined according to WHO guidelines, protamine deficiency assessed by chromomycin (CMA3) staining, and sperm DNA fragmentation (sDF) evaluated by TUNEL assay. Sperm parameters were significantly higher in non-smokers versus smokers and in non-drinkers versus drinkers (p < 0.005). However, protamine deficiency and sDF were significantly lower in non-smokers versus smokers and in non-drinkers versus drinkers (p < 0.0001). No significant difference in the semen analysis parameters was observed between heavy smokers and heavy drinkers (semen volume: 3.20 ± 1.43 vs. 2.81 ± 1.56 ml, semen count: 65.75 ± 31.32 vs. 53.51 ± 32.67 mill/ml, total motility: 24.27 ± 8.18 vs. 23.75 ± 1.75%, sperm vitality: 36.15 ± 18.57 vs. 34.62 ± 16.65%, functional integrity: 41.56 ± 18.57 vs. 45.96 ± 17.98% and the morphologically normal spermatozoa: 28.77 ± 11.82 vs. 27.06 ± 13.13%, respectively). However, protamine deficiency was significantly higher among drinkers than smokers (37.03 ± 9.75 vs. 33.27 ± 8.56%, p = 0.020). The sDF was also significantly higher among drinkers than smokers (22.37 ± 7.60 vs. 15.55 ± 3.33%, p < 0.0001). Thus, cigarette smoking, and heavy alcohol intake can deteriorate sperm quality. However, alcohol consumption deteriorates sperm maturity and damages DNA integrity at significantly higher rates than cigarette smoking.

Low and high postpubertal ethanol use: damage on adulthood reproduction and offspring

Graphical abstract

Abstract

The relationship between adolescent ethanol uses and its impacts throughout life are not conclusive. Thus, we evaluated if the low and high consumption of ethanol at postpuberty interferes with the reproduction and ethanol-naive offspring and if the effects are dose-related. Female and male rats were divided into three groups: low drinker (L), high drinker (H) and control (C). The L and H groups were exposed to ethanol up to 10 % from 65 to 80 days with withdrawal after this period. The ethanol consumed by low drinkers was 1.41 ± 0.21 g/kg/day and by high drinkers 4.59 ± 0.45 g/kg/day. The study was conducted in two phases. The first phase verified the reproductive capacity in adulthood on generations (litter size and sex ratio). Data were collected over 10 years. The second phase analyzed the parent reproductive parameters (body weight, reproductive organ weight, sperm parameters and estrous cycle) and the pup development. We observed a reduced litter size in both drinker groups. Gestational body weight gain and feed consumption were lower in L and H. We observed an alteration in reproductive organs weight in both sexes of H. Females presented a longer estrous cycle duration. Males presented an increase in abnormal sperm, a decrease in sperm count and accelerated transit time. The ethanol-naive offspring development was also impaired. We conclude that low and high postpubertal alcohol use impairs long-term reproductive parameters, even after alcohol withdrawal. There is also impaired ethanol-naive offspring. Besides, the effects are dose-related.

Lay summary

The effects of alcohol use have been reported in several studies. However, better knowledge about early alcohol use and its impact on reproduction in adulthood, after abstinence and on ethanol-naive offspring could help improve preventive measures and mechanisms of action. One of the methods used was retrospective analysis which allows to evaluate the effects of postpubertal ethanol use on the reproductive capacity of rats over generations. Despite our limitations, we verified that the post-adolescent period acts as a susceptibility window, and lifestyle at this age modulates the long-term reproductive parameters. The early ethanol use impairs reproduction function since sperm parameters and the estrous cycle have been altered. The dose of alcohol also contributes to damage on the drinkers’ reproduction and on the physical development of ethanol-naive offspring. Future studies are necessary to identify the mechanism involved in long-term alcohol use effects, even in withdrawal, as well as ethanol-naive offspring outcomes.

The hydrogen storage nanomaterial MgH2 improves irradiation-induced male fertility impairment by suppressing oxidative stress

OBJECTIVE

This study aimed to reveal the protective effect of hydrogen storage nanomaterial MgH₂ on radiation-induced male fertility impairment.

METHODS

The characterization of MgH₂ were analyzed by scanning electron microscopy (SEM) and particle size analyzer. The safety of MgH₂ were evaluated in vivo and in vitro. The radioprotective effect of MgH₂ on the reproductive system were analyzed in mice, including sperm quality, genetic effect, spermatogenesis, and hormone secretion. ESR, flow cytometry and western blotting assay were used to reveal the underlying mechanisms.

RESULTS

MgH₂ had an irregular spherical morphology and a particle size of approximately 463.2 nm, and the content of Mg reached 71.46%. MgH₂ was safe and nontoxic in mice and cells. After irradiation, MgH₂ treatment significantly protected testicular structure, increased sperm density, improved sperm motility, reduced deformity rates, and reduced the genetic toxicity. Particularly, the sperm motility were consistent with those in MH mice and human semen samples. Furthermore, MgH₂ treatment could maintain hormone secretion and testicular spermatogenesis, especially the generation of Sertoli cells, spermatogonia and round sperm cells. In vitro, MgH₂ eliminated the [·OH], suppressed the irradiation-induced increase in ROS production, and effectively alleviated the increase in MDA contents. Moreover, MgH₂ significantly ameliorated apoptosis in testes and cells and reversed the G2/M phase cell cycle arrest induced by irradiation. In addition, MgH₂ inhibited the activation of radiation-induced inflammation and pyroptosis.

CONCLUSION

MgH₂ improved irradiation-induced male fertility impairment by eliminating hydroxyl free radicals. Mice fertility and function were evaluated with or without MgH₂ treatment after 5 Gy irradiation. MgH₂ had the ability of hydroxyl radicals scavenging and MDA suppressing in testicular tissue induced by irradiation. Further, MgH₂ could participate in spermatogenesis and protect sperm development in three stages: the generation of Sertoli cells (Sox-9+), spermatogonia (Stra8+) and round sperm cells (Crem+). Moreover, MgH₂ alleviated the decrease of testosterone secreted by interstitial cells after irradiation. In addition, MgH₂ suppressed apoptosis, pyroptosis and inflammatory response and alleviated cell cycle arrest by mediating IR-induced ROS.

