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1.
Lack of association between endocrine disrupting chemicals and male fertility: A systematic review and meta-analysis.
Martínez, MÁ, Marquès, M, Salas-Huetos, A, Babio, N, Domingo, JL, Salas-Salvadó, J
Environmental research. 2023;217:114942
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Exposure to natural or synthetic chemicals is directly related to environmental conditions, dietary and other lifestyle factors. Some of these chemicals are named endocrine disrupting chemicals (EDCs) because of their capability to interfere with the endocrine system. The aim of this study was to summarise and explore the association between exposure to EDCs and human male fertility indicators. This study is a systematic review and meta-analysis of seven studies; 4 assessed bisphenol A (BPA) in urine and sperm quality parameters, while 3 articles evaluated PCB153 [polychlorinated biphenyls] in serum and sperm quality parameters. Results show that there weren’t any positive or inverse associations between BPA or PCB153 and the sperm parameters analysed. Authors conclude that the systematic review showed a high disparity between studies, making difficult a consensus on the possible detrimental effect of the 12 groups of EDCs on male fertility. Thus, no conclusive statements can be drawn. Further studies are needed in order to provide more robust data.
Abstract
The incidence of infertility currently affects about 15% of the world's population. Male factors are estimated to be responsible for up to 40-50% of these cases. While the cause of these reproductive disorders is still unclear, the exposure to a family of ubiquitous compounds in our daily life, named endocrine disrupting chemicals (EDCs) could be involved. This paper was aimed at performing a systematic review and meta-analysis of population studies exploring whether human male exposure to EDCs affects male fertility. Clinical and observational studies assessing the exposure to EDCs along with sperm quality, the most common reproductive disorders, sperm DNA damage, sperm oxidative stress, fertilization rate, implantation rate, clinical pregnancy rate, live birth rate, and miscarriage rate were included. The quality assessment tool from the NHLBI-NIH was used to assure that studies met standardized quality criteria. Sensitivity analysis and heterogeneity among studies was assessed. Overall, the 32 selected articles, including 7825 individuals in the systematic review, explored 12 families of EDCs. The results revealed a high heterogeneity among studies in relation to the association between exposure to EDCs and the endpoints analyzed. Meta-analyses were performed with data from 7 articles including 479 individuals, 4 articles assessing the association between BPA in urine and sperm quality, and 3 articles evaluating PCB153 in serum and sperm quality. In the meta-analysis, we identified an unpredicted significant positive association between PCB153 exposure and sperm concentration. However, it would not be clinically relevant. No positive or inverse associations were found neither for BPA, nor for PCB153 and the rest of sperm parameters analyzed. The high disparity between studies made difficult to draw conclusions on the potential harmful effects of EDCs on male fertility. Consequently, to delineate the potential relationship that EDCs can have on male fertility, an important condition stressing the health system, further investigations are required.
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Lifestyle-, environmental-, and additional health factors associated with an increased sperm DNA fragmentation: a systematic review and meta-analysis.
Szabó, A, Váncsa, S, Hegyi, P, Váradi, A, Forintos, A, Filipov, T, Ács, J, Ács, N, Szarvas, T, Nyirády, P, et al
Reproductive biology and endocrinology : RB&E. 2023;21(1):5
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The World Health Organization defines infertility as regular unprotected sexual intercourse without achieving conception within a year. In recent years, there has been a growing demand for functional, objective parameters reflecting fertility status more clearly than classical parameters. Of these, sperm DNA fragmentation (SDF) and the DNA fragmentation index – denoting the percentage of sperm with damaged DNA – seem to be of utmost importance. The aim of this study was to investigate all risk factors that may potentially be increasing SDF. This study is a systematic review and meta-analysis of one hundred and ninety articles. The earliest studies were published in 2003, and the latest in 2021. Results show that several modifiable risk factors negatively affect SDF, namely; a. health conditions: varicocele [when veins become enlarged inside the pouch of skin that holds the testicles] and impaired glucose tolerance, b. infections: Chlamydia, c. malignancies: testicular tumours, and d. lifestyle factors: smoking, alcohol consumption and body mass index. Authors conclude that several lifestyle-, environmental-, and additional health factors are associated with increased SDF.
