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JBRA Assisted Reproduction Jun 2024Infertility is a widespread global issue that affects approximately 15% of sexually active and active couples, which contributes to about 50% of cases. Currently, the... (Review)
Review
Infertility is a widespread global issue that affects approximately 15% of sexually active and active couples, which contributes to about 50% of cases. Currently, the condition remains prevalent and often inadequately treated. This systematic review aims to evaluate existing studies investigating the effects of probiotic supplementation in men. A comprehensive search was conducted across major databases, including PubMed, Cochrane, Science Direct, and Scielo, using relevant keywords such as 'probiotic' OR 'Lactobacillus' OR 'Bifidobacterium' AND 'Male infertility' OR 'male fertility' OR 'sperm quality' OR 'sperm motility' OR 'oligoasthenoteratozoospermia' and their Portuguese equivalents. Four randomized clinical studies met the inclusion criteria, focusing on men diagnosed with idiopathic male infertility (oligozoospermia, teratozoospermia, and asthenozoospermia). The findings revealed that probiotic administration exhibited promising antioxidant properties by combating reactive oxygen species (ROS), consequently protecting sperm DNA from damage that correlates with declining sperm quality. Significant improvements were observed across all sperm parameters, with notable enhancement in motility. Consequently, probiotic supplementation emerges as a potential therapeutic alternative for men diagnosed with idiopathic infertility, demonstrating positive effects on sperm quality.
Topics: Humans; Male; Probiotics; Infertility, Male; Dietary Supplements; Sperm Motility
PubMed: 38530761
DOI: 10.5935/1518-0557.20240013 -
Andrology Jan 2024Infertility affects 186 million people worldwide, with male factors contributing to 50% of infertility cases. Semen analysis is a key for diagnosing male factor... (Review)
Review
BACKGROUND
Infertility affects 186 million people worldwide, with male factors contributing to 50% of infertility cases. Semen analysis is a key for diagnosing male factor infertility, but sperm parameters can be influenced by ejaculatory abstinence (EA) duration. Shortening or prolonging EA can impact on semen quality and assisted reproductive technology (ART) outcomes, but the optimal EA duration remains unclear, particularly for infertility patients.
OBJECTIVES
This study conducts a comprehensive meta-analysis to explore the impact of varying abstinence durations on semen quality and fertility outcomes.
METHODS
Three English database (PubMed, Embase, and Cochrane Central Register of Controlled Trials) as well as four Chinese database (China National Knowledge Infrastructure, Chinese Scientific Journals database, WanFang database, and Chinese Biomedical Literature database) were searched from 2000 to August 2023. The classical meta-analysis and "one-stage" dose-response meta-analysis were conducted to compare the associations of different abstinence durations (short-term abstinence vs. long-term abstinence) on semen quality in healthy adult and different type of infertile patients.
RESULTS
There were 85 eligible studies were finally included. The meta-analysis of volume (mean difference [MD] = -0.95 mL, 95% confidence interval [CI]: -1.16 to -0.74 mL), total sperm count (TSC) (MD = -102.45×10 , 95% CI: -117.98×10 to -86.91×10 ), sperm concentration (SC) (MD = -11.88×10 /mL, 95% CI: -18.96×10 /mL to -4.80×10 /mL), DNA fragmentation index (DFI) (MD = -2.37%, 95% CI: -4.73% to -0.01%) in healthy men showed a significant decrease with different abstinence durations (short-term abstinence vs. long-term abstinence). The meta-analysis of infertile men showed significant decrease in volume in various subgroups (MD range: -0.73 to -1.17 mL) with P < 0.01; TSC (MD = -61.93×10 , 95% CI: -88.84×10 to -35.01×10 ), SC (MD = -5.39×10 /mL, 95% CI: -9.97×10 to -0.81×10 /mL), DFI (MD = -5.63%, 95% CI: -10.19% to -1.06%) in unexplained infertility subgroup; significant increase in viability (MD = 6.14%, 95% CI: 3.61% to 8.68%) in the unexplained infertility subgroup. The dose-response meta-analysis showed that TSC in oligozoospermia showed a nonlinear increase (coefficient from 3.38 to -5.76, P from 0.02 to 0.22) and the truncation point was around the 4th to 5th abstinence day. The percentage of progressive motile sperm (PR) in asthenozoospermia showed a significant decrease (coefficient = -2.39, 95% CI: -4.28 to -0.50). For fertility outcomes of different ARTs, only the clinical pregnancy rate (CPR) in the intrauterine insemination (IUI) subgroup showed a significant decrease around the 3rd day (coefficient = 0.85, 95% CI: 0.75 to 0.97).
