Metabolic syndrome and the seminal cytokine network in morbidly obese males

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

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

Immune Regulation of Seminal Plasma on the Endometrial Microenvironment: Physiological and Pathological Conditions

Seminal plasma (SP) accounts for more than 90% of semen volume. It induces inflammation, regulates immune tolerance, and facilitates embryonic development and implantation in the female reproductive tract. In the physiological state, SP promotes endometrial decidualization and causes changes in immune cells such as macrophages, natural killer cells, regulatory T cells, and dendritic cells. This leads to the secretion of cytokines and chemokines and also results in the alteration of miRNA profiles and the expression of genes related to endometrial tolerance and angiogenesis. Together, these changes modulate the endometrial immune microenvironment and contribute to implantation and pregnancy. However, in pathological situations, abnormal alterations in SP due to advanced age or poor diet in men can interfere with a woman's immune adaptation to pregnancy, negatively affecting embryo implantation and even the health of the offspring. Uterine pathologies such as endometriosis and endometritis can cause the endometrium to respond negatively to SP, which can further contribute to pathological progress and interfere with conception. The research on the mechanism of SP in the endometrium is conducive to the development of new targets for intervention to improve reproductive outcomes and may also provide new ideas for semen-assisted treatment of clinical infertility.

Higher IL-9 Level is Associated with Psoriasis Vulgaris Complicated by Metabolic Syndrome

Purpose

The underlying pathophysiology linking psoriasis vulgaris (PV) and metabolic syndrome (MetS) is not fully understood. The present study aimed to investigate the serum level of interleukin (IL)-9 and tissue levels of IL-9 and its receptor in PV patients with MetS and analyze the correlation of IL-9 levels with psoriasis disease severity and MetS.

Methods

This study enrolled 75 PV patients with MetS, 57 PV patients without MetS, 20 healthy blood donors, and 7 healthy skin donors. Clinical, socio-demographic, and anthropometric data were obtained from all individuals. Fasting blood glucose, insulin, lipid profile levels, and serum levels of IL-9 and IL-17A were measured. The expression of IL-9 and its receptor in skin specimens in PV patients and healthy controls was determined using immunohistochemistry. Normal human epidermal keratinocytes were stimulated with five pro-inflammatory cytokines (tumor necrosis factor-α, oncostatin M, IL-22, IL-17A, and IL-1α) to establish a psoriatic keratinocyte model and subsequently treated with IL-9. Their mRNA levels of antimicrobial peptides and chemokines were measured using quantitative real-time polymerase chain reaction.

Results

Serum level of IL-9 and tissue levels of IL-9 and its receptor were upregulated in PV patients with MetS. IL-9 level was positively correlated to IL-17A level; however, no significant correlation of IL-9 level with psoriasis area severity index was observed. IL-9 level had a positive correlation with the presence of MetS and its components. Correspondingly, IL-9 level positively correlated with waist circumference, body mass index, homeostasis model assessment-insulin resistance, blood pressure, and triglyceride level and negatively correlated with high-density lipoprotein cholesterol level. Additionally, IL-9 stimulated the expression of antimicrobial peptides and chemokines in a psoriatic keratinocyte model.

Conclusion

Our findings confirmed that higher IL-9 level is associated with PV complicated by MetS, suggesting that IL-9 may be a link between PV and MetS.

A Narrative Review Discussing Vasectomy-Related Impact upon the Status of Oxidative Stress and Inflammation Biomarkers and Semen Microbiota

Background: Male contraceptive approaches besides tubal sterilization involve vasectomy and represent the method of choice among midlife men in developing countries thanks to many advantages. However, the subsidiary consequences of this intervention are insufficiently explored since the involved mechanisms may offer insight into a much more complex picture. Methods: Thus, in this manuscript, we aimed to reunite all available data by searching three separate academic database(s) (PubMed, Web of Knowledge, and Scopus) published in the past two decades by covering the interval 2000–2023 and using a predefined set of keywords and strings involving “oxidative stress” (OS), “inflammation”, and “semen microbiota” in combination with “humans”, “rats”, and “mice”. Results: By following all evidence that fits in the pre-, post-, and vasectomy reversal (VR) stages, we identified a total of n = 210 studies from which only n = 21 were finally included following two procedures of eligibility evaluation. Conclusions: The topic surrounding this intricate landscape has created debate since the current evidence is contradictory, limited, or does not exist. Starting from this consideration, we argue that further research is mandatory to decipher how a vasectomy might disturb homeostasis.

