Andrology最新文献

Oxidative stress (OS) significantly contributes to male reproductive dysfunction, a factor implicated in a substantial fraction of infertility cases. This comprehensive review elucidates the intricate interplay between oxidative stress and male reproductive health, emphasizing the molecular and cellular mechanisms through which reactive oxygen species (ROS) impair sperm function. Key areas of focus include lipid peroxidation of sperm membranes, DNA damage, and apoptotic cell death, which collectively undermine sperm viability and fertility potential. The discussion extends to the impact of lifestyle and environmental factors on oxidative balance, highlighting how these elements intensify oxidative stress and subsequently exacerbate reproductive outcomes. Advances in therapeutic approaches are critically assessed, particularly the development and application of antioxidants in ameliorating oxidative damage and restoring reproductive functions. This review also explores innovative diagnostic techniques for detecting ROS and assessing oxidative damage within clinical settings, offering insights into future directions for research and clinical practice in managing male infertility related to oxidative stress.

Background: Premature ejaculation (PE) is one of the most prevalent sexual dysfunctions in males. Repetitive transcranial magnetic stimulation (TMS) demonstrates potential modulatory effects on ejaculatory function, however, the effects of different stimulation frequencies remain unclear.

Objectives: To investigate the effects of low-frequency and high-frequency rTMS in a rat model of rapid ejaculation and compare these outcome with dapoxetine, a standard pharmacological intervention.

Methods: Male rats exhibiting rapid ejaculation were identified based on sexual behavior parameters, then randomly allocated into four groups: 1-Hz rTMS, 10-Hz rTMS, dapoxetine control, and sham control groups. Ejaculatory behavior, hippocampal 5-hydroxytryptamine (5-HT) levels, brain-derived neurotrophic factor (BDNF) expression, and activation of the BDNF-receptor tyrosine kinase receptor B (TrkB) pathway were investigated before and after 2 weeks of treatment.

Results: Following 2 weeks of intervention, we found that all rTMS and dapoxetine groups showed significant improvements in ejaculation latency compared with controls, with the 10-Hz rTMS group showing the most substantial effect. While dapoxetine slightly outperformed 10-Hz rTMS in increasing 5-HT levels, 10-Hz rTMS induced a greater upregulation of BDNF and TrkB expression. Correlation analysis revealed that BDNF levels were positively associated with EL (r = 0.8817, p < 0.001) and negatively associated with ejaculation frequency (r = -0.8702, p < 0.001).

Conclusion: rTMS exhibited frequency-dependent therapeutic efficacy in rapid ejaculation rat models, with high-frequency protocols demonstrating superior benefits compared with low-frequency interventions. These effects are mediated through activation of the BDNF-TrkB pathway and enhanced serotonergic signaling, suggesting high-frequency rTMS as a promising non-pharmacological therapy for PE.

Background: While metabolic disorders are well-established contributors to testosterone decline and erectile dysfunction (ED), little is known about the natural progression of reproductive parameters in healthy aging men.

Objectives: This study aimed to evaluate longitudinal changes in reproductive parameters and sought to determine the influence of body mass index (BMI) and glycated hemoglobin (HbA1c) on these changes.

Patients and methods: A total of 197 healthy men (aged 18-84 years) were assessed at baseline (FAMe 1), with 117 participants returning for follow-up (FAMe 2) after approximately 6 years. All participants underwent a thorough andrological examination.

Results: Total and free testosterone levels declined significantly over 6 years in men older than 25 years at baseline (p < 0.05). FSH levels increased significantly in men older than 35 years at FAMe 1 (p < 0.05), while LH and SHBG remained unchanged. Despite moderate declines, semen parameters remained mostly within physiological limits. Erectile function exhibited a moderate but progressive decline (p < 0.001). In men over 45 years, neither age (p = 0.13) nor testosterone (p = 0.52) influenced erectile function, while an increment of HbA1c levels was significantly associated with deteriorating erectile function (p = 0.002). Similarly, AMS scores significantly increased after age 45, which was strongly correlated with higher HbA1c levels (p = 0.001).

Discussion: While testosterone levels declined with aging, they remained within the normal range, suggesting that healthy men experience only apparently mild reproductive aging. Erectile function and hypogonadism-like symptoms were more strongly associated with glycemic control than with testosterone levels.

Conclusion: In healthy men, reproductive and sexual aging occur gradually, with testosterone and semen parameters largely preserved over time. However, metabolic health, rather than testosterone, plays a key role in the progression of ED and hypogonadism-like symptoms, emphasizing the need for preventive metabolic interventions to maintain reproductive health.

Background: Male sexual dysfunctions (SDs) like erectile dysfunction (ED), premature ejaculation (PE), and Peyronie's disease (PD) are highly prevalent conditions affecting the quality of life of men and their partners. Botulinum toxin (BTX) is emerging as a promising injectable therapy to treat male SDs.

Objective: To systematically review the current evidence on the use of BTX in the treatment of male SDs.