CONCLUSIONS
Short-term abstinence may be associated with limited improvements in semen quality in healthy men but could be more beneficial for infertile men, especially within the first 4 days of abstinence. Caution is urged in making definitive conclusions about the causal relationship between abstinence time and semen quality changes due to potential confounding and interactions.
PubMed: 38197853
DOI: 10.1111/andr.13583 -
Andrology Feb 2024Telomeres are essential for the integrity of chromosome ends during cell division and their involvement in different processes linked to aging has been established.... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Telomeres are essential for the integrity of chromosome ends during cell division and their involvement in different processes linked to aging has been established. These chromosome components are involved in spermatogenesis and seem to play an important role in fertilization and embryo development. Telomere length is shortened with each cell division. Recently, short sperm telomere length has been proposed as a potential biomarker of male infertility.
OBJECTIVES
To conduct a systematic review and meta-analysis of studies exploring the association between spermatozoa and/or leukocyte telomere length with sperm quality parameters and different infertility conditions.
MATERIAL AND METHODS
A systematic review and meta-analysis was conducted with studies from Medline-PUBMED and Cochrane Library databases until May 2022. Eligible studies included cohort, cross-sectional and case-control studies, and telomere length in spermatozoa and/or leukocytes cells was defined as the exposure. Semen quality parameters or infertility conditions (e.g., oligozoospermia, asthenozoospermia, teratozoospermia, or other spermatogenic impairment combinations) were defined as the outcomes.
RESULTS
Twenty-three observational studies were included. In the qualitative analysis, high heterogeneity was observed between studies regarding the associations between telomere length and semen parameters in different normozoospermic/fertile and oligozoospermic/infertile populations. In the meta-analysis, spermatozoa and leukocyte telomere length were shorter in infertile individuals than in fertile individuals (mean difference [95% confidence interval]: -1.43 [-1.66 to -1.21], p-value <0.001 and -1.67 [-2.02 to -1.31], p-value <0.001, respectively). Moreover, in terms of sperm telomere length, these differences were also significant between individuals with a normal seminogram and individuals with a low quantity of spermatozoa in the ejaculate (-0.97 [-1.32, -0.61], p-value <0.001).
CONCLUSION
The current systematic review and meta-analysis suggests the potential role of spermatozoa or leukocyte telomere length as a reliable biomarker of semen quality, which may help distinguish between infertility conditions beyond the routine semen analysis.
Topics: Humans; Male; Semen Analysis; Semen; Cross-Sectional Studies; Spermatozoa; Infertility, Male; Telomere; Biomarkers
PubMed: 37328426
DOI: 10.1111/andr.13482 -
The World Journal of Men's Health Jan 2024The advent of proteomics provides new opportunities to investigate the molecular mechanisms underlying male infertility. The selection of relevant targets based on a...
PURPOSE
The advent of proteomics provides new opportunities to investigate the molecular mechanisms underlying male infertility. The selection of relevant targets based on a single analysis is not always feasible, due to the growing number of proteomic studies with conflicting results. Thus, this study aimed to systematically review investigations comparing the sperm proteome of normozoospermic and infertile men to define a panel of proteins with the potential to be used to evaluate sperm quality.
MATERIALS AND METHODS
A literature search was conducted on PubMed, Web of Science, and Scopus databases following the PRISMA guidelines. To identify proteins systematically reported, first the studies were divided by condition into four groups (asthenozoospermia, low motility, unexplained infertility, and infertility related to risk factors) and then, all studies were analysed simultaneously (poor sperm quality). To gain molecular insights regarding identified proteins, additional searches were performed within the Human Protein Atlas, Mouse Genome Informatics, UniProt, and PubMed databases.