Composition and effects of seminal plasma in the female reproductive tracts on implantation of human embryos

The function of seminal plasma involves acting as a transport medium for sperm and as a means of communication between the reproductive tissues of the male and female. It is also a vital factor to prime the reproductive tracts of the female for optimal pregnancy. When the reproductive tract of the female is exposed to seminal plasma, serious alterations take place, enhancing pathogen and debris clearance observed in the uterus throughout mating. It is also capable of supporting embryo growth, promoting the receptivity of the uterus, and establishing tolerance to the semi-allogenic embryo. Moreover, seminal plasma is capable of regulating the functions of several female reproductive organs and providing an ideal condition for effective embryo implantation and pregnancy. It is believed that the health state of the offspring is affected by exposure to seminal plasma. For the treatment of infertility, assisted reproductive technologies have been extensively employed. The application of seminal plasma as a therapeutic approach to enhance the development of embryo competency and rate of implantation, receptivity of endometrium, and establishment of maternal immune tolerance in cycles of ART appears possible. Herein, current knowledge on the composition of seminal plasma and the physiological roles it possesses on various parts of the female reproductive tract are summarized. Moreover, the role of seminal plasma in the development of embryos, implantation, and the following fetal growth and survival have been reviewed in this article.

Immuno-metabolic profile of patients with psychotic disorders and metabolic syndrome. Results from the FACE-SZ cohort

Background

Metabolic syndrome (MetS) is a highly prevalent and harmful medical disorder often comorbid with psychosis where it can contribute to cardiovascular complications. As immune dysfunction is a key shared component of both MetS and schizophrenia (SZ), this study investigated the relationship between immune alterations and MetS in patients with SZ, whilst controlling the impact of confounding clinical characteristics including psychiatric symptoms and comorbidities, history of childhood maltreatment and psychotropic treatments.

Method

A total of 310 patients meeting DSM-IV criteria for SZ or schizoaffective disorders (SZA), with or without MetS, were systematically assessed and included in the FondaMental Advanced Centers of Expertise for Schizophrenia (FACE-SZ) cohort. Detailed clinical characteristics of patients, including psychotic symptomatology, psychiatric comorbidities and history of childhood maltreatment were recorded and the serum levels of 18 cytokines were measured. A penalized regression method was performed to analyze associations between inflammation and MetS, whilst controlling for confounding factors.

Results

Of the total sample, 25% of patients had MetS. Eight cytokines were above the lower limit of detection (LLOD) in more than 90% of the samples and retained in downstream analysis. Using a conservative Variable Inclusion Probability (VIP) of 75%, we found that elevated levels of interleukin (IL)-6, IL-7, IL-12/23 p40 and IL-16 and lower levels of tumor necrosis factor (TNF)-α were associated with MetS. As for clinical variables, age, sex, body mass index (BMI), diagnosis of SZ (not SZA), age at the first episode of psychosis (FEP), alcohol abuse, current tobacco smoking, and treatment with antidepressants and anxiolytics were all associated with MetS.

Conclusion

We have identified five cytokines associated with MetS in SZ suggesting that patients with psychotic disorders and MetS are characterized by a specific “immuno-metabolic” profile. This may help to design tailored treatments for this subgroup of patients with both psychotic disorders and MetS, taking one more step towards precision medicine in psychiatry.

Male reproductive system inflammation after healing from coronavirus disease 2019

BACKGROUND

There is evidence that, after severe acute respiratory syndrome coronavirus 2 infection, male reproductive function and semen quality may be damaged OBJECTIVES: To evaluate a panel of inflammatory mediators in semen in patients recovered from coronavirus disease 2019.

MATERIAL AND METHODS

Sexually active men with previous severe acute respiratory syndrome coronavirus 2 infection and proven recovery from coronavirus disease 2019 were enrolled in a prospective cohort study. Clinical, uro-andrological data and semen specimens were prospectively collected. For previously hospitalized coronavirus disease 2019 patients, data on serum inflammatory markers were retrospectively collected.

RESULTS

A total of 43 men were enrolled in the study. Of these, 32 men were normozoospermic, three were oligozoospermic, and eight were crypto-azoospermic. Serum inflammatory markers (procalcitonin and C-reactive protein) were analyzed in previously hospitalized patients both at admission and at peak of infection. Levels at admission were statistically significantly higher in patients resulting in crypto-azoospermic with respect to those resulting in normozoospermic (p = 0.05; p = 0.03 and p = 0.02, respectively) after healing. Seminal cytokine levels were similar among all groups. Interleukin-1β and tumor necrosis factor-α levels were significantly negatively related to sperm total number and concentration, whereas interleukin-4 was correlated with sperm motility.

DISCUSSION AND CONCLUSION

Negative correlations between interleukin-1β and tumor necrosis factor-α and sperm number and the overall high levels of semen cytokines indicate a potential detrimental role of severe acute respiratory syndrome coronavirus 2 driven inflammation on spermatogenesis. Overall, our results indicate that male patients recovering from coronavirus disease 2019 deserve accurate follow-up for their fertility status.

Metabolic syndrome and male fertility disorders: Is there a causal link?

