MECHANISMS IN ENDOCRINOLOGY: Estradiol as a male hormone

Development of an ultrasensitive magnetic bead-based non-competitive chemiluminescent immunoassay for 17β-estradiol in milk

Chronic dietary intake of 17β-estradiol (E2) poses significant health risks, necessitating rapid and accurate analytical techniques for effective surveillance. This study presents a magnetic particle (MP)-assisted non-competitive chemiluminescent immunoassay (NCLIA) designed for E2 quantification in milk. The NCLIA employs anti-E2 monoclonal antibody (mAb)-coated MPs to capture E2 target molecules, followed by the recognition of acridinium ester (AE)-conjugated anti-E2@mAb immunocomplex antibody. Magnetic separation facilitates efficient isolation of immunocomplexes before automated luminescence measurement. This NCLIA demonstrated superior performance, without the need for complex pretreatment of milk samples, significantly simplifying the analysis process. The detection limit was as low as 1.57 pg/mL, and total detection time was 8 min. Additionally, NCLIA's results were highly consistent with those obtained by liquid chromatography-tandem mass spectrometry (LC-MS/MS), validating their reliability in analyzing real samples. Therefore, this study presents an efficient and reliable tool for the rapid screening and detection of 17β-estradiol in milk, which holds significant value for food safety monitoring.

Physiology-Related Variations in the Blood Hormone and Metabolome of Endangered Hog Deer (Axis porcinus)

Background/Objectives: The hog deer (Axis porcinus) is an endangered species facing significant threats from habitat loss and fragmentation, with only captive populations remaining in China. Expanding breeding programs and restoring wild populations are critical strategies for the species' conservation. Achieving this requires the development of an effective health database and the identification of molecular biomarkers for their physiological traits. Methods: In this study, we present the largest blood metabolomics dataset to date for captive hog deer, comprising 73 healthy individuals. We conducted targeted metabolomics to quantify blood hormone levels and untargeted metabolomics to characterize blood metabolic profiles, aiming to evaluate the associations of sex, age, and weight with metabolic profiles. Results: Our results reveal distinct growth patterns between females and males, with males reaching their body weight plateau at a larger size. We observed significant sex differences (p < 0.05) in blood hormones and metabolic profiles. Females exhibited higher levels of progesterone, hydroxyprogesterone, stress hormones (e.g., cortisol), and proline, while males had higher levels of testosterone, uric acid, phenylalanine, and guanidinosuccinic acid. Notably, body weight emerged as a more important factor than gender in explaining variations in the metabolome, particularly in males. Several blood biomarkers were identified as correlating with age and body weight. Specifically, blood progesterone levels in females were linked to both age and body weight, while in males, uric acid, prolylhydroxyproline, and 3-methylhistidine were associated with these factors. The potential significance of these results for the artificial breeding and conservation of hog deer were discussed. Conclusions: Our study provides a metabolic reference for identifying abnormal individuals and offers potential biomarkers for determining the gender, age, and body weight of hog deer. These findings may have significant implications for the artificial breeding and conservation efforts of the species.

The Potential of a Robot Presence in Close Relationship to Influence Human Responses to Experimental Pain

Pain management is a critical challenge in healthcare, often exacerbated by loneliness and emotional distress. This study investigated the potential of a communication robot, Moffuly, to reduce pain perception and influence hormonal responses in a controlled experimental setting. Nineteen healthy participants underwent heat pain stimulation under two conditions: with and without robotic interaction. Pain levels were assessed using the Short-form McGill Pain Questionnaire and the Visual Analogue Scale, while mood and mental states were evaluated through established questionnaires including the Profile of Mood States, Hospital Anxiety and Depression Scale, and Self-Rating Depression Scale. Hormonal changes, including cortisol, growth hormone, oxytocin, estradiol, and dehydroepiandrosterone-sulfate, were measured from blood samples collected at key time points. The results demonstrated significant reductions in subjective pain and improvements in mood following robotic interaction. These effects were accompanied by favorable hormonal changes, including increased oxytocin and decreased cortisol and growth hormone levels. The findings suggest that robotic interaction may serve as an innovative approach to pain management by addressing both physiological and psychological factors. This study highlights the potential of robotics to complement traditional therapies in alleviating pain and enhancing emotional well-being. By mitigating emotional distress and loneliness, robotic interventions may enhance existing pain therapies and offer innovative solutions for resource-limited healthcare systems.

Colorimetric quantitative detection of steroid hormones using an indicator displacement assay-based chemosensor array

A colorimetric chemosensor array based on an indicator displacement assay has achieved not only visualization of differences in hormone structures but also quantitative detection of sex hormones in their mixtures. Furthermore, the chemosensor array has allowed the detection of a steroid hormone in diluted human saliva.

Improvement of Late-Onset Hypogonadism Symptoms of Fermented Morinda citrifolia Extract in TM3 Leydig and TM4 Sertoli Cells

BACKGROUND/OBJECTIVES

Late-onset hypogonadism (LOH), characterized by declining testosterone levels with age, negatively affects the health of men, causing physical, psychological, and sexual dysfunction. Conventional testosterone replacement therapies have side effects, which has led to interest in natural alternatives. We investigated the effects of a standardized fermented Morinda citrifolia extract (FME) on oxidative stress-induced damage in TM3 Leydig and TM4 Sertoli cells. The cells were treated with H2O2 to simulate oxidative stress, followed by the FME treatment.

METHODS

Cytotoxicity assays, testosterone measurements, and gene and protein expression analyses were conducted to evaluate the restorative properties of FME.

RESULTS

The H2O2 treatment significantly decreased the cell viability, testosterone production, and the expression of proteins involved in testosterone synthesis and spermatogenesis, and the FME treatment improved testosterone production and restored the luteinizing hormone receptor, steroidogenic acute regulatory protein, CYP11A1, 3β-hydroxysteroid dehydrogenase, 17,20 desmolase, and 17β-hydroxysteroid dehydrogenase levels in the TM3 Leydig cells. It also reduced the expression of testosterone-degrading enzymes, aromatase and 5α-reductase. The FME treatment restored the levels of the androgen receptor and follicle-stimulating hormone receptor in the TM4 Sertoli cells.

CONCLUSIONS

FME alleviates oxidative stress-induced damage in Leydig and Sertoli cells by promoting testosterone synthesis and spermatogenesis while regulating testosterone metabolism. These findings suggest that FME could be a promising candidate for the management of LOH symptoms.

Sex hormones and reproductive factors with cardiac arrhythmia and ECG indices: a mendelian randomization study

BACKGROUND

Sex is a determinant of the incidence and etiology of arrhythmia. Observational and basic studies suggest that sex hormones are essential in this process; however, the relationship between sex hormones and arrhythmia remains unclear. Mendelian randomization (MR) was used to investigate the causal relationships between sex hormone levels, arrhythmia, and electrocardiographic (ECG) indices.

METHODS

Large genome-wide association studies (GWAS) data on sex hormones, stratified by sex, from the UK biobank consortium, were used as exposure data, and data on atrial fibrillation (AF), atrioventricular block, sick sinus syndrome, paroxysmal tachycardia, and ECG indices were obtained from the FinnGen consortium and summarized large GWAS data. Inverse variance weighting or wald odds was used as the primary analytical method, and weighted medians and MR-Egger regression were used for complementary analyses. The results of the MR of sex hormones and AF from different sources were analyzed using a meta-analysis. Summary-data-based MR analysis was utilized to explore the relationship between sex-hormone related drugs and arrhythmia.

RESULTS

In men, genetically predicted higher estradiol concentrations were associated with a lower risk of AF (odds ratio: 0.908 [0.852-0.967]; p = 0.0029], whereas genetically predicted higher concentrations of total testosterone were associated with lower heart rate variability. Sex hormones showed no association with atrioventricular block, sick sinus syndrome, paroxysmal tachycardia, resting heart rate, P wave duration, P wave terminal force in lead V1 [PTFV1], PR interval, QRS duration, QTc [QT interval corrected by heart rate], ST duration, spatial [spQRSTa] and frontal [fQRSTa] QRS-T angles in males. In females, there was no significant evidence that sex hormones are associated with arrhythmias or ECG indices.

CONCLUSION

In this study, we identified a potential causal relationship between estradiol and the risk of AF in males. However, there was no significant association between sex hormones and either arrhythmias or ECG indices in females. These results suggested that sex hormones may play a limited role in cardiac arrhythmias, which requires further verification.

