Novel perspectives of testosterone therapy in men with functional hypogonadism: traversing the gaps of knowledge

INTRODUCTION

In the past decade, there has been a significant augmentation in the corpus of evidence pertaining to functional hypogonadism. Despite this, prevailing clinical guidelines continue to advise against the universal screening for hypogonadism in middle-aged and elderly males.

FINDINGS

Numerous randomized controlled trials have scrutinized the effects of testosterone therapy in males afflicted with type 2 diabetes and/or obesity. However, these guidelines uniformly assert that lifestyle modifications and weight reduction should be the primary intervention strategies in overweight and obese males, relegating testosterone therapy to a secondary, selective option. It is extensively documented that testosterone therapy can yield substantial improvements in various metabolic parameters as well as ameliorate symptoms of erectile dysfunction. Moreover, recent studies have demonstrated the potential of testosterone therapy in reversing type 2 diabetes in males with low-normal testosterone levels who are at elevated risk for this condition, in comparison to the outcomes achievable through lifestyle modifications alone.

CONCLUSION

This focused review article aims to present a comprehensive update on the latest data concerning the innovative aspects of testosterone therapy in males with functional hypogonadism, particularly in the context of type 2 diabetes and/or obesity. Additionally, it will delve into the cardiovascular safety of such interventions within this high-risk demographic, with a special emphasis on insights gleaned from the TRAVERSE trial.

Effectiveness of blood steroidal passport markers for detecting testosterone abuse in Asians

The World Anti-Doping Agency (WADA) has introduced an Athlete Biological Passport (ABP) with a steroidal module, which is intended for the monitoring of longitudinal profiles of an athlete's steroid variables in urine to identify endogenous anabolic androgenic steroids that are administered exogenously. It has been in use since 2014. The prevalence of UGT2B17 gene deletion with relatively low levels of testosterone (T) glucuronide in urine is high in the Asian region. There are cases in which urinary T is below the detection limit in specific urine samples, for example, diluted urine, urine collected from females, or urine collected from UGT2B17 deletion individuals. Additional steroid markers T, 4-androstenedione (A4), and the T/A4 ratio in serum were newly added to the ABP steroidal module by WADA in 2023 to compensate for the urine steroid profile. In this study, populations of blood steroid markers in Asians (n = 510) were investigated and classified according to UGT2B17 polymorphism to confirm the effectiveness of blood steroid markers in monitoring Asian athletes. No significant difference in the T/A4 ratio was observed between the genotypes. Furthermore, an administration study of T enanthate in females (n = 10) who were classified according to UGT2B17 genotypes was performed. The concentration of T and the T/A4 ratio were found to be significantly increased in all post-administration samples until 15 days after administration (p < 0.01). The overall results supported the high effectiveness of subject-based monitoring for serum T and T/A4 ratio for recently identified shortcomings in the detection of T abuse in Asians.

Drug-target Mendelian randomization revealed a significant association of genetically proxied metformin effects with increased prostate cancer risk

The association between metformin use and risk of prostate cancer remains controversial, while data from randomized trials is lacking. We aim to evaluate the association of genetically proxied metformin effects with prostate cancer risk using a drug-target Mendelian randomization (MR) approach. Summary statistics for prostate cancer were obtained from the Prostate Cancer Association Group to Investigate Cancer Associated Alterations in the Genome Consortium (79,148 cases and 61,106 controls). Cis-expression quantitative trait loci (cis-eQTL) variants in the gene targets of metformin were identified in the GTEx project and eQTLGen consortium. We also obtained male-specific genome-wide association study data for type 2 diabetes, body mass index (BMI), total testosterone, bioavailable testosterone, estradiol, and sex hormone binding globulin for mediation analysis. Inverse-variance weighted (IVW) regression, weighted median, MR-Egger regression, and MR-PRESSO were performed in the main MR analysis. Multivariable MR was used to identify potential mediators and genetic colocalization analysis was performed to assess any shared genetic basis between two traits of interest. We found that genetically proxied metformin effects (1-SD HbA1c reduction, equivalent to 6.75 mmol/mol) were associated with higher risk of prostate cancer (odds ratioIVW [ORIVW]: 1.55, 95% confidence interval, CI: 1.23-1.96, p = 3.0 × 10-3). Two metformin targets, mitochondrial complex I (ORIVW: 1.48, 95% CI: 1.07-2.03, p = 0.016) and gamma-secretase complex (ORIVW: 2.58, 95%CI :1.47-4.55, p = 0.001), showed robust associations with prostate cancer risk, and their effects were partly mediated through BMI (16.4%) and total testosterone levels (34.3%), respectively. These results were further supported by colocalization analysis that expressions of NDUFA13 and BMI, APH1A, and total testosterone may be influenced by shared genetic factors, respectively. In summary, our study indicated that genetically proxied metformin effects may be associated with an increased risk of prostate cancer. Repurposing metformin for prostate cancer prevention in general populations is not supported by our findings.

Inflammatory markers and androstenedione modify the effect of serum testosterone on obesity among men: Findings from a Chinese population

BACKGROUND

Few studies are available on the relationship of androstenedione with inflammation and obesity and the effect of androstenedione and inflammation on the association between testosterone and obesity. This study intended to examine the mediation effect of inflammatory markers on the association of testosterone with obesity and the moderation effect of androstenedione on the association of testosterone with inflammation and obesity in Chinese rural men.

MATERIALS AND METHODS

This cross-sectional research enrolled 2536 male rural inhabitants from the Henan Rural Cohort study. The serum concentrations of testosterone and androstenedione were determined by liquid chromatography-tandem mass spectrometry. Linear and logistic regression were used to examine the relationships between testosterone, inflammatory markers, and obesity. Mediation and moderation analyses were carried out to evaluate the potential effects of inflammatory markers on the relationship between testosterone and obesity, as well as androstenedione on the relationships of testosterone with inflammation and obesity.

RESULTS

After adjusting for confounding factors, the results showed that testosterone and androstenedione were negatively related to obesity, and inflammatory markers were positively associated with obesity. Besides, testosterone and androstenedione were negatively associated with inflammatory markers. Mediation analysis showed that white blood cell, neutrophil, monocyte, and high-sensitivity C-reactive protein had mediating effects on the association between testosterone and obesity. The most vital mediator was high-sensitivity C-reactive protein, and its proportion of the effect was 11.02% (defined by waist circumference), 11.15% (defined by waist-to-hip ratio), 12.92% (defined by waist-to-height ratio), and full mediating effect (defined by body mass index). Moreover, androstenedione played negative moderation effects on the associations of testosterone with inflammation and obesity.

CONCLUSION

Inflammatory markers and androstenedione were first found to have modifying effects on the association of testosterone with obesity. Higher levels of testosterone and androstenedione could reduce the inflammation level and risk of obesity, indicating their potential roles in the prevention and treatment of chronic diseases.

Testosterone bounce predicts favorable prognoses for prostate cancer patients treated with degarelix

BACKGROUND

To clarify the clinical roles of changes in testosterone (T) levels with a cut-off level of 20 ng/dL as predictive factors for prostate cancer patients treated with degarelix acetate.

METHODS

A total of 120 prostate cancer patients who received hormone therapies with gonadotropin-releasing hormone antagonist degarelix acetate were retrospectively analyzed. The predictive values of nadir T levels, max T levels, T bounce, and other clinical factors were evaluated for overall survival (OS), cancer-specific survival (CSS), and progression-free survival (PFS). T bounce was defined as satisfying both nadir serum T levels of <20 ng/dL and max serum T levels of ≥20 ng/dL during hormone therapies.

RESULTS

In 120 prostate cancer patients, 16 (13%) patients did not achieve nadir T < 20 ng/dL, and 76 (63%) patients had max T ≥ 20 ng/dL. The median times to nadir T and max T are 108 and 312 days, respectively. T bounce was shown in 60 (50%) patients and is associated with favorable prognoses both for OS (p = 0.0019) and CSS (p = 0.0013) but not for PFS (p = 0.92). While in the subgroup analyses of the patients with the progression of the first-line hormone therapies, T bounce predicts favorable OS (p = 0.0015) and CSS (p = 0.0013) after biochemical recurrence.

CONCLUSIONS

The present study revealed that T bounce with cut-off levels of 20 ng/dL is a promising biomarker that predicts OS and CSS for prostate cancer patients treated with degarelix acetate.

Testicular function after non-cytotoxic and immunotherapy drug treatment

BACKGROUND

The effects of novel non-cytotoxic and immunotherapy drugs for cancer treatment on human testicular function have not been studied systematically.

OBJECTIVES

The present study aimed to characterize effects of non-cytotoxic and immunotherapy drugs in patients with cancers who had not been previously treated with gonadotoxic chemo- or radiotherapy.

MATERIALS AND METHODS

This study involved 34 men, not previously treated with gonadotoxic regimens, in a mixed longitudinal (Cohort 1: 19 men about to start and approximately 1 year on non-cytotoxic and immunotherapy treatment) and cross-sectional (Cohort 2: 15 men already on non-cytotoxic and immunotherapy treatment) study using data modeling to estimate within-person time-course changes in testicular exocrine and endocrine functions. Cohort 1 provided 45 paired semen and blood samples (34 prior to and nine during treatment) and Cohort 2 provided 45 sets of samples (15 pre-treatment, 30 on treatment), including six men in Cohort 2 who had pre-treatment spermatozoa cryostorage prior to the study. Men on non-cytotoxic and immunotherapy treatment had undergone a median of 33.5 months long-term treatment.