Infertility is a global health problem affecting 10-15% of couples in reproductive age. Recent studies have provided growing evidence supporting that lifestyle factors can affect male fertility through alterations in endocrine profiles, spermatogenesis and/or sperm function. One of these critical factors could be the change in the food intake behavior in modern societies that produces metabolic alterations. Regarding this, metabolic syndrome (MetS) prevalence has increased in epidemic in the last 40-50 years. Although MetS is associated with advanced age, changes in lifestyles have accelerated the appearance of symptoms in the reproductive age. We review herein the current understanding of the relationship between MetS and the male reproductive status. For this purpose, in this narrative review a comprehensive literature search was made in both animal models and men, allowing us to evaluate such relationship. This analysis showed a high variability in the reproductive phenotypes observed in patients and mice suffering MetS, including sperm parameters, fertility and offspring health. In view of this, we proposed that the reproductive effects, which are diverse and not robust, observed among MetS-affected males, might depend on additional factors not associated with the metabolic condition and contributed not only by the affected male but also by his partner. With this perspective, this review provides a more accurate insight of this syndrome critical for the identification of specific diagnostic indicators and treatment of MetS-induced fertility disorders.

Impact of metabolic syndrome on the viability of human spermatozoa: a cross-sectional descriptive study in men from infertile couples

Background

A direct association between metabolic syndrome (MetS) and sperm production/function has been proposed. In this cross-sectional study, we aimed to determine the impact of MetS on sperm survival. Men from infertile couples treated at Hue University Hospital, Vietnam, were enrolled in this study, which spanned the October 2018 to October 2020 period. The general characteristics of the patients, including body mass index (BMI), waist-to-hip ratio (WHR), the levels of different biochemicals, and semen parameters were determined, and sperm survival tests (SSTs) were performed. The modified National Cholesterol Education Program (NCEP) Adult Treatment Panel (ATP) III for the Asian population was used for MetS diagnosis.

Results

Men with an abnormal waist circumference (≥ 90 cm) showed a higher rate of abnormal SST results (30.1% vs. 16.7%, p = 0.012). The frequency of abnormal SST results in patients with MetS (72.3%) was significantly higher than that in individuals without MetS (53.4%) (p = 0.02). Furthermore, the percentage of abnormal SST results in patients with MetS and with BMI ≥ 23 was significantly higher than those in individuals without MetS (77.1% vs. 55.2%, p = 0.03). Weak negative correlations were also observed between the patients’ age and the SST results.

Conclusion

Sperm viability was lower in men with MetS. We also observed that age and BMI were independent factors associated with abnormal SST.

High-fat Diet Alters Male Seminal Plasma Composition to Impair Female Immune Adaptation for Pregnancy in Mice

Paternal experiences and exposures before conception can influence fetal development and offspring phenotype. The composition of seminal plasma contributes to paternal programming effects through modulating the female reproductive tract immune response after mating. To investigate whether paternal obesity affects seminal plasma immune-regulatory activity, C57Bl/6 male mice were fed an obesogenic high-fat diet (HFD) or control diet (CD) for 14 weeks. Although HFD consumption caused only minor changes to parameters of sperm quality, the volume of seminal vesicle fluid secretions was increased by 65%, and the concentrations and total content of immune-regulatory TGF-β isoforms were decreased by 75% to 80% and 43% to 55%, respectively. Mating with BALB/c females revealed differences in the strength and properties of the postmating immune response elicited. Transcriptional analysis showed >300 inflammatory genes were similarly regulated in the uterine endometrium by mating independently of paternal diet, and 13 were dysregulated by HFD-fed compared with CD-fed males. Seminal vesicle fluid factors reduced in HFD-fed males, including TGF-β1, IL-10, and TNF, were among the predicted upstream regulators of differentially regulated genes. Additionally, the T-cell response induced by mating with CD-fed males was blunted after mating with HFD-fed males, with 27% fewer CD4+ T cells, 26% fewer FOXP3+CD4+ regulatory T cells (Treg) cells, and 19% fewer CTLA4+ Treg cells, particularly within the NRP1+ thymic Treg cell population. These findings demonstrate that an obesogenic HFD alters the composition of seminal vesicle fluid and impairs seminal plasma capacity to elicit a favorable pro-tolerogenic immune response in females at conception.

