Circulating Testosterone as the Hormonal Basis of Sex Differences in Athletic Performance

Reproductive function in men conceived with in vitro fertilization and intracytoplasmic sperm injection

OBJECTIVE

To determine the semen quality and reproductive hormones of men conceived by in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI) compared with men conceived without assisted reproductive technology (ART).

DESIGN

Cohort study.

SETTING

IVF centers in Victoria and the Western Australian Raine Study.

PATIENT(S)

Men conceived with IVF/ICSI and men conceived without ART aged 18-25 years.

INTERVENTION(S)

Clinical review.

MAIN OUTCOME MEASURE(S)

The primary outcome was the prevalence of severe oligozoospermia (sperm concentration, <5 million/mL). The secondary outcomes were total sperm count, total and progressive motility, total motile count, normal morphology, and serum testosterone, luteinizing hormone (LH) and follicle-stimulating hormone (FSH).

RESULTS

There was no difference in the prevalence of severe oligozoospermia between 120 men conceived with IVF/ICSI and 356 men conceived without ART (9% vs. 5.3%). Men conceived with IVF/ICSI had similar sperm concentration, total sperm count, and total motile count but lower mean total (55.3% vs. 60.6%) and progressive (44.7% vs. 53.9%) sperm motility with higher mean normal morphology (8.5% vs. 5.4%). Differences in progressive motility (ß, -9.9; 95% confidence interval [CI], -16.7 - -3.0), normal morphology (ß, 4.3; 95% CI, 3.0-5.7), and proportion with abnormal morphology (adjusted odds ratios, 0.1; 95% CI, 0.04-0.5) remained significant after adjusting for confounders. Men conceived with IVF/ICSI had lower mean FSH (3.3 IU/L) and LH (3.9 IU/L) levels and higher mean testosterone levels (19.1 nmol/L) than controls (4.2 IU/L, 11.0 IU/L, and 16.8 nmol/L).

CONCLUSION

This study of men conceived with IVF/ICSI found similar sperm output to men conceived without ART. Overall, the results are reassuring.

Joint position statement of the International Federation of Sports Medicine (FIMS) and European Federation of Sports Medicine Associations (EFSMA) on the IOC framework on fairness, inclusion and non-discrimination based on gender identity and sex variations

The IOC recently published its framework on fairness, inclusion and non-discrimination based on gender identity and sex variations. This framework is drafted mainly from a human rights perspective, with less consideration for medical/scientific issues. The framework places the onus for gender eligibility and classification entirely on the International Federations (IFs), even though most will not have the capacity to implement the framework. The position of no presumption of advantage is contrary to the 2015 IOC consensus. Implementation of the 2021 framework will be a major challenge for IFs that have already recognised the inclusion of trans and women athletes with differences of sexual development (DSD) using a scientific/medical solution. The potential consequences for sports that need to prioritise fairness or safety could be one of two extremes (1) exclusion of all transgender or DSD athletes on the grounds of advantage or (2) self-identification that essentially equates to no eligibility rules. Exclusion of all transgender or DSD athletes is contrary to the Olympic charter and unlawful in many countries. While having no gender eligibility rules, sport loses its meaning and near-universal support. Athletes should not be under pressure to undergo medical procedures or treatment to meet eligibility criteria. However, if an athlete is fully informed and consents, then it is their free choice to undergo carefully considered or necessary interventions for gender classification for sport to compete fairly and safely in their chosen gender. Free choice is a fundamental human right, but so is the right to fair and safe competition.

The Effect of Age, Biological Maturation and Birth Quartile in the Kinanthropometric and Physical Fitness Differences between Male and Female Adolescent Volleyball Players

BACKGROUND

Differences in kinanthropometric and physical fitness performance between boys and girls usually start during adolescence, as a result of the changes in the hormonal environment that occur with the advance of age and biological maturation; Methods: A total of 96 1st Regional Division players adolescent volleyball players, 48 males, (age = 14.17 ± 1.00 years-old) and 48 females (age = 14.41 ± 1.21 years-old) underwent a kinanthropometric assessment, were asked to perform different physical fitness test and to complete a questionnaire. Chronological age, maturity offset, age at peak height velocity (APHV), and birth quartile were calculated; Results: Statistical differences were observed between male and female players in the APHV (p < 0.001). Male players showed higher values in the bone and muscle-related variables (p < 0.001-0.040), as well as in the strength and power production-related physical tests (p < 0.001-0.012), while the female showed higher values in the fat-related variables (p = 0.003-0.013), and performed better in the flexibility tests. Age, maturity offset, and birth quartile showed to have statistical influence in the differences found between sex groups; Conclusions: There is a clear influence of age and biological maturation on the differences found between sexes in adolescent volleyball players that could be taken into account regarding grouping in early stages.