Male hypogonadism: pathogenesis, diagnosis, and management

Organic male hypogonadism due to irreversible hypothalamic-pituitary-testicular (HPT) pathology is easily diagnosed and treated with testosterone-replacement therapy. However, controversy surrounds the global practice of prescribing testosterone to symptomatic men with low testosterone and non-gonadal factors reducing health status, such as obesity, type 2 diabetes, and ageing (ie, functional hypogonadism), but without identifiable HPT axis pathology. Health optimisation remains the gold-standard management strategy. Nevertheless, in the last decade large clinical trials and an individual patient data meta-analysis of smaller clinical trials confirmed that testosterone therapy induces modest, yet statistically significant, improvements in sexual function without increasing short-term to medium-term cardiovascular or prostate cancer risks in men with functional hypogonadism. Although testosterone improves bone mineral density and insulin sensitivity in these men, trials from the last decade suggest insufficient evidence to determine the safety and effectiveness of use of this hormone for the prevention of fractures or type 2 diabetes. This Review discusses the pathogenesis and diagnosis of male hypogonadism and appraises the evidence underpinning the management of this condition.

Endocrine gland size is proportional to its target tissue size

Endocrine glands secrete hormones into the circulation to target distant tissues and regulate their functions. The qualitative relationship between hormone-secreting organs and their target tissues is well established, but a quantitative approach is currently limited. Quantification is important, as it could allow us to study the endocrine system using engineering concepts of optimality and tradeoffs. In this study, we collected literature data on 24 human hormones secreted from dedicated endocrine cells. We find that the number of endocrine cells secreting a hormone is proportional to the number of its target cells. A single endocrine cell serves approximately 2,000 target cells, a relationship that spans 6 orders of magnitude of cell numbers. This suggests an economic principle of cells working near their maximal capacity, and glands that are no bigger than they need to be.

Adipokine secretion and lipolysis following gender-affirming treatment in transgender individuals

BACKGROUND

The organ-specific effects of gender-affirming sex hormone treatment (GAHT) in transgender women (TW) and transgender men (TM) are insufficiently explored. This study investigated the effects of GAHT on adipose tissue function.

METHODS

In a single-center interventional prospective study, 32 adults undergoing GAHT, 15 TW and 17 TM, were examined with anthropometry and abdominal subcutaneous adipose tissue biopsies obtained before initiation of treatment, 1 month after endogenous sex hormone inhibition and three and 11 months after initiated GAHT. Fat cell size, basal/stimulated lipolysis and cytokine secretion in adipose tissue were analyzed.

RESULTS

TW displayed an increase in complement component 3a and retinol-binding protein 4 (RBP4) secretion after sex hormone inhibition, which returned to baseline following estradiol treatment. No changes in lipolysis were seen in TW. TM showed downregulation of RBP4 after treatment, but no changes in basal lipolysis. In TM, the estrogen suppression led to higher noradrenaline stimulated (NA) lipolysis that was normalized following testosterone treatment. At 11 months, the ratio of NA/basal lipolysis was lower compared to baseline. There were no significant changes in fat cell size in either TW or TM.

CONCLUSION

In TW, gonadal hormone suppression results in transient changes in cytokines and in TM there are some changes in NA-stimulated lipolysis following testosterone treatment. However, despite the known metabolic effects of sex hormones, the overall effects of GAHT on adipose tissue function are small and likely have limited clinical relevance, but larger studies with longer follow-up are needed to confirm these findings.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02518009, Retrospectively registered 7 August 2015.

Sex differences in human performance

Sex as a biological variable is an underappreciated aspect of biomedical research, with its importance emerging in more recent years. This review assesses the current understanding of sex differences in human physical performance. Males outperform females in many physical capacities because they are faster, stronger and more powerful, particularly after male puberty. This review highlights key sex differences in physiological and anatomical systems (generally conferred via sex steroids and puberty) that contribute to these sex differences in human physical performance. Specifically, we address the effects of the primary sex steroids that affect human physical development, discuss insight gained from an observational study of 'real-world data' and elite athletes, and highlight the key physiological mechanisms that contribute to sex differences in several aspects of physical performance. Physiological mechanisms discussed include those for the varying magnitude of the sex differences in performance involving: (1) absolute muscular strength and power; (2) fatigability of limb muscles as a measure of relative performance; and (3) maximal aerobic power and endurance. The profound sex-based differences in human performance involving strength, power, speed and endurance, and that are largely attributable to the direct and indirect effects of sex-steroid hormones, sex chromosomes and epigenetics, provide a scientific rationale and framework for policy decisions on sex-based categories in sports during puberty and adulthood. Finally, we highlight the sex bias and problem in human performance research of insufficient studies and information on females across many areas of biology and physiology, creating knowledge gaps and opportunities for high-impact studies.

A Review on Testosterone: Estradiol Ratio-Does It Matter, How Do You Measure It, and Can You Optimize It?

There is a natural balance between the major sex steroids, testosterone and estradiol, controlled by gonadal secretion and peripheral conversion by aromatase. This balance is impacted by a variety of inborn and acquired conditions, and, more recently, by a growing use of exogenous testosterone therapy and off-label aromatase use under the guise of "men's health." We summarize reported testosterone:estradiol ratios, both naturally occurring and with pharmacologic manipulation and consider the ramifications of significant changes in these ratios. However, significant limitations exist in terms of steroid separation and measurement techniques, timing of samples, and lack of consistency from one assay to another, as well as definition of normative data. Limited data on the testosterone:estradiol ratio in men exists, particularly due to the scan data on concurrent estradiol values in men receiving testosterone therapy or aromatase inhibitors. Nonetheless, there seems to be a range of apparently beneficial values of the testosterone: estradiol radio at between 10 and 30, calculated as: testosterone in ng/dL/estradiol in pg/mL. Higher values appear to be associated with improved spermatogenesis and reduced bone density while lower values are associated with thyroid dysfunction. While there is growing awareness of the significance of the testosterone:estradiol ratio, and a sense of a desired range, the optimal value has not yet been determined. Further work is needed to clarify the measurement strategies and clearly-defined outcome measures related to the testosterone:estradiol ratio.

Testosterone in prevention and treatment of type 2 diabetes in men: Focus on recent randomized controlled trials

In epidemiological studies, lowered serum testosterone concentrations are common in men with obesity, prediabetes, and established type 2 diabetes (T2D). In men with prediabetes, lowered serum testosterone also predicts a future risk of T2D in men. Administration of testosterone consistently reduces fat mass and increases skeletal muscle mass-body compositional changes expected to be metabolically favorable. In men with established T2D, the effects of testosterone treatment on glycemic measures are inconsistent. Irrespective of baseline serum testosterone concentration in men with prediabetes or newly diagnosed early-onset T2D, testosterone treatment prescribed in conjunction with a lifestyle program has been reported to reduce the risk of T2D by 40% after 2 years, suggesting that either a lifestyle program is required to facilitate the glycemic benefit of testosterone treatment and/or that testosterone treatment has more favorable effects on glycemia in men early in the evolution or onset of the disease. The durability of the benefit and longer-term safety of testosterone treatment have not been established. Therefore, more studies are required before testosterone treatment can be recommended for the prevention and/or treatment of men with or at elevated risk of T2D who do not have hypogonadism due to an established disease of the hypothalamic-pituitary-testicular axis.

Pharmacological management of testosterone deficiency in men current advances and future directions

INTRODUCTION

Testosterone deficiency (TD) is relatively common in aging men, affecting around 2% of the general population. Testosterone replacement therapy (TRT) represents the most common medical approach for subjects who are not interested in fathering.

AREAS COVERED

This review summarizes advances in TRT, including approved or non-approved pharmacological options to overcome TD. When possible, a meta-analytic approach was applied to minimize subjective and biased interpretations of the available data.

EXPERT OPINION

During the last decade, several new TRT formulations have been introduced on the market, including oral, transdermal, and parenteral formulations. Possible advantages and limitations have been discussed appropriately. Anti-estrogens, including selective estrogen modulators or aromatase inhibitors still represent further possible off-label options. However, long-term side effects on sexual function and bone parameters constitute major limitations. Glucagon-like peptide 1 analogues can be an alternative option in particular for massive obesity-associated TD. Weight loss obtained through lifestyle modifications including diet and physical exercise should be encouraged in all overweight and obese patients. A combination of TRT and lifestyle changes can be considered in those subjects in whom a reversal of the condition cannot be expected in a reasonable time frame.

Levels of Sex Hormones and Abdominal Muscle Composition in Men from The Multi-Ethnic Study of Atherosclerosis

Information on the associations of testosterone levels with abdominal muscle volume and density in men is limited, while the role of estradiol and SHBG on these muscle characteristics are unclear. Therefore, this study aimed to investigate the association between fasting serum sex hormones and CT-derived abdominal muscle area and radiodensity in adult men. Conducted as a cross sectional observational study using data from the Multi-Ethnic Study of Atherosclerosis, our analyses focused on a community-based sample of 907 men aged 45-84 years, with 878 men having complete data. CT scans of the abdomen were interrogated for muscle characteristics, and multivariable linear regressions were used to test the associations. After adjustment for relevant factors, higher levels of both total testosterone and estradiol were associated with higher abdominal muscle area (1.74, 0.1-3.4, and 1.84, 0.4-3.3, respectively). In the final analyses, levels of total testosterone showed a positive association, while an inverse relationship was observed for SHBG with abdominal muscle radiodensity (0.3, 0.0-0.6, and - 0.33, - 0.6 to - 0.1, respectively). Our results indicate a complex association between sex hormones and abdominal muscle characteristics in men. Specifically, total testosterone and estradiol were associated with abdominal muscle area, while only total testosterone was associated with muscle radiodensity and SHBG was inversely associated with muscle radiodensity.Clinical Trial: NCT00005487.