Effects of Obesity and Diabetes on Sperm Cell Proteomics in Rats

Infertility caused by male factors is potentially associated with metabolic disorders such as obesity and/or diabetes. This experimental study was conducted in a male rodent model to assess the effects of different diseases on semen quality and sperm proteomics. Ten Wistar rats were used for each treatment. Rats were fed commercial food provided controllably to the control group and the diabetic group, and a hypercaloric diet supplemented with 5% sucrose in water was provided ad libitum to the obese group for 38 weeks. Diabetes was induced with 35 mg/kg streptozotocin. After euthanasia, testicles, spermatozoa, fat, and blood (serum) samples were collected. Spermatozoa were evaluated for quality and subjected to proteomics analyses. Histology and cytology of the testis, and serum leptin, adiponectin, interleukin 8 (IL-8), blood glucose, and testosterone levels, were also assessed. Body weight, retroperitoneal and testicular fat, and the Lee index were also measured. Obesity and diabetes were induced. The diabetic group showed noticeable changes in spermatogenesis and sperm quality. The mass spectrometry proteomics data have been deposited in Mendeley Data (doi: 10.17632/rfp7kfjcsd.5). Fifteen proteins varied in abundance between groups, especially proteins related to energy production and structural function of the spermatozoa, suggesting disturbances in energy production with a subsequent alteration in sperm motility in both groups, but with a compensatory response in the obese group.

Metabolic Syndrome and Reproduction

Metabolic syndrome (MetS) and infertility are two afflictions with a high prevalence in the general population. MetS is a global health problem increasing worldwide, while infertility affects up to 12% of men. Despite the high prevalence of these conditions, the possible impact of MetS on male fertility has been investigated by a few authors only in the last decade. In addition, underlying mechanism(s) connecting the two conditions have been investigated in few preclinical studies. The aim of this review is to summarize and critically discuss available clinical and preclinical studies on the role of MetS (and its treatment) in male fertility. An extensive Medline search was performed identifying studies in the English language. While several studies support an association between MetS and hypogonadism, contrasting results have been reported on the relationship between MetS and semen parameters/male infertility, and the available studies considered heterogeneous MetS definitions and populations. So far, only two meta-analyses in clinical and preclinical studies, respectively, evaluated this topic, reporting a negative association between MetS and sperm parameters, testosterone and FSH levels, advocating, however, larger prospective investigations. In conclusion, a possible negative impact of MetS on male reproductive potential was reported; however, larger studies are needed.

Impact of metabolic syndrome on sex hormones and reproductive function: a meta-analysis of 2923 cases and 14062 controls

Current evidence is inconsistent regarding the impact of metabolic syndrome (MetS) on sex hormones and reproductive function, and this meta-analysis aimed to illuminate the association. A literature search was conducted in public databases to identify all relevant studies, and study-specific standardized mean differences (SMD) and 95% confidence intervals (CI) were pooled using a random-effects model. Finally, 21 studies were identified with a total of 2923 MetS cases and 14062 controls. In males, MetS cases had a lower level of testosterone, inhibin B, total sperm count, sperm concentration, sperm normal morphology, sperm total motility, sperm progressive motility and sperm vitality, and a higher level of DNA fragmentation and mitochondrial membrane potential. In females, MetS cases had a higher level of testosterone. No significant difference was detected for follicle-stimulating hormone, luteinizing hormone, oestradiol, prolactin, anti-Müllerian hormone and semen volume in males, and for oestradiol, follicle-stimulating hormone, luteinizing hormone and progesterone in females. In conclusion, this meta-analysis indicated the impact of MetS on sex hormones and reproductive function, and MetS cases had a potential risk of infertility.

Elevated CCL2 causes Leydig cell malfunction in metabolic syndrome

Metabolic syndrome (MetS), which is associated with chronic inflammation, predisposes males to hypogonadism and subfertility. The underlying mechanism of these pathologies remains poorly understood. Homozygous leptin-resistant obese db/db mice are characterized by small testes, low testicular testosterone, and a reduced number of Leydig cells. Here we report that IL-1β, CCL2 (also known as MCP-1), and corticosterone concentrations were increased in the testes of db/db mice relative to those in WT controls. Cultured murine and human Leydig cells responded to cytokine stress with increased CCL2 release and apoptotic signals. Chemical inhibition of CCL2 rescued Leydig cell function in vitro and in db/db mice. Consistently, we found that Ccl2-deficient mice fed with a high-energy diet were protected from testicular dysfunction compared with similarly fed WT mice. Finally, a cohort of infertile men with a history of MetS showed that reduction of CCL2 plasma levels could be achieved by weight loss and was clearly associated with recovery from hypogonadism. Taken together, we conclude that CCL2-mediated chronic inflammation is, to a large extent, responsible for the subfertility in MetS by causing damage to Leydig cells.

MCP-1/CCL2 upregulation associates with metabolic syndrome–induced male subfertility in both mice and men.

The Relation of Birth Weight and Adiposity Across the Life Course to Semen Quality in Middle Age

BACKGROUND

Studies of body mass index and semen quality have reported mixed results, but almost all were cross-sectional and many were conducted in selected populations. Longitudinal studies in population-based cohorts are necessary to identify how timing and duration of excess adiposity may affect semen quality.