Reproductive toxicity investigation of silica nanoparticles in male pubertal mice

Silica nanoparticles (SiNPs), one of the most produced nanoparticles (NPs) in the world, are used in all aspects of life. The increased application of SiNPs, especially in medicine, has raised considerable concern regarding their toxicological impact. Previous studies have shown that SiNPs can pass through the reproductive barrier and cause reproductive organ dysfunction by destroying Sertoli cells, Leydig cells, and germ cells. However, little is known about the mechanism of SiNPs-induced reproductive toxicity. In the present study, 5-week-old male mice were intraperitoneally administered SiNPs per day for 1 week at a dose of 0.2 mg per mouse. The results showed that SiNPs could cause damage to the structure of the testis and the epididymis and change the reproductive organ coefficients, leading to decreases of 56.1% and 55.3% in the rates of sperm concentration and motility and an increase of 168.8% in the rate of sperm abnormality. Moreover, the serum testosterone level obviously decreased from 18.77 to 5.23 µg/ml after exposure, and the transcription statuses of some key genes involved in the synthesis and transport of testosterone in the testis were also affected. Additional experiments showed that SiNPs exposure during puberty induced oxidative stress and an inflammatory response, as shown by the changed activity of superoxide dismutase (SOD), increased contents of malondialdehyde (MDA), and excess expression of proinflammatory factors, including TNF-α and IL-1β. Furthermore, the administration of SiNPs caused DNA damage and cell apoptosis, which were presented by the increased apoptotic cells in the sections of testis and epididymis and activation of the TNF-α/TNFR I-mediated pro-apoptotic pathway. In conclusion, these results indicate that SiNPs exposure during puberty significantly damaged the structure and function of the testis and epididymis by inducing oxidative stress and cell apoptosis. This study provides novel insight into SiNPs-induced reproductive toxicity during puberty, which warrants a more careful assessment of SiNPs before their application in juvenile supplies.

Overweight and obesity: The allies of prostate inflammation

To the Editor, World Health Organization (WHO) defines infertility as the inability of a sexually active partner to achieve a clinically confirmed pregnancy after at least one year of intercourse without contraceptive protection on fertile days. As women are primarily responsible for the conception, childbirth, and postpartum, fertility problems have been related to fertile female capacity. However, men play an essential role, being responsible for about 50% of alterations in fertility due to dysfunctions in the male reproductive tract, including varicocele, hypogonadism, poorly descended testicles, testicular tumors, and even anti-sperm autoantibodies [...].

Measuring Reactive Oxygen Species in Semen for Male Preconception Care: A Scientist Perspective

Oxidative stress and elevated levels of seminal and sperm reactive oxygen species (ROS) may contribute to up to 80% of male infertility diagnosis, with sperm ROS concentrations at fertilization important in the development of a healthy fetus and child. The evaluation of ROS in semen seems promising as a potential diagnostic tool for male infertility and male preconception care with a number of clinically available tests on the market (MiOXSYS, luminol chemiluminescence and OxiSperm). While some of these tests show promise for clinical use, discrepancies in documented decision limits and lack of cohort studies/clinical trials assessing their benefits on fertilization rates, embryo development, pregnancy and live birth rates limit their current clinical utility. In this review, we provide an update on the current techniques used for analyzing semen ROS concentrations clinically, the potential to use of ROS research tools for improving clinical ROS detection in sperm and describe why we believe we are likely still a long way away before semen ROS concentrations might become a mainstream preconception diagnostic test in men.

Comparison of RNA content from hydrophobic interaction chromatography-isolated seminal plasma exosomes from intrauterine insemination (IUI) pregnancies

Male factors account for roughly half of infertility cases, with most male infertility diagnosed as idiopathic. Researchers predicting intrauterine insemination success rates have identified multiple prognostic factors, including semen parameters and seminal fluid composition. Seminal plasma contains extracellular exosomes, which contain RNAs and proteins involved in spermatogenesis. The contents of seminal plasma exosomes may be an indicator of overall sperm quality or fertility potential; therefore, analysis of exosomes may provide a measure for sperm viability and fertilization potential. In our study, exosomes were isolated and purified from seminal plasma obtained from IUI treatments with known pregnancy outcomes. We used a unique method to isolate the exosomes which made use of the hydrophobic interaction chromatography method. RNASeq was performed on RNAs from the purified exosomes. This analysis revealed holistic trends, including increased expression associated with RNA originating from chromosomes 1, 10, 12, 16 and 21. Overall, total RNA was significantly decreased and rRNA was significantly increased in successful IUI attempts. Furthermore, we found specific mRNAs and lincRNAs associated with positive versus negative pregnancy outcomes. Our study isolated and purified seminal plasma exosomes without ultracentrifugation, and it provides further evidence for differences in seminal plasma exosome molecular contents associated with pregnancy status.

Turkish validity and reliability study for the person-centered maternity care scale

AIM

The objective was to adapt the person-centered maternity care scale (PCMCS) developed by Afulani et al. in 2017 to Turkish and to perform the validity and reliability study of this scale.

METHODS

The population of this methodological study consisted of 280 mothers who were referred to the postpartum service of a public hospital in eastern Turkey. Linguistic validity, context validity, and pilot practice studies regarding the PCMCS that could be used in the first nine postpartum weeks were performed. Explanatory factor analysis and confirmatory factor analysis were performed to assess the construct validity of the form. Reliability of PCMCS was tested through the Cronbach's α internal consistency coefficient, total item correlation, and test-retest analysis.

RESULTS

The Turkish version of the PCMCS a 21-item scale with three sub-dimensions was obtained. These three sub-dimensions found as a result of explanatory factor analysis and confirmatory factor analysis supported the scale structure. Cronbach's α reliability coefficient scale was adequate for total and sub-dimensions.

CONCLUSION

Turkish version of PCMCS was found to be a valid and reliable instrument to be used for assessing the person-centered maternity care for women in the postpartum period.

