Is male factor infertility associated with midlife low-grade inflammation? A population based study

Redox Homeostasis and Nrf2-Regulated Mechanisms Are Relevant to Male Infertility

Infertility represents a significant global health challenge, affecting more than 12% of couples worldwide, and most cases of infertility are caused by male factors. Several pathological pathways are implicated in male infertility. The main mechanisms involved are driven by the loss of reduction-oxidation (redox) homeostasis and the resulting oxidative damage as well as the chronic inflammatory process. Increased or severe oxidative stress leads to sperm plasma membrane and DNA oxidative damage, dysregulated RNA processing, and telomere destruction. The signaling pathways of these molecular events are also regulated by Nuclear factor-E2-related factor 2 (Nrf2). The causes of male infertility, the role of oxidative stress in male infertility and the Keap1-Nrf2 antioxidant pathway are reviewed. This review highlights the regulatory role of Nrf2 in the balance between oxidants and antioxidants as relevant mechanisms to male fertility. Nrf2 is involved in the regulation of spermatogenesis and sperm quality. Establishing a link between Nrf2 signaling pathways and the regulation of male fertility provides the basis for molecular modulation of inflammatory processes, reactive oxygen species generation, and the antioxidant molecular network, including the Nrf2-regulated antioxidant response, to improve male reproductive outcomes.

Association between Hidradenitis Suppurativa and Abnormalities in Semen Parameters and Sexual Function: A Pilot Study

Hidradenitis suppurativa (HS) is a chronic inflammatory skin disease affecting patients of reproductive age. Although HS shares risk factors with male infertility, only 1 epidemiological study has evaluated this association. To further evaluate this potential association, findings on semen and hormonal analysis, testicular ultrasound, and the International Index of Erectile Function (IIEF-15) were compared between 28 men attending a tertiary HS clinic during the period April 2019 to April 2021, and 44 healthy controls, spouses of infertile women undergoing semen evaluation before in vitro fertilization. Patients with HS were divided based on the absence or presence of gluteal and genital lesions. Patients with HS were younger than controls (median 27 vs 34 years, p < 0.0004) and had a higher proportion of smokers (86% vs 33%, p < 0.0001). Semen parameters in patients with gluteal-genital lesions, specifically those with severe scrotal involvement necessitating surgery, were lower than the WHO reference values and significantly lower than in patients without gluteal-genital lesions and controls. Erectile dysfunction was reported by 93% of patients with HS. These findings suggest that spermatogenesis and sexual function may be impaired in young men with HS. Therefore, multidisciplinary management of HS should include their evaluation to identify patients who might benefit from semen cryopreservation and sexual treatment.

Female Infertility in Chronic Kidney Disease

This review summarises the current literature regarding infertility in women with chronic kidney disease (CKD), describing the epidemiology, pathophysiology, investigations, and management options. The pathophysiology is multifactorial, with proposed mechanisms including disruption of the hypothalamus-pituitary-ovarian axis, chronic inflammation, oxidative stress, psychological factors, and gonadotoxic effects of medications such as cyclophosphamide. Diagnostic investigations in CKD patients seeking to conceive should be considered earlier than in the healthy population. Investigations should include hormonal profiling, including markers such as Anti-Mullerian Hormone and imaging such as ultrasound, to evaluate ovarian reserve and identify gynaecology pathology. Treatment options for infertility in CKD patients include GnRH agonists to preserve ovarian function during cyclophosphamide treatment, as well as assisted reproductive technologies including in vitro fertilisation and ovulation induction. However, these treatments must be tailored to the individual's health status, comorbidities, fertility requirements, and CKD stage. In conclusion, fertility is an important consideration for women with CKD, necessitating early investigation and tailored management. Early discussions regarding fertility are important in order to understand patients' family planning and allow for prompt referral to fertility services. While challenges exist, ongoing research aims to clarify the underlying mechanism and optimise treatment strategies, which are crucial for improving quality of life and overall health outcomes.

Effects of Sleep Disorders and Circadian Rhythm Changes on Male Reproductive Health: A Systematic Review and Meta-analysis

Objectives: The purpose of this study was to elucidate the relationship between sleep disorders and male reproductive health, and to explore the underlying mechanisms via a systematic review and meta-analysis.

Methods: PubMed, Embase, The Cochrane library, Web of Science, Scopus databases were searched to collect clinical research on the effects of sleep disorders on male semen parameters from inception to February 24, 2022. RevMan 5.4 was used for meta-statistical analysis. Stata16 software was used to detect publication bias.

Results: The results of meta-analysis showed that sleep disorders were associated with reduced total sperm count (mean difference (MD) = −27.91, 95% CI = (−37.82, −18.01), p < 0.001), reduced sperm concentration (MD = −5.16, 95% CI = (−9.67, −0.65), p = 0.02), reduced progressive motility (MD = −2.94, 95% CI = (−5.28, −0.59), p = 0.01), and reduced normal morphology (MD = −0.52, 95% CI = (−0.80, −0.24), p < 0.001). However, there is no significant association between sleep disorders and semen volume/reproductive hormones. Further bioinformatics mining revealed that related clock genes (PER1, PER2, CRY2, NR1D1 and NPAS2) were down-regulated in non-obstructive azoospermia patients.

Conclusion: In conclusion, current evidence suggests that sleep disorders have a negative impact on male reproductive health, and its underlying mechanism may be related to circadian rhythm disorders. However, the relationship between sleep disorders and reproductive hormone levels has not been found. Due to the limited number and quality of included studies, the above findings need to be validated by more high-quality studies.