Sex differences in stretch-induced hypertrophy, maximal strength and flexibility gains

Introduction: If the aim is to increase maximal strength (MSt) and muscle mass, resistance training (RT) is primarily used to achieve these outcomes. However, research indicates that long-duration stretching sessions of up to 2 h per day can also provide sufficient stimuli to induce muscle growth. In RT literature, sex-related differences in adaptations are widely discussed, however, there is a lack of evidence addressing the sex-related effects on MSt and muscle thickness (MTh) of longer duration stretch training. Therefore, this study aimed to investigate the effects of 6 weeks of daily (1 h) unilateral static stretch training of the plantar flexors using a calf-muscle stretching device. Methods: Fifty-five healthy (m = 28, f = 27), active participants joined the study. MSt and range of motion (ROM) were measured with extended and flexed knee joint, and MTh was investigated in the medial and lateral heads of the gastrocnemius. Results: Statistically significant increases in MSt of 6%-15% (p < .001-.049, d = 0.45-1.09), ROM of 6%-21% (p < .001-.037, d = 0.47-1.38) and MTh of 4%-14% (p < .001-.005, d = 0.46-0.72) from pre-to post-test were observed, considering both sexes and both legs. Furthermore, there was a significant higher increase in MSt, MTh and ROM in male participants. In both groups, participants showed more pronounced adaptations in MSt and ROM with an extended knee joint as well as MTh in the medial head of the gastrocnemius (p < .001-.047). Results for relative MSt increases showed a similar result (p < .001-.036, d = 0.48-1.03). Discussion: Results are in accordance with previous studies pointing out significant increases of MSt, MTh and ROM due to long duration static stretch training. Both sexes showed significant increases in listed parameters however, male participants showed superior increases.

The influence of maturation on exercise-induced cardiac remodelling and haematological adaptation

KEY POINTS

It has long been hypothesised that cardiovascular adaptation to endurance training is augmented following puberty. We investigated whether differences in cardiac and haematological variables exist, and to what extent, between endurance-trained vs. untrained, pre- and post-peak height velocity (PHV) children, and how these central factors relate to maximal oxygen consumption. Using echocardiography to quantify left ventricular (LV) morphology and carbon monoxide rebreathing to determine blood volume and haemoglobin mass, we identified that training-related differences in LV morphology are evident in pre-PHV children, with haematological differences also observed between pre-PHV girls. However, the breadth and magnitude of cardiovascular remodelling was more pronounced post-PHV. Cardiac and haematological measures provide significant predictive models for maximal oxygen consumption in children that are much stronger post-PHV, suggesting that other important determinants within the oxygen transport chain could account for the majority of variance in before puberty.

ABSTRACT

Cardiovascular and haematological adaptations to endurance training facilitate greater maximal oxygen consumption, and such adaptations maybe augmented following puberty. Therefore, we compared left ventricular (LV) morphology (echocardiography), blood volume, haemoglobin (Hb) mass (CO-rebreathe) and in endurance-trained and untrained boys (n = 42, age = 9.0-17.1 years, = 61.6±7.2 mL∙kg∙min, and n = 31, age = 8.0-17.7 years, O_2max = 46.5±6.1 mL∙kg∙min, respectively) and girls (n = 45, age = 8.2-17.0 years, O_2max = 51.4±5.7 mL∙kg∙min and n = 36, age = 8.0-17.6 years, O_2max = 39.8±5.7 mL∙kg∙min, respectively). Pubertal stage was estimated via maturity offset, with participants classified as pre- or post-peak height velocity (PHV). Pre-PHV, only a larger LV end-diastolic volume/lean body mass (EDV/LBM) for trained boys (+0.28 mL∙kg^LBM , P = 0.007) and a higher Hb mass/LBM for trained girls (+1.65 g∙kg^LBM , P = 0.007) were evident compared to untrained controls. Post-PHV, LV mass/LBM (boys:+0.50 g∙kg^LBM , P = 0.0003; girls:+0.35 g∙kg^LBM , P = 0.003), EDV/LBM (boys:+0.35 mL∙kg^LBM , P<0.0001; girls:+0.31 mL∙kgLBM, P = 0.0004), blood volume/LBM (boys:+12.47 mL∙kg^LBM , P = 0.004; girls:+13.48 mL∙kg^LBM , P = 0.0002.) and Hb mass/LBM (boys:+1.29 g∙kg^LBM , P = 0.015; girls:+1.47 g∙kg^LBM , P = 0.002) were all greater in trained vs. untrained groups. Pre-PHV, EDV (R² _adj = 0.224, P = 0.001) in boys, and Hb mass and interventricular septal thickness (R² _adj = 0.317, P = 0.002) in girls partially accounted for the variance in O_2max . Post-PHV, stronger predictive models were evident via the inclusion of LV wall thickness and EDV in boys (R² _adj = 0.608, P<0.0001), and posterior wall thickness and Hb mass in girls (R² _adj = 0.490, P<0.0001). In conclusion, cardiovascular adaptation to exercise training is more pronounced post-PHV, with evidence for a greater role of central components for oxygen delivery. Abstract figure legend: Schematic diagram depicting cardiac structural and haematological differences between trained and untrained boys and girls, pre-peak height velocity (PHV) and post-PHV alongside cardiac and haematological variables contributions to the variance in O_2max . Cardiac and haematological variables are greater in trained vs. untrained pre-pubertal children, and a greater number and magnitude of differences are observed at post-PHV. These variables provide significant predictive models for maximal oxygen consumption in children and are much stronger post-PHV, suggesting that other important determinants within the oxygen transport chain could account for the majority of variance in O_2max before puberty. This article is protected by copyright. All rights reserved.

Relationships of sex hormones with muscle mass and muscle strength in male adolescents at different stages of puberty

This study analysed the associations of sex steroids with fat-free mass (FFM) and handgrip strength in 641 Chinese boys. Serum total testosterone (TT) and oestradiol were measured by chemiluminescence immunoassay. Free testosterone (FT) and oestradiol were calculated. FFM and handgrip strength were measured by bioelectrical impedance analysis and a hand dynamometer, respectively. Generalised additive models and multiple linear regression were used to explore the relationships. A subgroup analysis was conducted in early-mid pubertal and late-post pubertal groups. Age, height, weight, physical activity, intake of dietary protein and/or stage of puberty were adjusted. TT and FT were positively related to FFM and handgrip strength, with a curvilinear relationship being detected for handgrip strength (p<0.050). This curvilinear relationship was only observed in the late-post pubertal group, suggesting a potential threshold effect (FT>11.99ng/dL, β = 1.275, p = 0.039). In the early-mid pubertal group, TT and/or FT were linearly or near-linearly related to FFM or handgrip strength (β = 0.003-0.271, p<0.050). The association between FT and FFM was stronger than that in the late-post pubertal group. This study found that serum T had different associations with muscle parameters in Chinese early-mid pubertal and late-post pubertal boys. In the late-post pubertal boys, serum T was curvilinearly related to muscle strength with a threshold effect and its link with muscle mass was weaker.

