Relationship between male aging and semen quality: a retrospective study on over 2500 men.

PURPOSE: We aimed to evaluate whether and to what extent an association exists between male aging and worsening of semen parameters and to determine whether a threshold age can be identified above which the decline in semen quality becomes statistically significant. METHODS: 2612 men (age: 16-56 years) attending an andrology outpatient clinic for semen analysis and clinical evaluation were studied. Semen analyses were performed according to the ongoing WHO-recommended procedures. Total motile count (TMC) and total progressive motile count (TPMC) were calculated by multiplying total sperm number by total motility and progressive motility, respectively. RESULTS: Significant negative correlations were found between age and total motility (r = - 0.131, p < 0.0001), progressive motility (r = - 0.112, p < 0.0001), TPMC (r = - 0.042, p = 0.037), and normal sperm morphology (r = - 0.053, p = 0.007). All these associations persisted in multivariate regression models adjusted for abstinence time, smoking, history of male accessory gland infections, varicocele and the year in which semen analysis was performed. When comparisons were performed among quartiles of increasing age, the fourth quartile, corresponding to the age group > 40 years, was associated with a significant decrease in total and progressive motility. An earlier decline in the TPMC and percentage of normal forms was also observed. CONCLUSION: Advancing male age exhibits an independent association with a decrease in the percentage of motile and morphologically normal spermatozoa, with greater evidence from the age of > 40 years. Further studies are warranted to elucidate the mechanisms and clinical reflections of these associations.

Effects of gender affirming hormone therapy with testosterone on coagulation and hematological parameters in transgender people assigned female at birth: A systematic review and meta-analysis.

BACKGROUND: Hormone replacement therapy is associated with an increased thromboembolic risk. The effects of testosterone (T) on coagulation markers in people assigned female at birth (AFAB) under gender affirming hormone therapy (GAHT) are not well described. METHODS: Systematic review and meta-analysis on English-language articles retrieved from PubMed, Scopus and Cochrane Library up to April 2023 investigating T therapy in AFAB people. Coagulation parameters included international normalized ratio (INR), fibrinogen, activated partial thromboplastin clotting time (aPTT), plasminogen activator inhibitor-1 (PAI-1); hematological variables included hemoglobin (Hb) and hematocrit (HCT). We also reported the rate of thromboembolic events. Data were combined as mean differences (MD) with a 95 % confidence interval (CI) of pre- vs post-follow-up values, using random-effects models. RESULTS: We included 7 studies (6 prospective and 1 retrospective) providing information on 312 subjects (mean age: 23 to 30 years) who underwent GAHT with variable T preparation. T therapy was associated with a significant increase in INR values [MD: 0.02, 95 % confidence interval (CI): 0.01-0.03; p = 0.0001], with negligible heterogeneity (I2 = 4 %). T therapy was associated with increased Hb (MD: 1.48 g/dL, 95%CI: 1.17 to 1.78; I2 = 9 %) and HCT (4.39 %, 95%CI: 3.52 to 5.26; I2 = 23 %) values. No effect on fibrinogen, aPTT and PAI-1 was found. None of the study reported thromboembolic events during the follow-up. CONCLUSION: Therapy with T increased blood viscosity in AFAB men. A slight increase in INR values was also found, but the clinical relevance and mechanism(s) of this finding needs to be clarified.

Which PDE5 inhibitor is the most effective in the treatment of erectile dysfunction in men with spinal cord injury? A systematic review and network meta-analysis.

BACKGROUND: Phosphodiesterase 5 inhibitors (PDE5i) are the first-line drugs for erectile dysfunction (ED) but differences among available molecules should drive therapy personalization. Choosing one PDE5i over another is a challenge in men with spinal cord injury (SCI), as the evidence of efficacy for each molecule is derived from few studies and comparative "head-to-head" trials are lacking. OBJECTIVE: To assess the efficacy of the different PDE5i for SCI-related ED with a network meta-analysis (NMA) approach. MATERIALS AND METHODS: Databases from PubMed, Web of Science, Scopus, and Cochrane Library were checked for randomized controlled trials (RCTs) comparing any PDE5i to each other or placebo in men with traumatic SCI lasting ≥6 months. Data were incorporated in a random-effect NMA, where treatments' efficacy was ranked using the surface under the cumulative ranking curve (SUCRA). RESULTS: The 10 RCTs included provided information about 1,492 men with ED due to traumatic SCI. Intervention arms included sildenafil, tadalafil, and/or vardenafil. Overall, at the pairwise meta-analysis, PDE5i were four times more effective than placebo in improving erectile function (risk ratio: 4.13, 95% CI: 2.76, 6.19). The comparative analysis from NMA revealed that tadalafil was associated with the highest SUCRA value (81%), followed by vardenafil (68%) and sildenafil (49%). DISCUSSION AND CONCLUSION: Within the grading of comparison network, tadalafil appeared to be the best PDE5i in the treatment of SCI-related ED. Further focused studies are warranted to confirm these findings and define optimal doses and duration of therapy.