Long-term use of clomiphene in male macroprolactinomas with persistent hypogonadism

BACKGROUND

Men with macroprolactinoma can present persistent hypogonadism despite normoprolactinemia achieved with clinical and/or neurosurgical treatment. Usually, testosterone replacement therapy is indicated. Nevertheless, although off-label, clomiphene citrate (CC), a selective estrogen receptor modulator, has also been used, mainly when fertility is an issue. The aim of this study is to evaluate the effectiveness of CC in recovering the gonadal axis in men with macroprolactinoma, with or without hyperprolactinemia, and evaluate its safety as a long-term therapy.

METHODS

This is a retrospective study including 10 men with macroprolactinoma on cabergoline treatment and persistent hypogonadism. All patients received initially 50 mg/d of CC.

RESULTS

The median age at diagnosis of prolactinomas was 34 (range, 26-60) years old. All patients were treated with cabergoline at a median maximum dose of 2 (1-7) mg/week, with a median time of treatment of 8.5 (2-15) years. Prolactin was still above the normal range when CC was introduced only in two patients. The mean duration of CC therapy was 3.2 (±2.8) years. Prolactin levels maintained stable (p = 0.252) and testosterone increased (p = 0.027) significantly on CC therapy. Tumor size remained stable. Eight patients (80%) maintained testosterone above 300 ng/dL and were classified as responders. Three responders succeeded in using a lower dose of CC and one of them completed withdrawal CC and maintained eugonadism. There were no side effects or safety concerns reported.

CONCLUSION

CC should be seen as a safe treatment option for men with macroprolactinoma and persistent hypogonadism.

A competitive-type photoelectrochemical aptasensor for 17 beta-estradiol detection in microfluidic devices based on a novel Au@Cd:SnO2/SnS2 nanocomposite

A competitive-type photoelectrochemical (PEC) aptasensor coupled with a novel Au@Cd:SnO2/SnS2 nanocomposite was designed for the detection of 17β-estradiol (E2) in microfluidic devices. The designed Au@Cd:SnO2/SnS2 nanocomposites exhibit high photoelectrochemical activity owing to the good matching of cascade band-edge and the efficient separation of photo-generated e-/h+ pairs derived from the Cd-doped defects in the energy level. The Au@Cd:SnO2/SnS2 nanocomposites were loaded into carbon paste electrodes (CPEs) to immobilize complementary DNA (cDNA) and estradiol aptamer probe DNA (E2-Apt), forming a double-strand DNA structure on the CPE surface. As the target E2 interacts with the double-strand DNA, E2-Apt is sensitively released from the CPE, subsequently increasing the photocurrent intensity due to the reduced steric hindrance of the electrode surface. The competitive-type sensing mechanism, combined with high PEC activity of the Au@Cd:SnO2/SnS2 nanocomposites, contributed to the rapid and sensitive detection of E2 in a "signal on" manner. Under the optimized conditions, the PEC aptasensor exhibited a linear range from 1.0 × 10-13 mol L-1 to 3.2 × 10-6 mol L-1 and a detection limit of 1.2 × 10-14 mol L-1 (S/N = 3). Moreover, the integration of microfluidic device with smartphone controlled portable electrochemical workstation enables the on-site detection of E2. The small sample volume (10 µL) and short analysis time (40 min) demonstrated the great potential of this strategy for E2 detection in rat serum and river water. With these advantages, the PEC aptasensor can be utilized for point-of-care testing (POCT) in both clinical and environmental applications.

Associations of Testosterone and Related Hormones With All-Cause and Cardiovascular Mortality and Incident Cardiovascular Disease in Men : Individual Participant Data Meta-analyses

BACKGROUND

Whether circulating sex hormones modulate mortality and cardiovascular disease (CVD) risk in aging men is controversial.

PURPOSE

To clarify associations of sex hormones with these outcomes.

DATA SOURCES

Systematic literature review to July 2019, with bridge searches to March 2024.

STUDY SELECTION

Prospective cohort studies of community-dwelling men with sex steroids measured using mass spectrometry and at least 5 years of follow-up.

DATA EXTRACTION

Independent variables were testosterone, sex hormone-binding globulin (SHBG), luteinizing hormone (LH), dihydrotestosterone (DHT), and estradiol concentrations. Primary outcomes were all-cause mortality, CVD death, and incident CVD events. Covariates included age, body mass index, marital status, alcohol consumption, smoking, physical activity, hypertension, diabetes, creatinine concentration, ratio of total to high-density lipoprotein cholesterol, and lipid medication use.

DATA SYNTHESIS

Nine studies provided individual participant data (IPD) (255 830 participant-years). Eleven studies provided summary estimates (n = 24 109). Two-stage random-effects IPD meta-analyses found that men with baseline testosterone concentrations below 7.4 nmol/L (<213 ng/dL), LH concentrations above 10 IU/L, or estradiol concentrations below 5.1 pmol/L had higher all-cause mortality, and those with testosterone concentrations below 5.3 nmol/L (<153 ng/dL) had higher CVD mortality risk. Lower SHBG concentration was associated with lower all-cause mortality (median for quintile 1 [Q1] vs. Q5, 20.6 vs. 68.3 nmol/L; adjusted hazard ratio [HR], 0.85 [95% CI, 0.77 to 0.95]) and lower CVD mortality (adjusted HR, 0.81 [CI, 0.65 to 1.00]). Men with lower baseline DHT concentrations had higher risk for all-cause mortality (median for Q1 vs. Q5, 0.69 vs. 2.45 nmol/L; adjusted HR, 1.19 [CI, 1.08 to 1.30]) and CVD mortality (adjusted HR, 1.29 [CI, 1.03 to 1.61]), and risk also increased with DHT concentrations above 2.45 nmol/L. Men with DHT concentrations below 0.59 nmol/L had increased risk for incident CVD events.

LIMITATIONS

Observational study design, heterogeneity among studies, and imputation of missing data.

CONCLUSION

Men with low testosterone, high LH, or very low estradiol concentrations had increased all-cause mortality. SHBG concentration was positively associated and DHT concentration was nonlinearly associated with all-cause and CVD mortality.

PRIMARY FUNDING SOURCE

Medical Research Future Fund, Government of Western Australia, and Lawley Pharmaceuticals. (PROSPERO: CRD42019139668).

The Loss of Estradiol by Androgen Deprivation in Prostate Cancer Patients Shows the Importance of Estrogens in Males

The role of estradiol (E2; an estrogen) in men needs to be more appreciated. In this review, we address the clinical situations that allow the study of the clinical consequences of E2 deficiency in men and discuss the effects of restoration of levels of this reproductive steroid hormone. In men with advanced prostate cancer (PCa) undergoing androgen deprivation therapy (ADT), E2 is suppressed along with testosterone, leading to side effects affecting the quality of life. These include hot flashes, arthralgia, fatigue, mood changes, cognition problems, weight gain, bone loss, and increased risk of cardiovascular disease. Transdermal E2 alone for ADT has shown equivalent testosterone suppression compared to gonadotropin-releasing hormone (GnRH) agonists while also preventing estrogen-deficiency side effects, including hot flashes and bone loss. Co-treatment of ADT with fetal estrogen estetrol (E4) has shown significant improvements of estrogen-deficiency symptoms. These observations emphasize the need to raise awareness of the importance of estrogens in men among clinicians and the lay public.

Impact of androgenic anabolic steroid use on cardiovascular and mental health in Danish recreational athletes: protocol for a nationwide cross-sectional cohort study as a part of the Fitness Doping in Denmark (FIDO-DK) study

INTRODUCTION

The use of androgenic anabolic steroids (AASs) among recreational athletes is steadily increasing. However, knowledge regarding the potentially harmful effects of AAS primarily originates from case reports and small observational studies. This large-scale study aims to investigate the impact of AAS use on vascular plaque formation, preclinical coronary disease, cardiac function, circulating cardiovascular risk markers, quality of life (QoL) and mental health in a broad population of illicit AAS users.