RESULTS

Spermatozoa output and concentration were reduced by about 50%, with corresponding increases in serum follicle-stimulating hormone and decreases in serum inhibin B. Serum testosterone, luteinizing hormone, and sex hormone-binding globulin were unaffected by non-cytotoxic and immunotherapy treatment.

CONCLUSION

Within limits of the present study of sample size and duration of on-non-cytotoxic and immunotherapy treatment, non-cytotoxic and immunotherapy drugs have a modest effects on testicular exocrine function (sperm production) or its hormonal correlates (follicle-stimulating hormone, inhibin B), with minimal impact on testicular endocrine (testosterone, luteinizing hormone) function.

Peyronie's disease response to intralesional collagenase clostridium histolyticum therapy is independent of baseline testosterone

BACKGROUND

Testosterone plays an important role in collagen metabolism, transforming growth factor-β1 expression, and wound healing, which are all critical factors in pathogenesis of Peyronie's disease. Some clinical studies have suggested an association between Peyronie's disease and hypogonadism.

OBJECTIVE

We sought to investigate whether baseline total testosterone levels influence response to intralesional collagenase clostridium histolyticum in Peyronie's disease.

METHODS

A retrospective review of patients receiving collagenase clostridium histolyticum injections with available total testosterone levels within 1 year of initial injection was conducted at a single institution. Baseline demographics, hypogonadal status, total testosterone, number of collagenase clostridium histolyticum cycles, and pre- and post-treatment degrees of curvature were collected. Hypogonadism was defined as total testosterone <300 ng/dL.

RESULTS AND DISCUSSION

Thirty-six men were included with mean age of 58.2 years (SD 10.4) and mean body mass index 26.8 (SD 3.2). The mean total testosterone was 459.2 ng/dL (SD 144.0), and four (11.1%) were hypogonadal. Mean pre-treatment curvature was 47.6°, and mean post-treatment curvature was 27.8°, with mean improvement of 19.9° (40.1%). Hypogonadal status was not significantly associated with more severe curvature, 46.4° among hypogonadal men as to 57.5° among eugonadal men (p = 0.32). On linear regression analysis, total testosterone did not significantly predict improvement in degrees (β = -0.02; R2 = 0.06; p = 0.14) or percent (β = 0.0; R2 = 0.05; p = 0.18). Improvement in neither degrees nor percent differed significantly by hypogonadal status (p = 0.41 and 0.82, respectively). The cycle number did significantly predict greater improvement in curvature on both univariate and multivariate analyses (β = 5.7; R2 = 0.34; p < 0.01).

CONCLUSION

Neither total testosterone nor hypogonadism is associated with a degree of improvement after collagenase clostridium histolyticum treatment.

The chronic alcohol consumption influences the gonadal axis in men: Results from a meta-analysis

BACKGROUND

Low testosterone concentrations affect 2-13% of adult males, with a direct association between reduction in testosterone (T) concentrations and cardiovascular events. Lifestyle habits have been linked to visceral fat accumulation and endocrine disorders like secondary hypogonadism. Alcohol intake has also been a topic of debate, with studies showing a detrimental effect on sperm production and underlying mechanisms. This meta-analysis aims to comprehensively evaluate the effect of alcohol consumption on T serum concentrations in adult men.

METHODS

The literature search included only controlled clinical trials comparing men who drink alcohol to men who do not, or who assumed placebo or nonalcoholic beverages. The primary outcome was the comparison of total testosterone serum concentrations between the study and control groups. The publications were examined for publication bias using Egger's test.

RESULTS

Twenty-one studies were included in the analysis for a total of 30 trials that examined the effects of alcohol consumption on testosterone level in 10,199 subjects. The meta-analysis showed that alcohol consumption overall is related to significant reduction in circulating concentrations of total testosterone (mean difference [MD] = -4.02; 95% CI -6.30, -1.73), free T (MD = -0.17; 95% CI -0.23, -0.12), sex hormone binding globulin (SHBG) (MD = -1.94; 95% CI -3.37, -0.48), an increase in estradiol (E2) (MD = 7.65; 95% CI 1.06, 14.23) and neutral effect on luteinizing hormone (LH) (MD = -0.15; 95% CI -0.36, 0.06), independently by age, body mass index (BMI), E2, and LH serum concentrations and alcohol intake. However, these results are evident only in healthy men exposed to chronic alcohol consumption and not in those with a recognized diagnosis of alcohol use disorder or after acute alcohol intake.

CONCLUSION

This study suggests how chronic alcohol consumption may inhibit the gonadal axis in healthy men, although the exact pathophysiological mechanisms connecting alcohol exposure and steroidogenesis are still not completely clarified.

Effect of Testosterone on the Thyroarytenoid Muscle and Lamina Propria of Female Rat Vocal Folds

OBJECTIVE

To analyze the effects of androgen therapy on the thyroarytenoid (TA) muscle, expression of androgen receptors (ARs) and hyaluronic acid (HA) concentration in the vocal folds (VFs) of adult female rats.

METHODS

Twenty-one adult female Wistar rats were divided into experimental and control groups. The experimental group received weekly intramuscular injections of nandrolone decanoate for 9 weeks. Following euthanasia and dissection of the VFs, histomorphometric analysis of the TA muscle, immunohistochemical evaluation of ARs, and measurement of HA concentration using the ELISA-like fluorimetric method were performed.

RESULTS

The experimental group exhibited a significantly larger mean fiber cross-sectional area in the TA muscle compared to the control group (434.3 ± 68.6 μm2 versus 305.7 ± 110.1 μm2; p = 0.029), indicating muscle hypertrophy. There was no significant difference in the number of muscle fibers. The experimental group showed higher expression of ARs in the lamina propria (62.0% ± 30.3% versus 22.0% ± 22.8%; p = 0.046) and in the TA muscle (45.0% ± 22.6% versus 18.3% ± 9.8%; p = 0.024). There was no significant difference in the concentration of HA.

CONCLUSION

Exposure of adult female rats to androgen therapy resulted in hypertrophy of the TA muscle and increased expression of ARs in the VFs. The TA muscle seems to be the primary target of testosterone action in the VF, and the up-regulation of ARs might contribute to the persistent deepening of the voice.

LEVEL OF EVIDENCE

NA Laryngoscope, 134:2316-2321, 2024.

Chronic intermittent hypoxia-induced hypertension: the impact of sex hormones

Obstructive sleep apnea, a common form of sleep-disordered breathing, is characterized by intermittent cessations of breathing that reduce blood oxygen levels and contribute to the development of hypertension. Hypertension is a major complication of obstructive sleep apnea that elevates the risk of end-organ damage. Premenopausal women have a lower prevalence of obstructive sleep apnea and cardiovascular disease than men and postmenopausal women, suggesting that sex hormones play a role in the pathophysiology of sleep apnea-related hypertension. The lack of protection in men and postmenopausal women implicates estrogen and progesterone as protective agents but testosterone as a permissive agent in sleep apnea-induced hypertension. A better understanding of how sex hormones contribute to the pathophysiology of sleep apnea-induced hypertension is important for future research and possible hormone-based interventions. The effect of sex on the pathophysiology of sleep apnea and associated intermittent hypoxia-induced hypertension is of important consideration in the screening, diagnosis, and treatment of the disease and its cardiovascular complications. This review summarizes our current understanding of the impact of sex hormones on blood pressure regulation in sleep apnea with a focus on sex differences.

Efficacy, tolerability, and safety of teverelix DP in patients with advanced prostate cancer: A multicenter, open-label, phase 2 trial

BACKGROUND

Teverelix drug product (DP) is a novel injectable gonadotropin-releasing hormone antagonist.

METHODS

An adaptive phase 2, open-label, multicenter trial was conducted in patients with advanced prostate cancer to evaluate the efficacy and safety of a combined subcutaneous (SC) and intramuscular (IM) loading dose regimen of teverelix DP of 120 mg SC + 120 mg IM (Group 1; N = 9) or 180 mg SC + 180 mg IM (Group 2; N = 41) administered at a single visit, followed by 6-weekly SC maintenance doses of 120 mg (Group 1) or 180 mg (Group 2), up to Day 168. The primary endpoint was the proportion of patients achieving castration levels with serum testosterone <0.5 ng/mL at Day 28 with a target castration rate of 90%. Injection sites were inspected by the investigator at every visit and reactions (ISRs) were proactively recorded.

RESULTS

The target castration rate was reached in Group 2 (97.5%) but not in Group 1 (62.5%). The castration rates were not maintained to Day 42 (Group 2: 82.5%; Group 1: 50.0%). Suppression of testosterone to castrate levels occurred rapidly (median time: 2 days for both groups). Suppression of testosterone, prostate-specific antigen, follicle-stimulating hormone, and luteinizing hormone was sustained throughout the treatment period, being more prominent with the higher dose. The adverse event (AE) profile was similar between groups. The most common AEs were injection-site induration (n = 40: 80.0%), injection-site erythema (n = 35: 70.0%), and hot flush (n = 21: 42.0%). Most ISRs were Grade 1.