Is marijuana a foe of male sexuality? Data from a large cohort of men with sexual dysfunction.

BACKGROUND: Although it has been assumed that chronic cannabis use may have an unfavorable impact on male sexual function and its metabolic correlates, evidence from clinical studies remains inconclusive. OBJECTIVE: To investigate the relationship between cannabis use and sexual behavior, anthropometrics and metabolic/vascular profiles in a large series of men evaluated for sexual dysfunction. METHODS: A total of 4800 men (mean age 50.8 years) attending an andrology outpatient clinic for sexual dysfunction were studied. Sexual symptoms, hormonal, metabolic, and instrumental (penile color Doppler ultrasound, PCDU) parameters were evaluated according to the reported habitual use of recreational substances (no use, 1-2 joints/week, >2 joints/week, and use of illicit drugs other than cannabis). RESULTS: When compared with non-users, cannabis users were younger and exhibited a lower prevalence of comorbidities as well as better PCDU parameters, despite reporting higher alcohol and tobacco consumption. After adjustment for confounders, cannabis use was associated with a greater instability in the couple's relationship and a higher frequency of masturbation. In addition, the group smoking >2 joints/week showed a significantly lower body mass index than both controls and users of substances other than cannabis. Men who reported using recreational drugs (either cannabis or other) exhibited significantly lower levels of both total and low-density lipoprotein cholesterol than non-users. At the PCDU, smoking 1-2 joints/week was associated with significantly higher dynamic peak systolic velocity than both non-drug use and use of >2 joints/week. Prolactin levels were significantly higher in individuals smoking 1-2 joints/week and in those who used substances other than cannabis when compared with controls, whereas no difference in total testosterone levels was observed. DISCUSSION: In men with sexual dysfunction, mild cannabis consumption may be associated with a more favorable anthropometric and lipid profile and with a better penile arterial vascular response to intracavernous prostaglandin injection.

Does an increase in adipose tissue 'weight' affect male fertility? A systematic review and meta-analysis based on semen analysis performed using the WHO 2010 criteria.

INTRODUCTION: Obesity negatively impact on the metabolism of sex hormones, leading to reduced testosterone serum levels. However, how the obesity could negatively impact on the overall gonadal function, particularly on male fertility, remained unclear so far. OBJECTIVE: To systematically review evidences regarding the influence of body weight excess on the sperm production. METHODS: A meta-analysis was conducted, searching all prospective and retrospective observational studies reporting male subjects older than 18 years old, with body weight excess from overweight to severe obesity were considered. Only studies using the V edition of the World Health Organization (WHO) manual for semen analysis interpretation were considered. No specific interventions were considered. Search was focused on studies comparing overweight/obese to normal weight subjects. RESULTS: Twenty-eight studies were considered. Total sperm count and sperm progressive motility were significantly lower in overweight compared to normal weight subjects. Meta-regression analyses demonstrated that patients' age impacted on sperm parameters. Similarly, obese men showed lower sperm concentration, total sperm number, progressive and total motilities, and normal morphology lower than normal weight subjects. Reduced sperm concentration in obese men was influenced by age, smoking habit, varicocele, and total testosterone serum levels at meta-regression analyses. CONCLUSIONS: The male potential fertility is reduced in subjects with increased body weight, compared to normal weight men. The higher was the increased body weight, the worst was the sperm quantity/quality. This result comprehensively included obesity among non-communicable risk factor for male infertility, shedding new lights on the negative impact of increased body weight on overall gonadal function.

Effect of antioxidants on semen parameters in men with oligo-astheno-teratozoospermia: a network meta-analysis.

