Mechanisms of obesity-induced male infertility

Exploring online reproductive health promotion in Canada: a focus on behavioral and environmental influences from a sex and gender perspective

BACKGROUND

Reproductive health promotion can enable early mitigation of behavioral and environmental risk factors associated with adverse pregnancy outcomes, while optimizing health of women + (all genders that can gestate a fetus) and babies. Although the biological and social influences of partners on pregnancy are well established, it is unknown whether online Canadian government reproductive health promotion also targets men and partners throughout the reproductive lifespan.

METHODS

Reproductive health promotion, designed for the general public, was assessed in a multi-jurisdictional sample of Canadian government (federal, provincial/territorial, and municipal) and select non-governmental organization (NGO) websites. For each website, information related to environmental and behavioral influences on reproductive health (preconception, pregnancy, postpartum) was evaluated based on comprehensiveness, audience-specificity, and scientific quality.

RESULTS

Government and NGO websites provided sparse reproductive health promotion for partners which was generally limited to preconception behavior topics with little coverage of environmental hazard topics. For women + , environmental and behavioral influences on reproductive health were well promoted for pregnancy, with content gaps for preconception and postpartum stages.

CONCLUSION

Although it is well established that partners influence pregnancy outcomes and fetal/infant health, Canadian government website promotion of partner-specific environmental and behavioral risks was limited. Most websites across jurisdictions promoted behavioral influences on pregnancy, however gaps were apparent in the provision of health information related to environmental hazards. As all reproductive stages, including preconception and postpartum, may be susceptible to environmental and behavioral influences, online health promotion should use a sex- and gender-lens to address biological contributions to embryo, fetal and infant development, as well as contributions of partners to the physical and social environments of the home.

Effect of oestrogen modulation on semen parameters in men with secondary hypogonadism: Systematic review and meta-analysis

BACKGROUND

Selective oestrogen receptor modulators and aromatase inhibitors stimulate endogenous gonadotrophins and testosterone in men with hypogonadism. There are no systematic reviews/meta-analyses assessing the effects of selective oestrogen receptor modulators/aromatase inhibitors on semen parameters in men with secondary hypogonadism.

OBJECTIVES

To assess the effect of monotherapy or a combination of selective oestrogen receptor modulators/aromatase inhibitors on sperm parameters and/or fertility in men with secondary hypogonadism.

MATERIALS AND METHODS

A systematic search was conducted in PubMed, MEDLINE, Cochrane Library and ClinicalTrials.gov. Study selection and data extraction were performed by two reviewers independently. Randomised controlled trials and non-randomised studies of interventions reporting effects of selective oestrogen receptor modulators and/or aromatase inhibitors on semen parameters or fertility in men with low testosterone with low/normal gonadotrophins were selected. The risk of bias was assessed using ROB-2 and ROBINS-I tools. The results of randomised controlled trials were summarised using vote counting while summarising effect estimates where available. Non-randomised studies of intervention meta-analysis were conducted using the random-effect model. The certainty of evidence was assessed using GRADE.

RESULTS

Five non-randomised studies of interventions (n = 105) of selective oestrogen receptor modulators showed an increase in sperm concentration (pooled mean difference 6.64 million/mL; 95% confidence interval 1.54, 11.74, I2  = 0%) and three non-randomised studies of interventions (n = 83) of selective oestrogen receptor modulators showed an increase in total motile sperm count (pooled mean difference 10.52; 95% confidence interval 1.46-19.59, I2  = 0%), with very low certainty of evidence. The mean body mass index of participants was >30 kg/m2 . Four randomised controlled trials (n = 591) comparing selective oestrogen receptor modulators to placebo showed a heterogeneous effect on sperm concentration. Three included men with overweight or obesity. The results were of very low certainty of evidence. Limited pregnancy or live birth data were available. No studies comparing aromatase inhibitors with placebo or testosterone were found.

DISCUSSION AND CONCLUSION

Current studies are of limited size and quality but suggest that selective oestrogen receptor modulators may improve semen parameters in those patients, particularly when associated with obesity.