METHODS

In 193 members of the Child Health and Development Studies birth cohort, we examined associations of birth weight and adiposity at six time points spanning early childhood and adulthood with sperm concentration, motility, and morphology at mean age 44 years, as well as with corresponding 2010 World Health Organization (WHO) subfertility reference levels.

RESULTS

Birth weight for gestational age percentile was positively associated with square-root sperm concentration (regression coefficient B [95% confidence interval] = 0.02 × 103 sperm/ml [0.004, 0.04]). Overweight/obesity in men's 20s was associated with lower percent progressive motility (B =-5.2 [-9.9, -0.63]), higher odds of low motility (odds ratio (OR) = 2.4 [1.3, 4.4]), and higher odds of poor morphology (OR = 1.9 [0.94, 3.8]). Those who were overweight/obese in their 20s were also more likely to meet two or three WHO subfertility criteria (OR = 3.9 [1.6, 9.4]) compared with normal-weight men. Each additional adult decade in which a participant was overweight/obese was associated with higher odds of low motility (OR = 1.3 [0.96, 1.6]) and higher odds of meeting two or three WHO subfertility criteria (OR = 1.5 [1.0, 2.2]).

CONCLUSIONS

In our data, associations among adiposity and sperm concentration, motility, and morphology varied according to timing and duration of exposure, potentially reflecting different biological mechanisms that influence these semen parameters.

Metabolic syndrome and semen quality in adult population

BACKGROUND

Male obesity is suggested to impact negatively on male fertility and semen quality in numerous studies. However, previous literatures regarding health effects of the metabolic syndrome (MetS) on semen quality are rare and inconsistent. The aim of this study is to investigate the relationship between MetS and sperm parameters in a Taiwanese reproductive-age male population.

METHODS

A total of 8395 men who attended a private medical screening program in Taiwan from 2010 to 2016 were included in this cross-sectional study. Semen analysis was assessed in accordance with the WHO guidelines and included sperm concentration, total motility, progressive motility, and morphology. MetS was defined by the modified National Cholesterol Education Program Third Adult Treatment Panel (NCEP ATP III) criteria with the Asian cutoff for waist circumference (WC). The associations between MetS and semen analysis were examined by multivariable linear regressions.

RESULTS

After fully adjusting for pertinent covariables, MetS was significantly associated with a reduced percentage of sperm normal morphology. Blood pressure, WC, and serum glucose had a significantly negative association with sperm normal morphology. Individuals with an increased number of MetS components had a closer association with reduced sperm progressive motility and the percentage of normal morphology.

CONCLUSION

MetS and its components exhibited deleterious effects on semen quality among reproductive-age men. Further studies are warranted to explore these pathophysiologic relationship and underlying mechanisms.

Effects of Metabolic Syndrome on Semen Quality and Circulating Sex Hormones: A Systematic Review and Meta-Analysis

Previous studies were controversial in the effects of metabolic syndrome (MetS) on semen quality and circulating sex hormones, and thus we conducted a systematic review and meta-analysis to clarify the association. A systematic search was conducted in public databases to identify all relevant studies, and study-specific standardized mean differences (SMD) and 95% confidence intervals (CI) were pooled using a random-effects model. Finally, 11 studies were identified with a total of 1,731 MetS cases and 11,740 controls. Compared with the controls, MetS cases had a statistically significant decrease of sperm total count (SMD: -0.96, 95% CI: -1.58 to -0.31), sperm concentration (SMD: -1.13, 95% CI: -1.85 to -0.41), sperm normal morphology (SMD: -0.61, 95% CI: -1.01 to -0.21), sperm progressive motility (SMD: -0.58, 95% CI: -1.00 to -0.17), sperm vitality (SMD: -0.83, 95% CI: -1.11 to -0.54), circulating follicle-stimulating hormone (SMD: -0.87, 95% CI: -1.53 to -0.21), testosterone (SMD: -5.61, 95% CI: -10.90 to -0.31), and inhibin B (SMD: -2.42, 95% CI: -4.52 to -0.32), and a statistically significant increase of sperm DNA fragmentation (SMD: 0.76, 95% CI: 0.45 to 1.06) and mitochondrial membrane potential (SMD: 0.89, 95% CI: 0.49 to 1.28). No significant difference was found in semen volume, sperm total motility, circulating luteinizing hormone (LH), estradiol, prolactin and anti-Müllerian hormone (AMH) (P > 0.05). In conclusion, this meta-analysis demonstrated the effects of MetS on almost all the semen parameters and part of the circulating sex hormones, and MetS tended to be a risk factor for male infertility. Further larger-scale prospective designed studies were needed to confirm our findings.