CONCLUSION

Overall, the teverelix DP doses were generally well-tolerated but did not adequately maintain castration levels.

Deoxynivalenol Inhibits Progenitor Leydig Cell Development by Stimulating Mitochondrial Fission in Rats

Deoxynivalenol (DON) is a common food contaminant that can impair male reproductive function. This study investigated the effects and mechanisms of DON exposure on progenitor Leydig cell (PLC) development in prepubertal male rats. Rats were orally administrated DON (0-4 mg/kg) from postnatal days 21-28. DON increased PLC proliferation but inhibited PLC maturation and function, including reducing testosterone levels and downregulating biomarkers like HSD11B1 and INSL3 at ≥2 mg/kg. DON also stimulated mitochondrial fission via upregulating DRP1 and FIS1 protein levels and increased oxidative stress by reducing antioxidant capacity (including NRF2, SOD1, SOD2, and CAT) in PLCs in vivo. In vitro, DON (2-4 μM) inhibited PLC androgen biosynthesis, increased reactive oxygen species production and protein levels of DRP1, FIS1, MFF, and pAMPK, decreased mitochondrial membrane potential and MFN1 protein levels, and caused mitochondrial fragmentation. The mitochondrial fission inhibitor mdivi-1 attenuated DON-induced impairments in PLCs. DON inhibited PLC steroidogenesis, increased oxidative stress, perturbed mitochondrial homeostasis, and impaired maturation. In conclusion, DON disrupts PLC development in prepubertal rats by stimulating mitochondrial fission.

SHBG gene polymorphisms and their influence on serum SHBG, total and free testosterone concentrations in men

CONTEXT

Genetic variation in sex hormone-binding globulin (SHBG) structure may affect estimates of sex steroid exposure by altering the affinity of the protein for its ligand. Consequently, free hormone calculations assuming constant binding affinity may, for certain genetic variations, lead to incorrect diagnoses if genetic variation is not taken into consideration.

OBJECTIVE

To investigate the effects of genetic variation in SHBG on calculated and measured serum free testosterone (T) in men.

DESIGN, SETTING AND PARTICIPANTS

Population-based sibling-pair study in 999 healthy men aged 25 to 45 (mean: 34.5) years.

MAIN OUTCOME MEASURES

Genotyping using microarray (Illumina®) for SNPs suggested to affect binding affinity and/or concentration of SHBG or T. SHBG concentrations were measured using immunoassay and in a subset (n = 32) by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Total T was measured using LC-MS/MS. Free T was calculated and in a subset (n = 314) measured directly using LC-MS/MS after equilibrium dialysis.

RESULTS

Allelic frequencies of analyzed SNPs ranged from 0.5% to 58.2%. Compared to wild-type, SHBG concentrations were lower in rs6258 heterozygotes (-24.7%; p < 0.05) and higher in rs6259 heterozygotes, rs727428 homozygotes, and carriers of rs1799941 (+10.8 to 23.1%; all p < 0.05). Total T was higher in rs727428 homozygotes and carriers of rs5934505, rs1799941and rs6259 (+3.9 to 21.4%; all p < 0.05). No clear effects on measured free T were found, except for a trend towards higher values in rs6259 homozygotes, significant for calculated free T (+18.7%; p < 0.05) in the larger global study population.

CONCLUSION

In these men, analyzed SNPs were relatively prevalent and affected serum concentrations of total T and SHBG but not calculated or measured free T except for a higher trend in rs6259 homozygotes.

Serum testosterone levels and oxidative stress in type 1 diabetes, type 2 diabetes, and obesity

INTRODUCTION

Obesity, type 1 diabetes mellitus (T1DM), and type 2 diabetes mellitus (T2DM) are metabolic diseases that continue to be a global problem. Testosterone levels in men are affected by several factors, including obesity and DM. Although the relationship between diabetes and testosterone is not fully understood, oxidative stress is thought to play a major role. The aim of this study was to compare serum testosterone levels and oxidative stress markers [total antioxidant status (TAS), total oxidant capacity (TOS), oxidative stress index (OSI), and ischaemic modified albumin (IMA)] among the control group and experimentally induced obese, T1DM, and T2DM rats.

MATERIAL AND METHODS

The study included 28 male Sprague-Dawley rats divided into 4 groups: the obesity group were fed a high-fat diet (HFD), the T2DM group received a HFD plus a single dose of streptozocin (STZ), the T1DM group received only STZ, and there was a control group. Serum testosterone, TAS, TOS, OSI, and IMA were analysed.

RESULTS

Serum testosterone levels were lower in the T1DM and T2DM groups compared to the control and obesity groups. The TOS levels were highest in the T2DM group, followed by the T1DM group, the obesity group, and finally the control group. No significant difference was found between the obesity group and the control group in terms of TOS levels. Regarding TAS levels, the order observed was control group > obesity group > T2DM > T1DM. Testosterone was positively correlated with TAS and negatively correlated with TOS and OSI.

CONCLUSIONS

Increased oxidative stress in diabetes may be an important factor that decreases serum testosterone levels.

Erythrocytosis Is Rare With Exogenous Testosterone in Gender-Affirming Hormone Therapy

CONTEXT

Studies have found a variable incidence of erythrocytosis among people using testosterone as part of gender-affirming hormone therapy (GAHT).

OBJECTIVE

To examine the effect of using exogenous testosterone as GAHT on hematocrit in a large North American cohort.

METHODS

We conducted a cross-sectional analysis of testosterone and hematocrit laboratory values in 6670 patients who were prescribed testosterone through Plume, a national provider of GAHT. The prevalence of erythrocytosis, the mean hematocrit at predetermined testosterone thresholds and with varying routes of testosterone administration were assessed.

RESULTS

Among 6670 individuals, 560 (8.4%) had a hematocrit ≥50%, 182 ≥ 52% (2.7%), and 60 ≥ 54% (0.9%). There was significant variation (P < .001) in hematocrit between different clinically relevant testosterone thresholds (T < 50 vs T 50-299 vs T 300-999 vs T ≥ 1000 ng/dL) and when comparing serum testosterone in increments of 50 ng/dL within the target range for males (300-1000 ng/dL) (P < .001). Mean hematocrit ranged from 41.84% (T < 50 ng/dL) to 45.68% (T 900-949 ng/dL). Patients on intramuscular testosterone had a higher mean hematocrit than those on transdermal testosterone (44.96% vs 43.41%, P < .001). Both route of administration (P < .001) and testosterone level (P < .001) had statistically significant associations with hematocrit when controlling for each other.

CONCLUSION

While the magnitude of change in hematocrit with serum level and route of administration of testosterone was statistically significant, the absolute levels were within the normal range, unlikely to be clinically meaningful. These findings, along with the low prevalence of erythrocytosis, should help allay concerns about the use of testosterone as GAHT.

Lower malathion concentrations reduce testosterone biosynthesis by Leydig TM3 cells in vitro by altering cellular redox profile and inducing oxidative damage

Malathion is an organophosphate pesticide used in agriculture and control of the Aedes aegypti mosquito. As previous reports have indicated the potential of malathion to compromise testosterone production in in vivo models, the objective of this study was to elucidate the mechanisms underlying the impairment of Leydig cell function, considering its critical role in male reproductive function. To this end, murine Leydig TM3 cells were exposed to concentrations of 1, 10, 100 or 1000μM malathion for 24hours for evaluation of the compound on cell viability. Subsequently, concentrations of 1, 10, and 100μM malathion were employed for a 24-hour period to assess testosterone biosynthesis, levels of cytokines IL-1β, IL-6, IL-10, and TNF-α, as well as the redox profile. Malathion exerted a concentration-dependent impact on cell viability. Notably, the lower concentrations of malathion (1 and 10μM) were found to impair testosterone biosynthesis in TM3 cells. While there were changes in IL-1 and TNF-α levels at specific concentrations, no direct correlation with altered hormone production was established. Our investigation revealed that varied malathion concentrations induced oxidative stress by increase in superoxide anion and a compensatory rise in antioxidants. In conclusion, the observed changes in the oxidative profile of TM3 cells were linked to functional impairment, evidenced by reduced testosterone biosynthesis at lower malathion concentrations.

Inhibition of inosine metabolism of the gut microbiota decreases testosterone secretion in the testis

Growing evidence indicates that gut microbiota is involved in the regulation of the host's sex hormone levels, such as through interfering with the sex hormone metabolism in the intestine. However, if gut microbiota or its metabolites directly influence the sex hormone biosynthesis in the gonad remains largely unknown. Our previous study showed that colistin, as a narrow-spectrum antibiotic, can significantly downregulate the serum testosterone levels and thus enhance the antitumor efficiency of anti-PD-L1 in male mice; however, the underlying mechanism for the regulation of the host's testosterone levels remains uninvestigated. In the present study, we analyzed the impact of colistin on the immune microenvironment of the testis as well as the composition and metabolism of gut microbiota in male mice. Our results showed that colistin has an impact on the immune microenvironment of the testis and can downregulate serum testosterone levels in male mice through inhibition of Akkermansia, leading to destroyed inosine metabolism. Supplement with inosine can restore testosterone secretion probably by prompting the recovery of the intestinal mucus barrier and the serum lipopolysaccharides levels. All these findings reveal a new pathway for the regulation of the host's sex hormone levels by gut microbiota.IMPORTANCEThis study demonstrates that exposure to even narrow-spectrum antibiotics may affect the host's testosterone levels by altering the gut microbiota and its metabolites. Our findings provide evidence that some specific gut bacteria have an impact on the sex hormone biosynthesis in the testis.