Changes in levels of testosterone, insulin sensitivity and metabolic profiles during GnRH therapy: Reciprocity between insulin sensitivity and pituitary responsiveness to GnRH in teenage and young male patients with congenital hypogonadotropic hypogonadism

OBJECTIVES

A direct evaluation of insulin sensitivity on pituitary response to gonadotropin relasing hormone (GnRH) has not been shown in congenital hypogonadotropic hypogonadism (CHH), despite a growing body of evidence in the association of testosterone concentrations with insulin sensitiviy. The objective of the study was to explore whether increased testosterone concentrations in men with CHH improve insulin sensitivity, or vice versa.

DESIGN

A retrospective study at a tertiary centre.

PATIENTS

Series of male CHH patients were included from Jannuary 2014 to December 2019.

MEASUREMENTS

Insulin sensitivity indices calculated from oral glucose tolerance test and steroid hormone levels were examined in 52 patients with newly diagnosed CHH and 22 healthy controls. Thirty-two of the 52 CHH patients received pulsatile GnRH therapy with follow-up every 3-6 months.

RESULTS

Compared to healthy controls, CHH patients had elevated 2 h post-load glucose, HbA1c, fasting insulin, HOMA of insulin resistance (HOMA-IR) and decreased Matsuda index and testosterone (p ≤ .01). The median follow-up for patients (n = 32) who received pulsatile GnRH therapy was 13.5 (11.3-24) months (432 person-months in total). GnRH therapy increased testosterone and Matsuda index (p ≤ .0001), whilst decreased platelet count (p = .04), leptin (p = .04), fasting glucose (p = .01) and HOMA-IR (p < .0001) compared with baseline. The median treatment duration first time to reach the lower limit of normal testosterone concentrations of patients with high and low baseline insulin sensitivity was 15 (95% CI: 8.1-21.9) and 30 months (21.2-38.8), respectively. Correspondingly, after GnRH therapy, luteinizing hormone responsiveness to GnRH provocative test was more vigorous in patients with high insulin sensitivity than those with low insulin sensitivity [17.0 (9.5-25.9) vs. 8.2 (3.3-13.0), p = .01].

CONCLUSION

Pulsatile GnRH therapy elevated testosterone levels in male CHH patients, ameliorated impaired insulin sensitivity and attenuated subclinical inflammatory response, increased insulin sensitivity, in turn, may benefit the efficacy of pulsatile GnRH therapy.

The diagnosis of Gestational Diabetes Mellitus and its impact on In Vitro Fertilization pregnancies. A pilot study

BACKGROUND

In Vitro Fertilization (IVF) is increasingly becoming a necessary mode of reproduction. This high risk group is prone to Gestational Diabetes Mellitus (GDM) which further exposes these pregnancies to an increased risk of adverse outcomes. In light of the limited data in the current literature, further investigation is needed regarding the time of GDM diagnosis in IVF pregnancies as well as the outcome of IVF pregnancies complicated by GDM.

METHODS

In this three center pilot cross sectional study, the data of 101 singleton IVF pregnancies complicated by GDM were analyzed. Prompt GDM diagnosis in IVF pregnancies was accomplished by self-blood glucose monitoring (SMBG) from the first antenatal visit and confirmed by an OGTT. To evaluate pregnancy outcome, maternal and fetal complications in the 101 GDM IVF group was compared to 101 IVF as well as 101 spontaneous conceptions (SC). The three groups were matched by age. The effect of demographic and glycemic parameters on the outcome of GDM IVF pregnancies was investigated.

RESULTS

GDM diagnosis was made before the 24th week in 37.6% of the GDM IVF group. The week of delivery was earlier for the GDM IVF group (37 ± 1.7) relative to the IVF (37.9 ± 0.9, p < 0.001) and the SC group (38.1 ± 0.8, p < 0.001). GDM IVF pregnancies exhibited greater preeclampsia rates and 84.8% underwent caesarian section. No significant difference regarding LGA and SGA birth weights was found. Complications of GDM IVF pregnancies were associated with the 1-h postprandial BG (r = 0.267, p = 0.007).