Association between high-fat diet feeding and male fertility in high reproductive performance mice

The increasing worldwide prevalence of metabolic syndrome (MetS), especially in younger populations, is a risk factor for fertility disorders. However, a direct correlation of MetS with male infertility still remains unclear. In this work, we evaluated whether MetS has a negative impact on fertility of hybrid male mice with high reproductive performance. To induce a MetS-like condition, (C57BL/6xBALB/c) F1 male mice were fed a high-fat diet (HFD, 30% fat) for 19 weeks, while controls received a normal-fat diet (NFD, 6% fat). HFD-fed animals exhibited increased body weight, hypercholesterolemia, hyperglycemia and glucose intolerance. In vivo fertilisation assays performed along the treatment period showed no differences in fertilisation nor in vitro embryo development rates between groups. While testicular weight and morphology were similar in both groups, HFD-fed mice presented lighter epididymides and higher amounts of gonadal fat. Moreover, sperm count was lower in HFD-fed mice, despite normal sperm viability, morphology, motility or acrosome reaction. Finally, no differences were observed in in vitro fertilisation rates between groups. In summary, although HFD feeding altered some reproductive parameters, it did not impair male fertility in high performance breeders suggesting the possibility that a fertility impairment could be the result of the cumulative combination of environmental and/or genetic factors.

Modulatory effects of ghrelin on sperm quality alterations induced by a fructose-enriched diet

The objectives of this study were: 1) to evaluate the effects of a fructose enriched diet (FED) on rat sperm quality, epididymal function (i.e. oxidative stress and alpha-glucosidase expression) and testosterone concentrations; 2) to determine if the administration of ghrelin (Ghrl), reverses the effects induced by FED. After validating the protocol as an inductor of metabolic syndrome like-symptoms, adult male rats were assigned to one of the following treatments for 8 weeks: FED = 10% fructose enriched in water (v/v); FED + Ghrl = fructose enriched diet plus Ghrl (6 nmol/animal/day, s.c.) from week 6-8; or C = water without fructose (n = 5-10 animals/group). FED significantly decreased sperm concentration and motile sperm count/ml vs C (FED: 19.0 ± 1.6 × 10⁶sperm/ml and 834.6 ± 137.0, respectively vs C: 25.8 ± 2.8 × 10⁶ and 1300.4 ± 202.4, respectively; p < 0.05); ghrelin injection reversed this negative effect (23.5 ± 1.6 × 10⁶sperm/ml and 1381.7 ± 71.3 respectively). FED resulted in hypogonadism, but Ghrl could not normalize testosterone concentrations (C: 1.4 ± 0.1 ng/ml vs FED: 0.8 ± 0.2 ng/ml and FED + Ghrl: 0.6 ± 0.2 ng/ml; p < 0.05). Ghrelin did not reverse metabolic abnormalities secondary to FED. FED did not alter epididymal expression of antioxidants enzymes (superoxido-dismutase, catalase and glutathione peroxidases -Gpx-). Nevertheless, FED + Ghrl significantly increased the expression of Gpx3 (FED + Ghrl: 3.47 ± 0.48 vs FED: 0.69 ± 0.28 and C: 1.00 ± 0.14; p < 0.05). The expression of neutral alpha-glucosidase, which is a marker of epididymal function, did not differ between treatments. In conclusion, the administration of Ghrl modulated the negative effects of FED on sperm quality, possibly by an epididymal increase in Gpx3 expression. However, Ghrl could not neither normalize the metabolism of FED animals, nor reverse hypogonadism.

Metabolically healthy and unhealthy obesity in erectile dysfunction and male infertility

Introduction: Metabolically unhealthy obesity (MUHO) is the most important preventable cardiovascular (CV) risk factor. Recently, the significance of metabolically healthy obesity (MHO) as a CV risk factor has raised increasing interest. MUHO is a known risk factor for erectile dysfunction (ED); however, the effect of MHO on ED has barely been investigated. This review aims at summarizing the evidence supporting the relation of MUHO and MHO to male sexual functioning and fertility. Areas covered: An extensive Medline search on obesity and ED or male infertility was conducted to summarize the role of MUHO or MHO on male sexual dysfunction and infertility. Expert opinion: Longitudinal studies have demonstrated that MHO causes vascular damage, which is consistent with the impairment in penile blood flows found in ED subjects. In this population, MHO is a predictor of CV events. The relationship between male infertility and MUHO is currently debated and data on MHO are almost completely lacking. The only available study did not find an association between obesity classes and semen parameters. Although the andrological correlates of MHO must be better assessed, in the current state, evidence suggests that MHO does not represent a benign condition and measures for improving lifestyle are mandatory.