Cardiovascular Health of Youth During Gender-Affirming Testosterone Treatment: A Review

PURPOSE

Many birth-assigned female/transgender male and nonbinary people (identified as masculine spectrum here) begin gender-affirming testosterone therapy by the age of 24 years. Few data inform assessment of cardiovascular health of masculine spectrum youth as a specific subgroup of the 1.5 million transgender people in the United States. The purpose of this review is to help youth-serving practitioners consider, understand, and evaluate cardiovascular health in adolescent and young adult masculine spectrum patients receiving gender-affirming testosterone treatment.

METHODS

This is a narrative review intended to synthesize a broad body of clinical and research literature.

RESULTS

Common cardiovascular health changes associated with testosterone include increased red blood cell mass and likely insignificant changes in high-density lipoprotein and low-density lipoprotein levels. Changes in heart mass, heart electrophysiology, and endothelial reactivity are likely, based on extrapolation of data from adults. Testosterone may have indirect effects on cardiovascular health through influences on depression, anxiety, stress, and anorexia nervosa as well as on behaviors such as tobacco use.

CONCLUSIONS

Testosterone contributes importantly to the cardiovascular health and well-being of masculine spectrum gender-diverse youth. We need to do a better job of supporting these young people with data on cardiovascular health over the life span.

Depot Pure GnRH Antagonist for Long-term Treatment of Ovarian Hyperthecosis Monitored by Multisteroid LCMS Profiling

Ovarian hyperthecosis (OHT), severe hyperandrogenism after menopause in the absence of ovarian or adrenal tumors, is usually treated by surgical excision. We report a 58-year-old woman presenting with severe hyperandrogenism (serum testosterone 15.7-31.0 nmol/L, normal female <1.8 nmol/L) with menopausal gonadotropins and virilization but no adrenal or ovarian lesions. Multisteroid profiling by liquid chromatography mass spectrometry (LCMS) of adrenal and ovarian vein samples identified strong gradients in the left ovarian vein (10- to 30-fold vs peripheral blood in 17OHP₄, 17 hydroxyprogesterone, 17 hydroxypregnenolone, androstenedione, testosterone, dehydroepiandrosterone) but the right ovarian vein could not be cannulated with the same findings in a second ovarian vein cannulation. OHT diagnosis was confirmed by an injection of a depot pure gonadotropin-releasing hormone (GnRH) antagonist (80 mg Degarelix, Ferring) producing a rapid (<24 hour) and complete suppression of ovarian steroidogenesis as well as serum luteinizing hormone and follicle-stimulating hormone lasting at least 8 weeks, with reduction in virilization but injection site reaction and flushing and vaginal spotting ameliorated by an estradiol patch. Serum testosterone remained suppressed at 313 days after the first dose despite recovery of menopausal gonadotropins by day 278 days. This illustrates use of multisteroid LCMS profiling for confirmation of the OHT diagnosis by ovarian and adrenal vein sampling and monitoring of treatment by peripheral blood sampling. Injection of a depot pure GnRH antagonist produced rapid and long-term complete suppression of ovarian steroidogenesis maintained over 10 months. Hence a depot pure GnRH antagonist can not only rapidly confirm the OHT diagnosis but also induce long-term remission of severe hyperandrogenism without surgery.

SPORTS AND PERFORMANCE IN THE TRANSGENDER POPULATION: A SYSTEMATIC REVIEW AND META-ANALYSIS

ABSTRACT Introduction: The debate surrounding the regulations on the participation of transgender individuals in sports is not recent, but it is still ongoing. Some sports organizations are more flexible in this regard, while others are more conservative. Objective: Through a systematic review and meta-analysis, this study summarizes the scientific evidence of the effects of cross-sex hormone therapy on muscle strength, hematocrit, and hemoglobin measurements, parameters that seem to be linked to sports performance. Methods: We conducted electronic searches for manuscripts published before November 20th, 2020. Studies published in three different databases (PubMed, SciELO, and Lilacs) were included, without any time or language restriction, and using keywords such as “transgender”, “gender dysphoria”, “strength”, “hematocrit”, and “hemoglobin”. The PRISMA systematization was used for the elaboration of this review, while a meta-analysis was conducted to mathematically evidence the results. The meta-analysis was performed using the random effect model, to find the pooled estimate effect of cross-sex hormone therapy on the parameters analyzed. Results: The electronic search retrieved 21 articles that were eligible for inclusion. Cross-sex hormone therapy influenced the three parameters analyzed in almost all the studies. Overall, there was a significant increase in muscle strength in female-to-males (FtMs), per muscle group analyzed: +17.7% (95% confidence interval [CI]14.9;20.6). In male-to-females (MtFs) the results of the muscle strength analysis were more controversial, but the pooled estimate effect showed a decrease: −3.6% (95% confidence interval [CI] −6.6; −0.6). Conclusion: Muscle strength, hematocrit, and hemoglobin were altered as a result of cross-sex hormone therapy in both FtMs and MtFs. However, there was a lack of studies comparing the transgender individuals to the population of the same desired gender. Such studies are needed, to better infer rules for the participation of transgender athletes in Olympic sports. Level of Evidence I; Systematic Review and Meta-analysis.