CONCLUSION

GDM screening in IVF pregnancies may be considered earlier than the 24th week. IVF pregnancies affected by GDM are prone to increased maternal and fetal complications which are associated with 1-h postprandial BG.

Serum 25OHD3 of Obese Mice Is Affected by Liver Injury and Correlates with Testosterone Levels and Sperm Motility

INTRODUCTION

The concentration of 25-hydroxycholecalciferol (25OHD3) in the serum of obese people is low and often accompanied by symptoms of low fertility. Therefore, vitamin D is recommended as a potential treatment option. However, after clinical trials, it was found that vitamin D cannot effectively increase the concentration of 25OHD3 in the serum of obese people. How obesity causes low 25OHD3 concentration and low fertility is unclear.

METHODS

We analyzed the physiological and pathological changes in obese mice induced by a high-fat diet (HFD) and the changes in mice after supplementing with 25OHD3.

RESULTS

The concentration of 25OHD3 in the serum of obese mice induced by HFD was significantly reduced, and these mice showed liver hypertrophy accompanied by abnormal liver injury, testicular hypertrophy, low testosterone levels, high leptin levels, and low sperm motility. The mRNA and protein expression of CYP2R1 of hydroxylated vitamin D3 was significantly reduced; CYP11A1 and CYP11A2, which synthesize testosterone, were significantly reduced. After supplementing with 25OHD3, there was an increase in serum 25OHD3 concentration, testosterone level, and sperm motility, but it cannot improve the degree of obesity, CYP2R1 expression, and liver damage.

CONCLUSION

Our research shows that there is a metabolic interference mediated by 25OHD3 and testosterone between obesity and low sperm motility. The results of this study can provide a scientific basis for studying the mechanism of 25OHD3 and hormone regulation and treating obese people with low sperm motility.

The Mechanisms Involved in Obesity-Induced Male Infertility

BACKGROUND

Obesity resulted by imbalance between the intake of energy and energy consumption can lead to growth and metabolic disease development in people. Both in obese men and animal models, several studies indicate that obesity leads to male infertility.

OBJECTIVE

This review has discussed some mechanisms involved in obesity-induced male infertility.

METHODS

Online documents were searched through Science Direct, Pubmed, Scopus, and Google Scholar websites dating from 1959 to recognize studies on obesity, kisspeptin, leptin, and infertility.

RESULTS

Obesity induced elevated inflammatory cytokines and oxidative stress can affect male reproductive functions, including spermatogenesis disorders, reduced male fertility power and hormones involved in the hypothalamus-pituitary-gonadal axis.

CONCLUSION

There is significant evidence that obesity resulted in male infertility. Obesity has a negative effect on male reproductive function via several mechanisms such as inflammation and oxidative stress.

Functional Analysis of Steroidogenic Factor 1 (sf-1) and 17α-Hydroxylase/Lyase (cyp17α) Promoters in Yellow Catfish Pelteobagrus fulvidraco

The present study was performed to clone and characterize the structures and functions of steroidogenic factor 1 (sf-1) and 17α-hydroxylase/lyase (cyp17α) promoters in yellow catfish Pelteobagrus fulvidraco, a widely distributed freshwater teleost. We successfully obtained 1981 and 2034 bp sequences of sf-1 and cyp17α promoters, and predicted the putative binding sites of several transcription factors, such as Peroxisome proliferator-activated receptor alpha (PPARα), Peroxisome proliferator-activated receptor gamma (PPARγ) and Signal transducer and activator of transcription 3 (STAT3), on sf-1 and cyp17α promoter regions, respectively. Overexpression of PPARγ significantly increased the activities of sf-1 and cyp17α promoters, but overexpression of PPARα significantly decreased the promoter activities of sf-1 and cyp17α. Overexpression of STAT3 reduced the activity of the sf-1 promoter but increased the activity of the cyp17α promoter. The analysis of site-mutation and electrophoretic mobility shift assay suggested that the sf-1 promoter possessed the STAT3 binding site, but did not the PPARα or PPARγ binding sites. In contrast, only the PPARγ site, not PPARα or STAT3 sites, was functional with the cyp17α promoter. Leptin significantly increased sf-1 promoter activity, but the mutation of STAT3 and PPARγ sites decreased leptin-induced activation of sf-1 promoter. Our findings offered the novel insights into the transcriptional regulation of sf-1 and cyp17α and suggested leptin regulated sf-1 promoter activity through STAT3 site in yellow catfish.