Exertional heat stroke on fertility, erectile function, and testicular morphology in male rats

The association of exertional heat stroke (EHS) and testicular morphological changes affecting sperm quality, as well as the association of EHS and hypothalamic changes affecting sexual behavior, has yet to be elucidated. This study aimed to elucidate the effects of EHS on fertility, erectile function, and testicular morphology in male rats. Animals were exercised at higher room temperature (36 ℃ relative humidity 50%) to induce EHS, characterized by excessive hyperthermia, neurobehavioral deficits, hypothalamic cell damage, systemic inflammation, coagulopathy, and multiple organ injury. In particular, EHS animals had erectile dysfunction (as determined by measuring the changes of intracavernosal pressure and mean arterial pressure in response to electrical stimulation of cavernous nerves). Rats also displayed testicular temperature disruption, poorly differentiated seminiferous tubules, impaired sperm quality, and atrophy of interstitial Leydig cells, Sertoli cells, and peri-tubular cells in the testicular tissues accompanied by no spermatozoa and broken cells with pyknosis in their seminal vesicle and prostatitis. These EHS effects were still observed after 3 days following EHS onset, at least. Our findings provide a greater understanding of the effect of experimentally induced EHS on masculine sexual behavior, fertility, stress hormones, and morphology of both testis and prostate.

Effects of a Lifestyle Change Intervention on Semen Quality in Healthy Young Men Living in Highly Polluted Areas in Italy: The FASt Randomized Controlled Trial

BACKGROUND

Human semen quality is affected by lifestyle and environmental factors.

OBJECTIVE

To evaluate the short-term effects of a diet and physical activity intervention on semen quality of healthy young men living in highly polluted areas of Italy.

DESIGN, SETTING, AND PARTICIPANTS

A randomized controlled trial was conducted. Healthy young men were assigned to an intervention or a control group.

INTERVENTION

A 4-mo Mediterranean diet and moderate physical activity program.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The primary outcomes were sperm concentration, motility and morphology, concentration of round cells, and semen total antioxidant capacity. Secondary outcomes were adherence to Mediterranean diet and physical activity. All outcomes were measured twice, at the enrollment (t0) and at the end of the intervention (t4).

RESULTS AND LIMITATIONS

A total of 263 individuals attended all visits, and underwent examinations and laboratory analyses: 137 in the intervention group and 126 in the control group. The adherence to Mediterranean diet and physical activity level increased more in the intervention group than in the control group from t0 to t4. Sperm concentration, total and progressive motility, and proportion of normal morphology cells increased in the intervention group but decreased in the control group, with statistically significant differences between the two groups at t4. The total antioxidant capacity increased in the intervention group but decreased in the control group, from t0 to t4.

CONCLUSIONS

Study results showed that an intervention based on Mediterranean diet and regular physical activity can determine an improvement of semen quality in healthy young men.

PATIENT SUMMARY

Our study aimed to evaluate the effect of a lifestyle intervention on semen quality of healthy young men. We assigned the 263 enrolled individuals to an intervention or a control group. The intervention group followed a 4-mo Mediterranean diet and moderate physical activity program, at the end of which the participants showed an improvement of semen quality parameters.

The relationship between health life style and spermogram Indicators among infertile men: preliminary data

Objective

Inappropriate life style has destructive effects on sperm quality and, male fertility, so that lifestyle modification may improve spermogram indexes preliminary data. This study aimed to determine the relationship between health life style and spermogram Indicators among infertile men. This analytical descriptive cross-sectional study was conducted on 199 infertile men. The data were collected through the socio-demographic and Health Promoting Lifestyle Profile questionnaires Descriptive statistics independent t-test and Pearson correlation were used to analyze the data through SPSS.

Results

The mean (standard deviation) of total score of the health promoting lifestyle was (2.39 ± 0.39). The highest mean score was in Health Responsibility subscale (2.51 ± 0.52) and the lowest mean score was in the nutrition subscale (2.24 ± 0.44). Stress management showed significantly correlated with sperm morphology (p = 0.025). Also, spiritual growth with the Sperm concentration (p < 0.001), and sperm motility (p = 0.004) were statistically correlated, and health responsibility dimensions were statistically correlated with the Sperm concentration (p = 0.003) and sperm motility (p = 0.002). Considering that the mean of total score of the health promoting lifestyle and its correlation with some of spermogram indicators shows a need for improving lifestyle in infertile men who referred to infertility clinics.

Designing and psychometric of reproductive health related behaviors assessment tool in Iranian males: an exploratory mixed method study protocol

BACKGROUND

Male reproductive health is a relatively new concept, and most men are neglected in reproductive health discussions. Therefore, it appears that there is insufficient information about the male reproductive health. This study aims to design a psychometric instrument for assessing the male reproductive health-related behavior.

METHODS/DESIGN

This is a sequential exploratory mixed-method study with a classical instrument development design. It will be conducted in two qualitative and quantitative phases on the studied units including the men living in Tehran. In the first phase, a qualitative study of a contractual content analysis approach will be conducted in order to perceive the concept of male reproductive health-related behavior, determine the dimensions of the questionnaire, and explore the items. In the second phase, a quantitative study will be carried out to evaluate the psychometric properties as well as (form, content, and construct) validity and reliability of the instrument designed in the first phase. Finally, the instrument will be scored and interpreted.

DISCUSSION

Discovering men's perception of concept of reproductive health-related behavior can help design a valid and reliable questionnaire which can be used in studies evaluating the male reproductive health-related behavior.

ETHICAL CODE

IR.TUMS.FNM.REC.1397.157.

Do lifestyle practices impede male fertility?

Alongside an increasing prevalence of couple and male infertility, evidence suggests there is a global declining trend in male fertility parameters over the past few decades. This may, at least in part, be explained through detrimental lifestyle practices and exposures. These include alcohol and tobacco consumption, use of recreational drugs (e.g., cannabis, opioids and anabolic steroids), poor nutritional habits, obesity and metabolic syndrome, genital heat stress (e.g., radiation exposure through cell phones and laptops, prolonged periods of sitting, tight-fitting underwear and recurrent hot baths or saunas), exposure to endocrine-disrupting chemicals (e.g., pesticide residue, bisphenol A, phthalates and dioxins) and psychological stress. This review discusses these lifestyle practices and the current evidence associated with male infertility. Furthermore, known mechanisms of action are also discussed for each of these. Common mechanisms associated with a reduction in spermatogenesis and/or steroidogenesis due to unfavourable lifestyle practices include inflammation and oxidative stress locally or systemically. It is recommended that relevant lifestyle practices are investigated in clinical history of male infertility cases, particularly in unexplained or idiopathic male infertility. Appropriate modification of detrimental lifestyle practices is further suggested and recommended in the management of male infertility.