Associations of serum androgens with coronary heart disease and interaction with age: The Henan Rural Cohort Study

BACKGROUND AND AIMS

We aimed to investigate the associations of testosterone and androstenedione with coronary heart disease, and the interaction effect of testosterone or androstenedione and age on coronary heart disease.

METHODS AND RESULTS

A total of 6178 participants were included in this study. Serum testosterone and androstenedione were detected by liquid chromatography-tandem mass spectrometry. Logistic regression and restricted cubic splines were used to assess the independent effects of testosterone and androstenedione on coronary heart disease. Interactive plots were employed to examine the interaction effects of testosterone or androstenedione with age on coronary heart disease. After adjusting for multiple variables, serum testosterone and androstenedione levels were negatively associated with coronary heart disease in males (tertile 3 vs tertile 1, odd ratio (OR) = 0.56, 95% confidence interval (CI) (0.33, 0.96), and OR = 0.40, 95% CI (0.22, 0.74)). Per 1 unit increase in ln-testosterone and ln-androstenedione was associated with a 24% (OR = 0.76, 95% CI (0.63, 0.91)) and 30% (OR = 0.69, 95% CI (0.55, 0.86)) lower risk of coronary heart disease, respectively. Additionally, the positive association of age with coronary heart disease was attenuated by increasing concentrations of ln-testosterone and ln-androstenedione concentration in males.

CONCLUSIONS

The results indicated that serum testosterone and androstenedione were negatively associated with coronary heart disease risk in Chinese rural males. To some extent, this study supports the application of hormone therapy in males with coronary heart disease, which can contribute to reducing the burden of coronary heart disease and related cardiovascular disease.

A Botanical Product Containing Cistanche and Ginkgo Extracts Potentially Improves Chronic Fatigue Syndrome Symptoms in Adults: A Randomized, Double-Blind, and Placebo-Controlled Study

Dietary therapy may be beneficial in alleviating symptoms of chronic fatigue syndrome (CFS), a disorder that is characterized by extreme fatigue and other symptoms, but the cause of which remains unclear. The aim of this study was to evaluate the protective effect of a botanical product containing cistanche (Cistanche tubulosa [Schenk] Wight) and ginkgo (Ginkgo biloba L.) extracts on adults with CFS in a randomized, double-blind, placebo-controlled clinical trial. A total of 190 subjects (35-60 years old, non-obese) with CFS were randomized to receive one tablet of a low dose (120-mg ginkgo and 300-mg cistanche), a high dose (180-mg ginkgo and 450-mg cistanche) or a placebo once daily for 60 days. Blood samples and responses on the Chalder fatigue scale (CFQ 11), the World Health Organization's quality of life questionnaire (WHOQOL), and the sexual life quality questionnaire (SLQQ) were collected at baseline and post-intervention. CFS symptoms of impaired memory or concentration, physical fatigue, unrefreshing sleep, and post-exertional malaise were significantly improved (p < 0.001) in both of the treatment groups. The botanical intervention significantly decreased physical and mental fatigue scores of CFQ 11 and improved WHOQOL and SLQQ scores of the subjects (p < 0.01). Levels of blood ammonia and lactic acid in the treatment groups were significantly lower than those of the placebo group (low-dose: p < 0.05; high-dose: p < 0.01). In addition, the change in lactic acid concentration was negatively associated with the severity of CFS symptoms (p = 0.0108) and was correlated with the change in total physical fatigue score of the CFQ (p = 0.0302). Considering the trivial effect size, the results may lack clinical significance. In conclusion, this botanical product showed promising effects in ameliorating the symptoms of CFS. Clinical trials with improved assessment tools, an expanded sample size, and an extended follow-up period are warranted to further validate the findings. Clinical Trial Registration: https://clinicaltrials.gov/, identifier: NCT02807649.

Detection of testosterone microdosing in healthy females

The ready detectability of synthetic androgens by mass spectrometry (MS)-based antidoping tests has reoriented androgen doping to using testosterone (T), which must be distinguished from its endogenous counterpart making detection of exogenous T harder. We investigated urine and serum steroid and hematological profiling individually and combined to determine the optimal detection model for T administration in women. Twelve healthy females provided six paired blood and urine samples over 2 weeks prior to treatment consisting of 12.5-mg T in a topical transdermal gel applied daily for 7 days. Paired blood and urine samples were then obtained at the end of treatment and Days 1, 2, 4, 7, and 14 days later. Compliance with treatment and sampling was high, and no adverse effects were reported. T treatment significantly increased serum and urine T, serum dihydrotestosterone (DHT), urine 5α-androstane-3α,17β-diol (5α-diol) epitestosterone (E), and urine T/E ratio with a brief window of detection (2-4 days) as well as total and immature (medium and high fluorescence) reticulocytes that remained elevated over the full 14 posttreatment days. Carbon isotope ratio MS and the OFF score and Abnormal Blood Profile score (ABPS) were not discriminatory. The optimal multivariate model to identify T exposure combined serum T, urine T/E ratio with three hematological variables (% high fluorescence reticulocytes, mean corpuscular hemoglobin, and volume) with the five variables providing 93% correct classification (4% false positive, 10% false negatives). Hence, combining select serum and urine steroid MS variables with reticulocyte measures can achieve a high but imperfect detection of T administration to healthy females.