BACKGROUND: Although antioxidants are largely used in subfertile men with oligo-astheno-teratozoospermia (OAT), the choice among different molecules is challenged by the lack of comparative head-to-head studies. The network meta-analysis (NMA) can overcome limitations of pairwise meta-analyses, since it incorporates direct and indirect evidence into a single model generating an effectiveness hierarchy. OBJECTIVE: To assess with a NMA the effects of antioxidants in improving seminal parameters in idiopathic OAT. MATERIALS AND METHODS: PubMed, Scopus, Cinahl, and Cochrane Library databases were searched for randomized controlled trials (RCTs) comparing any antioxidant treatment to each other or placebo in men with at least one idiopathic seminal abnormality. Data were included in a random-effects NMA, where efficacy of treatments was ranked by surface under the cumulative ranking curve (SUCRA). RESULTS: 29 RCTs provided information on 2045 men (mean age: 33.5 years) with idiopathic OAT and 19 antioxidant preparations. Compared to placebo, l-carnitine, especially in combination with l-acetyl-carnitine (LAC), had the highest SUCRA for sperm concentration, progressive motility, and morphology. Folate was the only other compound effective on sperm concentration. Vitamin E+selenium or zinc had the highest SUCRA for total motility. A contribution on progressive motility was revealed for pentoxifylline and vitamin E+CoQ10.

Iodine Intake and Testosterone.

This cross-sectional study evaluates whether urinary iodine concentration is associated with testosterone among men who participated in the National Health and Nutrition Examination Survey.

Arachidonic Acid Pathways and Male Fertility: A Systematic Review.

Arachidonic acid (AA) is a polyunsaturated fatty acid that is involved in male fertility. Human seminal fluid contains different prostaglandins: PGE (PGE1 and PGE2), PGF2α, and their specific 19-hydroxy derivatives, 18,19-dehydro derivatives of PGE1 and PGE2. The objective of this study is to synthesize the available literature of in vivo animal studies and human clinical trials on the association between the AA pathway and male fertility. PGE is significantly decreased in the semen of infertile men, suggesting the potential for exploitation of PGE agonists to improve male fertility. Indeed, ibuprofen can affect male fertility by promoting alterations in sperm function and standard semen parameters. The results showed that targeting the AA pathways could be an attractive strategy for the treatment of male fertility.

Neurotensin Gene rs2234762 C>G Variant Associates with Reduced Circulating Pro-NT Levels and Predicts Lower Insulin Resistance in Overweight/Obese Children.

Neurotensin (NT) is a small protein implicated in the regulation of energy balance which acts as both a neurotransmitter in the central nervous system and as a gastrointestinal peptide. In the gut, NT is secreted after fat ingestion and promotes the absorption of fatty acids. The circulating levels of its precursor, pro-NT, predicts the presence and development of metabolic and cardiovascular diseases. Despite the extensive knowledge on the dynamic changes that occur to pro-NT = after fat load, the determinants of fasting pro-NT are unknown. The aim of this study was to determine the possible genetic regulation of plasma pro-NT. The NT gene (NTS) was sequenced for potential functional variants, evaluating its entire genomic and potentially regulatory regions, in DNA from 28 individuals, stratified by low and high pro-NT levels. The identified variant differently distributed in the two pro-NT subgroups was genotyped in a cohort of nine hundred and thirty-two overweight/obese children and adolescents. A total of seven sequence variations across the NTS gene, none of them located in coding regions, were identified. The rs2234762 polymorphism, sited in the NTS gene promoter, was statistically more frequent in the lowest pro-NTS level group. Carriers of the rs2234762 variant showed lower pro-NT levels, after adjusting for sex, age, BMI, triglycerides and the Tanner stage. Having NTS rs2234762 predicted less pronounced insulin resistance at the 6.5-year follow-up with OR: 0.46 (0.216-0.983), at the logistic regression analysis adjusted for age, sex and BMI. In conclusion, the NTS rs2234762 gene variant is a determinant of reduced circulating pro-NT levels in overweight and obese children, which predisposes this group to a more favorable metabolic profile and a reduced insulin resistance later in life, independently from metabolic confounders.

Selective modulation of estrogen receptor in obese men with androgen deficiency: A systematic review and meta-analysis.