Associations of ambient air pollutant exposure with seminal plasma MDA, sperm mtDNA copy number, and mtDNA integrity

BACKGROUND

Current available evidence regarding the detrimental effects of low-level ambient air pollution on conventional semen parameters is inconclusive. In nonreproductive systems, air pollutant exposure has been demonstrated to induce oxidative stress (OS), which is a crucial mechanism that mediates sperm damage and male infertility. Thus, it may be essential to investigate the effects of air pollution on sperm quality in terms of the perspectives of OS and relative molecular damage.

OBJECTIVES

We assessed the associations of major air pollutant exposure to oxidative stress-mediated alterations in semen, including seminal plasma malondialdehyde (MDA), sperm mtDNA copy number, and integrity.

METHODS

The present study used data gathered from 516 young men participating in the Male Reproductive Health in Chongqing College student (MARCHS) cohort study during the follow-up stage in 2014 (n = 427 on the old campus, which is located in an urban area and has worse air quality, and n = 89 on the new campus, which is not urban and has better air quality). Data regarding major air pollutant exposure during 0-90, 0-9, 10-14 and 70-90 days before each semen examination (corresponding to the entire and three key periods of sperm development, respectively) were collected. The Mann-Whitney U nonparametric test was employed to compare distributions of major air pollutants and to explore differences in MDA, mtDNA copy number, and mtDNA integrity between the two campuses. A linear regression model was used as multivariable analysis to investigate associations of major air pollutant exposure with these biomarkers of oxidative damage to sperm and to adjust for potential confounders.

RESULTS

During all four key periods of sperm development, compared with college students on the new campus, college students on the old campus were exposed to higher levels of PM10, PM2.5, NO₂, and CO, and had higher air quality index (AQI) values, indicating that these participants suffered from worse air quality. The levels of seminal plasma MDA in college students on the old campus were higher than those for the new campus (2.0 nmol/ml; 0.7, 3.6 vs. 1.6 nmol/ml; 0.4, 3.4, p < 0.001) (medians with 5th and 95th percentiles). There were no significant differences in sperm mtDNA copy number and mtDNA integrity between the two campuses. Furthermore, daily average PM10 exposure during 0-90 days before semen ejaculation was found to be significantly and positively associated with seminal plasma MDA level (10.4; 95% CI, 4.4, 16.4) (percentage change per 10-unit increase in air pollutant concentration; same meanings for the results below); daily average SO₂ exposure for 70-90 days and NO₂ exposure for 0-9 days prior to sampling were also positively associated with MDA level (74.7; 95% CI, 32.1, 119 and 11.9; 95% CI, 4.8, 19.0, respectively). AQI for 0-90 days and 70-90 days prior to sampling positively correlated with seminal plasma MDA concentrations (11.4; 95% CI, 4.7, 18.1 and 12.2; 95% CI, 5.3, 19.1, respectively). Additionally, daily average SO₂ exposures for 10-14 and 0-9 days prior to sampling were negatively associated with sperm mtDNA copy number and mtDNA integrity, respectively (-9.0; 95% CI, -16.4, -1.6 and -38.3; 95% CI, -64.1, -11.8, respectively). However, only the correlations between SO₂ exposure and AQI value for 70-90 days prior to sampling and MDA levels remained significant after multiplicity adjustment.

CONCLUSIONS

The results indicate that bad air quality, especially SO₂ exposure during certain periods of sperm development, might be correlated with oxidative damage to sperm. These findings can deepen the understanding of the potential impacts of air pollution on sperm quality.

Silica nanoparticles exacerbates reproductive toxicity development in high-fat diet-treated Wistar rats

To demonstrate the combined adverse effect and the mechanism of silica nanoparticles (SiNPs) with 57.66 ± 7.30 nm average diameter and high-fat diet (HFD) on Wistar rats, 60 male Wistar rats were randomly divided into six groups (n = 10): Control group, SiNPs group, HFD group, 2 mg kg^-1 SiNPs + HFD group, 5 mg kg^-1 SiNPs + HFD group and 10 mg kg^-1 SiNPs + HFD group. HFD was administrated for 2 weeks for the rats in advance and SiNPs were supplied every 3 d for 48 d subsequently. The present study illustrated that both HFD and SiNPs could decrease sperm concentration, mobility rates, increase abnormality rates, damage testicular structure, reduce spermatogonium numbers and spermatoblast numbers, reduce ATP levels, and affect expression of regulatory factors for meiosis in testis. HFD and SiNPs further damaged the sperm and lowered the ATP level and expression of factors associated with meiotic signaling pathway compared with the HFD without SiNPs in testicular tissue of Wistar rats. These results suggested that SiNPs significantly promoted reproductive toxicity induced by HFD in Wistar rats, which provides novel experimental evidence and an explanation for magnified reproductive toxicity triggered by SiNPs in HFD rats.

New Biological Insights on X and Y Chromosome-Bearing Spermatozoa

A spermatozoon is a male germ cell capable of fertilizing an oocyte and carries genetic information for determining the sex of the offspring. It comprises autosomes and an X (X spermatozoa) or a Y chromosome (Y spermatozoa). The origin and maturation of both X and Y spermatozoa are the same, however, certain differences may exist. Previous studies proposed a substantial difference between X and Y spermatozoa, however, recent studies suggest negligible or no differences between these spermatozoa with respect to ratio, shape and size, motility and swimming pattern, strength, electric charge, pH, stress response, and aneuploidy. The only difference between X and Y spermatozoa lies in their DNA content. Moreover, recent proteomic and genomic studies have identified a set of proteins and genes that are differentially expressed between X and Y spermatozoa. Therefore, the difference in DNA content might be responsible for the differential expression of certain genes and proteins between these cells. In this review, we have compiled our present knowledge to compare X and Y spermatozoa with respect to their structural, functional, and molecular features. In addition, we have highlighted several areas that could be explored in future studies in this field.

The Role of Number of Copies, Structure, Behavior and Copy Number Variations (CNV) of the Y Chromosome in Male Infertility

The World Health Organization (WHO) defines infertility as the inability of a sexually active, non-contracepting couple to achieve spontaneous pregnancy within one year. Statistics show that the two sexes are equally at risk. Several causes may be responsible for male infertility; however, in 30–40% of cases a diagnosis of idiopathic male infertility is made in men with normal urogenital anatomy, no history of familial fertility-related diseases and a normal panel of values as for endocrine, genetic and biochemical markers. Idiopathic male infertility may be the result of gene/environment interactions, genetic and epigenetic abnormalities. Numerical and structural anomalies of the Y chromosome represent a minor yet significant proportion and are the topic discussed in this review. We searched the PubMed database and major search engines for reports about Y-linked male infertility. We present cases of Y-linked male infertility in terms of (i) anomalies of the Y chromosome structure/number; (ii) Y chromosome misbehavior in a normal genetic background; (iii) Y chromosome copy number variations (CNVs). We discuss possible explanations of male infertility caused by mutations, lower or higher number of copies of otherwise wild type, Y-linked sequences. Despite Y chromosome structural anomalies are not a major cause of male infertility, in case of negative results and of normal DNA sequencing of the ascertained genes causing infertility and mapping on this chromosome, we recommend an analysis of the karyotype integrity in all cases of idiopathic fertility impairment, with an emphasis on the structure and number of this chromosome.