Serum estradiol levels in infertile men with non-obstructive azoospermia

PURPOSE

To report the different patterns of estradiol levels in infertile men with non-obstructive azoospermia and correlate these levels with their clinical and laboratory findings.

MATERIALS AND METHODS

A retrospective study was launched, and a retrieval of data for infertile men with non-obstructive azoospermia (n = 166) and fertile controls (n = 40) was performed. The retrieved data included demographics, clinical findings, scrotal duplex, semen analysis, and hormonal assay (testosterone, follicle-stimulating hormone, luteinizing hormone, prolactin, and estradiol).

RESULTS

Our findings showed a wide spectrum of estradiol concentrations. The patients were arranged into three groups (high, normal, and low estradiol groups). The normal estradiol group was the most prevalent (71.1%). Testosterone, gonadotrophins, testicular volumes, and the number of patients with jobs in polluted workplaces showed significant differences among the study groups (p = 0.001, <0.001, <0.001, and 0.004, respectively). Age, body mass index, varicocele prevalence, prolactin, and smoking habits did not show any significant differences among the groups. Obesity was lacking in the low estradiol group, but it had significantly higher prevalence in the normal (p = 0.013) or high group (p = 0.023) compared with the controls.

CONCLUSION

Serum estradiol, in infertile men with non-obstructive azoospermia, may be present at different levels. It is recommended that estradiol be measured in infertile men with non-obstructive azoospermia when there is an alteration in testosterone concentration, obesity, a polluted workplace occupation, or before trying hormonal therapy. Extended studies are highly recommended to provide a clear clue whether alterations in estradiol concentrations in men with non-obstructive azoospermia are the cause or a consequence of the condition.

Direct actions of adiponectin on changes in reproductive, metabolic, and anti-oxidative enzymes status in the testis of adult mice

Obesity is a major health problem that is linked to decreased sperm count. It is hypothesized that an obesity-associated reduction in adiponectin secretion may be responsible for impairment of spermatogenesis. Therefore, the aim of the study was to evaluate the direct role of adiponectin in spermatogenesis and steroid synthesis in adult mice. This study showed that adiponectin receptors (AdipoR1 and AdipoR2) were localized in Leydig cells and seminiferous tubules in the testis of adult mice. The result of the in vitro study showed the direct action of adiponectin on spermatogenesis by stimulating cell proliferation (PCNA) and survival (Bcl2) and by suppressing cell apoptosis. Treatment of testis with adiponectin also enhanced transport of the energetic substrates glucose and lactate to protect cells from undergoing apoptosis. Adiponectin treatment further showed a significant reduction in oxidative stress and nitric oxide. Our findings suggest that adiponectin effectively facilitates cell survival and proliferation, as well as protects from apoptosis. Thus, adiponectin treatment may be responsible for enhancing sperm counts. Interestingly, this study showed the stimulatory effect of adiponectin in spermatogenesis but showed an inhibitory effect on testosterone and estradiol synthesis in the testes. Based on the present study, it is hypothesized that systemic adiponectin treatment may be a promising therapeutic strategy for the improvement of spermatogenesis and sperm count.

Pubertal Status and Gonadal Functions in Obese Boys with Fatty Liver

BACKGROUND

In adult studies, obese subjects with nonalcoholic fatty liver disease (NAFLD) have been shown to have poor sperm quality, and lower testosterone and luteinizing hormone levels. The aim of this study was to investigate the pubertal status and gonadal functions in obese boys with NAFLD.

MATERIALS AND METHODS

The study included 119 obese and 78 nonobese age-matched adolescents. The obese boys were separated into two groups based on the presence (NAFLD group) or absence of liver steatosis with high transaminases (non-NAFLD group). The levels of serum AMH (anti-Mullerian hormone), inhibin B, gonadotropins, total testosterone, lipids, high-sensitivity C-reactive protein, fasting glucose, insulin levels, and aortic intima media thickness were measured in all subjects.