BACKGROUND: Although selective estrogen receptor modulators have been proposed as a treatment for men with central functional hypogonadism, only a few data have been produced in men with obesity-related functional androgen deficiency. OBJECTIVE: To determine whether and to what extent selective estrogen receptor modulators are an effective and safe therapy in men with obesity-related functional androgen deficiency. MATERIALS AND METHODS: A thorough search of PubMed, Web of Science, Scopus, and Cochrane Library databases was performed to identify studies comparing testosterone levels before and after treatment. Mean differences with 95% coefficient intervals were combined using random effects models. Funnel plot, Egger's test, and trim-and-fill analysis were used to assess publication bias. RESULTS: Seven studies met the inclusion criteria providing information on 292 men with obesity-related functional androgen deficiency treated with clomiphene citrate (12.5-50 mg daily) or enclomiphene citrate (12.5-25 mg daily) for 1.5-4 months. The pooled estimates indicated a significant increase in testosterone levels both with clomiphene (mean difference: 11.56 nmol/L; 95% coefficient interval: 9.68, 13.43; I2  = 69%, pfor heterogeneity  = 0.01) and enclomiphene citrate (mean difference: 7.50 nmol/L; 95% coefficient interval: 6.52, 8.48; I2  = 4%, pfor heterogeneity  = 0.37). After the exclusion of one study on severely obese men, who exhibited the highest response rate to clomiphene citrate, the heterogeneity disappeared (mean difference: 10.27 nmol/L; 95% coefficient interval: 9.39, 11.16; I2  = 0%, pfor heterogeneity  = 0.66). No publication bias was revealed by Egger's test and trim-and-fill analysis. No treatment-related unexpected findings regarding safety profile were registered. DISCUSSION AND CONCLUSION: Treatment with clomiphene citrate and enclomiphene citrate may be an effective and safe alternative to testosterone replacement therapy in men with obesity-related functional androgen deficiency. Further long-term studies are warranted to define clinical reflections of the selective estrogen receptor modulators-induced increase in testosterone levels and to better clarify the safety profile.

Infection rate of penile prosthesis implants in men with spinal cord injury: a meta-analysis of available evidence.

The risk of penile prosthesis implants (PPIs) infection in men with spinal cord injury (SCI), empirically theorized to be high, is widely variable among the studies. We performed a meta-analysis to define the pooled PPI infection rate and its possible risk factors in men with SCI. A thorough search of PubMed, Scopus and Web of Science was performed. The eighteen included studies provided information on 1079 implantation procedures, determining a pooled PPI infection rate of 8.0% (95% CI: 5.0-11.0%), with significant heterogeneity (I² = 67.0%). Trim-and-fill adjustment for publication bias had a small effect on the pooled estimate (adjusted odds ratio: 6.3%, 95% CI: 2.5-10.0%) with a substantial reduction in heterogeneity (I2 = 32.4%). The PPI infection rate was higher for inflatable PPIs than for malleable PPIs (16.4% vs 8.9%, p = 0.027). No differences were found between the different levels of SCI. In conclusion, the risk of PPI infection in SCI would be higher than that reported in the general population. However, the results were produced from dated and low/moderate quality studies that may not fully reflect the outcomes of modern PPIs and implantation protocols. There is an urgent need to gather more information on this topic through studies relevant to contemporary practice.

The European Academy of Andrology (EAA) ultrasound study on healthy, fertile men: An overview on male genital tract ultrasound reference ranges.

BACKGROUND: So far, male genital tract color-Doppler ultrasound (MGT-CDUS) was not standardized. Recently, the European Academy of Andrology (EAA) published the results of a multicenter study assessing the CDUS characteristics of healthy-fertile men (HFM) to obtain normative parameters. OBJECTIVES: To report the EAA US study (i) standard operating procedures (SOPs) for assessing MGT-CDUS, (ii) main MGT-CDUS normative parameters, and (iii) compare the EAA and previously published "normal" CDUS values. METHODS: A cohort of 248 HFM (35.3 ± 5.9 years) was studied, evaluating MGT-CDUS before and after ejaculation following SOPs. RESULTS: SOPs for MGT-CDUS assessment are summarized here. All subjects underwent scrotal CDUS and 188 men underwent transrectal ultrasound before and after ejaculation. The main CDUS reference ranges and characteristics of the HFM-MGT are reported here. The mean testicular volume was ∼17 mL. The lower limit for right and left testis was 12 and 11 mL, defining testicular hypotrophy. The upper limit for epididymal head, body, tail, and vas deferens was 11.5, 5, 6, and 4.5 mm, respectively. Testicular and epididymal arterial reference ranges are reported. The EAA varicocoele classification is reported. CDUS-varicocoele was detected in ∼37% of men. Prostate mean volume was ∼25 mL, while lower and upper limits were 15 and 35 mL, defining hypotrophy and enlargement, respectively. Prostate arterial reference ranges are reported. Prostate calcifications and inhomogeneity were frequent; midline prostatic cysts were rare and small. Ejaculatory duct abnormalities were absent. The upper limit for periprostatic venous plexus was 4.5 mm. Lower and upper limits of seminal vesicles (SV) anterior-posterior diameter were 6 and 16 mm, defining hypotrophy or dilation, respectively. Seminal vesicle volume and ejection fraction reference ranges are reported. SV-US abnormalities were rare. Deferential ampullas upper limit was 6 mm. A discussion on the EAA and previously published "normal" CDUS values is reported here. CONCLUSIONS: The EAA findings will help in reproductive and general male health management.