Assessing men with opioid use disorder for testosterone deficiency after the development of symptoms

OBJECTIVE

Individuals with opioid use disorder (OUD) have reduced life expectancy and inferior outcomes when treated for depression, diabetes, and fractures. Their elevated risk of testosterone deficiency may contribute to all of these relationships, however few individuals prescribed opioids are evaluated with testosterone assays. The purpose of this study is to determine whether patients with opioid use disorder are evaluated for testosterone deficiency after development of a symptom that may merit investigation, such as erectile dysfunction (ED).

METHOD

We conducted a retrospective longitudinal cohort study that utilized data from a national database called TriNetX. Patients were eligible for inclusion if they were 20 to 90 years of age, male, and diagnosed with erectile dysfunction. We utilized descriptive statistics and logistic regression to address study aims.

RESULTS

Testosterone testing was uncommon for all patients with ED. Among 20,658 patients, it was assessed in 11.2% with OUD and 15.1% without OUD. Among those screened, 40% individuals with OUD and ED had testosterone deficiency. Odds of screening those with OUD were lower than matched controls (RR 0.74).

CONCLUSIONS

Individuals with OUD are at increased risk of testosterone deficiency than the general population, but nearly 90% are not evaluated for this condition even after development symptoms. That 40% of individuals assessed were classified as testosterone deficient suggests endocrine disorders may be contributing to increased fracture risk, chronic pain, and severe depression commonly encountered in patients with OUD. Addressing this care gap may reduce morbidity and mortality associated with opioid use disorder.

Chronotype changes after sex hormone use: A prospective cohort study in transgender users of gender-affirming hormones

Chronotype, an individual's preferred sleep-wake timing, is influenced by sex and age. Men sometimes report a later chronotype than women and older age is associated with earlier chronotype. The sex-related changes in chronotype coincide with puberty and menopause. However, the effects of sex hormones on human chronotype remain unclear. To examine the impact of 3 months of gender-affirming hormone therapy (GAHT) on chronotype in transgender persons, this study used data from 93 participants from the prospective RESTED cohort, including 49 transmasculine (TM) participants starting testosterone and 44 transfeminine (TF) participants starting estrogens and antiandrogens. Midpoint of sleep and sleep duration were measured using the ultra-short Munich ChronoType Questionnaire (µMCTQ). After 3 months of GAHT, TM participants' midpoint of sleep increased by 24 minutes (95% CI: 3 to 45), whereas TF participants' midpoint of sleep decreased by 21 minutes (95% CI: -38 to -4). Total sleep duration did not change significantly in either group. This study provides the first prospective assessment of sex hormone use and chronotype in transgender persons, showing that GAHT can change chronotype in line with cisgender sex differences. These findings provide a basis for future studies on biological mechanisms and clinical consequences of chronotype changes.

Metabolic effects of testosterone added to intensive lifestyle intervention in older men with obesity and hypogonadism

BACKGROUND

Whether testosterone replacement therapy (TRT) conveys additional cardiometabolic benefit to an intensive lifestyle therapy (LT) in older men with obesity and hypogonadism remains unclear.

OBJECTIVE

To determine whether TRT augments the effect of LT on metabolic outcomes in older men with obesity and hypogonadism.

DESIGN

Secondary analysis of a randomized, double-blind, placebo-controlled trial.

SETTING

Veterans Affairs Medical Center.

PARTICIPANTS

83 older (age ≥ 65 years) men with obesity (BMI ≥ 30 kg/m2) and persistently low AM testosterone (< 10.4 nmol/L) associated with frailty.

INTERVENTIONS

LT (weight management and exercise training) plus either testosterone (LT+TRT) or placebo (LT+Pbo) for six months.

OUTCOME MEASURES

Primary outcome was change in glycated hemoglobin (HbA1c). Secondary outcomes included changes in other glucometabolic and lipid profile components, liver enzymes, inflammatory markers, adipokines; subcutaneous, visceral, intramuscular, and hepatic fat; blood pressure, and metabolic syndrome score.

RESULTS

HbA1c decreased similarly in LT+TRT and LT+Pbo groups (-0.5% vs. -0.6%, respectively; p= 0.35). While TRT showed no synergistic effect with LT on ameliorating secondary outcomes, it eliminated the augmentative effect of LT on high-density lipoprotein cholesterol concentration (5.4 ± 1.0 mg/dL in LT+Pbo group vs. 0.2 ± 1.1 mg/dL in LT+TRT group, p= 0.01) and adiponectin levels (-408 ± 489 ng/mL in TRT+LT group vs 1832 ± 468 ng/mL in LT+Pbo group, p= 0.02).

CONCLUSION

In older men with obesity and hypogonadism, adding TRT for six months to LT does not result in further improved cardiometabolic profiles, and could potentially blunt some of the metabolic benefits induced by LT.

Excessive androgen exposure and risk of malignancies: A cohort study

BACKGROUND

A link between androgen use and the risk of cancers, especially prostate and breast cancer, has been suggested. The knowledge about a possible association is limited.

OBJECTIVE

The study aimed to investigate cancer incidence rates, particularly those related to prostate and breast cancer, in male androgen users and compare them to a control group.

METHODS

We included male androgen users identified through a nationwide anti-doping testing program in Danish fitness centers from 2006 to 2018. We paired each case with 50 male controls of the same age, selected randomly. The cohort was followed from baseline and until 2023. The outcome was the incidence of prostate cancer, breast cancer, or any cancer excluding non-melanoma skin cancer.

RESULTS

The study included 1,189 androgen users and 59,450 controls, with a mean age of 27 years at enrolment. During the follow-up period with a mean length of 11 years, 13 androgen users, and 612 controls were diagnosed with cancer. This resulted in an incidence rate ratio of 1.05 (95% CI: 0.55-1.81). None of the androgen users were diagnosed with prostate or breast cancer.

DISCUSSION AND CONCLUSION

Male androgen users did not face an increased short-term risk of cancer, neither overall nor related to prostate or breast cancer. Our study indicates that the absolute risk of malignancies in androgen users is comparable to that in the background population. However, we cannot exclude androgens as a cancer risk factor due to the limited sample size, relatively short follow-up period, and subject age.

Associations between sex hormones, receptors, binding proteins and inflammatory bowel disease: a Mendelian randomization study

Background

Gender differences existed in inflammatory bowel disease (IBD), including Crohn's disease (CD) and ulcerative colitis (UC). Observational studies have revealed associations between sex hormones and IBD, such as estrogen and testosterone. However, the exact relationship between these sex hormones and IBD is unclear.

Method

Based on the genome-wide association studies data of eight sex hormones, two sex hormone receptors, sex hormone-binding globulin (SHBG), total IBD and its two subtypes, we performed a two-sample Mendelian randomization (MR) study to analyze their mutual relationship. For estradiol (E2), progesterone (PROG), bioavailable testosterone (BAT), total testosterone (TT) and SHBG, sex-stratified MR analyses were also performed. Inverse variance weighted method, MR-Egger regression and Weighted median method were used for causal analyses. Sensitivity analyses were conducted to test the stability of causal relationships. Besides, a reverse MR analysis was performed to estimate the reverse causation.

Results

E2 (P=0.028) and TT (P=0.034) had protective effects on CD. Sex-stratified analyses revealed protective roles of E2 in males on total IBD (P=0.038) and CD (P=0.020). TT in females had protective effects on total IBD (P=0.025) and CD (P=0.029), and BAT in females decreased the risk of developing CD (P=0.047) and UC (P=0.036). Moreover, SHBG in males was also associated with a decreased risk of CD (P=0.021). The reversed MR analysis showed that CD was negatively correlated with estrogen receptor (P=0.046). UC was negatively correlated with PROG in females (P=0.015) and positively correlated with SHBG levels in males (P=0.046).

Conclusion

Findings of this study revealed the mutual causal associations between sex hormones and the risk of developing IBD.

Lower pretreatment serum testosterone level predicts poor prognosis in the patients with metastatic hormone-sensitive prostate cancer undergoing androgen deprivation therapy

OBJECTIVE

This study aimed to reveal the association between pretreatment serum testosterone levels and prognosis in patients with metastatic hormone-sensitive prostate cancer treated with androgen deprivation therapy.

METHODS

A total of 91 patients were included in this retrospective study. Clinical data were obtained through chart review. Multivariate cox proportional hazards analyses addressed the impact of variables on castration-resistant prostate cancer-free and overall survivals.

RESULTS

During a median follow-up of 41.7 months, 61 (67%) and 49 (54%) patients developed castration-resistant prostate cancer and died, respectively. The median castration-resistant prostate cancer-free and overall survivals were 15.5 and 59.9 months, respectively. The cutoff value for discriminating between low- and high-testosterone levels was determined as 450 ng/dl by calculating the receiver operating characteristic curve. Patients in the low-testosterone group (n = 37) had a significantly higher body mass index, worse comorbidities represented by the higher Charlson comorbidity index and higher serum lactate dehydrogenase levels, than those in the high-testosterone group (n = 54). Castration-resistant prostate cancer free and overall survivals were significantly shorter in the low-testosterone group than in the high-testosterone group (P = 0.021 and P < 0.001, respectively). Multivariate analysis identified testosterone level of <450 ng/dl as an independent factor predicting development of castration-resistant prostate cancer (hazard ratio 2.28, P = 0.007), along with high-volume disease and Gleason score 9-10. Similarly, testosterone level of <450 ng/dl was independently associated with shorter overall survival (hazard ratio 2.84, P = 0.006), along with higher Charlson comorbidity index, visceral metastasis and higher alkaline phosphatase level.