METHODS AND ANALYSES

A nationwide cross-sectional cohort study including a diverse population of men and women aged ≥18 years, with current or previous illicit AAS use for at least 3 months. Conducted at Odense University Hospital, Denmark, the study comprises two parts. In part A (the pilot study), 120 recreational athletes with an AAS history will be compared with a sex-matched and age-matched control population of 60 recreational athletes with no previous AAS use. Cardiovascular outcomes include examination of non-calcified coronary plaque volume and calcium score using coronary CT angiography, myocardial structure and function via echocardiography, and assessing carotid and femoral artery plaques using ultrasonography. Retinal microvascular status is evaluated through fundus photography. Cardiovascular risk markers are measured in blood. Mental health outcomes include health-related QoL, interpersonal difficulties, body image concerns, aggression dimensions, anxiety symptoms, depressive severity and cognitive function assessed through validated questionnaires. The findings of our comprehensive study will be used to compose a less intensive investigatory cohort study of cardiovascular and mental health (part B) involving a larger group of recreational athletes with a history of illicit AAS use.

ETHICS AND DISSEMINATION

The study received approval from the Regional Committee on Health Research Ethics for Southern Denmark (S-20210078) and the Danish Data Protection Agency (21/28259). All participants will provide signed informed consent. Research outcomes will be disseminated through peer-reviewed journals and scientific conferences.

TRIAL REGISTRATION NUMBER

NCT05178537.

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.

Cocaine sensitization in male rats requires activation of estrogen receptors

Gonadal steroids play a modulatory role in cocaine use disorders, and are responsible for many sex differences observed in the behavioral response to cocaine. In females, it is well established that estradiol enhances the behavioral response to cocaine. In males, we have recently shown that testosterone enhances sensitization to cocaine but its mechanism of action remains to be elucidated. The current study investigated the contribution of DHT, a non-aromatizable androgen, and of estradiol, in regulating cocaine-induced sensitization in male rats. Gonadectomized (GDX) male rats treated with estradiol sensitized to repeated cocaine administration, while GDX rats treated with DHT did not, implicating estradiol in cocaine sensitization. Furthermore, intact male rats treated with the antiestrogen ICI 182,780 did not show sensitization to repeated cocaine. This study demonstrates the pivotal role of estradiol in cocaine-induced neuroplasticity and neuroadaptations in the rodent brain.

Effect of oestrogen modulation on semen parameters in men with secondary hypogonadism: Systematic review and meta-analysis

BACKGROUND

Selective oestrogen receptor modulators and aromatase inhibitors stimulate endogenous gonadotrophins and testosterone in men with hypogonadism. There are no systematic reviews/meta-analyses assessing the effects of selective oestrogen receptor modulators/aromatase inhibitors on semen parameters in men with secondary hypogonadism.

OBJECTIVES

To assess the effect of monotherapy or a combination of selective oestrogen receptor modulators/aromatase inhibitors on sperm parameters and/or fertility in men with secondary hypogonadism.

MATERIALS AND METHODS

A systematic search was conducted in PubMed, MEDLINE, Cochrane Library and ClinicalTrials.gov. Study selection and data extraction were performed by two reviewers independently. Randomised controlled trials and non-randomised studies of interventions reporting effects of selective oestrogen receptor modulators and/or aromatase inhibitors on semen parameters or fertility in men with low testosterone with low/normal gonadotrophins were selected. The risk of bias was assessed using ROB-2 and ROBINS-I tools. The results of randomised controlled trials were summarised using vote counting while summarising effect estimates where available. Non-randomised studies of intervention meta-analysis were conducted using the random-effect model. The certainty of evidence was assessed using GRADE.

RESULTS

Five non-randomised studies of interventions (n = 105) of selective oestrogen receptor modulators showed an increase in sperm concentration (pooled mean difference 6.64 million/mL; 95% confidence interval 1.54, 11.74, I2  = 0%) and three non-randomised studies of interventions (n = 83) of selective oestrogen receptor modulators showed an increase in total motile sperm count (pooled mean difference 10.52; 95% confidence interval 1.46-19.59, I2  = 0%), with very low certainty of evidence. The mean body mass index of participants was >30 kg/m2 . Four randomised controlled trials (n = 591) comparing selective oestrogen receptor modulators to placebo showed a heterogeneous effect on sperm concentration. Three included men with overweight or obesity. The results were of very low certainty of evidence. Limited pregnancy or live birth data were available. No studies comparing aromatase inhibitors with placebo or testosterone were found.

DISCUSSION AND CONCLUSION

Current studies are of limited size and quality but suggest that selective oestrogen receptor modulators may improve semen parameters in those patients, particularly when associated with obesity.

Lifelong exercise training promotes the remodelling of the immune system and prostate signalome in a rat model of prostate carcinogenesis

This work aimed to understand how lifelong exercise training promotes the remodelling of the immune system and prostate signalome in a rat model of PCa. Fifty-five male Wistar rats were divided into four groups: control sedentary, control exercised, induced PCa sedentary and induced PCa exercised. Exercised animals were trained in a treadmill for 53 weeks. Pca induction consisted on the sequential administration of flutamide, N-methyl-N-nitrosourea and testosterone propionate implants. Serum concentrations of C-reactive protein (CRP) and tumor necrosis factor (TNF)-like weak inducer of apoptosis (TWEAK) were not different among groups. Peripheral levels of γδ T cells were higher in Pca exercised group than in the PCa sedentary group (p < 0.05). Exercise training also induced Oestrogen Receptor (ESR1) upregulation and Mitogen-activated Protein Kinase 13 (MAPK13) downregulation, changed the content of the phosphorylated (at Ser-104) form of this receptor (coded by the gene ESR1) and seemed to increase Erα phosphorylation and activity in exercised PCa rats when compared with sedentary PCa rats. Our data highlight the exercise-induced remodelling of peripheral lymphocyte subpopulations and lymphocyte infiltration in prostate tissue. Moreover, exercise training promotes the remodelling prostate signalome in this rat model of prostate carcinogenesis.

The Biological Basis of Sex Differences in Athletic Performance: Consensus Statement for the American College of Sports Medicine

ABSTRACT

Biological sex is a primary determinant of athletic performance because of fundamental sex differences in anatomy and physiology dictated by sex chromosomes and sex hormones. Adult men are typically stronger, more powerful, and faster than women of similar age and training status. Thus, for athletic events and sports relying on endurance, muscle strength, speed, and power, males typically outperform females by 10%-30% depending on the requirements of the event. These sex differences in performance emerge with the onset of puberty and coincide with the increase in endogenous sex steroid hormones, in particular testosterone in males, which increases 30-fold by adulthood, but remains low in females. The primary goal of this consensus statement is to provide the latest scientific knowledge and mechanisms for the sex differences in athletic performance. This review highlights the differences in anatomy and physiology between males and females that are primary determinants of the sex differences in athletic performance and in response to exercise training, and the role of sex steroid hormones (particularly testosterone and estradiol). We also identify historical and nonphysiological factors that influence the sex differences in performance. Finally, we identify gaps in the knowledge of sex differences in athletic performance and the underlying mechanisms, providing substantial opportunities for high-impact studies. A major step toward closing the knowledge gap is to include more and equitable numbers of women to that of men in mechanistic studies that determine any of the sex differences in response to an acute bout of exercise, exercise training, and athletic performance.

Nuclear Estrogen Receptors in Prostate Cancer: From Genes to Function

Estrogens are almost ubiquitous steroid hormones that are essential for development, metabolism, and reproduction. They exert both genomic and non-genomic action through two nuclear receptors (ERα and ERβ), which are transcription factors with disregulated functions and/or expression in pathological processes. In the 1990s, the discovery of an additional membrane estrogen G-protein-coupled receptor augmented the complexity of this picture. Increasing evidence elucidating the specific molecular mechanisms of action and opposing effects of ERα and Erβ was reported in the context of prostate cancer treatment, where these issues are increasingly investigated. Although new approaches improved the efficacy of clinical therapies thanks to the development of new molecules targeting specifically estrogen receptors and used in combination with immunotherapy, more efforts are needed to overcome the main drawbacks, and resistance events will be a challenge in the coming years. This review summarizes the state-of-the-art on ERα and ERβ mechanisms of action in prostate cancer and promising future therapies.

Factors Associated With Circulating Sex Hormones in Men : Individual Participant Data Meta-analyses

BACKGROUND

Various factors modulate circulating testosterone in men, affecting interpretation of testosterone measurements.

PURPOSE

To clarify factors associated with variations in sex hormone concentrations.

DATA SOURCES

Systematic literature searches (to July 2019).

STUDY SELECTION

Prospective cohort studies of community-dwelling men with total testosterone measured using mass spectrometry.

DATA EXTRACTION

Individual participant data (IPD) (9 studies; n = 21 074) and aggregate data (2 studies; n = 4075). Sociodemographic, lifestyle, and health factors and concentrations of total testosterone, sex hormone-binding globulin (SHBG), luteinizing hormone (LH), dihydrotestosterone, and estradiol were extracted.