Abstract
INTRODUCTION Infertility affects one in every six couples in developed countries, and approximately 50% is of male origin. In 2021, sperm DNA fragmentation (SDF) testing became an evidence-based test for fertility evaluations depicting fertility more clearly than standard semen parameters. Therefore, we aimed to summarize the potential prognostic factors of a higher SDF. METHODS We conducted a systematic search in three medical databases and included studies investigating any risk factors for SDF values. We calculated mean differences (MD) in SDF with 95% confidence interval (CI) for exposed and non-exposed individuals. RESULTS We included 190 studies in our analysis. In the group of associated health conditions, varicocele (MD = 13.62%, CI: 9.39-17.84) and impaired glucose tolerance (MD = 13.75%, CI: 6.99-20.51) had the most significant increase in SDF. Among malignancies, testicular tumors had the highest impact, with a maximum of MD = 11.3% (CI: 7.84-14.76). Among infections, the overall effects of both Chlamydia and HPV were negligible. Of lifestyle factors, smoking had the most disruptive effect on SDF - an increase of 9.19% (CI: 4.33-14.06). Different periods of sexual abstinence did not show significant variations in SDF values. Age seemed to have a more drastic effect on SDF from age 50 onwards, with a mean difference of 12.58% (CI: 7.31-17.86). Pollution also had a detrimental effect - 9.68% (CI: 6.85-12.52). CONCLUSION Of the above risk factors, varicocele, impaired glucose tolerance, testicular tumors, smoking, pollution, and paternal age of over 50 were associated with the highest SDF. TRIAL REGISTRATION CRD42021282533.
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Mycotoxin-Linked Mutations and Cancer Risk: A Global Health Issue.
Ekwomadu, T, Mwanza, M, Musekiwa, A
International journal of environmental research and public health. 2022;19(13)
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Mycotoxins are toxic substances produced by fungi, which can be found in common foods like maize, wheat, nuts, and foods containing them. Mycotoxins such as aflatoxins, ochratoxin, fumonisins, zearalenone, and some Penicillium toxins can alter genetic material. According to previous studies, they can damage genetic material and affect cell growth. Usage of chemicals such as fertilizers and fungicides is a common practice in the agricultural industry to protect plants from fungus and to feed them. However, fungicides can accelerate mycotoxin production. 16 studies were included in this Systematic Review and 11 in Meta-Analysis. This research looked at the harmful effects of mycotoxins such as aflatoxins, fumonisins, ochratoxin, T2, zearalenone, and some Penicillium toxins in causing cancers. The researchers evaluated the link between aflatoxin exposure and liver cancer, fumonisin B1 exposure and liver cancer, zearalenone exposure and breast cancer, zearalenone exposure and cervical cancer, citrinine and patulin exposure and colorectal cancer, and NEO, HT-2, and T-2 exposure and Oesophageal cancer. This research did not show significant associations between various mycotoxins and cancer risk. As currently, most studies are primarily focused on aflatoxin; more robust studies are needed to assess the cancer risk associated with different mycotoxin exposure. Using the results of this study, healthcare professionals can gain a better understanding of how mycotoxins affect our bodies.
Abstract
Humans continue to be constantly exposed to mycotoxins, mainly through oral exposure (dietary), inhalation, or dermal contact. Recently, it has been of increasing interest to investigate mycotoxin-linked carcinogenicity. This systematic review was conducted to synthesize evidence of the association between mycotoxin-linked mutations and the risk of cancer, to provide an overview of the data linking exposure to different mycotoxins with human cancer risk, and to provide an update on current research on the risk of cancer associated with human exposure to mycotoxins. PRISMA guidelines were used when conducting the systematic review. PubMed, MEDLINE, and CINAHL electronic databases were comprehensively searched to extract the relevant studies published from inception to May 2022. A total of sixteen relevant studies (4907 participants) were identified and included in this review. Of these, twelve studies were from Asia, while four of the studies were conducted in Africa. The overall meta-analysis result found no significant association, although some of the studies confirmed an association between mycotoxin-linked mutations and primary liver cancer risk. Mainly, the experimental studies have shown associations between mycotoxin-linked mutations and cancer risk, and there is a need for researchers to confirm these links in epidemiological studies in order to guide public health policies and interventions.