β-Endorphin Induction by Psychological Stress Promotes Leydig Cell Apoptosis through p38 MAPK Pathway in Male Rats

Psychological stress (PS) disturbs the reproductive endocrine system and promotes male infertility, but the underlying pathogenic mechanisms have not been extensively studied. This study aimed to uncover the mechanisms of PS-induced male reproductive related abnormalities subjected to a ‘terrified sound’ exposure. Male rats subjected to PS displayed slow growth, decreased sperm quality, abnormal levels of the reproductive endocrine hormones, decreased expression of the reproductive-related proteins androgen-binding protein (ABP) and bromodomain-containing protein (BRDT), increased apoptosis in the testis, and accompanied by elevated levels of β-endorphin (β-EP). These effects were reversed by naloxone. Furthermore, PS-induced β-EP could promote mu opioid receptor (MOR) activation and ensure intracellular p38 MAPK phosphorylation and then lead to Leydig cells (LCs) apoptosis. The current result showed that β-EP was a key factor to PS-induced male infertility.

Correlation of plasma kisspeptin with total testosterone levels in smokeless tobacco and smoking tobacco users in a healthy cohort: A cross-sectional study

Human infertility is a worldwide health issue and is the inability to conceive following twelve months of unprotected sexual intercourse. Consistent studies reiterated tobacco abuse to be an important risk factor which adversely effects male fertility. This study aims to determine the correlation of kisspeptin and total testosterone levels in smokeless tobacco, smoking tobacco users and healthy controls. A total of 180 subjects were selected using random sampling technique. Non-fasting blood samples (5 ml) were drawn, and ELISA technique was used for the evaluation of plasma levels of kisspeptin and total testosterone. Total testosterone was found to be significantly high in smokers and smokeless tobacco users, while the level of kisspeptin was found to be significantly high in smokeless tobacco users only as compared to control group. Furthermore, the level of cholesterol was found to be significantly low, whereas HDL and triglycerides were found to be significantly high in smokeless tobacco users relative to control subjects. Findings of this study suggest that tobacco use has impact on HPG axis by affecting kisspeptin level. The increase in kisspeptin level can affect hypothalamic function leading to pituitary and gonadal dysfunction along with impairment of reproduction. The finding that smokeless tobacco significantly raises kisspeptin strengthens the idea that smokeless tobacco use has more potent effects centrally compared to smoking.

The Potential Role of Seminal Plasma in the Fertilization Outcomes

For human infertility both male and female factors may be equally important. Searching for molecular biomarkers of male infertility, neglected for decades, and the attempts to explain regulatory mechanisms of fertilization become thus extremely important. Apart from examination of the structure and function of male gametes, also the possible importance of seminal plasma components should be considered. In this article we discuss data that indicate for the substantial significance of active seminal plasma components for conception and achievement of healthy pregnancy. Seminal plasma impact on the storage and cryopreservation of human and animal sperm and regulatory role of glycodelin on human sperm capacitation as well as hypothesized course of female immune response to allogenic sperm and conceptus has been discussed. The possible involvement of carbohydrates in molecular mechanism of fetoembryonic defense has been also mentioned.

Impact of physical activity on semen quality among men from infertile couples

OBJECTIVE

To determine the implication of general physical activity and some specific sports in semen quality in men from infertile couples.

STUDY DESIGN

This is an observational study performed in men from infertile couples (n = 454). The interventions performed involved analyzing semen quality parameters according to 2010 WHO criteria and assessing physical activity by means of an International Physical Activity Questionnaire.

RESULT(S)

There was no association between different levels of general physical activity and semen parameters. We neither found association with running, cycling and racquet sports. Interestingly, people who practice weightlifting more than two hours per week presented significantly lower sperm concentration (linear coefficient = -24.80) and lower total sperm count (linear coefficient = -70.87) in comparison with participants that did not practice regular exercise.

CONCLUSION(S)

From a reproductive point of view, there does not seem to be any reason to recommend the increase or the decrease in general physical activity in males from infertile couples. However, additional studies are needed to investigate the relationship between weightlifting and sperm quality.

Associations between major dietary patterns and testicular function in a population-based cohort of young men: results from the Western Australian Pregnancy Cohort (Raine) Study

BACKGROUND

Controversial speculation suggestions that dietary intake may affect semen quality and testicular function, however, there are limited comprehensive studies observing dietary patterns.

OBJECTIVE

To study associations between major dietary patterns and markers of testicular function in adulthood.

MATERIAL AND METHODS

Observational cross-sectional study of two hundred and ninety men with an average age of 20 years, from the Western Australian Pregnancy Cohort (Raine) Study. Usual dietary intake assessed using a semi-quantitative food frequency questionnaire at 20 years of age. Two dietary patterns previously identified using exploratory factor analysis ("Healthy" or "Western") and participants received z-scores for each dietary pattern. Primary endpoints were testicular volume, total sperm per ejaculate, morning serum testosterone concentration. Secondary endpoints were semen sample parameters, inhibin B and sex steroids (DHT: 3α-diol, 3β-diol; LH; FSH; DHEA; estradiol; estrone).

RESULT(S)

Participants were on average 20.0 ± 0.4 years old, had a median of 2 days sexual abstinence and a body mass index of 24.1 ± 3.9 kg/m² , 13% were smokers, 52% were 'moderate' alcohol drinkers, 23% frequently used recreational drugs and 68% reported 'high' physical activity levels. Sperm concentration and DHT 3α-diol were negatively associated with a greater z-score for the "Western" dietary pattern (p = 0.007 and; p = 0.044, respectively), and serum estradiol concentration was positively associated with a "Western" dietary pattern (p = 0.007) after adjustment for BMI, varicocele, cryptorchidism and sexual abstinence.