RESULTS
Thirty-two studies were included and divided into 4 sub-analysis groups. A total of 2752 proteins were collected, of which 38, 1, 3 and 2 were indicated as potential markers for asthenozoospermia, low motility, unexplained infertility and infertility related to risk factors, respectively, and 58 for poor sperm quality. Among the identified proteins, ACR, ACRBP, ACRV1, ACTL9, AKAP4, ATG3, CCT2, CFAP276, CFAP52, FAM209A, GGH, HPRT1, LYZL4, PRDX6, PRSS37, REEP6, ROPN1B, SPACA3, SOD1, SPEM1, SPESP1, SPINK2, TEKT5, and ZPBP were highlighted due to their roles in male reproductive tissues, association with infertility phenotypes or participation in specific biological functions in spermatozoa.
CONCLUSIONS
Sperm proteomics allows the identification of protein markers with the potential to overcome limitations in male infertility diagnosis and to understand changes in sperm function at the molecular level. This study provides a reliable list of systematically reported proteins that could be potential targets for further basic and clinical studies.
PubMed: 37118964
DOI: 10.5534/wjmh.220262 -
Journal of Clinical Medicine Dec 2022In recent years, a growing number of studies have supported the beneficial effects of a very short abstinence period on sperm parameters, especially in patients with... (Review)
Review
PURPOSE
In recent years, a growing number of studies have supported the beneficial effects of a very short abstinence period on sperm parameters, especially in patients with oligoasthenozoospermia. However, the results are controversial and no consensus exists regarding whether to request a second semen collection in clinical practice. Therefore, this systematic review and meta-analysis aimed to evaluate the influence of a very short abstinence period (within 4 h) on conventional sperm parameters and sperm DNA fragmentation (SDF) rate.
MATERIALS AND METHODS
The literature search was performed using Scopus and PubMed databases. The meta-analysis was conducted according to the Preferred Reporting Items for Systematic Review and Meta-Analysis Protocol (PRISMA-P) guidelines. All eligible studies were selected according to the Population, Intervention, Comparison/Comparator, Outcomes, and Study design (PICOS) model. The quality of evidence of the included studies was analyzed through the Cambridge Quality Checklists. The standardized mean difference (SMD) was used to analyze the outcomes. Cochran-Q and I statistics were used to evaluate statistical heterogeneity.
RESULTS
We assessed for eligibility 1334 abstracts, and 19 studies were finally included. All 19 articles evaluated the effects of a very short abstinence period on sperm parameters and, among these, 5 articles also evaluated the effects on SDF rate. The quantitative analysis showed a significant reduction in semen volume after a very short abstinence period in both normozoospermic men and patients with oligozoospermia, asthenozoospermia, and/or teratozoospermia (OAT) patients. We found a statistically significant increase in sperm concentration and total and progressive motility in the second ejaculation of patients with OAT. In contrast, the SDF rate decreased significantly in the second ejaculate of OAT patients.
CONCLUSIONS
This is the first systematic review and meta-analysis investigating the impact of a very short abstinence period on sperm parameters and SDF rate. The results suggest that collecting a second consecutive ejaculation after a very short time from the first could represent a simple and useful strategy for obtaining better-quality spermatozoa, especially in patients with abnormal sperm parameters.
PubMed: 36555920
DOI: 10.3390/jcm11247303 -
Journal of Assisted Reproduction and... Jan 2023Modeling methods for busulfan-induced oligoasthenozoospermia are controversial. We aimed to systematically review the modeling method of busulfan-induced oligospermia... (Meta-Analysis)
Meta-Analysis Review
OBJECTIVE
Modeling methods for busulfan-induced oligoasthenozoospermia are controversial. We aimed to systematically review the modeling method of busulfan-induced oligospermia and asthenozoospermia, and analyze changes in various evaluation indicators at different busulfan doses over time.
METHODS
We searched the Cochrane Library, PubMed databases, Web of Science, the Chinese National Knowledge Infrastructure, and the Chinese Biomedical Literature Service System until April 9, 2022. Animal experiments of busulfan-induced spermatogenesis dysfunction were included and screened. The model mortality and parameters of the evaluation indicators were subjected to meta-analysis.