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The Influence of Vitamin E and Omega-3 Fatty Acids on Reproductive Health Indices Among Male Workers Exposed to Electromagnetic Fields.
Mohammadi, H, Golbabaei, F, Dehghan, SF, Imani, H, Ramezani Tehrani, F, Khodakarim Ardakani, S
American journal of men's health. 2022;16(1):15579883221074821
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Studies have suggested that low-frequency electromagnetic fields (EMF) may have a detrimental effect on male fertility. Lower hormone levels and higher free radicals in the body damaging sperm cells have been indicated to play a role in this relationship. Supporting the development of sperm cells in individuals who have been subjected to EMF may be an effective therapy. Sperm cells contain large amounts of polyunsaturated fatty acids such as omega-3 and supplementation may be of benefit. Although high amounts of omega-3 can have side effects, which can be limited with the dual supplementation of vitamin E. This randomised control trial aimed to determine the effect of omega-3 and vitamin E supplementation on reproductive indices of individuals who work with EMF. The results showed that EMF exposure affected sperm count, morphology, and motility and that the supplementation of omega-3 and vitamin E in conjunction could limit effects on morphology and motility. It was concluded that simultaneous vitamin E and omega-3 consumption could be of benefit for fertility in men exposed to EMF, however further studies are required to confirm this finding due to study limitations and size. This study could be used by healthcare professionals to understand that EMF is of detriment to fertility in men but there may be ways to limit the effects involving the use of omega-3 and vitamin E supplementation.
Expert Review
Conflicts of interest:
None
Take Home Message:
- Vitamin E and Omega 3 fatty acids have been reported to influence sperm morphology and sperm motility.
- This study reported that the intake of 100 mg of vitamin E accompanied by Omega 3 fatty acids (180 mg eicosatetraenoic acid [EPA] and 120 mg docosahexaenoic acid [DHA]) had a significant improvement in sperm morphology and motility after 3 months.
- In addition, this study also reported that electric magnetic fields may have a negative effect on sperm morphology and motility.
Evidence Category:
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A: Meta-analyses, position-stands, randomized-controlled trials (RCTs)
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B: Systematic reviews including RCTs of limited number
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C: Non-randomized trials, observational studies, narrative reviews
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D: Case-reports, evidence-based clinical findings
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E: Opinion piece, other
Summary Review:
Introduction
A block-randomized, double-blind, placebo-controlled study was conducted to investigate the effects of using vitamin E and Omega 3 fatty acid supplementation on reproductive indices among workers in an automobile parts manufacturing facility. The effect of exposure to electromagnetic fields on certain sex hormones and sperm parameters was also assessed.
Methodology
92 married males between the ages of 20-50 were deployed into 4 groups. The first group was given vitamin E (100 mg) accompanied by a placebo capsule. The second group was given Omega 3 fatty acids (180 mg eicosatetraenoic acid [EPA] and 120 mg docosahexaenoic acid [DHA]) accompanied by a placebo capsule. The third group was given vitamin E along with Omega 3 fatty acids. Finally, the fourth group acted as a placebo group and was given 2 placebo capsules.
The semen parameters of the participants were analysed before and after three months of consuming the supplements. Sex hormones within the blood serum were also analysed after the 3-month supplement period. At the endpoint, 80/92 subjects completed the study.