Materials and methods: PubMed, Cochrane, and EMBASE databases were queried for all published studies indexed up to October 2024 using predefined keywords.

Results: Of 108 identified articles, 9 (6 on ED, 2 on PE, and only 1 on PD) met our inclusion criteria. In ED, BTX improved International Index of Erectile Function-Erectile Function domain (IIEF-EF) scores in 41%-57.4% of patients, with benefits lasting up to 6 months. In PE, BTX increased ejaculation latency and subjective satisfaction at 1-3 months, but the effects diminished by 6 months. In PD, a single study showed a significant reduction in penile curvature (-7.9°), plaque thickness, and penile pain. Adverse effects were mild and local, reported in less than 10% of cases.

Conclusions: BTX injections demonstrate promising improvements in erectile function, ejaculation latency, and penile curvature with a favourable safety profile. However, current evidence is limited by small, heterogeneous studies and the absence of large randomized controlled trials. Further research is needed to establish optimal dosing, timing, and patient selection.

Background: Emerging evidence suggests that the seminal microbiota may play a role in male reproductive health, yet its relationship with sperm parameters remains poorly understood.

Objective: This study explores the link between seminal microbiota composition and sperm parameters to understand their impact on the male reproductive function.

Materials and methods: This prospective cross-sectional study included 100 eugonadal adult men evaluated at a university-affiliated Endocrinology and Andrology Division. Seminal concentrations of lactobacilli, anerobic, and facultative bacteria, along with serum luteinizing hormone, follicle-stimulating hormone, and testosterone, were assessed alongside conventional sperm parameters. Conventional sperm parameters and seminal leukocyte counts were analyzed. Regression models were used to explore associations, and predictive thresholds for sperm concentration >16 mil/mL and sperm progressive motility >30% were determined.

Results: Seminal lactobacillus concentration positively correlated with sperm concentration (r = 0.42, p < 0.001). Seminal leukocyte concentration and percentage of immature germ cells (spermatids) identified at semen analysis showed negative correlations (r = -0.35, p = 0.002; r = -0.37, p < 0.001, respectively). Anerobic and facultative bacteria negatively correlated with sperm progressive motility (r = -0.77, p < 0.001) and positively correlated with percentage of spermatids (r = 0.72, p < 0.001). The lactobacilli-to-total bacteria ratio negatively correlated with leukocyte concentration (r = -0.96, p < 0.001) and percentage of spermatids (r = -0.89, p <0.001), and positively with sperm progressive motility (r = 0.95, p < 0.001). All of these correlations remained significant after adjustments. Concentrations of lactobacilli, anerobic/facultative bacteria, and the lactobacilli/total bacteria ratio were strong predictors of sperm concentration and motility, demonstrating high sensitivity and specificity.

Discussion: Our findings suggest that the composition of the seminal microbiota, particularly the relative abundance of lactobacilli versus anerobic/facultative bacteria, may influence key sperm parameters such as concentration and motility. This highlights the potential clinical relevance of microbiota profiling in the male fertility assessment.

Conclusion: A higher abundance of seminal lactobacilli is associated with more favorable sperm parameters, while anerobic and facultative bacteria are linked to poorer outcomes. Microbiota analysis may offer additional insights into male infertility diagnostics, though further studies are needed to confirm causality.

Background: An unhealthy lifestyle negatively affects male fertility. Despite this, men that are part of an infertile couple often fail to improve their lifestyle and evidence on influencing factors is limited.

Objectives: To identify facilitators and barriers involved in lifestyle changes of men seeking fertility care and in lifestyle counseling by fertility health care providers (HCPs).

Materials and methods: A mixed-methods study was performed including semi-structured interviews with 14 men seeking fertility care and seven fertility HCPs. Fifty other men completed a questionnaire evaluating various aspects of lifestyle change. Eligible participants were men part of an infertile couple and met at least one lifestyle criterion: BMI ≥ 25 kg/m², smoker, alcohol use of ≥ 7 units/week, and recreational drug use. Included HCPs provided lifestyle counseling to infertile couples.

Results: The most important facilitators for lifestyle changes in men seeking fertility care are the wish to improve their chances to father a child and their partner's support. The most important barriers are stress, a busy life, an unhealthy lifestyle being part of social activities, and normal semen quality. HCPs experienced limited time, unclear and insufficient scientific evidence on lifestyle and male infertility, and lack of uniform care as barriers. Professional responsibility and societal factors were facilitators.

Discussion: HCPs could use these results to improve and personalize lifestyle counseling of men seeking fertility care. For example, by emphasizing the impact of lifestyle on pregnancy loss and offspring in men with normal semen quality. This study is limited by its small sample size and its confinement to a Dutch context.

Conclusion: This study identifies previously unknown facilitators and barriers for lifestyle changes in men seeking fertility care. It also reveals barriers experienced by HCPs when counseling male patients about lifestyle. These results should inspire fertility departments to (re)design lifestyle interventions and policies for men seeking fertility care.