CONCLUSIONS

Lower baseline serum testosterone levels predict poor prognosis in patients with metastatic hormone-sensitive prostate cancer.

Towards a Robust Definition of Sport Sex

Elite individual sports in which success depends on power, speed or endurance are conventionally divided into male and female events using traditional binary definitions of sex. Male puberty creates durable physical advantages due to the 20-30-fold increase in circulating testosterone producing a sustained uplift in men's muscle, bone, hemoglobin, and cardiorespiratory function resulting from male puberty and sustained during men's lives. These male physical advantages provide strong justification for separate protected category of female events allowing women to achieve the fame and fortune from success they would be denied if competing against men. Recent wider social acceptance of transgender individuals, together with the less recognized involvement of intersex (46 XY DSD) individuals, challenge and threaten to defeat the sex classifications for elite individual female events. This can create unfair advantages if seeking inclusion into elite female events of unmodified male-bodied athletes with female gender identity who have gained the physical advantages of male puberty. Based on reproductive physiology, this paper proposes a working definition of sport sex based primarily on an individual's experience of male puberty and can be applied to transgender and various XY intersex conditions. Consistent with the multidimensionality of biological sex (chromosomal, genetic, hormonal, anatomical sex), this definition may be viewed as a multistrand cable whose overall strength survives when any single strand weakens or fails, rather than as a unidimensional chain whose strength is only as good as its weakest link.

Erectile Dysfunction as an Obesity-Related Condition in Elderly Men with Coronary Artery Disease

Background: This cross-sectional study aimed to investigate the prevalence of erectile dysfunction (ED) in elderly men with overweight or obesity and coronary artery disease. Methods: Patients recruited in cardiac rehabilitation centers post-myocardial infarction provided demographic and anthropomorphic data. ED was assessed using the abbreviated International Index of Erectile Function 5 (IIEF-5) Questionnaire. Results: The study included 661 men with a mean age of 67.3 ± 5.57 years, a mean BMI of 27.9 ± 3.6 m/kg2, and a mean waist circumference of 98.9 ± 10.23 cm. Over 90% of men experienced ED, with similar proportions across BMI categories. The development of ED in men with a waist circumference of ≥100 cm had 3.74 times higher odds (OR 3.74; 95% CI: 1.0-13.7; p = 0.04) than in men with a waist circumference of <100 cm. Men with obesity and moderate-to-severe and severe ED were older compared to those without these disorders (67.1 ± 5.29 vs. 65.3 ± 4.35; p = 0.23). Conclusions: The prevalence of ED in men with coronary artery disease surpasses 90%. An increased body weight raises the risk of ED, with waist circumference proving to be a more reliable predictor of this risk compared to BMI. Physicians are encouraged to screen elderly patients with cardiovascular disease for ED and address obesity to enhance overall health.

Testosterone does not mediate the correlation between dietary inflammation and serum klotho levels among males: insights from NHANES database

Introduction

Serum Klotho (S-Klotho) is a transmembrane protein holds pivotal roles in anti-aging. The Dietary Inflammation Index (DII), a meticulously dietary tool, quantifies the inflammatory potential of an individual's diet. The existing research strongly suggests that a low DII diet plays a significant role in delaying aging and reducing aging-related symptoms in males. Testosterone could potentially act as a mediating intermediary between DII and S-Klotho. However, this aspect remains unexplored. This study aims to investigate the potential causal link of testosterone between DII and S-Klotho in males.

Methods

We utilized data from National Health and Nutrition Examination Survey (NHANES) which focused on male participants from 2013-2016. Mediation analyses were used to investigate the effects of testosterone (TT), free testosterone (FT), and free androgen index (FAI) on the DII-S-Klotho relationship, using three modes adjusting for covariates.

Results

Mediation analysis unveiled a significant inverse correlation between DII and S-Klotho levels (model 1: c = -14.78, p = 0.046). The interaction between DII and S-Klotho was modulated by TT in model 1 (ab = -1.36; 95% CI: -5.59, -0.55; p = 0.008), but lost significance after adjustments (model 2: ab = -0.39; 95% CI: -4.15, 1.66; p = 0.378; model 3: ab = -0.59; 95% CI: -4.08, 2.15; p = 0.442). For FT, the mediating impact was not statistically significant (model 1: ab = 0.43; 95% CI: -0.51, 5.44; p = 0.188; model 2: ab = 0.72; 95% CI: -0.26, 5.91; p = 0.136; model 3: ab = 0.84; 95% CI: -0.02, 8.06; p = 0.056). Conversely, FAI consistently influenced the DII-S-Klotho relationship (model 1: ab = 2.39; 95% CI: 0.69, 9.42; p = 0.002), maintaining significance after adjustments (model 2: ab = 3.2; 95% CI: 0.98, 11.72; p = 0.004; model 3: ab = 3.15; 95% CI: 0.89, 14.51; p = 0.026).

Discussion

This study observed no mediating influence of TT or FT on the correlation between DII and S-Klotho after covariate control. Remarkably, FAI continued to significantly mediate the DII-S-Klotho connection even following covariate adjustment, although its significance in males warrants careful consideration.

Trans men can achieve adequate muscular development through low-dose testosterone therapy: A long-term study on body composition changes

BACKGROUND

Transgender individuals undergo the gender-affirming hormone therapy (GAHT) to achieve physical changes consistent with their gender identity. Few studies are available on the long-term safety and efficacy of GAHT.

OBJECTIVES

To investigate the long-term physical effects and the safety of the testosterone therapy for trans men and to assess the impact of differential hormone dose.

MATERIALS AND METHODS

Trans men who initiated GAHT between May 2000 and December 2021 were included in this retrospective analysis. Physical findings (body mass index, body fat percentage (BFP), lean body mass (LBM), and grip strength), blood testing results (hemoglobin, hematocrit, uric acid, creatinine, total cholesterol, triglycerides, and total testosterone), and menstrual cessation were recorded. We assessed the effects of testosterone on body composition changes and laboratory parameters, comparing a low-dose group (≤ 62.5 mg/wk) to a high-dose group (> 62.5 mg/wk).

RESULTS

Of 291 participants, 188 patients (64.6%) were in the low-dose group and 103 (35.4%) in the high-dose group. Cumulative menstrual cessation rates up to 12 months were not significantly different between groups. Both groups showed a decrease in BFP and an increase in LBM during the first year of therapy, followed by a slight increase in both over the long term. The high-dose group exhibited greater LBM gains during the first year. Higher hormone doses and lower initial LBM values were associated with LBM increases at 3 and 6 months (3 mo, P = 0.006, P < 0.001; 6 mo, P = 0.015, P < 0.001). There were no long-term, dose-dependent side effects such as polycythemia or dyslipidemia.

CONCLUSION

Long-term GAHT for trans men is safe and effective. Low-dose testosterone administration is sufficient to increase LBM in trans men. Higher testosterone doses can lead to an earlier increase in muscle mass.

Evaluating relugolix for the treatment of prostate cancer in real-world settings of care: the OPTYX study protocol

OPTYX is a multi-center, prospective, observational study designed to further understand the actual experience of patients with advanced prostate cancer treated with relugolix (ORGOVYX®), an oral androgen deprivation therapy (ADT), by collecting clinical and patient-reported outcomes from routine care settings. The study aims to enroll 1000 consented patients with advanced prostate cancer from community, academic and government operated clinical practices across the USA. At planned timepoints, real-world data analysis on treatment patterns, adherence and safety as well as health outcomes and health-related quality-of-life (HRQOL) after treatment discontinuation will be published in scientific peer-reviewed journals and presented at relevant conferences. This study will provide real-world data for practitioners and researchers in their understanding of the safety and effectiveness of relugolix. Clinical Trial Registration: NCT05467176 (ClinicalTrials.gov).

Association between Fish Intake and Serum Testosterone Levels in Older Males: The Hitachi Health Study II

Background

Fish are rich in omega-3 polyunsaturated fatty acids and vitamin D, which can promote testosterone synthesis and secretion. However, some contaminants present in fish may disrupt testosterone production.

Objective

This study aimed to investigate the association between fish intake (total, fatty, and lean fish) and serum testosterone levels in older males.

Methods

This cross-sectional study included 1545 Japanese males aged 60-69 y who participated in the baseline survey of the Hitachi Health Study II. Fish intake was estimated using a validated brief-type self-administered diet history questionnaire. Total testosterone levels were measured by chemiluminescence immunoassay. Multivariable linear regression analysis was used to analyze the association between fish intake and serum testosterone levels.