DISCUSSION

Despite associations between greater intake of the "Western" dietary pattern and a decreased male reproductive health markers, our lack of consistent associations of either a "Healthy" or a "Western" dietary pattern, limit clinical or biological significance in isolation.

CONCLUSIONS

A potential negative association of a "Western" dietary pattern with male reproductive health was detected and should be studied further in population-based studies.

Chromatin condensation, fragmentation of DNA and differences in the epigenetic signature of infertile men

Epidemiological studies report an increase of pathologies of male reproductive tracts and suggest a link between this trend and the increased exposure of men to endocrine disruptors (EDs). The mechanisms by which EDs impact male fertility are far to be elucidated although DNA, chromatin and epigenome of spermatozoa appear to be relevant targets for these molecules. Indeed, many studies report associations between increased levels of sperm DNA fragmentation (sDF) or aberrant chromatin condensation or epigenetic modifications and poor semen quality and/or infertile phenotype. In this scenario, therapies able to reduce sperm damage to DNA, chromatin and epigenome are sought. Currently, antioxidants and FSH administration is proposed for treating high levels of sDF, but whether or not such therapies are really effective is still debated. Further studies are necessary to understand the link between endocrine disruptor exposure and damage to sperm function and/or structure and thus to define effective therapeutic strategies.

An update on semen quality among young Finnish men and comparison with Danish data

Background

Finnish men used to have higher semen quality than Danish men. However, recent studies showed that semen quality in Finland has declined, but it has been relatively stable in Denmark.

Objective

This study aimed to compare new data on semen quality of the young Finnish men to that of Danish men.

Materials and methods

In this cross‐sectional study, 18‐ to 19‐year‐old men residing in Turku, Finland and Copenhagen, Denmark, were invited to participate in 2008–2011. Each man filled in a questionnaire, provided one semen sample and underwent andrological examination. Semen samples were analyzed according to WHO. Multiway ANOVA was used to adjust semen variables for duration of sexual abstinence and age (and time from ejaculation to the start of semen analysis for sperm motility).

Results

Altogether 287 Finnish men and 873 Danish men participated in the study. The adjusted median sperm concentrations were 49 and 47 million/mL for Finnish and Danish men, respectively (p = 0.48). The adjusted median total sperm counts were 148 million in Finland and 146 million in Denmark (p = 0.87). The adjusted median percentages of morphologically normal spermatozoa were 6.9% in Finland and 6.5% in Denmark, p = 0.27. Finnish men had higher adjusted median percentages of motile spermatozoa (A+B+C) than Danish men (80% vs. 69%, p < 0.001). The proportion of men who had low semen quality (sperm concentration, percentage of morphologically normal spermatozoa or percentage of progressively motile spermatozoa below WHO reference limits) was lower in Finland (25.4%) than in Denmark (34.6%), p = 0.004.

Discussion

Considerable percentage of men in both countries had low semen quality. The deteriorating semen quality in Finland may result in decreasing fecundity, which is a cause of concern.

Conclusion

The formerly high semen quality in Finland has converged to the lower Danish levels. Our findings demonstrate the importance of continuing surveillance of semen quality.

Reactive oxygen species and male reproductive hormones

Reports of the increasing incidence of male infertility paired with decreasing semen quality have triggered studies on the effects of lifestyle and environmental factors on the male reproductive potential. There are numerous exogenous and endogenous factors that are able to induce excessive production of reactive oxygen species (ROS) beyond that of cellular antioxidant capacity, thus causing oxidative stress. In turn, oxidative stress negatively affects male reproductive functions and may induce infertility either directly or indirectly by affecting the hypothalamus-pituitary-gonadal (HPG) axis and/or disrupting its crosstalk with other hormonal axes. This review discusses the important exogenous and endogenous factors leading to the generation of ROS in different parts of the male reproductive tract. It also highlights the negative impact of oxidative stress on the regulation and cross-talk between the reproductive hormones. It further describes the mechanism of ROS-induced derangement of male reproductive hormonal profiles that could ultimately lead to male infertility. An understanding of the disruptive effects of ROS on male reproductive hormones would encourage further investigations directed towards the prevention of ROS-mediated hormonal imbalances, which in turn could help in the management of male infertility.

Paternal lifestyle factors in relation to semen quality and in vitro reproductive outcomes

This prospective-cohort study aimed at investigating the influence of paternal lifestyle factors on semen parameters and intracytoplasmic sperm injection (ICSI) outcomes. The influence of paternal lifestyle factors on seminal quality and ICSI outcomes was investigated in male patients undergoing conventional semen analysis. Cigarette smoking negatively influenced semen volume (B: -0.417, slope: 1.570, p = 0.047), sperm count/ml (B: -7.363, slope: 52.298, p = 0.014), total sperm count (B: -4.43, slope: 178.165, p = 0.023), total motile sperm count (B: -1.38, slope: 100.276, p = 0.045) and SDF (B: 0.014, slope: 9.767, p = 0.033). Alcohol consumption negatively influenced sperm count/ml (B: -12.527, slope: 42.255, p = 0.040) and sperm DNA fragmentation (B: 5.833, slope: 9.680, p = 0.002). There were no significant influences of other paternal lifestyle factors. Cigarette smoking negatively influenced the fertilisation rate (B: -1.349, slope: 21.950, p = 0.039) and the blastocyst formation rate (B: -14.244, slope: 28.851, p = 0.025). Alcohol consumption negatively influenced fertilisation rate (B: -3.617, slope: 20.138, p = 0.041) and blastocyst formation rate (B: -34.801, slope: 30.044, p = 0.042). Cigarette smoking and alcohol consumption appear to reduce semen quality, fertilisation and blastocyst formation rates; thus, it would be wise to recommend that male partners reconsider their lifestyle during in vitro reproduction treatment.