The European Academy of Andrology (EAA) ultrasound study on healthy, fertile men: Prostate-vesicular transrectal ultrasound reference ranges and associations with clinical, seminal and biochemical characteristics.

BACKGROUND: Transrectal ultrasound (TRUS) parameters are not standardized, especially in men of reproductive age. Hence, the European Academy of Andrology (EAA) promoted a multicenter study to assess the TRUS characteristics of healthy-fertile men (HFM) to establish normative parameters. OBJECTIVES: To report and discuss the prostate and seminal vesicles (SV) reference ranges and characteristics in HFM and their associations with clinical, seminal, biochemical parameters. METHODS: 188 men (35.6 ± 6.0 years) from a cohort of 248 HFM were studied, evaluating, on the same day, clinical, biochemical, seminal, TRUS parameters following Standard Operating Procedures. RESULTS: TRUS reference ranges and characteristics of the prostate and SV of HFM are reported herein. The mean PV was ∼25 ml. PV lower and upper limits were 15 and 35 ml, defining prostate hypotrophy and enlargement, respectively. PV was positively associated with age, waistline, current smoking (but not with T levels), seminal volume (and negatively with seminal pH), prostate inhomogeneity, macrocalcifications, calcification size and prostate arterial parameters, SV volume before and after ejaculation, deferential and epididymal size. Prostate calcifications and inhomogeneity were frequent, while midline prostatic cysts were rare and small. Ejaculatory duct abnormalities were absent. Periprostatic venous plexus size was positively associated with prostate calcifications, SV volume and arterial peak systolic velocity. Lower and upper limits of SV anterior-posterior diameter after ejaculation were 6 and 16 mm, defining SV hypotrophy or dilation, respectively. SV total volume before ejaculation and delta SV total volume (DSTV) positively correlated with ejaculate volume, and DSTV correlated positively with sperm progressive motility. SV total volume after ejaculation was associated negatively with SV ejection fraction and positively with distal ampullas size. SV US abnormalities were rare. No association between TRUS and time to pregnancy, number of children or history of miscarriage was observed. CONCLUSIONS: The present findings will help in better understanding male infertility pathophysiology and the meaning of specific TRUS findings.

ACE2 Receptor and Its Isoform Short-ACE2 Are Expressed on Human Spermatozoa.

Angiotensin-converting enzyme 2 (ACE2) is a protein widely expressed in numerous cell types, with different biological roles mainly related to the renin-angiotensin system. Recently, ACE2 has been in the spotlight due to its involvement in the SARS-CoV-2 entry into cells. There are no data available regarding the expression of ACE2 and its short-ACE2 isoform at the protein level on human spermatozoa. Here, protein expression was demonstrated by western blot and the percentage of sperm displaying surface ACE2 was assessed by flow cytometry. Immunocytochemistry assays showed that full-length ACE2 was mainly expressed in sperm midpiece, while short ACE2 was preferentially distributed on the equatorial and post-acrosomal region of the sperm head. To our knowledge, this is the first study demonstrating the expression of protein ACE2 on spermatozoa. Further studies are warranted to determine the role of ACE2 isoforms in male reproduction.

Deep Resequencing of 9 Candidate Genes Identifies a Role for ARAP1 and IGF2BP2 in Modulating Insulin Secretion Adjusted for Insulin Resistance in Obese Southern Europeans.