Results

Higher total fish intake was associated with higher levels of serum testosterone, with an adjusted mean [95% confidence interval (CI) of 5.63 (5.43, 5.83) and 5.99 (5.78, 6.20)] ng/mL for the 1st and 4th quartiles of total fish intake, respectively (P for trend = 0.06). When analyzing fatty and lean fish separately, higher intake of lean fish, but not fatty fish, was associated with higher levels of serum testosterone: adjusted mean (95% CI): 5.63 (5.43, 5.82) and 6.00 (5.79, 6.20) ng/mL for the 1st and 4th quartiles of lean fish intake, respectively (P for trend = 0.01).

Conclusions

Among older males, higher intake of total fish, particularly lean fish, was associated with higher serum testosterone levels. Curr Dev Nutr 20xx;x:xx.

Plasma steroid concentrations reflect acute disease severity and normalise during recovery in people hospitalised with COVID-19

OBJECTIVE

Endocrine systems are disrupted in acute illness, and symptoms reported following coronavirus disease 2019 (COVID-19) are similar to those found with clinical hormone deficiencies. We hypothesised that people with severe acute COVID-19 and with post-COVID symptoms have glucocorticoid and sex hormone deficiencies.

DESIGN/PATIENTS

Samples were obtained for analysis from two UK multicentre cohorts during hospitalisation with COVID-19 (International Severe Acute Respiratory Infection Consortium/World Health Organisation [WHO] Clinical Characterization Protocol for Severe Emerging Infections in the UK study), and at follow-up 5 months after hospitalisation (Post-hospitalisation COVID-19 study).

MEASUREMENTS

Plasma steroids were quantified by liquid chromatography-mass spectrometry. Steroid concentrations were compared against disease severity (WHO ordinal scale) and validated symptom scores. Data are presented as geometric mean (SD).

RESULTS

In the acute cohort (n = 239, 66.5% male), plasma cortisol concentration increased with disease severity (cortisol 753.3 [1.6] vs. 429.2 [1.7] nmol/L in fatal vs. least severe, p < .001). In males, testosterone concentrations decreased with severity (testosterone 1.2 [2.2] vs. 6.9 [1.9] nmol/L in fatal vs. least severe, p < .001). In the follow-up cohort (n = 198, 62.1% male, 68.9% ongoing symptoms, 165 [121-192] days postdischarge), plasma cortisol concentrations (275.6 [1.5] nmol/L) did not differ with in-hospital severity, perception of recovery, or patient-reported symptoms. Male testosterone concentrations (12.6 [1.5] nmol/L) were not related to in-hospital severity, perception of recovery or symptom scores.

CONCLUSIONS

Circulating glucocorticoids in patients hospitalised with COVID-19 reflect acute illness, with a marked rise in cortisol and fall in male testosterone. These findings are not observed 5 months from discharge. The lack of association between hormone concentrations and common post-COVID symptoms suggests steroid insufficiency does not play a causal role in this condition.

Incidence of breakthrough bleeding in transgender and gender-diverse individuals on long-term testosterone

BACKGROUND

Little is known about the maintenance of amenorrhea among transgender and gender-diverse individuals with uteri who are using long-term testosterone gender-affirming hormone therapy. Emerging data describe breakthrough bleeding among adolescents on long-term testosterone therapy and among adults who are seeking a gender-affirming hysterectomy. More studies are needed to better understand breakthrough bleeding patterns among transgender and gender-diverse individuals with uteri who are using testosterone, including the frequency, timing, and etiology of bleeding and how these patterns may differ between adults and younger populations.

OBJECTIVE

The primary aim of this study was to characterize the incidence and patterns of breakthrough bleeding in a cohort of transgender and gender-diverse individuals who had been on testosterone for longer than 12 months and who had uteri in situ. Secondary aims included identifying the time to first bleed for those who experienced breakthrough bleeding and the risk factors associated with breakthrough bleeding while on testosterone therapy.

STUDY DESIGN

This was an institutional review board-approved, single tertiary center, retrospective chart review of transgender and gender diverse individuals who had been on testosterone for at least 1 year. A primary survival analysis that evaluated the incidence of bleeding was combined with descriptive analyses and an evaluation of the factors associated with bleeding.

RESULTS

Of the 279 patients included in the analysis, the median age of testosterone initiation was 22 years (interquartile range, 19-41), and the median follow-up time was 34 months (range, 12-278). The absolute proportion of individuals who ever experienced breakthrough bleeding on testosterone was 34% (n=96; 95% confidence interval, 29-40). Patients who experienced breakthrough bleeding initiated testosterone at a younger age (20.5 vs 22.0 years; P=.04), had lower mean serum testosterone levels (389.14 vs 512.7 ng/dL; P=.001), were more likely to have a mean testosterone level <320 ng/dL (52% vs 48%; P=.001), and had higher mean estradiol levels (62% vs 49%; P=.003). Survival analyses estimated a breakthrough bleeding incidence rate of 0.09 per year (95% confidence interval, 0.07-1.0). Although 58 people underwent a hysterectomy during the follow-up period, 64% of the cohort who maintained a uterus eventually experienced breakthrough bleeding. The median time to the initial bleeding episode was 22 months (interquartile range, 12-201) after testosterone initiation.

CONCLUSION

These results suggest that a substantial fraction of transgender and gender-diverse individuals who are using testosterone will experience at least 1 episode of breakthrough bleeding even after their initial year of testosterone use. We recommend that clinicians inform all patients that breakthrough bleeding is a common occurrence even after the first year on testosterone therapy.

Chemerin affects blood lipid profile of high-fat diet male mice in sedentary and exercise states via glucose and lipid metabolism enzymes

Adipokine chemerin plays important roles in disorders of glucose and lipid metabolism of obesity and obesity-related diseases, and exercise-induced improvement of glucose and lipid metabolism is closely related to the decrease of chemerin, but the mechanisms by which chemerin regulates glucose and lipid metabolism remain unclarified. Hypotestosterone induces male obesity and disorders of glucose and lipid metabolism through androgen receptor (AR) and its target genes: glucose and lipid metabolism-related molecules (including FOXO1, PEPCK, PGC-1α, and SCD1). Recently, the link between them has been reported that chemerin modulated the secretion of androgen. In this study, global chemerin knockout (chemerin (-/-)) mice were established to demonstrate the roles of chemerin in regulating blood glucose and blood lipid of mice under diet (high-fat (HFD) and normal diet) and exercise interventions and then to explore its mechanisms (AR - glucose and lipid metabolism enzymes). We found that the blood lipid and adipocyte size were low accompanied by the improvements in the levels of serum testosterone, gastrocnemius AR, and gastrocnemius FOXO1, SCD1, and PGC-1α in HFD chemerin (-/-) mice, but exercise-induced improvements of these indicators in HFD WT mice were attenuated or abolished in HFD chemerin (-/-) mice. In conclusion, the decrease of chemerin improved the blood lipid profile of HFD male mice at sedentary and exercise states, mediated partly by the increases of testosterone and AR to regulate glucose and lipid metabolism enzymes. To our knowledge, it is the first report that chemerin's regulation of glucose and lipid metabolism might be mediated by testosterone and AR in vivo.

Testosterone Supplementation Promotes Estrogen Synthesis of Buffalo Cumulus Cells Surrounding In Vitro-Matured Oocytes

Cumulus cells (CCs) synthesize estrogens that are essential for follicular development. However, the effects of androgen on estrogen production in buffalo CCs remain unknown. In the present study, the impacts of testosterone on estrogen synthesis of buffalo CCs surrounding in vitro-matured oocytes were investigated. The results showed that testosterone supplementation improved both the expression levels of estrogen synthesis-related genes (CYP11A1, CYP19A1, and 17β-HSD) and the secretion levels of estradiol in buffalo CCs surrounding in vitro-matured oocytes. Furthermore, testosterone treatment enhanced the sensitivity of buffalo CCs surrounding in vitro-matured oocytes to follicle-stimulating hormone (FSH). This study indicated that testosterone supplementation promoted the estrogen synthesis of buffalo CCs surrounding in vitro-matured oocytes mainly through strengthening the responsiveness of CCs to FSH. The present study serves as a foundation of acquiring high-quality recipient oocytes for buffalo somatic cell nuclear transfer.

Associations Between Blood Concentrations of Sex Hormones and Physical Function in Community-Dwelling Older Women: A Prospective Cohort Study

BACKGROUND

Blood concentrations of testosterone and estrone tend to increase in women aged ≥70 years, whereas concentrations of their precursor hormone dehydroepiandrosterone decline. It is unknown whether these changes influence physical function. We investigated whether concentrations of these hormones were associated with grip strength and self-reported physical function in community-dwelling older women.

METHODS

A total of 9 179 Australian women, aged ≥70 years, were recruited to the ASPirin in Reducing Events in the Elderly (ASPREE) trial. Sex hormones were measured in Sex Hormones in Older Women, an ASPREE substudy, by liquid chromatography-tandem mass spectrometry in 6 358 women. The associations between hormone concentrations and physical function (handgrip strength and self-reported physical function assessed by SF-12v2 physical component summary [PCS]) were examined using multiple linear regression.

RESULTS

The median age of the 5,447 participants was 74.0 (interquartile range 71.7-77.6) years. Testosterone concentrations above the lowest quartile were associated with less decline in grip strength (mean -1.39 [95% CI -1.54 to -1.24] vs -1.75 [-2.00 to -1.50] kg, p = .02), and dehydroepiandrosterone concentrations above the lowest quartile were associated with less decline in grip strength (-1.39 [-1.54 to -1.25] vs -1.82 [-2.11 to -1.55] kg, p = .007) and PCS scores (-1.49 [-1.80 to -1.17] vs -2.33 [-2.93 to -1.72], p = .02) over 4 years, compared with those in the respective lowest quartile.