DATA SYNTHESIS

Two-stage random-effects IPD meta-analyses found a nonlinear association of testosterone with age, with negligible change among men aged 17 to 70 years (change per SD increase about the midpoint, -0.27 nmol/L [-7.8 ng/dL] [CI, -0.71 to 0.18 nmol/L {-20.5 to 5.2 ng/dL}]) and decreasing testosterone levels with age for men older than 70 years (-1.55 nmol/L [-44.7 ng/dL] [CI, -2.05 to -1.06 nmol/L {-59.1 to -30.6 ng/dL}]). Testosterone was inversely associated with body mass index (BMI) (change per SD increase, -2.42 nmol/L [-69.7 ng/dL] [CI, -2.70 to -2.13 nmol/L {-77.8 to -61.4 ng/dL}]). Testosterone concentrations were lower for men who were married (mean difference, -0.57 nmol/L [-16.4 ng/dL] [CI, -0.89 to -0.26 nmol/L {-25.6 to -7.5 ng/dL}]); undertook at most 75 minutes of vigorous physical activity per week (-0.51 nmol/L [-14.7 ng/dL] [CI, -0.90 to -0.13 nmol/L {-25.9 to -3.7 ng/dL}]); were former smokers (-0.34 nmol/L [-9.8 ng/dL] [CI, -0.55 to -0.12 nmol/L {-15.9 to -3.5 ng/dL}]); or had hypertension (-0.53 nmol/L [-15.3 ng/dL] [CI, -0.82 to -0.24 nmol/L {-23.6 to -6.9 ng/dL}]), cardiovascular disease (-0.35 nmol/L [-10.1 ng/dL] [CI, -0.55 to -0.15 nmol/L {-15.9 to -4.3 ng/dL}]), cancer (-1.39 nmol/L [-40.1 ng/dL] [CI, -1.79 to -0.99 nmol/L {-51.6 to -28.5 ng/dL}]), or diabetes (-1.43 nmol/L [-41.2 ng/dL] [CI, -1.65 to -1.22 nmol/L {-47.6 to -35.2 ng/dL}]). Sex hormone-binding globulin was directly associated with age and inversely associated with BMI. Luteinizing hormone was directly associated with age in men older than 70 years.

LIMITATION

Cross-sectional analysis, heterogeneity between studies and in timing of blood sampling, and imputation for missing data.

CONCLUSION

Multiple factors are associated with variation in male testosterone, SHBG, and LH concentrations. Reduced testosterone and increased LH concentrations may indicate impaired testicular function after age 70 years. Interpretation of individual testosterone measurements should account particularly for age older than 70 years, obesity, diabetes, and cancer.

PRIMARY FUNDING SOURCE

Medical Research Future Fund, Government of Western Australia, and Lawley Pharmaceuticals. (PROSPERO: CRD42019139668).

Association of blood metals with serum sex hormones in adults: A cross-sectional study

Heavy metals such as lead, mercury, and cadmium have been identified to have negative impacts on human health. Although the individual effects of these metals have been extensively researched, the present study aims to explore their combined effects and their association with serum sex hormones among adults. Data for this study were obtained from the general adult population of the 2013-2016 National Health and Nutrition Survey (NHANES) and included five metal (mercury, cadmium, manganese, lead, and selenium) exposures and three sex hormones (total testosterone [TT], estradiol [E2], and sex hormone-binding globulin [SHBG]) levels. The free androgen index (FAI) and TT/E2 ratio were also calculated. The relationships between blood metals and serum sex hormones were analysed using linear regression and restricted cubic spline regression. The effect of blood metal mixtures on sex hormone levels was examined using the quantile g-computation (qgcomp) model. There were 3,499 participants in this study, including 1,940 males and 1,559 females. In males, positive relationships between blood cadmium and serum SHBG (β=0.049 [0.006, 0.093]), lead and SHBG (β=0.040 [0.002, 0.079]), manganese and FAI (β=0.080 [0.016, 0.144]), and selenium and FAI (β=0.278 [0.054, 0.502]) were observed. In contrast, manganese and SHBG (β=-0.137 [-0.237, -0.037]), selenium and SHBG (β=-0.281 [-0.533, -0.028]), and manganese and TT/E2 ratio (β=-0.094 [-0.158, -0.029]) were negative associations. In females, blood cadmium and serum TT (β=0.082 [0.023, 0.141]), manganese and E2 (β=0.282 [0.072, 0.493]), cadmium and SHBG (β=0.146 [0.089, 0.203]), lead and SHBG (β=0.163 [0.095, 0.231]), and lead and TT/E2 ratio (β=0.174 [0.056, 0.292]) were positive relationships, while lead and E2 (β=-0.168 [-0.315, -0.021]) and FAI (β=-0.157 [-0.228, -0.086]) were negative associations. This correlation was stronger among elderly women (>50 years old). The qgcomp analysis revealed that the positive effect of mixed metals on SHBG was mainly driven by cadmium, while the negative effect of mixed metals on FAI was mainly driven by lead. Our findings indicate that exposure to heavy metals may disrupt hormonal homeostasis in adults, particularly in older women.

Bone Tissue Evaluation Indicates Abnormal Mineralization in Patients with Autoimmune Polyendocrine Syndrome Type I: Report on Three Cases

Autoimmune polyendocrine syndrome type-1 (APS1) is characterized by autoimmune manifestations affecting different organs from early childhood on. Immunological abnormalities, the resulting endocrinopathies, and their treatments may compromise bone health. For the first time in APS1, we analyzed transiliac bone biopsy samples by bone histomorphometry and quantitative backscattered electron imaging in three adult patients (female P1, 38 years; male P2, 47 years; male P3, 25 years). All had biallelic mutations in the autoimmune regulator gene and in addition to endocrinopathies, also significant bone fragility. Histomorphometry showed bone volume in the lower normal range for P1 (BV/TV, - 0.98 SD) and P3 (- 1.34 SD), mainly due to reduced trabecular thickness (TbTh, - 3.63 and - 2.87 SD). In P1, osteoid surface was low (OS/BS, - 0.96 SD); active osteoblasts and double labeling were seen only on cortical bone. P3 showed a largely increased bone turnover rate (BFR/BV, + 4.53 SD) and increased mineralization lag time (Mlt, + 3.40 SD). Increased osteoid surface (OS/BS, + 2.03 and + 4.71 SD for P2 and P3) together with a large proportion of lowly mineralized bone area (Trab CaLow, + 2.22 and + 9.81 SD for P2 and P3) and focal mineralization defects were consistent with abnormal mineralization. In all patients, the density and area of osteocyte lacunae in cortical and trabecular bone were similar to healthy adults. The bone tissue characteristics were variable and included decreased trabecular thickness, increased amount of osteoid, and abnormal mineralization which are likely to contribute to bone fragility in patients with APS1.

Gulp1 deficiency augments bone mass in male mice by affecting osteoclasts due to elevated 17β-estradiol levels

The engulfment adaptor phosphotyrosine-binding domain containing 1 (GULP1) is an adaptor protein involved in the engulfment of apoptotic cells via phagocytosis. Gulp1 was first found to promote the phagocytosis of apoptotic cells by macrophages, and its role in various tissues, including neurons and ovaries, has been well studied. However, the expression and function of GULP1 in bone tissue are poorly understood. Consequently, to determine whether GULP1 plays a role in the regulation of bone remodeling in vitro and in vivo, we generated Gulp1 knockout (KO) mice. Gulp1 was expressed in bone tissue, mainly in osteoblasts, while its expression is very low in osteoclasts. Microcomputed tomography and histomorphometry analysis in 8-week-old male Gulp1 KO mice revealed a high bone mass in comparison with male wild-type (WT) mice. This was a result of decreased osteoclast differentiation and function in vivo and in vitro as confirmed by a reduced actin ring and microtubule formation in osteoclasts. Gas chromatography-mass spectrometry analysis further showed that both 17β-estradiol (E2) and 2-hydroxyestradiol levels, and the E2/testosterone metabolic ratio, reflecting aromatase activity, were also higher in the bone marrow of male Gulp1 KO mice than in male WT mice. Consistent with mass spectrometry analysis, aromatase enzymatic activity was significantly higher in the bone marrow of male Gulp1 KO mice. Altogether, our results suggest that GULP1 deficiency decreases the differentiation and function of osteoclasts themselves and increases sex steroid hormone-mediated inhibition of osteoclast differentiation and function, rather than affecting osteoblasts, resulting in a high bone mass in male mice. To the best of our knowledge, this is the first study to explore the direct and indirect roles of GULP1 in bone remodeling, providing new insights into its regulation.