RESULTS

Of the total 197 children, 174 had reached puberty. There were no significant differences between the groups in respect of testicular sizes and the prevalence of pubertal status among the groups (84.3% of NAFLD vs. 70.6% of non-NAFLD vs. 98.7% of control subjects). No significant differences were found in respect of gonadotropins and AMH levels. Total testosterone levels in the NAFLD group were significantly lower than those of the non-NAFLD obese group (P < 0.001) and the control group (P < 0.001). Inhibin B levels were also significantly lower in all (NAFLD and non-NAFLD) obese groups compared to the control group (P = 0.008).

CONCLUSIONS

The results of the study demonstrated that diminished testosterone and inhibin B levels occur in pubertal obese boys with NAFLD. No significant differences were detected according to pubertal status, AMH levels, and testicular volumes in the age-matched groups.

Role of estrogen receptors, P450 aromatase, PCNA and p53 in high-fat-induced impairment of spermatogenesis in rats

Obesity and overweight are frequently associated with male subfertility. To address new findings on the players involved in the obesity-induced impairment of spermatogenesis, we used a high-fat diet-induced overweight-rat model. Following four weeks of high-fat diet, the organization of seminiferous epithelium was affected, and tubules lumen showed immature/degenerated cells, typical signs of hormonal imbalance and testicular damage. Real-time PCR analysis allowed us to detect increased levels of ERα and decreased levels of aromatase CYP19 transcripts in testis, suggesting an increase in circulating estrogens derived from the accumulating adipose tissue rather than the induction of testicular estrogen synthesis. Moreover, in situ hybridization analysis showed an increased susceptibility towards estrogens in testis from high-fat fed rats, being ERs expressed not only in spermatogonia, as in control testis, but also in spermatids. Western blot and immunohistochemical analyses revealed an increase in the amount of p53 and PCNA, together with a change in their immunodetection, being the proteins localised on germ cells at different stages of maturation. Differences in p53 and PCNA expression may give evidence and be part of a cellular response to stress conditions and damage caused by the excessive intake of saturated fatty acids.

Adipokines in Semen: Physiopathology and Effects on Spermatozoas

Adipokines are secreted by adipose tissue and could be the link between obesity and infertility. Different studies investigated the involvement of adipokines in reproductive functions but only a few have looked into the male part. This review assesses adipokine functions on male reproductive parameters. Adiponectin seems to have a positive effect on sperm parameters, whereas other adipokines such as resistin or chemerin would have a rather deleterious effect on spermatogenesis. Semen parameters seem to be impacted when resistin and chemerin are increased: indeed, there is a decrease of sperm motility. Sperm morphology is improved when adiponectin is increased. The most studied adipokine, leptin, has a dual effect with a positive effect on sperm at physiological levels and a negative one for high seminal concentrations. Many semen parameters and fertility itself are disturbed according to semen adipokine levels, even if it is not the only interfering element. Taken together, adipokines are found in human and animal semen and most of them or their receptors are expressed in male genital tract. Although the pathophysiological role of adipokines in semen is not clearly elucidated, the adipokines could influence sperm functionality and could be potential biomarkers of male fertility.

Obesity, An Enemy of Male Fertility: A Mini Review

Obesity is a highly prevalent non-communicable disease worldwide and is commonly associated with male infertility. Several etiopathological theories have been mentioned in the literature by which obesity affects spermatogenesis, thus affecting the male fertility potential. Mechanisms for explaining the effect of obesity on male infertility include endocrinopathy, increased aromatization activity, associated erectile dysfunction, psychological and thermal effects, obstructive sleep apnea, increased leptin and oxygen free radicals, and associated inflammatory and obstructive elements of epididymitis. Treatment of such a complex problem includes weight reduction (by lifestyle modification and increased physical activity), optimization of altered testosterone-to-estradiol ratio using aromatase inhibitors and/or gonadotropins, treatment of associated comorbidities by phosphodiesterase inhibitors for erectile dysfunction, and insulin-sensitizing agents for the management of diabetes. The aim of this mini-review is to highlight the pathological basis of this problem and to focus on obesity as an etiology of male infertility.