Type 2 diabetes is characterized by impairment in insulin secretion, with an established genetic contribution. We aimed to evaluate common and low-frequency (1-5%) variants in nine genes strongly associated with insulin secretion by targeted sequencing in subjects selected from the extremes of insulin release measured by the disposition index. Collapsing data by gene and/or function, the association between disposition index and nonsense variants were significant, also after adjustment for confounding factors (OR = 0.25, 95% CI = 0.11-0.59, p = 0.001). Evaluating variants individually, three novel variants in ARAP1, IGF2BP2 and GCK, out of eight reaching significance singularly, remained associated after adjustment. Constructing a genetic risk model combining the effects of the three variants, only carriers of the ARAP1 and IGF2BP2 variants were significantly associated with a reduced probability to be in the lower, worst, extreme of insulin secretion (OR = 0.223, 95% CI = 0.105-0.473, p < 0.001). Observing a high number of normal glucose tolerance between carriers, a regression posthoc analysis was performed. Carriers of genetic risk model variants had higher probability to be normoglycemic, also after adjustment (OR = 2.411, 95% CI = 1.136-5.116, p = 0.022). Thus, in our southern European cohort, nonsense variants in all nine candidate genes showed association with better insulin secretion adjusted for insulin resistance, and we established the role of ARAP1 and IGF2BP2 in modulating insulin secretion.

Erectile dysfunction in hyperuricemia: A prevalence meta-analysis and meta-regression study.

BACKGROUND: Whether and to what extent an association exists between hyperuricemia and erectile dysfunction (ED) has not yet been fully determined. OBJECTIVE: To define pooled prevalence estimates and correlates of erectile dysfunction in men with hyperuricemic disorders. MATERIALS AND METHODS: A thorough search of Medline, Scopus, and Cochrane Library databases was performed. Data were combined using random-effects models and the between-study heterogeneity was assessed by Cochrane's Q and I2 tests. A funnel plot was used to assess publication bias. RESULTS: Overall, 8 studies included gave information about 85,406 hyperuricemic men, of whom 5023 complained of erectile dysfunction, resulting in a pooled erectile dysfunction prevalence estimate of 33% (95% Confidence Interval: 13-52%; I² = 99.9%). The funnel plot suggested the presence of a publication bias. At the meta-regression analyses, among the available covariates that could affect estimates, only type 2 diabetes mellitus was significantly associated with a higher prevalence of erectile dysfunction (ß = 0.08; 95% Confidence Interval: 0.01, 0.15, p = 0.025). At the sub-group analysis, the pooled erectile dysfunction prevalence decreased to 4% (95% Confidence Interval: 0%-8%) when only the largest studies with the lowest prevalence of type 2 diabetes mellitus were included and increased up to 50% (95% Confidence Interval: 17%-84%) when the analysis was restricted to studies enrolling smaller series with higher prevalence of type 2 diabetes mellitus. CONCLUSIONS: A not negligible proportion of men with hyperuricemia can complain of erectile dysfunction. While a pathogenetic contribution of circulating uric acid in endothelial dysfunction cannot be ruled out, the evidence of a stronger association between hyperuricemia and erectile dysfunction in type 2 diabetes mellitus points to hyperuricemia as a marker of systemic dysmetabolic disorders adversely affecting erectile function.

Association between urinary bisphenol A concentrations and semen quality: A meta-analytic study.

Although preclinical research has revealed disrupting effects on male reproductive functions of bisphenol A (BPA), as yet clinical studies have led to inconsistent results. The present meta­analysis aims to establish the existence and the extent of the association between BPA exposure and semen quality. A thorough search of PubMed, Scopus and Web of Science databases was carried out. Only studies reporting data from multivariable linear regression analyses (ß-coefficients with 95% CI), assessing the association between urinary levels of BPA and standard semen parameters were included. Nine studies provided information about an overall sample of 2,399 men. Only the negative association between urinary BPA levels and sperm motility reached statistical significance (pooled ß-coefficient = -0.82; 95% CI: -1.51 to -0.12, p = 0.02; Pfor heterogeneity = 0.1, I2 = 42.9%). Yet, such a significance was lost after data adjustment for publication bias, as well as at the sensitivity analysis, when each of the two studies that contributed most to the overall estimate was excluded. In conclusion, the overall estimates of data produced by clinical studies point to a clinically negligible, if any, association between urinary BPA concentrations and semen quality. Further studies in workers at high risk of occupational exposure are warranted to corroborate the herein revealed weak correlation with a worse sperm motility.