Results
Primary clinical outcomes were:
- Certain demographic parameters had significant effects on sluggish and full sperm motility: age (B = −1.344, p = .034); employment duration (B = −1.863, p = .022); and smoking (B = −94.24, p = .003).
- The difference in the level of testosterone before and after the intervention was not statistically significant for any age group.
- The difference in follicle-stimulating hormone (FSH) and Luteinizing Hormone (LH) before and after the intervention were not statistically significant for any of the supplement groups.
- There was a statistically significant effect on sperm count and sperm with full motility before and after the intervention in the vitamin E + Omega 3 group, p =.016.
- The effect of supplement use on sperm morphology was significant in the vitamin E + Omega 3 group (B = -4.961; p = .001).
- The effect of supplement use on full and sluggish sperm motility was also significant in the vitamin E + Omega 3 group (B = 72.211, p = .021).
Secondary clinical outcomes were:
- Electric fields had the largest effect on the percentage of immotile sperm amongst the exposure variables (B = 9.541; p = .053).
Clinical practice applications:
- Prior studies have reported on the antioxidant effects of vitamin E and the effect of Omega 3 fatty acids on the testicles and the hypothalamic-pituitary-gonadal axis.
- This study concluded that participants increased their normal sperm morphology by 16% and their sperm motility by 12% over a 3-month period by supplementing with vitamin E and Omega 3 fatty acids.
- Based on these findings, a practitioner could therefore consider recommending 100 mg of vitamin E accompanied by Omega 3 fatty acids (180 mg eicosatetraenoic acid [EPA] and 120 mg docosahexaenoic acid [DHA]) for at least 3 months to help support the reproductive health of their male patients struggling with sperm morphology and/or sperm motility.
Considerations for future research:
- In this study vitamin E and Omega 3 did not show significant effects on certain sex hormones (testorterone, FSH and LH) therefore, there is a need to investigate if a higher dosage or longer consumption of the supplements could make a difference to these outcomes.
- There are mixed findings on the potential effects of electric magnetic fields on male reproductive indices and therefore there is a need for further clinical studies to be done using the same type of frequency, intensity, and exposure protocols to draw further conclusions.
Abstract
The present study aims to investigate the effects of using the supplementation of vitamin E and Omega 3 fatty acids on reproductive indices among workers in an automobile parts manufacturing plant. The effect of exposure to electromagnetic fields on certain sex hormones and sperm parameters will also be assessed. The participants were deployed into four groups as per the double-blind block randomization method. Semen parameters and sex hormones of the participants were analyzed before and after 3-month consumption of supplements. The level of workers' exposure to low-frequency magnetic and electrical fields was measured through the recommendation of National Institute for Occupational Safety and Health. Univariate analysis of variance indicated that exposure to electric fields had a statistically significant effect on sperm count, morphology, and motility. The simultaneous consumption of vitamin E + Omega 3 had a statistically significant effect on sperm morphology and motility.
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The impact of diabetes mellitus type 1 on male fertility: Systematic review and meta-analysis.
Facondo, P, Di Lodovico, E, Delbarba, A, Anelli, V, Pezzaioli, LC, Filippini, E, Cappelli, C, Corona, G, Ferlin, A
Andrology. 2022;10(3):426-440
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The relationship between type 2 diabetes mellitus and male hypogonadism is well known, whereas the impact of type 1 diabetes mellitus (DM1) on male fertility and testis functions has been less studied. The aim of this study was to systematically review and discuss the available evidence evaluating paternity rate, male gonadal axis, and sperm parameters in men with DM1. This study is a systematic review and meta-analysis of fourteen studies. Results show: - reduced fertility potential in patients with DM1, as they have a lower number of children compared with unaffected population. In fact, the rate of children is statistically significantly lower among men who had been diagnosed with DM1 at an earlier age, according to a longer duration of the disease. - that men with DM1, compared with controls, have significantly lower normal sperm morphology, progressive motility and a trend toward a reduced semen volume, without difference in total sperm count and concentration. Authors conclude that DM1 might impair reproductive health at different levels, including functional sperm alterations definitively leading to reduced fertility rate in these patients.