Perspectives of complementary and alternative medicine (CAM) practitioners in the support and treatment of infertility

BACKGROUND

Infertility patients are increasingly using complementary and alternative medicine (CAM) to supplement or replace conventional fertility treatments. The objective of this study was to determine the roles of CAM practitioners in the support and treatment of infertility.

METHODS

Ten semi-structured interviews were conducted in Ottawa, Canada in 2011 with CAM practitioners who specialized in naturopathy, acupuncture, traditional Chinese medicine, hypnotherapy and integrated medicine.

RESULTS

CAM practitioners played an active role in both treatment and support of infertility, using a holistic, interdisciplinary and individualized approach. CAM practitioners recognized biological but also environmental and psychosomatic determinants of infertility. Participants were receptive to working with physicians, however little collaboration was described.

CONCLUSIONS

Integrated infertility patient care through both collaboration with CAM practitioners and incorporation of CAM's holistic, individualized and interdisciplinary approaches would greatly benefit infertility patients.

A qualitative study of Ottawa university students' awareness, knowledge and perceptions of infertility, infertility risk factors and assisted reproductive technologies (ART)

BACKGROUND

Awareness of infertility risk factors is an essential first step to safeguard future fertility. Whereas several studies have examined university students' awareness of female fertility and related risk factors, the topic of male infertility has not been well examined. The objective of this study was to assess young men and women's awareness, knowledge and perceptions of infertility, male and female infertility risk factors and assisted reproductive technologies (ART).

METHODS

Semi-structured interviews were conducted in 2008 with a multi-ethnic sample of sixteen male and twenty-three female Ottawa university students, followed by qualitative data analysis to identify major themes. Interview topics included awareness of male and female infertility risk factors, infertility diagnosis/treatments and personal options in the event of future infertility.

RESULTS

Participants were generally familiar with infertility as a biomedical health problem, could identify sex-specific risk factors but overestimated fertility of women in their thirties and ART success rates. Reproductive health knowledge gaps and confusion of the physiological life-stage of menopause with infertility were apparent. Most participants would pursue in vitro fertilization or international adoption in the event of personal infertility. Some participants wished to use a 'natural' approach and were concerned with potential side effects of ART-related medications.

CONCLUSIONS

The general awareness of infertility in young adults is promising and supports the potential uptake for health promotion of fertility preservation. This study underscores the continued need for comprehensive sexual and reproductive health education and promotion for adolescents and young adults.

University students' perceptions of environmental risks to infertility

BACKGROUND

Canadian young adults may be at risk of future infertility due to the high incidence of sexually transmissible infections (STIs) in this population. Young adults' perceptions of environmental risks, including contaminants, STIs and lifestyle habits on infertility, have not been examined. We have therefore designed a qualitative study to explore risk perceptions, awareness and knowledge of common environmental risk factors for infertility in a multiethnic sample of young adults.

METHODS

Semistructured interviews were carried out with 40 university undergraduate students (16 men and 24 women) in Ottawa, Canada, followed by qualitative analysis of interview transcripts to identify major themes.

RESULTS

The following broad themes described participants' risk perceptions about infertility and (1) environmental contaminants: knowledge gaps, media reports and negative perception of chemicals; (2) STIs: superficial understanding of their role in infertility, general awareness, associations with sexual behaviours and knowledge gaps; and (3) lifestyle: protective benefits of healthy lifestyle, dose or exposure effects for smoking and alcohol, and knowledge gaps. Students demonstrated a superficial understanding of environmental risks, at times relying on media reports and anecdotal information to support their beliefs.

CONCLUSIONS

This next generation of potential infertility patients exhibits a general understanding of environmental risks to infertility; however, young adults are overly optimistic that healthy lifestyle behaviours will safeguard future fertility. STIs represent the most significant modifiable risk factors for this age group; a message that can be supported by sexual and reproductive health education and promotion with greater emphasis on the long-term outcomes of STIs, including infertility.