Serum testosterone and sex hormone-binding globulin are inversely associated with leucocyte telomere length in men: a cross-sectional analysis of the UK Biobank study

OBJECTIVE

Older men on an average have lower testosterone concentrations, compared with younger men, and more age-related comorbidities. Whether lower testosterone concentrations contribute to biological ageing remains unclear. Shorter telomeres are a marker for biological age. We tested the hypothesis that testosterone concentrations are associated with leucocyte telomere length (LTL), in middle- to older-aged men.

DESIGN

Cross-sectional analysis of the UK Biobank study, involving community-dwelling men aged 40-69 years.

METHODS

Serum testosterone and sex hormone-binding globulin (SHBG) were assayed. Free testosterone was calculated (cFT). Leucocyte telomere length was measured using polymerase chain reaction. Multivariable models were used to assess associations of hormones with standardised LTL.

RESULTS

In 167 706 men, median age 58 years, adjusting for sociodemographic, lifestyle, and medical factors, total testosterone was inversely associated with standardised LTL, which was 0.09 longer (95% confidence interval [CI], 0.08-0.10, P < .001) in men with total testosterone at median of lowest quintile [Q1] vs highest [Q5]. This relationship was attenuated after additional adjustment for SHBG (0.03 longer, CI = 0.02-0.05, P = .003). The association between cFT and LTL was similar in direction but lower in magnitude. In multivariable analysis, SHBG was inversely associated with standardised LTL, which was 0.12 longer (CI = 0.10-0.13, P < .001) for SHBG at median Q1 vs Q5. Results were similar with testosterone included in the model (0.10 longer, CI = 0.08-0.12, P < .001).

CONCLUSIONS

Total testosterone and SHBG were independently and inversely associated with LTL. Men with higher testosterone or SHBG had shorter telomeres, arguing against a role for testosterone to slow biological ageing in men.

The Effect of Gender-Affirming Hormone Therapy on the Risk of Subclinical Atherosclerosis in the Transgender Population: A Systematic Review

OBJECTIVE

The impact of gender-affirming hormone therapy (GAHT) on cardiovascular (CV) health is still not entirely established. A systematic review was conducted to summarize the evidence on the risk of subclinical atherosclerosis in transgender people receiving GAHT.

METHODS

A systematic review was performed following Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines, and data were searched in PubMed, LILACS, EMBASE, and Scopus databases for cohort, case-control, and cross-sectional studies or randomized clinical trials, including transgender people receiving GAHT. Transgender men and women before and during/after GAHT for at least 2 months, compared with cisgender men and women or hormonally untreated transgender persons. Studies reporting changes in variables related to endothelial function, arterial stiffness, autonomic function, and blood markers of inflammation/coagulation associated with CV risk were included.

RESULTS

From 159 potentially eligible studies initially identified, 12 were included in the systematic review (8 cross-sectional and 4 cohort studies). Studies of trans men receiving GAHT reported increased carotid thickness, brachial-ankle pulse wave velocity, and decreased vasodilation. Studies of trans women receiving GAHT reported decreased interleukin 6, plasminogen activator inhibitor-1, and tissue plasminogen activator levels and brachial-ankle pulse wave velocity, with variations in flow-mediated dilation and arterial stiffness depending on the type of treatment and route of administration.

CONCLUSIONS

The results suggest that GAHT is associated with an increased risk of subclinical atherosclerosis in transgender men but may have either neutral or beneficial effects in transgender women. The evidence produced is not entirely conclusive, suggesting that additional studies are warranted in the context of primary prevention of CV disease in the transgender population receiving GAHT.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO, identifier CRD42022323757.

Clinical and hormonal characteristics and growth data of 45,X/46,XY mosaicism in 38 Chinese patients

Backgrounds

45,X/46,XY mosaicism is the most common type of sex chromosomal abnormality in disorders of sex development (DSD). We investigated the clinical manifestations, serum sex hormone levels and growth data of 38 45,X/46,XY mosaicism patients, which provides better insight into this disease.

Methods

We prospectively evaluated 38 patients who were diagnosed with 45,X/46,XY mosaicism at the Department of Endocrinology of Shanghai Children's Hospital from 2010 to 2020. We analyzed clinical data from the patients, including hormone levels, height, weight, body mass index (BMI) and gonadal pathology results.

Results

Among the 38 cases of 45,X/46,XY mosaicism, 18 cases showed a female external genitalia phenotype (the female group) with an external masculinization score (EMS) of 1 (0-3) [median (range)], and 20 cases showed a male external genitalia phenotype (the male group) with an EMS of 7.63 (3-11) [median (range)]. The age at diagnosis ranged from 0.7 to 16.1 years. Under 2 years of age, the standard deviation scores of height (HtSDS) were in the normal range and then they gradually decreased. The inhibin B (INHB), anti-Mullerian hormone (AMH), and testosterone (T) levels after human chorionic gonadotropin (HCG) stimulation and the T:DHT ratio in the male group were significantly higher than those in the female group (P < 0.001). The basal luteinizing hormone (LH), basal follicle-stimulating hormone (FSH), peak LH and peak FSH in females were significantly higher than those in males (P < 0.05). Their height showed a positive correlation with T levels after HCG stimulation (r = 0.636, P < 0.01), T:DHT ratio (r = 0.724, P < 0.01), growth hormone (GH) (r = 0.827, P < 0.05), and insulin-like growth factor 1 (IGF-1) (r = 0.067, P > 0.05) and a negative correlation with gonadal pathology in ovarian tissue (r = -0.663, P < 0.05) and the number of chimaeric XY cells (r = -0.533, P < 0.05).

Conclusions

Patients with 45,X/46,XY mosaicism have specific growth patterns. Their HtSDS was in the normal range during 0-2 years of age and then they began to show a short stature after 2 years of age. The probability of short stature in females was higher than that in males. WtSDS were all in the normal range, but below the median. BMISDS was in the normal range, and there was no evidence of obesity. The gonads in the male group retained a certain androgen secretion function, while the gonadal damage is more severe in the female group.

Association of blood lead with estradiol and sex hormone-binding globulin in 8-19-year-old children and adolescents

BACKGROUND

Metals can interfere with hormonal functioning through indirect mechanisms and by binding at the receptor site; thus, they may be associated with hormonal changes. However, there have been few studies on the health impact of metal exposure among children and adolescents. Thus, we aimed to examine the associations of blood lead level (BLL) with estradiol (E2) and sex hormone-binding globulin (SHBG) among children and adolescents aged 8-19 years in the National Health and Nutrition Examination Survey (NHANES) database.

METHODS

This was a cohort study of 2188 individuals from the NHANES. BLL was taken as independent variables, E2 and SHBG as dependent variable. We conducted weighted multivariate linear regression models and smooth curve fittings to evaluate the association between them.

RESULTS

The BLL was significantly positively associated with serum SHBG level in females, especially when the LnBLL quartiles are between Q3 and Q4. There was an inverted U-shaped association between BLL and E2 with the point of inflection at 1.86 μg/L and a U-shaped association between BLL and SHBG with the point of inflection at 1.86 μg/L in female adolescents aged 16-19 years. Meanwhile, In males, there was a positive trend of correlation between BLL and E2 in the 8-11 years, and 16-19 years groups.

CONCLUSIONS

This study found an inverted U-shaped association of BLL with E2 and a U-shaped association between BLL and SHBG in female adolescents aged 16-19 years. This indicates that adjusting blood lead exposure to mitigate the effects of lead on growth and development is important for adolescents aged 16-19 years. Controlling the BLL below 1.86 μg/L may minimize the damage to E2.

Puzzling relationship between levels of toxic metals in blood and serum levels of reproductive hormones: Benchmark dose approach in cross-sectional study

Reproductive disorders and infertility have become more common recently among the general population. Toxic metals are known as endocrine disruptors and as they are widespread in nature they may be linked to reproductive problems. This study was conducted as a cross-sectional study and its aim was to examine the dose–response relationship between cadmium, arsenic, mercury, chromium and nickel and serum hormone levels of testosterone (women) and estradiol and progesterone (men) using the Benchmark dose approach (BMD). Blood samples were collected from 218 women and 217 men digested in a microwave, and the levels of the tested metals were determined by atomic absorption spectrophotometry (AAS) or inductively coupled plasma-mass spectrometry (ICP-MS). Dose–response analysis was performed in PROAST software (version 70.1). The model averaging method was used to calculate the Benchmark dose interval (BMDI). A dose–response relationship has been established between all metals and hormones. The narrowest BMDI was found for the As-testosterone and Hg-testosterone. Levels estimated to produce the extra risk of testosterone serum levels disturbances of 10% were lower than median levels measured in the general population. Moreover, this research suggests the possibility of use of the BMD approach in analyzing data pool generated from extensive human-biomonitoring studies.

Primary, secondary and compensated male biochemical hypogonadism in people living with HIV (PLWH): relevance of sex hormone-binding globulin (SHBG) measurement and comparison between liquid chromatography-tandem mass spectrometry (LC-MS/MS) and chemiluminescent immunoassay for sex steroids assay

BACKGROUND

Data about classification of hypogonadism and estrogen deficiency in male people living with HIV (PLWH) are scanty.