Understanding the seminal plasma proteome and its role in male fertility

Seminal plasma is a complex fluid comprised of secretions from the seminal vesicles, the prostate, bulbourethral glands and from the seminiferous tubule lumen / epididymides / vasa deferentia. While it has been established that seminal plasma serves not only as a medium to carry, protect, and nourish sperm after ejaculation up to fertilization, but also as a functional modulator of sperm function, there is still a need to properly characterize the molecular make-up of seminal plasma in fertile men, and to understand how this is altered in different causes of male infertility. The main purpose of this manuscript was to review articles that studied the human seminal plasma proteome, ranging from characterizing a fertile seminal plasma proteomic map to studies comparing seminal plasma from fertile and infertile men, and comparing seminal plasma of fertile or normozoospermic men to a diverse range of biological causes for male infertility. Finally, this review has focused on the association between semen and sperm functional quality and the seminal plasma proteome, in order to demonstrate cellular and molecular mechanisms of male infertility. Due to the untargeted nature of the majority of the studies presented in this review, and to the diverse range of techniques utilized to study the seminal plasma proteomic composition, many differentially expressed proteins were observed. However, in general, it seems that there is a seminal plasma proteome associated to male fertility, and that different biological conditions or cellular phenotypes shift its pathways away from its homeostatic condition to altered energy production pathways. Moreover, it seems there is an inflammatory component to the seminal plasma of infertile men. In conclusion, there are a number of studies focused on the proteomic composition of human seminal plasma; downstream confirmatory studies will help to understand specific pathways of infertility in different biological conditions.

Male infertility among bakers associated with exposure to high environmental temperature at the workplace

Objective

This study aimed to evaluate the prevalence of male infertility among bakers exposed to high environmental temperature.

Methods

This cross-sectional study was conducted to obtain information using a validated questionnaire administered through an interview. The mean wet bulb globe temperature (WBGT) index in the bakeries was measured. A new statistical formula was used to estimate the prevalence of infertility among bakers.

Results

A total of 137 bakers working in 20 bakeries and 107 individuals included in the comparable control group with variations in age, race, marital status, and income and with history of cigarette smoking were recruited. Using a newly devised formula, the prevalence of infertility among the exposed group was 22.7%, compared with 3.0% in the control group (p = 0.013). All possible confounding factors associated with infertility among bakers were excluded such as cigarette smoking, age, and race. There were unfavorable hot working conditions in bakeries, with a WBGT index of 37.4 °C, while the average WBGT for offices was 25.5 °C (p < 0.0001).

Conclusion

Our study showed that the rate of infertility among bakers was high, which resulted from exposure to high environmental temperature at the workplace as evidenced by the WBGT index. This finding should alert the healthcare authorities to take necessary measures under the labor code to curtail infertility among bakers.

Smoke, alcohol and drug addiction and male fertility

In recent decades, the decline in human fertility has become increasingly more worrying: while therapeutic interventions might help, they are vexing for the couple and often burdened with high failure rates and costs. Prevention is the most successful approach to fertility disorders in males and females alike. We performed a literature review on three of the most common unhealthy habits - tobacco, alcohol and drug addiction - and their reported effects on male fertility. Tobacco smoking is remarkably common in most first-world countries; despite a progressive decline in the US, recent reports suggest a prevalence of more than 30% in subjects of reproductive age - a disturbing perspective, given the well-known ill-effects on reproductive and sexual function as well as general health. Alcohol consumption is often considered socially acceptable, but its negative effects on gonadal function have been consistently reported in the last 30 years. Several studies have reported a variety of negative effects on male fertility following drug abuse - a worrying phenomenon, as illicit drug consumption is on the rise, most notably in younger subjects. While evidence in these regards is still far from solid, mostly as a result of several confounding factors, it is safe to assume that cessation of tobacco smoking, alcohol consumption and recreational drug addiction might represent the best course of action for any couple trying to achieve pregnancy.

Aberrations in sperm DNA methylation patterns of males suffering from reduced fecundity

The purpose of this study was to evaluate the aberrations in sperm DNA methylation patterns of males suffering from reduced fecundity. A total of 108 males (65 males suffering from reduced fecundity as cases and 43 proven fertile males as a control) were included in the study. Thirty samples were subjected to 450K arrays as a screening phase, and then, three CpG sites located in the following genes: TYRO3, CGβ and FAM189A1 were selected to validate on 78 samples using deep bisulphite sequencing. A significant difference in the methylation level was found between cases and controls at all CpGs in TYRO3 gene-related amplicon (CpG1, p ≤ .003, CpG2, p ≤ .0001, CpG3, p ≤ .003 and CpG4, p ≤ .030) and CpG1 in CGβ gene-related amplicon (p ≤ .0001). Besides, a significant difference was found at two CpGs (CpG1, p ≤ .004 and CpG2, p ≤ .002) tested in the FAM189A1 gene-related amplicon. A significant correlation was found between the methylation level at CpG1 in the FAM189A1 gene and the different types of sperm motility. In conclusion, an alteration in the methylation levels of sperm DNA from males with reduced fecundity was showed. In addition, a relationship between variations in the methylation level of these CpGs and sperm motility has been observed.

Endosulfan induces cell dysfunction through cycle arrest resulting from DNA damage and DNA damage response signaling pathways

Our previous study showed that endosulfan increases the risk of cardiovascular disease. To identify toxic mechanism of endosulfan, we conducted an animal study for which 32 male Wistar rats were randomly and equally divided into four groups: Control group (corn oil only) and three treatment groups (1, 5 and 10mgkg^-1·d^-1). The results showed that exposure to endosulfan resulted in injury of cardiac tissue with impaired mitochondria integrity and elevated 8-OHdG expression in myocardial cells. Moreover, endosulfan increased the expressions of Fas, FasL, Caspase-8, Cleaved Caspase-8, Caspase-3 and Cleaved Caspase-3 in cardiac tissue. In vitro, human umbilical vein endothelial cells (HUVECs) were treated with different concentrations of endosulfan (1, 6 and 12μgmL^-1) for 24h. An inhibitor for Ataxia Telangiectasia Mutated Protein (ATM) (Ku-55933, 10μM) was added in 12μgmL^-1 group for 2h before exposure to endosulfan. Results showed that endosulfan induced DNA damage and activated DNA damage response signaling pathway (ATM/Chk2 and ATR/Chk1) and consequent cell cycle checkpoint. Furthermore, endosulfan promoted the cell apoptosis through death receptor pathway resulting from oxidative stress. The results provide a new insight for mechanism of endosulfan-induced cardiovascular toxicity which will be helpful in future prevention of cardiovascular diseases induced by endosulfan.