Risk of Venous Thromboembolism in Transgender People Undergoing Hormone Feminizing Therapy: A Prevalence Meta-Analysis and Meta-Regression Study.

Background: Although venous thromboembolism (VTE) is a recognized side effect of some formulations of estrogen therapy, its impact in transgender people remains uncertain. The aim of this study was to define pooled prevalence estimate and correlates of VTE in Assigned Males at Birth (AMAB) trans people undergoing gender affirming hormone therapy. Methods: A thorough search of MEDLINE, COCHRANE LIBRARY, SCOPUS and WEB OF SCIENCE databases was carried out to identify suitable studies. Quality of the articles was scored using the Assessment Tool for Prevalence Studies. Data were combined using random effects models and the between-study heterogeneity was assessed by the Cochrane's Q and I2. Results: The eighteen studies included gave information about 11,542 AMAB undergoing gender affirming hormone therapy. The pooled prevalence of VTE was 2% (95%CI:1-3%), with a large heterogeneity (I2 = 89.18%, P<0.0001). Trim-and-fill adjustment for publication bias produced a negligible effect on the pooled estimate. At the meta-regression analysis, a higher prevalence of VTE was significantly associated with an older age (S=0.0063; 95%CI:0.0022,0.0104, P=0.0027) and a longer length of estrogen therapy (S=0.0011; 95%CI:0.0006,0.0016, P<0.0001). When, according to the meta-regression results, the analysis was restricted to series with a mean age ≥37.5 years, the prevalence estimate for VTE increased up to 3% (95%CI:0-5%), but with persistence of a large heterogeneity (I2 = 88,2%, P<0.0001); studies on younger participants (<37.5 years) collectively produced a pooled VTE prevalence estimate of 0% (95%CI:0-2%) with no heterogeneity (I2 = 0%, P=0.97). Prevalence estimate for VTE in series with a mean length of estrogen therapy ≥53 months was 1% (95%CI:0-3%), with persistent significant heterogeneity (I2 = 84,8%, P=0.0006); studies on participants subjected to a shorter length of estrogen therapy (<53 months), collectively produced a pooled VTE prevalence estimate of 0% (95%CI:0-3%) with no heterogeneity (I2 = 0%, P=0.76). Conclusions: The overall rate of VTE in AMAB trans people undergoing gender affirming hormone therapy was 2%. In AMAB population with <37.5 years undergoing estrogen therapy for less than 53 months, the risk of VTE appears to be negligible. Further studies are warranted to assess whether different types and administration routes of estrogen therapy could decrease the VTE risk in AMAB trans people over 37.5 years subjected to long-term therapy. Systematic Review Registration: [https://www.crd.york.ac.uk/PROSPERO/], identifier [CRD42021229916].

Men with spinal cord injury have a smaller prostate volume than age-matched able-bodied men: a meta-analysis of case-control studies.

STUDY DESIGN: Meta-analysis OBJECTIVES: Denervation and androgen deficiency, peculiar to individuals with chronic spinal cord injury (SCI), could hinder, to some extent, both prostate growth and activity. To comprehensively assess the relationship between SCI and prostate volume, we carried out a meta-analysis of the available case-control studies. METHODS: A thorough search of MEDLINE, Scopus and Web of Science was carried out to identify studies comparing prostate volume in men with and without SCI. Quality of the studies was assessed using the Newcastle-Ottawa Scale (NOS). Mean differences (MDs) in prostate volume were combined using a random effect model. Funnel plot was used to assess publication bias. RESULTS: Four studies met the inclusion criteria and provided information on 278 men with SCI and 1385 able-bodied controls. The overall difference in prostate volume between the two groups reached the statistical significance (pooled MD: -14.85 ml, 95% CI: -27.10 to -2.61, p = 0.02). In a subgroup analysis including only the studies with the highest NOS score, the pooled MD remained significant (pooled MD: -18.56, 95% CI: -33.14 to -3.99, p = 0.01). The shape of funnel plot did not allow to rule out a possible publication bias. CONCLUSIONS: This meta-analysis suggests that in men with SCI, prostate volume tends to be smaller than in age-matched able-bodied men. Longitudinal studies of men with long-lasting SCI in advanced age are warranted to clarify whether this condition is associated with a lower risk of age-related prostate proliferative diseases.