AIM

To investigate the prevalence and characterization of biochemical hypogonadism and relative estrogen deficiency in male PLWH aged < 50 comparing liquid chromatography-tandem mass spectrometry (LC-MS/MS) with chemiluminescent immunoassay (CI), and combining gonadotropin, sex hormone-binding globulin (SHBG) and serum estradiol (E2) measurements.

METHODS

Prospective, cross-sectional, observational study. Serum total testosterone (TT), E2, gonadotropins, SHBG were measured by CI. TT and E2 were also assessed by LC-MS/MS. Free testosterone (cFT) was calculated by Vermeulen equation.

RESULTS

A total of 316 PLWH (45.3 ± 5.3 years) were enrolled. TT and cFT by LC-MS/MS were lower compared to CI (p < 0.0001). The prevalence of biochemical hypogonadism was higher with LC-MS/MS than CI, both for TT (5.1% vs 3.2%, p < 0.0001) or cFT (9.5% vs 7%, p < 0.0001). The prevalence of hypogonadism (overt + compensated) was 17.1% for cFT using LC-MS/MS. Secondary form of hypogonadism was more prevalent than primary. The prevalence of relative estrogen deficiency was of 30.0% among hypogonadal patients and 15.5% among eugonadal.

CONCLUSIONS

The prevalence of male hypogonadism results underestimated by CI compared to LC-MS/MS in PLWH, both for TT and cFT. SHBG and gonadotropins are essential for detecting T deficiency.

Organophosphorus insecticides exposure and sex hormones in general U.S. population: A cross-sectional study

BACKGROUND

Evidence showed organophosphorus (OPs) insecticide exposure is common in general population with endocrine-disrupting effects. However, the association between OPs metabolites and sex hormones remains unclear.

OBJECTIVE

To investigate the association between OPs metabolites and sex hormones.

METHODS

Data of 1438 participants from NHANES 2015-2016 was applied. Urinary OPs metabolites, dialkyl phosphates (DAPs), and serum sex hormones (total testosterone (TT), estradiol (E₂), and sex hormone-binding globulin (SHBG)) were measured. Free androgen index (FAI) and TT/E₂ ratio were also calculated. The generalized linear regression model and restricted cubic spline (RCS) model were employed to evaluate the association and exposure-response curve of DAPs and sex hormones in males and females. The modulation effect of age on their associations in female participants was also explored.

RESULTS

After adjusting for confounding factors, DETP was negatively associated with E₂ (β = -0.03; 95% CI: -0.05, -0.01) and FAI (β = -0.03; 95% CI: -0.06, -0.001) in males. In females, all the four DAP metabolites (DMP, DEP, DMTP, and DETP) were negatively associated with FAI (DMP: β = -0.06, 95% CI: -0.11, -0.01; DEP: β = -0.06, 95% CI: -0.12, -0.01; DMTP: -0.05, 95% CI: -0.09, -0.02; DETP: -0.09, 95% CI: -0.14, -0.04). DETP was also found negatively associated with TT and TT/E₂ ratio in females. The associations between DETP and TT, FAI, and TT/E₂ ratio were modified by gender (P_interaction<0.05). RCS analysis found these associations were in linear decreased exposure-response curves. For females of different age groups, the inverse associations of DETP with TT and FAI remained stable. Decreased FAI with DMP and DMTP was also found in females ≤50 years old.

CONCLUSIONS

Our study indicates OPs metabolites had negative associations with androgen indicators, which was characterized as decreased FAI and E₂ in males and decreased TT, FAI, and TT/E₂ ratio in females, particularly among females ≤50 years old. Further studies are warranted in larger-scale populations.

Association of sex steroid hormones and new bone formation rate after iliac onlay grafting: a prospective clinical pilot study

Purpose

The present prospective study evaluates the association between new bone formation rate in the iliac onlay graft and sex steroid hormone serum levels.

Methods

A total of 15 partially or completely edentulous postmenopausal females and 9 males with less than 5 mm height of the remaining alveolar bone underwent iliac onlay grafting followed by dental implant placement using a two-stage approach. Sex hormone binding globulin and 17β-estradiol serum levels were investigated by electrochemiluminescence immunoassay, while total testosterone level was analyzed using radioimmunoassay. At the time of implant placement, 12 weeks after grafting, bone biopsies were obtained and analyzed histomorphometrically. Statistical analysis was performed using linear mixed models.

Results

Grafting procedure was successfully performed in all patients. The mean new bone formation rate was 32.5% (116 samples). In men the mean new bone formation rate (38.1%) was significantly higher (p < 0.01) than in women (27.6%). Independent of gender 17β-estradiol and testosterone were positively associated to overall new bone formation rate, albeit a significant influence was only seen for 17β-estradiol in men (p = 0.020). Sex hormone binding globulin had no influence on new bone formation rate (p = 0.897). There was no significant association between new bone formation rate and age (p = 0.353) or new bone formation rate and body mass index (p = 0.248).

Conclusion

Positive association of 17ß-estradiol as well as testosterone with new bone formation rate after iliac onlay grafting indicates a role of sex steroid hormones in alveolar bone regeneration, although the observed influence was only significant for 17ß-estradiol in men.

Graphical Abstract

Low endogenous estradiol levels are associated with elevated risk of cardiovascular disease mortality in young and middle-aged men in the United States

BACKGROUND AND AIMS

Evidence for the association of total estradiol (E2) with cardiovascular disease (CVD) in young men is limited. We investigated the association of total E2 or free estradiol (FE2) and CVD mortality in a nationally representative multiracial sample of young and middle-aged men in the United States.

METHODS

Data were from 954 men without CVD, cancer, diabetes and not on androgen therapy or taking anabolic steroids, who participated in the National Health and Nutrition Examination Survey (1988-1991), for whom E2 was measured, and were followed for mortality through to 2015. Fasting serum levels of E2 were measured using competitive electrochemiluminescence immunoassays. Free estradiol was estimated from the levels of estradiol, sex hormone binding globulin, and albumin. International Classification of Diseases codes were used to define CVD mortality. Cox regression models were used to calculate hazard ratios (HR) and 95% confidence intervals (CI).

RESULTS

The average age of participants at baseline was 35.7 ± 11.6 years, with 11% and 6% reporting Black and Hispanic race and ethnicity, respectively. During a median follow-up of 25.2 years, 40 CVD deaths were recorded. Controlling for baseline demographic and CVD risk factors, and total testosterone levels, a 1 standard deviation decrement in log E2 (HR: 2.33, 95%CI: 1.11-5.00) or FE2 (HR: 1.89, 95%CI: 1.01-3.57) was associated with elevated risk of CVD mortality. This elevated risk was largely limited to non-Hispanic White men.

CONCLUSIONS

In this study, low levels of E2 or FE2 were associated with elevated risk of CVD mortality.

Effects of oestradiol treatment on hot flushes in men undergoing androgen deprivation therapy for prostate cancer: a randomised placebo-controlled trial

OBJECTIVE

Most men undergoing androgen deprivation therapy (ADT) for prostate cancer experience hot flushes. Current treatments have low or limited evidence of efficacy. It is likely that oestradiol depletion is the mediator of these hot flushes, and transdermal oestradiol might be an effective treatment.

DESIGN

This is a 6-month randomised, placebo-controlled trial with the hypothesis that oestradiol would reduce hot flush frequency and intensity and improve quality of life (QoL).

METHODS

Seventy-eight participants receiving ADT were randomised to 0.9 mg of 0.1% oestradiol gel per day or matched placebo. Hot flush frequency and severity were assessed by 7-day diary at baseline, month 1, month 3, and month 6. QoL was assessed by validated questionnaire.

RESULTS

Oestradiol reduced daily hot flush frequency, with a mean adjusted difference (MAD) of -1.6 hot flushes per day (95% CI: -2.7 to -0.5; P = 0.04). The effect on weekly hot flush score was non-significant, with a MAD -19.6 (95% CI: -35.5 to -3.8; P = 0.11). On per protocol analysis, E2 significantly reduced daily hot flush frequency, with a MAD of -2.2 hot flushes per day (95% CI: -3.2 to -1.1; P = 0.001), and weekly hot flush score, with a MAD of -27.0 (-44.7 to -9.3; P = 0.02). Oestradiol had no significant effect on QoL.

CONCLUSION

We confirmed our hypothesis of a clinical effect of assignment to oestradiol to reduce hot flush frequency in men with castrate testosterone due to ADT. Transdermal oestradiol could be considered for men with burdensome hot flushes in whom other treatments have failed as long as the risk of breast effects and fat gain are considered.