CONCLUSIONS

Low endogenous concentrations of testosterone and dehydroepiandrosterone were associated the greatest likelihood of physical function decline in community-based women aged ≥70 years. Further studies are warranted to determine whether testosterone and dehydroepiandrosterone therapy prevent functional decline in this at-risk group using sensitive measures of muscle strength and performance.

Charles Brenton Huggins: A historical review of the Nobel laureate's pioneering discoveries

Androgen deprivation therapy for prostate cancer was pioneered by Charles Huggins, laureate of the Nobel Prize in Medicine in 1966. The authors tried to understand the scientific context and how previous findings paved Huggins way to his discoveries. With the help of summary or review articles on androgen deprivation therapy, the authors identified key publications and used his Nobel Prize speech as a basis to understand his discoveries. Furthermore, they used a recording of the laboratory-talk interview he gave about his findings to guide them to relevant publications. The authors found that the basis for Huggins' discoveries was the isolation of testosterone in 1935, not long before Huggins' 1941 hallmark publication. Huggins' work follows major experiments in the 19th century in orchiectomy done as a treatment for prostate hypertrophy. Researching the etiology of idiopathic hydrocele, Huggins analyzed the composition of prostate fluid. Further research led to the discovery of the influence of castration, testosterone, and estrogen on acid phosphatase. Recently developed methods facilitated the measurement of the phosphatases. He, therefore, had a biomarker for metastatic prostate cancer to measure treatment response. Very early on, he reported clinical improvements after castration in metastatic patients. Although the effect of orchiectomy on prostate hypertrophy was already known, Huggins was the first to show that testosterone stimulated and estrogen decreased the activity of prostate cancer. Huggins also established phosphatases as a tumor marker to measure disease response.

The prevalence, phenotype and cardiometabolic risk of polycystic ovary syndrome in treatment-naïve transgender people assigned female at birth

PURPOSE

Polycystic ovary syndrome (PCOS) is the most common endocrine disorder among women of reproductive age. We aimed to investigate the prevalence and phenotypic characteristics of PCOS in testosterone treatment-naïve transgender people assigned female at birth (AFAB), as well as to determine whether cardiometabolic risk factors vary based on the presence of PCOS and its components.

METHODS

Evaluation of 112 testosterone treatment-naïve transgender adults AFAB for PCOS and its individual components, including androgen excess, ovulatory dysfunction and polycystic ovarian morphology (PCOM).

RESULTS

In our cohort, 79.5% of transgender individuals AFAB had at least one component of PCOS. The prevalence of PCOS was 38.4% (43/112). Phenotype C was the most common phenotype (17.8%), followed by phenotype B (10.7%). Transgender individuals AFAB with at least one component of PCOS had higher blood pressure (BP) measurements and higher fasting plasma glucose levels compared to those with none. Sixty-one subjects (54%) had hyperandrogenism (HA), with 20 (17.9%) having HA without other components of PCOS. When compared to those without HA, transgender individuals AFAB with HA had higher body mass index (BMI), BP, triglyceride and lower HDL-cholesterol levels.

CONCLUSION

PCOS and androgen excess appear to be prevalent among transgender people AFAB. Transgender individuals AFAB with HA or PCOS may exhibit an unfavorable cardiometabolic risk profile compared to those without any PCOS component. Assessment of androgen excess and the specific components of PCOS at baseline could inform long-term management.

Epigenetic underpinnings of tumor-immune dynamics in prostate cancer immune suppression

Prostate cancer (PC) is immunosuppressive and refractory to immunotherapy. Infiltration of myeloid-derived suppressor cells (MDSCs) and senescent-like neutrophils and T cell exhaustion are observed in the tumor microenvironment (TME) following androgen receptor (AR) antagonism with antiandrogens or androgen ablation. De novo post-translational acetylation of the AR, HOXB13, and H2A at K609, K13, and K130, respectively, and phosphorylation of H4 at Y88 have emerged as key epigenetic modifications associated with castration-resistant PC (CRPC). The resulting chromatin changes are integrated into cellular processes via phosphorylation of the AR, ACK1, ATPF1A, and SREBP1 at Y267, Y284, Y243/Y246, and Y673/Y951, respectively. In this review, we discuss how these de novo epigenetic alterations drive resistance and how efforts aimed at targeting these regulators may overcome immune suppression observed in PC.

Sex differences in the cardiovascular effects of GnRH analogues

The integral role of the hypothalamic-pituitary-gonadal axis in reproductive processes makes it a prime therapeutic target. By inhibiting sex steroid synthesis, gonadotropin-releasing hormone (GnRH) analogues are used in the management of cancers, benign neoplasms, infertility and gender dysphoria. However, the wide application of these therapeutics raises concerns regarding the unintended effects upon the cardiovascular system. In males with prostate cancer, GnRH analogues when used as an androgen deprivation therapy appear to increase the risk of cardiovascular disease, which is the leading cause of death in this population. Therefore, due to the utilisation of GnRH analogues across the lifespan and gender spectrum, this relationship merits discussion. Existing data suggest an association between GnRH analogues and major adverse cardiovascular events in males. Conversely, females receiving GnRH analogues for breast cancer treatment appear to be at an increased risk of developing hypertension. In this narrative review, we describe the uses of GnRH analogues in adults, adolescents and children. We discuss whether sex plays a role in the cardiovascular effects of GnRH analogues and explore the significance of sex hormone receptors in the vasculature. We also consider confounding factors such as malignancy, advanced age and infertility.

Neural control of reproduction in reptiles

Reptiles display considerable diversity in reproductive behavior, making them great models to study the neuroendocrine control of reproductive behavior. Many reptile species are seasonally breeding, such that they become reproductively active during their breeding season and regress to a nonreproductive state during their nonbreeding season, with this transition often prompted by environmental cues. In this review, we will focus on summarizing the neural and neuroendocrine mechanisms controlling reproductive behavior. Three major areas of the brain are involved in reproductive behavior: the preoptic area (POA), amygdala, and ventromedial hypothalamus (VMH). The POA and VMH are sexually dimorphic areas, regulating behaviors in males and females respectively, and all three areas display seasonal plasticity. Lesions to these areas disrupt the onset and maintenance of reproductive behaviors, but the exact roles of these regions vary between sexes and species. Different hormones influence these regions to elicit seasonal transitions. Circulating testosterone (T) and estradiol (E2) peak during the breeding season and their influence on reproduction is well-documented across vertebrates. The conversion of T into E2 and 5α-dihydrotestosterone can also affect behavior. Melatonin and corticosterone have generally inhibitory effects on reproductive behavior, while serotonin and other neurohormones seem to stimulate it. In general, there is relatively little information on the neuroendocrine control of reproduction in reptiles compared to other vertebrate groups. This review highlights areas that should be considered for future areas of research.

Androgenic steroids induce pathologic scarring in a preclinical porcine model via dysfunctional extracellular matrix deposition

Hypertrophic scarring is a major source of morbidity. Sex hormones are not classically considered modulators of scarring. However, based on increased frequency of hypertrophic scarring in patients on testosterone, we hypothesized that androgenic steroids induce abnormal scarring and developed a preclinical porcine model to explore these effects. Mini-swine underwent castration, received no testosterone (noT) or biweekly testosterone therapy (+T), and underwent excisional wounding. To create a delayed wound healing model, a subset of wounds were re-excised at 2 weeks. Scars from postoperative day 42 (POD42) and delayed wounds (POD28) were harvested 6 weeks after initial wounding for analysis via histology, bulk RNA-seq, and mechanical testing. Histologic analysis of scars from +T animals showed increased mean fibrosis area (16 mm2noT, 28 mm2+T; p = .007) and thickness (0.246 mm2noT, 0.406 mm2+T; p < .001) compared to noT. XX+T and XY+T scars had greater tensile burst strength (p = .024 and p = .013, respectively) compared to noT swine. Color deconvolution analysis revealed greater deposition of type I and type III collagen as well as increased collagen type I:III ratio in +T scars. Dermatopathologist histology scoring showed that +T exposure was associated with worse overall scarring (p < .05). Gene ontology analysis found that testosterone exposure was associated with upregulation of cellular metabolism and immune response gene sets, while testosterone upregulated pathways related to keratinization and laminin formation on pathway analysis. In conclusion, we developed a preclinical porcine model to study the effects of the sex hormone testosterone on scarring. Testosterone induces increased scar tissue deposition and appears to increase physical strength of scars via supraphysiologic deposition of collagen and other ECM factors. The increased burst strength seen in both XX and XY animals suggests that hormone administration has a strong influence on scar mechanical properties independent of chromosomal sex. Anti-androgen topical therapies may be a promising future area of research.