Testosterone, estradiol, DHEA and cortisol in relation to anxiety and depression scores in adolescents

Background Adrenal and sex hormone dysregulation have been independently associated with increased depression and anxiety. Cortisol can modify production of sex hormones and hormone-mood associations. This study evaluated associations and interplay of sex and adrenal hormones with depression and anxiety. Methods We assessed 545 Ecuadorian adolescents (11-17y, 50.4% female, ESPINA) for depression and anxiety symptoms using standardized scales. Testosterone, cortisol, dehydroepiandrosterone (DHEA), and estradiol (boys only) were measured in saliva. We performed logistic regression modeling to calculate odds ratios (OR) of elevated depression or anxiety (scores ≥60) comparing participants with low (<10th percentile) and elevated hormones (≥90th percentile) to normal concentrations (10th-90th percentile). Effect modification by cortisol and testosterone was assessed. Models adjusted for demographic, anthropometric, and circadian measures. Results In all participants, elevated testosterone (OR [95%CI:]=1.78 [0.98, 3.23]) and cortisol (OR=1.69 [0.95, 2.99]) were marginally associated with elevated anxiety scores. In boys, elevated estradiol was associated with elevated depression (OR=4.75 [1.95, 11.56]) and anxiety scores (OR=2.43 [1.01, 5.84]). In linear regression, estradiol was positively associated with depression (difference/10% hormone increase (β=0.45 [0.15, 0.75]) and anxiety scores (β=0.42 [0.13, 0.72]). Higher cortisol levels strengthened the depression association with estradiol in boys (β=0.54 [0.12, 0.96]), and with testosterone (β= -0.19 [-0.35, -0.03]) and DHEA (β= -0.12 [-0.22, -0.02]) in girls. Testosterone also modified associations. Limitations This was a cross-sectional analysis. Discussion Elevated testosterone, cortisol, and estradiol (≥90th percentile) were associated with altered mood. Cortisol and testosterone were considerable effect modifiers to the associations of most hormones with depression and anxiety.

Female Hyperandrogenism in Elite Sports and the Athletic Triad

Essential hyperandrogenism seems to be overrepresented in female elite athletes. This applies to mild forms such as polycystic ovary syndrome, as well as rare differences/disorders of sex development (DSD). The reason is likely a selection bias since there is increasing evidence that androgens are beneficial for athletic performance by potent anabolic effects on muscle mass and bone mass, and stimulation of erythropoiesis. XY DSD may cause a greatly increased production of testosterone in the male range, that is, 10 to 20 times higher than the normal female range. The established regulations concerning the eligibility of female athletes with severe hyperandrogenism to compete in the female classification remain controversial. The most common cause of menstrual disorders in female athletes, however, is probably an acquired functional hypothalamic disturbance due to energy deficiency in relation to energy expenditure, which could lead to low bone mineral density and increased risk of injury. This condition is particularly common in endurance and esthetic sports, where a lean body composition is considered an advantage for physical performance. It is important to carefully evaluate endocrine disturbances and menstrual disorders in athletes since the management should be specific according to the underlying cause.

Influence of Female Sex Hormones on Ultra-Running Performance and Post-Race Recovery: Role of Testosterone

In recent years, increasing numbers of women have participated in extremely long races. In adult males, there is a clear association between physiological levels of endogenous sex hormones and physical performance. However, the influence of plasmatic sex hormones and the effects of different types of hormonal contraception (HC) on the modulation of physical performance in adult females remain to be fully clarified. Eighteen female ultra-endurance athletes were recruited to participate in the study. Different variables were studied, including hematological parameters, body mass index, and body composition. Strength measurements were obtained using the squat-jump and hand-grip test. A repeated-measures analysis demonstrated significant differences in hematological values of CK and LDH pre-race as compared to immediately post-race and after 24/48 h. Furthermore, statistical differences were found in squat-jump and hand-grip test results after the ultramarathon. Testosterone, estradiol, and the testosterone/estrogen ratio were significantly correlated with muscle fatigue and were found to be indirect markers of muscle damage. A multivariate analysis demonstrated the protective role of testosterone against muscle damage and severe fatigue. Fluctuations in endogenous testosterone levels were correlated with greater fatigability and muscle damage after the competition. Adjusting the menstrual cycle with HC would not provide any further benefit to the athlete's competitive capacity.

L-Carnitine Tartrate Supplementation for 5 Weeks Improves Exercise Recovery in Men and Women: A Randomized, Double-Blind, Placebo-Controlled Trial

L-carnitine tartrate has been shown to improve relatively short-term recovery among athletes. However, there is a lack of research on the longer-term effects in the general population.

OBJECTIVE

The primary objectives of this randomized double-blind, placebo-controlled trial were to evaluate the effects of daily L-carnitine tartrate supplementation for 5 weeks on recovery and fatigue.

METHOD

In this study, eighty participants, 21- to 65-years-old, were recruited. Participants were split into two groups of forty participants each, a placebo, and a L-carnitine Tartrate group. Seventy-three participants completed a maintenance exercise training program that culminated in a high-volume exercise challenge.

RESULTS

Compared to placebo, L-carnitine tartrate supplementation was able to improve perceived recovery and soreness (p = 0.021), and lower serum creatine kinase (p = 0.016). In addition, L-carnitine tartrate supplementation was able to blunt declines in strength and power compared to placebo following an exercise challenge. Two sub-analyses indicated that these results were independent of gender and age. Interestingly, serum superoxide dismutase levels increased significantly among those supplementing with L-carnitine tartrate.