RESULTS
Twenty-nine animal studies were included (control/model: 669/1829). The mortality of mice increased with busulfan dose. Significant spermatogenesis impairment occurred within 5 weeks, regardless of busulfan dose (10-40 mg/kg). Testicular weight (weighted mean difference [WMD]: - 0.04, 95% CI: - 0.05, - 0.03), testicular index (WMD: - 2.10, 95% CI: - 2.43, - 1.76), and Johnsen score (WMD: - 4.67, 95% CI: - 5.99, - 3.35) were significantly decreased. The pooled sperm counts of the model group were reduced by 32.8 × 10/ml (WMD: - 32.8, 95% CI: - 44.34, - 21.28), and sperm motility decreased by 37% (WMD: - 0.37, 95% CI: - 0.47, - 0.27). Sperm counts decreased slightly (WMD: - 3.03, 95% CI: - 3.42, - 2.64) in an intratesticular injection of low-dose busulfan (4 - 6 mg/kg), and the model almost returned to normal after one seminiferous cycle.
CONCLUSION
The model using low-dose busulfan (10 - 20 mg/kg) returned to normal after 10 - 15 weeks. However, in some spermatogenesis cycles, testicular weight reduction and testicular spermatogenic function damage were not proportional to busulfan dose. Sperm counts and motility results in different studies had significant heterogeneity. Standard protocols for sperm assessment in animal models were needed to reduce heterogeneity between studies.
Topics: Humans; Mice; Male; Animals; Oligospermia; Busulfan; Asthenozoospermia; Sperm Count; Sperm Motility; Semen
PubMed: 36508035
DOI: 10.1007/s10815-022-02674-y -
Biology Oct 2022Male infertility is a complex disorder affecting many couples worldwide. Long noncoding RNAs (lncRNAs) regulate important cellular processes; however, a comprehensive... (Review)
Review
Male infertility is a complex disorder affecting many couples worldwide. Long noncoding RNAs (lncRNAs) regulate important cellular processes; however, a comprehensive understanding of their role in male infertility is limited. This systematic review investigates the differential expressions of lncRNAs in male infertility or variations in lncRNA regions associated with it. The PRISMA guidelines were used to search Pubmed and Web of Science (1 June 2022). Inclusion criteria were human participants, patients diagnosed with male infertility, and English language speakers. We also performed an in silico analysis investigating lncRNAs that are reported in many subtypes of male infertility. A total of 625 articles were found, and after the screening and eligibility stages, 20 studies were included in the final sample. Many lncRNAs are deregulated in male infertility, and interactions between lncRNAs and miRNAs play an important role. However, there is a knowledge gap regarding the impact of variants found in lncRNA regions. Furthermore, eight lncRNAs were identified as differentially expressed in many subtypes of male infertility. After in silico analysis, gene ontology (GO) and KEGG enrichment analysis of the genes targeted by them revealed their association with bladder and prostate cancer. However, pathways involved in general in tumorigenesis and cancer development of all types, such as p53 pathways, apoptosis, and cell death, were also enriched, indicating a link between cancer and male infertility. This evidence, however, is preliminary. Future research is needed to explore the exact mechanism of action of the identified lncRNAs and investigate the association between male infertility and cancer.
PubMed: 36290414
DOI: 10.3390/biology11101510 -
Andrologia Dec 2022Follicle-stimulating hormone (FSH) is commonly used in assisted reproductive technology to promote the development and maturation of follicles in female patients.... (Meta-Analysis)
Meta-Analysis Review
Follicle-stimulating hormone (FSH) is commonly used in assisted reproductive technology to promote the development and maturation of follicles in female patients. However, there is no consensus on treating FSH in males with idiopathic oligoasthenoteratozoospermia (iOAT), especially in patients with normal serum FSH levels. To determine the role of FSH in improving semen quality in patients with iOAT, we conducted a detailed search in the commonly used database to find all studies on FSH in the treatment of iOAT. We compared the results, including semen volume, sperm count, sperm concentration, percentage of forward sperm motility, percentage of total sperm motility, percentage of normal forms and DNA fragmentation index (DFI) between the two groups treated with FSH or not. A total of 12 randomized controlled trials and one retrospective case-control study, including 924 people, were included in our meta-analysis. We found that sperm counts (MD 17.75; 95% CI 11.53-23.98 and p < 0.00001) were significantly increased in patients treated with FSH, along with improvements in sperm concentration (MD 4.52; 95% CI 1.46-7.58 and p = 0.004), percentage of normal forms (MD 2.87; 95% CI 0.19-5.56 and p = 0.04) and DFI (MD -12.62; 95% CI -19.27-5.97 and p = 0.002). However, we found no significant differences in the two groups' changes in other semen parameters. The use of FSH can improve some semen parameters in patients with iOAT, such as sperm count, percentage of normal forms, sperm concentration and DFI.