High prevalence of urogenital infection/inflammation in patients with azoospermia does not impede surgical sperm retrieval

Considering infection/inflammation to be an important risk factor in male infertility, the aim of this study was to make a comprehensive evaluation of the prevalence of urogenital tract infection/inflammation and its potential impact on sperm retrieval in azoospermic patients. In this prospective study, 71 patients with azoospermia were subjected to an extensive andrological workup including comprehensive microbiological diagnostics (2-glass test, semen, testicular swab and testicular tissue analysis) and testicular biopsy/testicular sperm extraction (TESE). Medical history suggested urogenital tract infection/inflammation in 7% of patients, 11% harboured STIs, 14% showed significant bacteriospermia, 15% had seminal inflammation, 17% fulfilled the MAGI definition, and 27% had relevant pathogens. At the testicular level, 1 patient had a swab positive for bacteria, no viruses were detected, tissue specimens never indicated pathogens, whereas histopathology revealed focal immune cell infiltrates in 23% of samples. Testicular sperm retrieval rate was 100% in obstructive and 46% in nonobstructive azoospermia. None of the infection/inflammation-related variables was associated with the success of sperm retrieval or inflammatory lesions in the testis. The high prevalence of urogenital infection/inflammation among azoospermic men underpins their role as significant aetiologic factors in male infertility. However, this observation does not refer to the chances of sperm retrieval at the time of surgery/TESE.

Metabolic syndrome and smoking are independent risk factors of male idiopathic infertility

Background

Overweight and obesity are known to impact male fertility and are commonly associated with abdominal obesity and metabolic disorders. The association between abdominal obesity or metabolic syndrome with male reproduction has not been fully investigated. Moreover, many factors may interfere with the evaluation of the impact of metabolic syndrome on male fertility. Thus, tobacco is known to alter the spermatic parameters and phenomena linking smoking with metabolic syndrome are therefore complex. The main objective of this study has been to investigate the potential association of metabolic syndrome with male idiopathic infertility given smoking status.

Materiel and methods

The data of this study concerned infertile (n = 96) and fertile (n = 100) men under 45 years of age who have been recruited in the ALIFERT case-control study. Body mass index and waist circumference were measured. Serum triglycerides, cholesterol (total, high density lipoprotein, and low density lipoprotein cholesterol) and fasting blood glucose were assayed. Metabolic syndrome has been diagnosed in the presence of at least three of the following criteria: increased waist circumference, high triglycerides, fasting glucose or arterial blood pressure and low high density lipoprotein cholesterol.

Results

The present study reports that infertile men are in poorer health condition compared to fertile men and are more often smokers. The results of this study suggested metabolic syndrome and smoking to be independent risk factor for idiopathic infertility.

Conclusions

Metabolic syndrome and smoking should systematically be checked at the beginning of medical care in infertile males and personal and multifaceted coaching should be proposed to deal jointly with smoking and metabolic disorders.

Trial registration

NCT01093378 ALIFERT. Registered: March 25, 2010.

Systemic Inflammation in Metabolic Syndrome: Increased Platelet and Leukocyte Activation, and Key Role of CX3CL1/CX3CR1 and CCL2/CCR2 Axes in Arterial Platelet-Proinflammatory Monocyte Adhesion

BACKGROUND

Metabolic syndrome is associated with low-grade systemic inflammation, which is a key driver of premature atherosclerosis. We characterized immune cell behavior in metabolic syndrome, its consequences, and the potential involvement of the CX₃CL1/CX₃CR1 and CCL2/CCR2 chemokine axes.

METHODS

Whole blood from 18 patients with metabolic syndrome and 21 age-matched controls was analyzed by flow cytometry to determine the leukocyte immunophenotypes, activation, platelet-leukocyte aggregates, and CX₃CR1 expression. ELISA determined the plasma marker levels. Platelet-leukocyte aggregates adhesion to tumor necrosis factor-α (TNFα)-stimulated arterial endothelium and the role of CX₃CL1/CX₃CR1 and CCL2/CCR2 axes was investigated with the parallel-plate flow chamber.

RESULTS

When compared with the controls, the metabolic syndrome patients presented greater percentages of eosinophils, CD3⁺ T lymphocytes, Mon2/Mon3 monocytes, platelet-eosinophil and -lymphocyte aggregates, activated platelets, neutrophils, eosinophils, monocytes, and CD8⁺ T cells, but lower percentages of Mon1 monocytes. Patients had increased circulating interleukin-8 (IL-8) and TNFα levels and decreased IL-4. CX₃CR1 up-regulation in platelet-Mon1 monocyte aggregates in metabolic syndrome patients led to increased CX₃CR1/CCR2-dependent platelet-Mon1 monocyte adhesion to dysfunctional arterial endothelium.

CONCLUSION

We provide evidence of generalized immune activation in metabolic syndrome. Additionally, CX₃CL1/CX₃CR1 or CCL2/CCR2 axes are potential candidates for therapeutic intervention in cardiovascular disorders in metabolic syndrome patients, as their blockade impairs the augmented arterial platelet-Mon1 monocyte aggregate adhesiveness, which is a key event in atherogenesis.