CONCLUSIONS

These findings agree with previous observations among healthy adult subjects and demonstrate that L-carnitine tartrate supplementation beyond 35 days is beneficial for improving recovery and reducing fatigue following exercise across gender and age.

Testosterone in COVID-19: An Adversary Bane or Comrade Boon

COVID-19 is a pandemic disease caused by severe acute respiratory coronavirus 2 (SARS-CoV-2), which leads to pulmonary manifestations like acute lung injury (ALI) and acute respiratory distress syndrome (ARDS). In addition, COVID-19 may cause extra-pulmonary manifestation such as testicular injury. Both high and low levels of testosterone could affect the severity of COVID-19. Herein, there is substantial controversy regarding the potential role of testosterone in SARS-CoV-2 infection and COVID-19 severity. Therefore, the present study aimed to review and elucidate the assorted view of preponderance regarding the beneficial and harmful effects of testosterone in COVID-19. A related literature search in PubMed, Scopus, Web of Science, Google Scholar, and Science Direct was done. All published articles related to the role of testosterone and COVID-19 were included in this mini-review. The beneficial effects of testosterone in COVID-19 are through inhibition of pro-inflammatory cytokines, augmentation of anti-inflammatory cytokines, modulation of the immune response, attenuation of oxidative stress, and endothelial dysfunction. However, its harmful effects in COVID-19 are due to augmentation of transmembrane protease serine 2 (TMPRSS2), which is essential for cleaving and activating SARS-CoV-2 spike protein during acute SARS-CoV-2 infection. Most published studies illustrated that low testosterone levels are linked to COVID-19 severity. A low testosterone level in COVID-19 is mainly due to testicular injury, the primary source of testosterone.

Urinary Steroid Profile in Elite Female Athletes in Relation to Serum Androgens and in Comparison With Untrained Controls

Introduction

In female athletes, the interpretation of doping tests is complex due to hormonal variations during the menstrual cycle and hormonal contraceptive use, both influencing the urinary steroid profile. Exercise is suggested to affect circulating steroid hormone levels, and in women, the urinary steroid profile differs between in competition testing and out of competition testing. No previous study has investigated the relationship between amount of exercise and the urinary steroid profile in female elite athletes.

Purpose

To compare the urinary steroid profile between female Olympic athletes and age- and BMI-matched untrained controls, and to study the urinary steroid profile in relation to serum hormones and amount of exercise.

Methods

In this cross-sectional study conducted at the Women’s Health Research Unit, Karolinska University Hospital, Stockholm, 94 female elite athletes and 86 untrained controls were included. Serum estrogens and testosterone and the urinary steroid profile were analyzed by liquid chromatography–tandem mass spectrometry and gas chromatography-tandem mass spectrometry, respectively. Exercise hours/week were evaluated by questionnaire.

Results

Although serum steroid hormones were comparable between groups, the athletes demonstrated approximately 30% lower urinary steroid metabolites of testosterone, epitestosterone, androsterone, etiocholanolone, 5α-androstan-3α, 17β-diol, and 5β-androstan-3α, 17β-diol compared to the controls. The urinary steroid metabolites correlated positively with serum steroid hormones. In the athletes, urinary steroid metabolites: androsterone (r_s = −0.28, p = 0.007), epitestosterone (r_s = −0.22, p = 0.034), 5αAdiol (r_s = −0.31, p = 0.002) and testosterone (r_s = −0.24, p = 0.026), were negatively correlated with amount of training (hours per week).

Conclusion

The urinary concentrations of steroid metabolites were lower in elite athletes than in sedentary controls, although serum steroids were comparable between groups. Moreover, exercise time was negatively associated with the urinary concentrations. Our findings suggest alternative excretion routes of androgens in the athletes related to training.

Microvessel Density: Integrating Sex-Based Differences and Elevated Cardiovascular Risks in Metabolic Syndrome

Metabolic syndrome (MetS) is a complex pathological state consisting of metabolic risk factors such as hypertension, insulin resistance, and obesity. The interconnectivity of cellular pathways within various biological systems suggests that each individual component of MetS may share common pathological sources. Additionally, MetS is closely associated with vasculopathy, including a reduction in microvessel density (MVD) (rarefaction) and elevated risk for various cardiovascular diseases. Microvascular impairments may contribute to perfusion-demand mismatch, where local metabolic needs are insufficiently met due to the lack of nutrient and oxygen supply, thus creating pathological positive-feedback loops and furthering the progression of disease. Sexual dimorphism is evident in these underlying cellular mechanisms, which places males and females at different levels of risk for cardiovascular disease and acute ischemic events. Estrogen exhibits protective effects on the endothelium of pre-menopausal women, while androgens may be antagonistic to cardiovascular health. This review examines MetS and its influences on MVD, as well as sex differences relating to the components of MetS and cardiovascular risk profiles. Finally, translational relevance and interventions are discussed in the context of these sex-based differences.

Reference data on anthropometrics, aerobic fitness and muscle strength in young Norwegian men and women

Purpose

Anthropometrics, aerobic fitness and muscle strength are measured in one-third of all 18-year-old Norwegian men and women during yearly selection for compulsory military service. The large sample size and geographical representativity make these data valuable for reference. The main purpose of this study was to present reference data for anthropometrics and physical fitness in young Norwegian men and women.

Methods

All 154,659 subjects (66% men and 34% women, 17–21 years old) who completed physical examinations at conscript selection from 2011 to 2019 were included in the study. Body mass index (BMI) was calculated from height and weight measurements. Peak oxygen uptake (VO_2peak) was estimated from performance on a maximal treadmill test. Muscle strength was measured by isometric chest and leg press, or seated medicine ball throw, standing long jump and pull-ups.