Abstract
BACKGROUND Some evidence suggests that diabetes mellitus type 1 (DM1) could affect male fertility, gonadal axis, semen parameters, and spermatogenesis because of effects of hyperglycemia and insulin deficiency. Anyhow, the exact impact of DM1 on male fertility is unclear. OBJECTIVES To review the studies evaluating paternity rate, male gonadal axis, and semen parameters in men with DM1. MATERIALS AND METHODS A review of relevant literature from January 1980 to December 2020 was performed. Only studies published in English reporting data on fatherhood (rate of children by natural fertility), hormonal and seminal parameters were included. Out of 14 retrieved articles, the eight studies evaluating semen parameters were meta-analyzed. RESULTS The rate of children (four studies) was lower than controls among men affected by DM1, especially in men with a longer duration of disease. The data of gonadal hormonal profile in DM1 men (six studies) are very heterogeneous and a neutral effect of DM1 or a condition of subclinical hypogonadism could not be concluded. Meta-analysis showed that men with DM1 (n = 380), compared with controls (n = 434), have significantly lower normal sperm morphology [-0.36% (-0.66; -0.06), p < 0.05, six studies] and sperm progressive motility [33.62% (-39.13; -28.11), p < 0.001, two studies] and a trend toward a lower seminal volume [-0.51 (-1.03; 0.02), p = 0.06, eight studies], without difference in total sperm count and concentration. Data on scrotal ultrasound and sperm DNA fragmentation are too few. No study evaluated other factors of male infertility, such as transrectal ultrasound, semen infections, sperm auto-antibodies, and retrograde ejaculation. DISCUSSION DM1 might impair male fertility and testis functions (endocrine, spermatogenesis), but definition of its actual impact needs further studies. CONCLUSION Men with DM1 should be evaluated with a complete hormonal, seminal, and ultrasound workup to better define their fertility potential and need for follow up of testis functions.
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Menstruation-Related Disorders-Dysmenorrhea and Heavy Bleeding-as Significant Epiphenomena in Women With Rheumatic Diseases.
Orlandi, M, Vannuccini, S, El Aoufy, K, Melis, MR, Lepri, G, Sambataro, G, Bellando-Randone, S, Guiducci, S, Cerinic, MM, Petraglia, F
Frontiers in pharmacology. 2022;13:807880
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Rheumatic diseases (RDs) affect significantly more women than men, and for this reason, gynaecological disorders may have an additional negative impact on women’s health. The aim of this study was to describe gynaecological symptoms among fertile age women with RDs and their impact on quality of life. This study is a monocentric, cross-sectional observational study. Results show that a large number of women with RDs report menstrual disorders. In fact, more than half of the population reported of having dysmenorrhea since adolescence. Similarly, during fertile age, menstrual pain was frequently reported, and in 72% of the cases, the intensity resulted to be moderate/severe. Additionally, heavy menstrual bleeding was found in 38% of the patients during adulthood and in 52% of patients during adolescence. Authors conclude that the management of female patients with RDs is a challenge for clinicians and should include an accurate evaluation of gynaecological aspects (menstruation, fertility, maternity, and sexuality) as well as manage an interdisciplinary teamwork approach (rheumatologist and gynaecologists).