Topics: Humans; Male; Asthenozoospermia; Case-Control Studies; Follicle Stimulating Hormone; Infertility, Male; Oligospermia; Randomized Controlled Trials as Topic; Retrospective Studies; Semen; Semen Analysis; Sperm Count; Sperm Motility; Spermatozoa
PubMed: 36104938
DOI: 10.1111/and.14596 -
Andrology Nov 2022The dynein-related genes may have a role in the etiology of male infertility, particularly in cases of impaired sperm motility. (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
The dynein-related genes may have a role in the etiology of male infertility, particularly in cases of impaired sperm motility.
OBJECTIVES
The goal of this review is to compile a list of the most important dynein-related candidate genes that may contribute to male factor infertility.
MATERIALS AND METHODS
Databases were searched using the keywords "dynein," "male," "infertility," and by applying strict inclusion criteria. A meta-analysis was also performed by using the eligible case-control studies. The odd ratios (ORs), the Z-test score, and the level of significance were determined using a fixed model with a p value of 0.05. Funnel plots were used to check for publication bias.
RESULTS
There were 35 studies that met the inclusion criteria. There were a total of 15 genes responsible for the production of dynein structural proteins, the production of dynein assembling factors, and potentially associated with male infertility. A total of five case-control studies were eligible for inclusion in the meta-analysis. Variants in the dynein-related genes were linked to an increased the risk of male infertility (OR = 21.52, 95% confidence interval 8.34-55.50, Z test = 6.35, p < 0.05). The percentage of heterogeneity, I , was 47.00%. The lack of variants in the dynein genes was an advantage, and this was statistically significant.
DISCUSSION
The results from the present review illustrate that pathogenic variants in genes both for dynein synthesis and for dynein assembly factors could be associated with isolated cases of male infertility without any other symptoms.
CONCLUSIONS
The genes addressed in this study, which are involved in both the production and assembly of dynein, could be used as molecular targets for future research into the etiology of sperm motility problems.
Topics: Dyneins; Humans; Infertility, Male; Male; Mutation; Sperm Motility; Spermatozoa
PubMed: 36057791
DOI: 10.1111/andr.13287 -
International Journal of Molecular... Apr 2022In mammals, sperm fertilization potential relies on efficient progression within the female genital tract to reach and fertilize the oocyte. This fundamental property is... (Review)
Review
In mammals, sperm fertilization potential relies on efficient progression within the female genital tract to reach and fertilize the oocyte. This fundamental property is supported by the flagellum, an evolutionarily conserved organelle that provides the mechanical force for sperm propulsion and motility. Importantly several functional maturation events that occur during the journey of the sperm cells through the genital tracts are necessary for the activation of flagellar beating and the acquisition of fertilization potential. Ion transporters and channels located at the surface of the sperm cells have been demonstrated to be involved in these processes, in particular, through the activation of downstream signaling pathways and the promotion of novel biochemical and electrophysiological properties in the sperm cells. We performed a systematic literature review to describe the currently known genetic alterations in humans that affect sperm ion transporters and channels and result in asthenozoospermia, a pathophysiological condition defined by reduced or absent sperm motility and observed in nearly 80% of infertile men. We also present the physiological relevance and functional mechanisms of additional ion channels identified in the mouse. Finally, considering the state-of-the art, we discuss future perspectives in terms of therapeutics of asthenozoospermia and male contraception.
Topics: Animals; Asthenozoospermia; Female; Humans; Ion Channels; Male; Mammals; Mice; Models, Animal; Sperm Motility; Spermatozoa
PubMed: 35409285
DOI: 10.3390/ijms23073926