Results

Mean BMI (SD) was 23.1 (3.4) and 22.9 (3.3) kg·m⁻² in men and women, respectively (P < 0.001), and 24% of men and 21% of women had a BMI ≥ 25 kg·m⁻². Estimated VO_2peak was 52.9 (4.6) and 42.7 (3.9) mL·kg⁻¹·min⁻¹ in men and women, respectively (P < 0.001). Men performed significantly better than women on all muscle strength tests, with corresponding effect sizes varying from 1.14 for isometric leg press to 2.96 for seated medicine ball throw.

Conclusion

The presented reference data on physical fitness in young Norwegian men and women can be used to evaluate population health, serve as reference material for future studies and describes sex differences in several physical fitness parameters.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00421-021-04784-4.

Sexual Dimorphism in the Functional Development of the Cochlear Amplifier in Humans

OBJECTIVES

Otoacoustic emissions, a byproduct of active cochlear mechanisms, exhibit a higher magnitude in females than in males. The relatively higher levels of androgen exposure in the male fetus are thought to cause this difference. Postnatally, the onset of puberty is also associated with the androgen surge in males. In this study, we investigated sexual dimorphism in age-related changes in stimulus-frequency otoacoustic emissions for children.

DESIGN

In a retrospective design, stimulus-frequency otoacoustic emissions were analyzed from a cross-sectional sample of 170 normal-hearing children (4 to 12 years) and 67 young adults. Wideband acoustic immittance and efferent inhibition measures were analyzed to determine the extent to which middle ear transmission and efferent inhibition can account for potential sex differences in stimulus-frequency otoacoustic emissions.

RESULTS

Male children showed a significant reduction in otoacoustic emission magnitudes with age, whereas female children did not show any such changes. Females showed higher stimulus-frequency otoacoustic emission magnitudes compared with males. However, the effect size of sex differences in young adults was larger compared with children. Unlike the otoacoustic emission magnitude, the noise floor did not show sexual dimorphism; however, it decreased with age. Neither the wideband absorbance nor efferent inhibition could account for the sex differences in stimulus-frequency otoacoustic emissions.

CONCLUSIONS

The cochlear-amplifier function remains robust in female children but diminishes in male children between 4 and 12 years of age. We carefully eliminated lifestyle, middle ear, and efferent factors to conclude that the androgen surge associated with puberty likely caused the observed masculinization of stimulus-frequency otoacoustic emissions in male children. These findings have significant theoretical consequences. The cochlea is considered mature at birth; however, the present findings highlight that functional cochlear maturation, as revealed by otoacoustic emissions, can be postnatally influenced by endogenous hormonal factors, at least in male children. Overall, work reported here demonstrates sexual dimorphism in the functional cochlear maturational processes during childhood.

Prevalence of polycythaemia with different formulations of testosterone therapy in transmasculine individuals

BACKGROUND

Masculinising hormone therapy with testosterone is used to align an individual's physical characteristics with his or her gender identity. Testosterone therapy is typically administered via intramuscular or transdermal routes, and polycythaemia is the most common adverse event.

AIMS

To compare the risk of polycythaemia with different formulations of testosterone therapy in transmasculine individuals.

METHODS

A retrospective cross-sectional analysis was undertaken of transmasculine individuals at a primary and secondary care clinic in Melbourne, Australia. A total of 180 individuals who were on testosterone therapy for >6 months was included. Groups included those receiving: (i) intramuscular testosterone undecanoate (n = 125); (ii) intramuscular testosterone enantate (n = 31); or (iii) transdermal testosterone (n = 24). Outcome was prevalence of polycythaemia (defined as haematocrit > 0.5).

RESULTS

Mean age was 28.4 (8.8) years, with a median duration of testosterone therapy of 37.7 (24.2) months; 27% were smokers. There was no difference between groups in serum total testosterone concentration measured. While there was no difference between groups in haematocrit, there was a higher proportion of patients with polycythaemia in those who were on intramuscular testosterone enantate (23.3%) than on transdermal testosterone (0%), P = 0.040. There was no statistically significant difference in polycythaemia between intramuscular testosterone undecanoate (15%) and transdermal testosterone, P = 0.066 nor between intramuscular testosterone enantate and undecanoate, P = 0.275.

CONCLUSIONS

One in four individuals treated with intramuscular testosterone enantate and one in six treated with testosterone undecanoate had polycythaemia. No individual treated with transdermal testosterone had polycythaemia. This highlights the importance of regular monitoring of haematocrit in transmasculine individuals treated with testosterone, and findings may inform treatment choices.

Anabolic-Androgenic Steroid Use in Sports, Health, and Society

This consensus statement is an update of the 1987 American College of Sports Medicine (ACSM) position stand on the use of anabolic-androgenic steroids (AAS). Substantial data have been collected since the previous position stand, and AAS use patterns have changed significantly. The ACSM acknowledges that lawful and ethical therapeutic use of AAS is now an accepted mainstream treatment for several clinical disorders; however, there is increased recognition that AAS are commonly used illicitly to enhance performance and appearance in several segments of the population, including competitive athletes. The illicit use of AAS by competitive athletes is contrary to the rules and ethics of many sport governing bodies. Thus, the ACSM deplores the illicit use of AAS for athletic and recreational purposes. This consensus statement provides a brief history of AAS use, an update on the science of how we now understand AAS to be working metabolically/biochemically, potential side effects, the prevalence of use among athletes, and the use of AAS in clinical scenarios.