Seminal pro-inflammatory cytokines and pH are affected by Chlamydia infection in asymptomatic patients with teratozoospermia

Introduction

Infection and inflammation of the reproductive tract by Chlamydia trachomatis (CT) are recognized as significant risk factors for male infertility. This study aimed to evaluate CT infection and its effects on seminal parameters and cytokines in asymptomatic patients with teratozoospermia.

Material and methods

Semen samples from one hundred four male patients were collected, and CT detection was performed by polymerase chain reaction (PCR). The quality (volume, sperm concentration, pH, motility, morphology, and leucocytes) of the semen was measured by standard procedures recommended by the World Health Organization (WHO). Pro-inflammatory cytokines [interleukin (IL)-1 β, IL-6, IL-8, tumor necrosis factor α (TNF-α), and interferon γ (IFN-γ)], as well as anti-inflammatory cytokines (IL-4, IL-10), were determined by using enzyme-linked immunosorbent assay (ELISA). The frequency of CT infection was expressed as a percentage. Descriptive statistics were used for comparison of cytokines from infertile men, and then the Mann-Whitney U test was applied for the contrast of seminal parameters and cytokines from CT-infected versus non-CT infected men.

Results

A ratio of 33/104 (31.7%) patients were positive for CT infection. The ejaculate of positive CT infection was found to have increased pH (pH = 7.65 in non-CT infected vs. 7.94 CT-infected men; p = 0.026). High levels of pro-inflammatory cytokines were found in the population studied; however, infected males were noted to have high levels of IL-1 β [184.66 (0-3985.33 pg/ml), p = 0.001] and IL-6 [87.8 (0-1042.8 pg/ml), p = 0.001].

Conclusions

CT infection increased seminal pH, as well as IL-1 β and IL-6 cytokines, suggesting a potential role of infection and inflammation in asymptomatic patients with teratozoospermia.

The "Hitchhiker's Guide to the Galaxy" of Endothelial Dysfunction Markers in Human Fertility

Endothelial dysfunction is an early event in the pathogenesis of atherosclerosis and represents the first step in the pathogenesis of cardiovascular diseases. The evaluation of endothelial health is fundamental in clinical practice and several direct and indirect markers have been suggested so far to identify any alterations in endothelial homeostasis. Alongside the known endothelial role on vascular health, several pieces of evidence have demonstrated that proper endothelial functioning plays a key role in human fertility and reproduction. Therefore, this state-of-the-art review updates the endothelial health markers discriminating between those available for clinical practice or for research purposes and their application in human fertility. Moreover, new molecules potentially helpful to clarify the link between endothelial and reproductive health are evaluated herein.

Significance of mast cells in spermatogenesis, implantation, pregnancy, and abortion: Cross talk and molecular mechanisms

Both subsets of MCs including MC_TC (tryptase-positive, chymase-positive) and MC_T (tryptase-positive, chymase-negative) are present in the testis and epididymis. Increased number of MCs, higher levels of MC-released tryptase in testis and seminal plasma of males with fertility problems, and promoting sperm motility in individuals with oligozoospermia after using MC blockers provide evidence that MCs may play a role in male infertility/subfertility disturbances. MC-released tryptase and histamine contribute to the fibrosis and may disrupt spermatogenesis. MCs not only influence the process of spermatogenesis but also have effects on the function of other testis-residing cells. MC-derived histamine may influence the steroidogenesis of Leydig cells by acting through H1R and H2R receptors. Additionally, the interaction between MC-released ATP and P2X receptors expressed on the peritubular cells may induce the production of the pro-inflammatory mediators by peritubular cells. Further investigations showed that MCs may be involved in the pathology of female infertility during implantation, pregnancy, and abortion. In the uterus, MC_T subtype is abundant in myometrium and adjacent basal layer while MC_TC subtype is distributed in all layers. MCs in response to hormones mainly estradiol and progesterone become activated and release a wide range of mediators including histamine, VEGF, proteases, and metalloproteinases (MMPs) that have a role in different stages of pregnancy. An increasing influx of MCs to the cervix during the pregnancy occurs that helps to the physiologic cervical ripening. While MMPs degrade the extracellular matrix (ECM), VEGF modulates neovascularization and histamine influences the embryo implantation. MC-derived histamine may have a positive effect during implantation due to its participation in tissue remodeling. MC proteases including tryptase and chymase activate the precursors of MMP2 and MMP9 to mediate ECM degradation during the physiologic menstrual cycle. There is a line of evidence that MCs have a role in abortion by releasing TNF-α.

Male factor infertility and risk of multiple sclerosis: A register-based cohort study

Background:

Gender, possibly due to the influence of gonadal hormones, is presumed to play a role in the pathogenesis of multiple sclerosis (MS), but no studies have evaluated whether male infertility is associated with MS.

Objective:

To study the association between male factor infertility and prevalent as well as incident MS.

Method:

Our cohort was established by linkage of the Danish National in vitro fertilization (IVF) registry to The Danish Multiple Sclerosis Registry and consisted of 51,063 men whose partners had undergone fertility treatment in all public and private fertility clinics in Denmark between 1994 and 2015.

Results:

With a median age of 34 years at baseline, 24,011 men were diagnosed with male factor infertility and 27,052 did not have male factor infertility and made up the reference group. Men diagnosed with male factor infertility had a higher risk of prevalent (odds ratio (OR) = 1.61, 95% confidence interval (95% CI) 1.04–2.51) and incident MS (hazard ratio (HR) = 1.28, 95% CI 0.76–2.17) when compared to the reference group.

Conclusion:

This nationwide cohort study has shown, for the first time, an association between male infertility and MS which may be due to underlying common etiologies such as hypogonadism, shared genetics, or a joint autoimmune component.