Obesity related metabolic endotoxemia is associated with oxidative stress and impaired sperm DNA integrity

Background

Obesity is known to be associated with inflammation, oxidative stress and a resulting reduction in sperm DNA integrity. Importantly, obesity is also reported to be associated with an increase in intestinal permeability with the passage of intestinal bacteria into the circulation (metabolic endotoxemia) that triggers a systemic state of inflammation and resultant oxidative stress. Therefore, we hypothesised that this obesity related increase in intestinal permeability and resultant metabolic endotoxemia (ME) may activate inflammation within the male reproductive tract, leading to increased reactive oxygen species production, sperm oxidative stress and a decline in DNA integrity.

Results

Our pilot study of 37 infertile men confirmed a significant positive correlation between body mass index (BMI), increased intestinal permeability (serum zonulin), metabolic endotoxaemia (LBP), sperm DNA oxidative damage (seminal 8 OhDG) and increasing levels of sperm DNA fragmentation (Halosperm). Metabolic endotoxemia was positively correlated with increasing levels of sperm DNA oxidative damage with this relationship remaining significant, even after adjustment for relevant confounders such as age, BMI and days of abstinence. These observations suggest that metabolic endotoxemia and its associated oxidative stress may be a key driver of sperm DNA damage in obese men.

Conclusion

This study confirms a link between obesity, increasing intestinal permeability and endotoxin exposure, and oxidative mediated sperm DNA damage. This warrants further investigation to fully understand the effect of metabolic endotoxemia on male reproductive function which could result in the new therapies to improve male fertility potential.

The effect of metabolic syndrome on male reproductive health: A cross-sectional study in a group of fertile men and male partners of infertile couples

This study aimed to determine the effect of metabolic syndrome (MS) on the reproductive function in fertile (FM) and male partners of infertile couples (MPIC). We performed a cross-sectional study formatting two study groups: partners of pregnant women (n = 238; mean age 32.0) as FM and male partners of infertile couples (n = 2642; mean age 32.6) as MPIC. A standard semen analysis was performed and clinical, laboratory and lifestyle data were analysed. The adapted NCEP-ATPIII criteria were used to define MS. 12.2% of FM and 17.8% of MPIC had MS. In both groups, men with MS were older, they were centrally obese and had higher triglycerides, systolic and diastolic blood pressure and decreased HDL cholesterol values as compared to men without MS. However, glucose concentrations as well as fasting insulin levels were significantly higher only in the MPIC-MS⁺ group. MS was not associated with semen parameters. Testosterone levels were negatively correlated to MS in both groups. This negative association persisted within the BMI categories between MPIC-MS^- and MPIC-MS⁺ groups. LH was negatively correlated to MS but only in MPIC. FSH and oestradiol were not correlated to MS. Smoking and alcohol consumption were higher among men with MS. This study shows that except for testosterone, MS has no independent effect on major fertility parameters in different subgroups of men.

Serum Levels of Interleukin-13 Increase in Subjects with Insulin Resistance but Do Not Correlate with Markers of Low-Grade Systemic Inflammation

Experimental evidence in mice suggests a role for interleukin- (IL-) 13 in insulin resistance and low-grade systemic inflammation. However, IL-13 serum levels have not been assessed in subjects with insulin resistance, and associations of IL-13 with parameters of low-grade systemic inflammation are still unknown. Our main goal was to examine the systemic levels of IL-13 in patients with insulin resistance, while also studying the relationship of IL-13 with anthropometric, metabolic, and low-grade systemic inflammatory markers. Ninety-two participants were included in the study and divided into insulin-resistant patients and noninsulin-resistant controls. Blood levels of IL-13, glucose, insulin, triglycerides, cholesterol, tumor necrosis factor-alpha (TNF-α), IL-10, proinflammatory (Mon-CD11c⁺CD206^-), and anti-inflammatory (Mon-CD11c^-CD206⁺) monocytes, as well as anthropometric parameters, were measured in all volunteers. Insulin-resistant patients showed 2.5-fold higher serum levels of IL-13 than controls (P < 0.0001) and significantly increased values of TNF-α and Mon-CD11c⁺CD206^-, with concomitant reductions in IL-10 and Mon-CD11c^-CD206⁺. Increased IL-13 was extraordinarily well associated with hyperglycemia (r = 0.7362) and hypertriglyceridemia (r = 0.7632) but unexpectedly exhibited no significant correlations with TNF-α (r = 0.2907), IL-10 (r = -0.3882), Mon-CD11c⁺CD206^- (r = 0.2745) or Mon-CD11c^-CD206⁺ (r = -0.3237). This study demonstrates that IL-13 serum levels are elevated in patients with insulin resistance without showing correlation with parameters of low-grade systemic inflammation.