Is paternal oxytocin an oxymoron? Oxytocin, vasopressin, testosterone, oestradiol and cortisol in emerging fatherhood

How do hormonal levels in men change from pregnancy to after the birth of their firstborn child, and what is the role of oxytocin, alone or in interplay with other hormones, in explaining variance in their parenting quality? We explored in 73 first-time fathers the development of five hormones that have been suggested to play a role in parenting: oxytocin (OT), vasopressin (AVP), testosterone (T), oestradiol (E2) and cortisol (Cort). In an extended group of fathers (N = 152) we examined associations with fathers' behaviour with their 2-month-old infants. OT and E2 showed stability from the prenatal to the postnatal assessments, whereas AVP and T decreased significantly, and Cort decreased marginally. OT on its own or in interplay with other hormones was not related to paternal sensitivity. Using an exploratory approach, the interaction between T and E2 emerged as relevant for fathers' sensitive parenting. Among fathers with high E2, high T was associated with lower sensitivity. Although we did not find evidence for the importance of OT as stand-alone hormone or in interplay with other hormones in this important phase in men's lives, the interaction between T and E2 in explaining variation in paternal behaviour is a promising hypothesis for further research. This article is part of the theme issue 'Interplays between oxytocin and other neuromodulators in shaping complex social behaviours'.

Sex differences in the participation of endothelial mediators and signaling pathways involved in the vasodilator effect of a selective GPER agonist in resistance arteries of gonadectomized Wistar rats

AIM

Endothelial mechanisms underlying the vascular effects of estrogen modulated by the G protein-coupled estrogen receptor (GPER) are not well understood, especially in gonadal sex hormone deprivation. Thus, we investigated vascular function and endothelial signaling pathways involved in the selective activation of GPER in resistance arteries of gonadectomized rats.

METHODS

Gonadectomy was performed in Wistar rats of both sexes. After 21 days, the animals were euthanized. Concentration-response curves were obtained by cumulative additions of G-1 in third-order mesenteric arteries. The vasodilatory effects of G-1 were evaluated before and after endothelium removal or incubation with pharmacological inhibitors. Tissue protein expression was measured by western blotting. Assays with 4-amino-5-methylamino-2',7'-difluorofluorescein diacetate (DAF-FM) and 2',7' dichlorodihydrofluorescein-diacetate (DCF-DA) were performed in the arteries investigated. Immunolocalization was assessed by immunofluorescence.

RESULTS

G-1 induced partially endothelium-dependent relaxation in both sexes. The three isoforms of the enzyme nitric oxide synthase contributed to the production and release of nitric oxide in both gonadectomized groups, but the role of inducible nitric oxide synthase is more expressive in males. The mechanistic pathway by which endothelial nitric oxide synthase is phosphorylated appears to differ between sexes, with the rapid signaling pathway phosphatidylinositol-3-kinase/protein kinase B/endothelial nitric oxide synthase (PI3k-Akt-eNOS) being identified for males and mitogen-activated protein kinase/extracellular signal-regulated kinase/endothelial nitric oxide synthase (MEK-ERK-eNOS) for females. The contribution of hydrogen peroxide as an endothelial relaxation mediator seems to be greater in females.

CONCLUSION

These results provide new insights into the effects of estrogen-induced responses via GPER on vascular function in gonadal sex hormone deprivation.

Effects of estradiol on bone in men undergoing androgen deprivation therapy: a randomized placebo-controlled trial

OBJECTIVE

In men, many effects of testosterone (T) on the skeleton are thought to be mediated by estradiol (E2), but trial evidence is largely lacking. This study aimed to determine the effects of E2 on bone health in men in the absence of endogenous T.

DESIGN

This study is a 6-month randomized, placebo-controlled trial with the hypothesis that E2 would slow the decline of volumetric bone mineral density (vBMD) and bone microstructure, maintain areal bone mineral density (aBMD), and reduce bone remodelling.

METHODS

78 participants receiving androgen deprivation therapy for prostate cancer were randomized to 0.9 mg of 0.1% E2 gel daily or matched placebo. The outcome measures were vBMD and microarchitecture at the distal tibia and distal radius by high-resolution peripheral quantitative CT, aBMD at the spine and hip by dual-energy x-ray absorptiometry, and serum bone remodelling markers.

RESULTS

For the primary endpoint, total vBMD at the distal tibia, there was no significant difference between groups, mean adjusted difference (MAD) 2.0 mgHA/cm3 (95% CI: -0.8 to 4.8), P = 0.17. Cortical vBMD at the distal radius increased in the E2 group relative to placebo, MAD 14.8 mgHA/cm3 (95% CI: 4.5 to 25.0), P = 0.005. Relative to placebo, E2 increased estimated failure load at tibia, MAD 250 N (95% CI: 36 to 465), P = 0.02, and radius, MAD 193 N (95% CI: 65 to 320), P = 0.003. Relative to placebo, E2 increased aBMD at the lumbar spine, MAD 0.02 g/cm2 (95% CI: 0.01 to 0.03), P = 0.01, and ultra-distal radius, MAD 0.01 g/cm2 (95% CI: 0.00 to 0.02), P = 0.01, and reduced serum bone remodelling markers.

CONCLUSION

Relative to placebo, E2 treatment increases some measures of bone density and bone strength in men and reduces bone remodelling, effects that occur in the absence of endogenous T.

The male infertility evaluation still matters in the era of high efficacy assisted reproductive technology

Today's reproductive endocrinology and infertility providers have many tools at their disposal when it comes to achieving pregnancy. In the setting of highly efficacious assisted reproductive technology, it is natural to assume that male factor infertility can be overcome by acquiring sperm and then bypassing the male evaluation. In this review, we go through guideline statements and a stepwise male factor infertility evaluation to propose that a thorough male evaluation remains important to optimize pregnancy and live birth. The foundation of this parallel evaluation is referral to a reproductive urologist for the optimization of the male partner, for advanced diagnostics and interventions, and for the detection of other underlying male pathology. We also discuss what future developments might have an impact on the workup of the infertile male.

Ageing male (part 2): Management of functional hypogonadism in older men, a patient-centric holistic approach

The diagnosis of functional hypogonadism should prompt a thorough assessment and optimization of general health, including lifestyle changes, weight reduction, care of comorbidities and cessation of offending medications, some of which can lead to meaningful gains in endogenous testosterone (T) concentrations. Having excluded or addressed reversible causes and contra-indications, patients with functional hypogonadism can be offered a trial of testosterone replacement therapy (TRT) after full discussion on the anticipated benefits and potential risks. T treatment improves libido but may be less effective for erectile dysfunction (ED). T treatment can also have modest positive effects on insulin resistance, bone strength, some measures of physical strength, and mild depressive symptoms but the clinical significance of these relatively short-term improvements remain uncertain in terms of longer-term patient-important outcomes. Initiation of TRT is a joint decision between patient and clinician since longer-term benefits and risks have not been adequately defined.

Ageing male (part I): Pathophysiology and diagnosis of functional hypogonadism

This narrative review summarizes key points of the pathogenesis and diagnosis of the ageing-related decline of testosterone (T) in men. The condition is commonly termed late-onset hypogonadism (LOH), but because it is more often caused by other factors than chronological ageing (obesity and other comorbidities), a more appropriate term is functional hypogonadism (FH). Unlike the classical organic hypogonadism, no anatomical or genetic aberrations are found in FH, and the suppression of T is milder. Moreover, FH can be reversible if the underlying cause (e.g. obesity, chronic disease) is removed/treated. Low serum total T in connection with more specific hypogonadism-associated symptoms (primarily sexual) form the basis of the diagnosis of FH. When T concentrations are borderline, the accuracy of diagnosis can be improved by assessment of free or calculated free T, especially when suppressed SHBG levels (usually related to obesity) are likely. Current data indicate that FH (low T and sexual symptoms) is not a common condition, and it is detectable in about 2% of community-dwelling men aged 40-80 years.

Biomolecular Effects of Dance and Dance/Movement Therapy: A Review

The positive health impacts of dance and dance/movement therapy can be seen all the way down to the molecular level. This narrative-style review illustrates this connection by presenting a collection of clinical and preclinical studies that evaluate the effects of dance activities on hormones and other small-molecule metabolites within the human body. The results of these studies show that dance activities can increase levels of nitric oxide, serotonin, estrogen hormones, and HDL cholesterol, while they can decrease levels of dopamine, serum glucose, serum triglycerides, and LDL cholesterol. Levels of cortisol can either be increased or decreased, depending on the type of dance. Many of these results parallel the biomolecular effects of traditional (non-dance) exercise activities, although some contrasting results can also be seen. The concentrations of these molecules and their distributions throughout the body impact health and a wide variety of disease states. This connection to the molecular level provides a perspective for understanding how it is that dance activities are able to affect larger-scale physiological and psychological responses and lead to the positive health outcomes that are observed in many situations.