Abstract
Background: In women with rheumatic diseases (RDs) menstruation-related disorders have never been investigated. The aim of this study was to evaluate gynecological symptoms/disorders in fertile age women with RDs. Materials and methods: All patients (n = 200) filled up a self-administered questionnaire on their gynecological history, menstrual cycle pattern, menstrual-related symptoms, and quality of life (QoL). The RD group was then compared to a control group of 305 age-matched fertile age women. Results: Among patients with RDs, 58% had arthritis, 40% connective tissue diseases (CTDs), and 1.5% systemic vasculitis. No differences were observed between CTDs and arthritis, except for a family history of HMB which was more common among women with CTDs (p < .01). When compared to controls, women with RDs reported more frequent heavy menstrual bleeding (HMB) during adolescence (51.7 and 25.4%, respectively; p = .0001) and adult life (37.7 and 25.9%, respectively; p = .0065). Also, dysmenorrhea in adolescence was significantly more common among cases (55.6 and 45.4%, respectively; p = .0338). Gynecological pain (dysmenorrhea, non-menstrual pelvic pain, dyspareunia, dysuria, and dyschezia) in patients with RDs was more frequent than in controls (p = .0001, .0001, .0001, .0001, .0002, respectively). Considering women who reported moderate and severe symptoms in RDs, dysmenorrhea and dyspareunia remain significantly more frequent in women with RDs than in controls (p = .0001; p = .0022; respectively). QoL scores were significantly reduced in women with RDs, either in physical (p = .0001) and mental domains (p = .0014) of short-form 12. Conclusion: Women affected by RDs frequently presented menstruation-related disorders; thus, female patients with RDs should be questioned about gynecological symptoms and referred to the gynecologist for an accurate evaluation.
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A Systematic Review of Organic Versus Conventional Food Consumption: Is There a Measurable Benefit on Human Health?
Vigar, V, Myers, S, Oliver, C, Arellano, J, Robinson, S, Leifert, C
Nutrients. 2019;12(1)
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The demand for organic products has risen rapidly over the last decades. The reasons why consumers may favour organic over conventional products are varied. They may be for personal health and wellbeing, environmental considerations, animal welfare or perceived higher nutritional profile - which is true for some, but not all components. While the long-term safety of pesticide consumption through conventional food production has been questioned, organic foods clearly show lower levels of toxic metabolites, like heavy metals and synthetic fertilizer and pesticide residues. This systematic review aimed to assess the current evidence of organic diet consumption and human health compared to conventionally produced foods. Included were 35 papers on clinical trials and observational studies. The clinical trials studied pesticide and phytochemical excretion, antioxidant capacity, body composition, lipids and inflammatory markers. The observational studies were focused on fertility, foetal and childhood development, pregnancy, lactation and levels of pesticides in children and adults, as well as nutritional biomarkers and cancer risk in adults. An increased intake of organic produce in long-term studies appeared to reduce the incidence of infertility, birth defects, allergies, middle ear infection, pre-eclampsia, metabolic syndrome, high BMI, and non-Hodgkin lymphoma. Organic intake was also linked to reduced urinary levels of organophosphorus pesticides and herbicides. Yet, the author highlighted that organic consumers are more likely to be health conscious, physically active, eat a more plant-based diet, have higher education levels and income, and therefore are not representative of the general population. They also argue that the possible benefits from an organic diet may be partially due to the quality and composition of the diet rather than a direct effect of organic food consumption. Whereby a growing number of findings demonstrate the health benefits of organic food consumption, according to the authors, the current evidence does not yield a solid and definitive answer.
Abstract
The current review aims to systematically assess the evidence related to human health outcomes when an organic diet is consumed in comparison to its conventional counterpart. Relevant databases were searched for articles published to January 2019. Clinical trials and observational research studies were included where they provided comparative results on direct or indirect health outcomes. Thirty-five papers met the criteria for inclusion in the review. Few clinical trials assessed direct improvements in health outcomes associated with organic food consumption; most assessed either differences in pesticide exposure or other indirect measures. Significant positive outcomes were seen in longitudinal studies where increased organic intake was associated with reduced incidence of infertility, birth defects, allergic sensitisation, otitis media, pre-eclampsia, metabolic syndrome, high BMI, and non-Hodgkin lymphoma. The current evidence base does not allow a definitive statement on the health benefits of organic dietary intake. However, a growing number of important findings are being reported from observational research linking demonstrable health benefits with organic food consumption. Future clinical research should focus on using long-term whole-diet substitution with certified organic interventions as this approach is more likely to determine whether or not true measurable health benefits exist.