Hormonal Basis of Biological Sex Differences in Human Athletic Performance

Biological sex is a primary determinant of athletic human performance involving strength, power, speed, and aerobic endurance and is more predictive of athletic performance than gender. This perspective article highlights 3 key medical and physiological insights related to recent evolving research into the sex differences in human physical performance: (1) sex and gender are not the same; (2) males and females exhibit profound differences in physical performance with males outperforming females in events and sports involving strength, power, speed, and aerobic endurance; (3) endogenous testosterone underpins sex differences in human physical performance with questions remaining on the roles of minipuberty in the sex differences in performance in prepubescent youth and the presence of the Y chromosome (SRY gene expression) in males, on athletic performance across all ages. Last, females are underrepresented as participants in biomedical research, which has led to a historical dearth of information on the mechanisms for sex differences in human physical performance and the capabilities of the female body. Collectively, greater effort and resources are needed to address the hormonal mechanisms for biological sex differences in human athletic performance before and after puberty.

A European Network for the Investigation of Gender Incongruence in adolescents

BACKGROUND

Knowledge regarding the effects and side effects of gender-affirming hormone therapy (GAHT) in adults is rapidly growing, partly through international research networks such as the European Network for the Investigation of Gender Incongruence (ENIGI). However, data on the effects of puberty suppression (PS) and GAHT in transgender and gender diverse (TGD) youth are limited, although these data are of crucial importance, given the controversies surrounding this treatment.

AIM

We sought to present a detailed overview of the design of the ENIGI Adolescents study protocol, including the first baseline data.

METHODS

The ENIGI Adolescents study is an ongoing multicenter prospective cohort study. This study protocol was developed by 3 European centers that provide endocrine care for TGD adolescents and were already part of the ENIGI collaboration: Amsterdam, Ghent, and Florence.

OUTCOMES

Study outcomes include physical effects and side effects, laboratory parameters, bone mineral density, anthropometric characteristics, attitudes toward fertility and fertility preservation, and psychological well-being, which are measured in the study participants during PS and GAHT, up to 3 years after the start of GAHT.

RESULTS

Between November 2021 and May 2023, 172 TGD adolescents were included in the ENIGI Adolescents protocol, of whom 51 were assigned male at birth (AMAB) and 121 were assigned female at birth (AFAB); 3 AFAB participants reported a nonbinary gender identification. A total of 76 participants were included at the start of PS, at a median (IQR) age of 13.7 (12.9-16.5) years in AMAB and 13.5 (12.4-16.1) years in AFAB individuals. The remaining 96 participants were included at start of GAHT, at a median (IQR) age of 15.9 (15.1-17.4) years in AFAB and 16.0 (15.1-16.8) years in AMAB individuals. At the time of this report the study was open for inclusion and follow-up measurements were ongoing.

CLINICAL IMPLICATIONS

In response to the rising demand for gender-affirming treatment among TGD youth, this ongoing study is fulfilling the need for prospective data on the effects and safety of PS and GAHT, thus providing a foundation for evidence-based healthcare decisions.

STRENGTHS AND LIMITATIONS

This study has a strong multicenter, prospective design that allows for systematic data collection. The use of clinical and self-reported data offers a broad range of outcomes to evaluate. Nevertheless, the burden of additional measurements and questionnaires may lead to withdrawal or lower response rates. Few participants with a non-binary gender identity have been included.

CONCLUSION

With the ENIGI Adolescents study we aim to create a comprehensive dataset that we can use for a wide range of studies to address current controversies and uncertainties and to improve healthcare for TGD adolescents.

Salvage Androgen Deprivation Therapy as Potential Treatment for Recurrence after Robot-Assisted Radical Prostatectomy

BACKGROUND

The efficacy of intermittent androgen deprivation therapy (ADT) for biochemical recurrence (BCR) after robot-assisted radical prostatectomy (RARP) is unknown, and its usefulness in Japanese practice needs to be investigated.

METHODS

We conducted a retrospective analysis of 85 patients who underwent RARP and were selected for intermittent ADT for postoperative recurrence at Kanazawa University Hospital between 2009 and 2019. Intermittent ADT was administered for 2 years. If prostate-specific antigen levels increased post-treatment, intermittent ADT was reinitiated. The median follow-up period was 47 months.

RESULTS

The 73 patients had completed the initial course of ADT, and 12 were under initial ADT. The 5-year castration-resistant prostate-cancer-free survival rates, cancer-specific survival, and overall survival were 92.7%, 98.3%, and 94.7%, respectively. A subgroup analysis of 69 patients who completed intermittent ADT was conducted to evaluate the BCR rate following initial ADT. The 5-year BCR-free survival rate was 53.2%. Multivariate analysis identified testosterone ≤ 0.03 ng/mL during ADT as the sole predictor of BCR after ADT.

CONCLUSIONS

Salvage intermittent ADT may be an effective treatment option for BCR after RARP. In addition, it would be useful to confirm strong testosterone suppression as a criterion for transition to intermittent therapy.

The testis, eunuchs, and testosterone: a historical review over the ages and around the world

INTRODUCTION

Testosterone therapy for men with testosterone deficiency is widely used, yet remains controversial. The rich and fascinating history of the testicles, including human castration, provides a valuable perspective on this important topic.

OBJECTIVES

This study reviewed the history of testosterone from antiquity to the modern day.

METHODS

Primary sources consisted of books and relevant articles, augmented by a MEDLINE search using the key words "testis," "testicles," "castration," "eunuchs," "testosterone," and "testicular function."

RESULTS

An early scientific observation was that castration reduced sexual development and activity, originating with domestication of animals approximately 10 000 years ago. Human castration appears in ancient Egyptian mythology more than 4000 years ago, in Greek mythology from 8th century BCE, and in the Bible. The history of eunuchs in China spanned 2000 years, beginning with the Hsia dynasty (2205-1766 BCE). The concept that the testicles produced some factor responsible for male sexual development and behavior was thus known throughout the world since the beginning of recorded history. Testosterone was isolated and synthesized in 1935 and was soon available as a treatment. Multiple benefits of testosterone therapy were apparent by 1940. Recent large, controlled testosterone studies have conclusively demonstrated sexual and general health benefits, with a strong safety profile.

CONCLUSION

Testosterone has been a known substance for <1% of the historical timeline, yet knowledge that the testes were responsible for male sexual development and behavior has been known since the beginning of recorded history. Today, modern evidence has demonstrated the importance of normal levels of testosterone for general health as well as sexual function and desire. Yet, testosterone therapy remains controversial. We believe this historical review provides a helpful perspective on this age-old issue.

Interplay of combat deployment harassment, testosterone concentrations and post-deployment suicide risk in male veterans

OBJECTIVE

Many combat veterans exhibit suicidal ideation and behaviour, but the relationships among experiences occurring during combat deployment and suicidality are still not fully understood. In this study, we tested the hypothesis that harassment during a combat deployment is associated with post-deployment suicidality and testosterone function.

METHODS

Male combat veterans who made post-deployment suicide attempts and demographically matched veterans without a history of suicide attempts were enrolled in the study. Demographic and clinical parameters of study participants were assessed and recorded. Study participants were interviewed by a trained clinician using the Mini-International Neuropsychiatric Interview (MINI), the Deployment Risk and Resilience Inventory (DRRI) – Relationships within unit scale, the Scale for Suicidal Ideation (SSI), and the Brown–Goodwin Aggression Scale. Free testosterone levels were assessed in morning blood samples.

RESULTS

DRRI harassment scores were higher and free testosterone levels were lower among suicide attempters in comparison with non-attempters. In the whole sample, DRRI harassment scores positively correlated with SSI scores and negatively correlated with free testosterone levels. Free testosterone levels negatively correlated with SSI scores. Aggression scale scores positively correlated with DRRI harassment scores among non-attempters but not among attempters.

CONCLUSION

Our observations that harassment scores are associated with suicidality and testosterone levels, and suicidality is associated with testosterone levels may indicate that there is a link between deployment harassment, testosterone function and suicidality.

Multiple sclerosis and hypogonadism: is there a relationship?

INTRODUCTION

Multiple sclerosis (MS) is a chronic autoimmune disease that affects the central nervous system and is widely recognized as a disease primarily affecting women. The relationship between MS and hypogonadism is complex and not fully understood, with recent evidence showing that hypogonadism may have a significant impact on the quality of life and disease progression of patients with MS.

OBJECTIVES

This review aims to provide an overview of the current knowledge regarding the relationship between MS and hypogonadism, including the mechanisms underlying this relationship; the effects of hypogonadism on patients with MS; and the potential benefits and drawbacks of testosterone replacement therapy for patients with MS and hypogonadism.

METHODS

This scientific review analyzed 19 articles that investigated the potential relationship among MS, testosterone levels, and hypogonadism. The articles were published between November 2008 and March 2022 and were identified through a comprehensive search of the PubMed database. The search terms used included "multiple sclerosis," "testosterone," "hypogonadism," and "MS and testosterone levels."

RESULTS

Of the 19 articles reviewed, 11 described a positive correlation between low testosterone levels and dysfunction within the hypothalamic-pituitary-gonadal axis in individuals with MS. These findings suggest that low testosterone levels may contribute to dysfunction within the hypothalamus-pituitary-gonadal axis, which plays a crucial role in regulating testosterone production. The results also showed a relationship between sexual dysfunction and low testosterone levels, as well as a positive correlative relationship between these factors.

CONCLUSION

The reviewed articles indicate a complex relationship among MS, testosterone levels, and the hypothalamic-pituitary-gonadal axis, with low testosterone levels potentially contributing to dysfunction in this axis and to sexual dysfunction. Further research is needed to better understand the effects of testosterone therapy on MS and sexual dysfunction in patients with MS.