Study on the short-term effects of increased alcohol and cigarette consumption in healthy young men's seminal quality

Many studies have reported a negative impact of lifestyle factors on testicular function, spermatozoa parameters and pituitary-gonadal axis. However, conclusions are difficult to draw, since studies in the general population are rare. In this study we intended to address the early and late short-term impact of acute lifestyle alterations on young men’s reproductive function. Thirty-six healthy male students, who attended the Portuguese academic festivities, provided semen samples and answered questionnaires at three time-points. The consumption of alcohol and cigarette increased more than 8 and 2 times, respectively, during the academic festivities and resulted in deleterious effects on semen quality: one week after the festivities, a decrease on semen volume, spermatozoa motility and normal morphology was observed, in parallel with an increase on immotile spermatozoa, head and midpiece defects and spermatozoa oxidative stress. Additionally, three months after the academic festivities, besides the detrimental effect on volume, motility and morphology, a negative impact on spermatozoa concentration was observed, along with a decrease on epididymal, seminal vesicles and prostate function. This study contributed to understanding the pathophysiology underlying semen quality degradation induced by acute lifestyle alterations, suggesting that high alcohol and cigarette consumption are associated with decreased semen quality in healthy young men.

Mitochondrial Biomarkers Reflect Semen Quality: Results from the MARCHS Study in Chongqing, China

Unexplained infertility requires that more sensitive and mechanism-based biomarkers should be developed and used independently of or in addition to conventional semen parameters for an infertility diagnosis. In the present study, semen samples were collected from young men participating in the Male Reproductive Health in Chongqing College students (MARCHS) cohort study in the follow-up stage in 2014. Conventional semen parameters were measured in all 656 participants, whereas sperm mitochondrial membrane potential (MMP), mitochondrial DNA copy number (mtDNAcn), mtDNA integrity and apoptotic parameters were measured among 627, 386, 362, and 628 participants, respectively. We found that sperm MMP was significantly positively correlated with all of conventional semen parameters including semen volume (r = 0.090, p = 0.025), sperm concentration (r = 0.301, p<0.01), total sperm count (r = 0.324, p<0.01), and progressive motility (r = 0.399, p<0.01); sperm MMP was also negatively correlated with Annexin V⁺ sperm (r = -0.553, p<0.01); mtDNAcn was significantly negatively correlated with sperm concentration (r = -0.214, p<0.01), total sperm count (r = -0.232, p<0.01), and progressive motility (r = -0.164, p = 0.01); mtDNA integrity was also significantly positively correlated with sperm concentration (r = 0.195, p<0.01), total sperm count (r = 0.185, p<0.01), and progressive motility (r = 0.106, p = 0.043). After adjusting for potential confounders, these relationships remained significant. Furthermore, we explored the potential effects of lifestyles on such mitochondrial biomarkers and found that the current drinkers displayed a higher level of sperm MMP; additionally, mt DNAcn was increased with age. The results indicated that certain mitochondrial biomarkers could serve as predictors of semen quality in a general population, and the study provides a baseline for the effects of population characteristics and lifestyles on such mitochondrial markers.

Environmental pollutants: genetic damage and epigenetic changes in male germ cells

About a quarter of the human diseases occurs for exposure to air pollution. The male reproductive system, and especially spermatogenesis, seems to be particularly sensitive. As result, male infertility is increasing in industrial countries becoming a top priority for public health. In addition to psychological distress and economic constraints, poorer semen quality may have trans-generational effects including congenital malformations in the offspring and predispose to later onset adult diseases. Genetic and epigenetic alterations are involved in the failure of spermatogenesis. In this paper, we reviewed the major evidences of the effects of air pollutants on male infertility as well as the role of sperm DNA damage and epigenetic changes in affecting spermatogenesis. A better knowledge on the effects of air contaminants on the molecular mechanisms leading to infertility is of huge importance to help clinicians in identifying the cause of infertility but above all, in defining preventive and therapeutic protocols.

Effects of Glutamate and Aspartate on Serum Antioxidative Enzyme, Sex Hormones, and Genital Inflammation in Boars Challenged with Hydrogen Peroxide

Background. Oxidative stress is associated with infertility. This study was conducted to determine the effects of glutamate and aspartate on serum antioxidative enzymes, sex hormones, and genital inflammation in boars suffering from oxidative stress. Methods. Boars were randomly divided into 4 groups: the nonchallenged control (CON) and H₂O₂-challenged control (BD) groups were fed a basal diet supplemented with 2% alanine; the other two groups were fed the basal diet supplemented with 2% glutamate (GLU) or 2% aspartate (ASP). The BD, GLU, and ASP groups were injected with hydrogen peroxide (H₂O₂) on day 15. The CON group was injected with 0.9% sodium chloride solution on the same day. Results. Dietary aspartate decreased the malondialdehyde (MDA) level in serum (P < 0.05) compared with the BD group. Additionally, aspartate maintained serum luteinizing hormone (LH) at a relatively stable level. Moreover, glutamate and aspartate increased transforming growth factor-β1 (TGF-β1) and interleukin-10 (IL-10) levels in the epididymis and testis (P < 0.05) compared with the BD group. Conclusion. Both glutamate and aspartate promoted genital mRNA expressions of anti-inflammatory factors after oxidative stress. Aspartate more effectively decreased serum MDA and prevented fluctuations in serum sex hormones after H₂O₂ challenge than did glutamate.

In touch with your feminine side: how oestrogen metabolism impacts prostate cancer

Prostate cancer is the primary cancer in males, with increasing global incidence rates making this malignancy a significant healthcare burden. Androgens not only promote normal prostate maturity but also influence the development and progression of prostate cancer. Intriguingly, evidence now suggests endogenous and exogenous oestrogens, in the form of phytoestrogens, may be equally as relevant as androgens in prostate cancer growth. The prostate gland has the molecular mechanisms, catalysed by steroid sulphatase (STS), to unconjugate and utilise circulating oestrogens. Furthermore, prostate tissue also expresses enzymes essential for local oestrogen metabolism, including aromatase (CYP19A1) and 3β- and 17β-hydroxysteroid dehydrogenases. Increased expression of these enzymes in malignant prostate tissue compared with normal prostate indicates that oestrogen synthesis is favoured in malignancy and thus may influence tumour progression. In contrast to previous reviews, here we comprehensively explore the epidemiological and scientific evidence on how oestrogens impact prostate cancer, particularly focusing on pre-receptor oestrogen metabolism and subsequent molecular action. We analyse how molecular mechanisms and metabolic pathways involved in androgen and oestrogen synthesis intertwine to alter prostate tissue. Furthermore, we speculate on whether oestrogen receptor status in the prostate affects progression of this malignancy.