Long-term exposure to particulate matter and residential greenness in relation to androgen and progesterone levels among rural Chinese adults

BACKGROUND

Population-based studies on the associations of long-term exposure to particulate matter (PM) with androgen and progesterone are still scant. Residential greenness is benefits health by promoting physical activity, reducing air pollution, and improving mental health, but it remains unclear whether it is related to androgen and progesterone levels among humans.

AIMS

This study aimed to explore the individual and interactive effects of PM and residential greenness on serum testosterone and progesterone levels among rural Chinese adults.

METHODS

A total of 6017 subjects were recruited from the baseline of the Henan Rural Cohort Study in 2016. Serum testosterone and progesterone were measured with liquid chromatography-tandem mass spectrometry. Particulate matters (PM) (PM₁, PM_2.5, and PM₁₀) were assessed by machine learning algorithms. Residential greenness was assessed using the normalized difference vegetation index (NDVI) within 500-m, 1000-m, and 3000-m buffers around participants' residences. The effects of air pollutants and residential greenness and their interaction on serum testosterone and progesterone levels were assessed using linear mixed-effects models with township as a random intercept.

RESULTS

After adjusting for potential confounding factors, a 1 μg/m³ increase in PM_2.5 or PM₁₀ was associated with a 0.037 or 0.030 ng/ml increase in serum testosterone, respectively, in females and with a 0.111 or 0.182 ng/ml decrease in serum progesterone, respectively, in males. A 1 μg/m³ increase in PM₁, PM_2.5 or PM₁₀ was associated with a 0.222, 0.306, or 0.295 ng/ml decrease in serum progesterone, respectively, among females. Moreover, a 0.1-unit increase in NDVI was associated with a 0.310 ng/ml increase in serum testosterone and a 0.170 ng/ml increased in serum progesterone in males, as well as with a 0.143 ng/ml increase in serum progesterone in females. Interaction effects of PM and residential greenness on serum testosterone and progesterone levels were observed, indicating that the effects of residential greenness on serum testosterone and progesterone were modified by high levels of PM. In addition, physical activity significantly mediated 2.92% of the estimated association between greenness and testosterone levels.

CONCLUSIONS

Our study suggested that long-term exposure to PM was positively associated with serum testosterone in males but negatively associated with progesterone levels in both genderssin. In addition, positive associations of residential greenness with serum testosterone and progesterone levels were observed, but they were modified by high levels of PM. Furthermore, the estimated effects of residential greenness on testosterone levels were partly mediated by physical activity.

Obesity, but not hyperandrogenism or insulin resistance, predicts skeletal muscle mass in reproductive-aged women with polycystic ovary syndrome: A systematic review and meta-analysis of 45 observational studies

Women with polycystic ovary syndrome (PCOS) exhibit reduced muscle insulin-mediated glucose uptake, potentially attributed to altered muscle mass; however, this is inconclusive. Altered muscle mass may aggravate PCOS complications. Our systematic review and meta-analysis evaluated whether PCOS alters muscle mass and function. Databases (MEDLINE, Web of Science, Scopus) were searched through September 2, 2020, for studies documenting skeletal muscle mass (lean tissue mass) and function (strength) in PCOS and control groups. The primary outcome was total lean body mass (LBM) or fat-free mass (FFM). Data were pooled by random-effects models and expressed as mean differences and 95% confidence intervals. Forty-five studies (n = 3676 participants) were eligible. Women with PCOS had increased total (0.83 [0.08,1.58] kg; p = 0.03; I²  = 72.0%) yet comparable trunk (0.84 [-0.37,2.05] kg; p = 0.15; I²  = 73.0%) LBM or FFM versus controls. Results of meta-regression analyses showed no associations between mean differences between groups in total testosterone or homeostatic model assessment of insulin resistance and total or trunk LBM or FFM (All: p ≥ 0.75). Mean differences in body mass index (BMI) were associated with total (0.65 [0.23,1.06] kg; p < 0.01; I²  = 56.9%) and trunk (0.56 [0.11,1.01] kg; p = 0.02; I²  = 42.8%) LBM or FFM. The PCOS subgroup with BMI ≥ 25 kg/m² had greater total LBM or FFM versus controls (1.58 [0.82,2.34] kg; p < 0.01; I²  = 64.0%) unlike the PCOS subgroup with BMI < 25 kg/m² (-0.45 [-1.94,1.05] kg; p = 0.53; I²  = 69.5%). Appendicular lean mass and muscle strength data were contradictory and described narratively, as meta-analyses were impossible. Women with PCOS have higher total and trunk lean tissue mass attributed to overweight/obesity, unlike hyperandrogenism or insulin resistance.

Androgen Misuse and Abuse

Androgens are potent drugs requiring prescription for valid medical indications but are misused for invalid, unproven, or off-label reasons as well as being abused without prescription for illicit nonmedical application for performance or image enhancement. Following discovery and first clinical application of testosterone in the 1930s, commercialization of testosterone and synthetic androgens proliferated in the decades after World War II. It remains among the oldest marketed drugs in therapeutic use, yet after 8 decades of clinical use, the sole unequivocal indication for testosterone remains in replacement therapy for pathological hypogonadism, organic disorders of the male reproductive system. Nevertheless, wider claims assert unproven, unsafe, or implausible benefits for testosterone, mostly representing wishful thinking about rejuvenation. Over recent decades, this created an epidemic of testosterone misuse involving prescription as a revitalizing tonic for anti-aging, sexual dysfunction and/or obesity, where efficacy and safety remains unproven and doubtful. Androgen abuse originated during the Cold War as an epidemic of androgen doping among elite athletes for performance enhancement before the 1980s when it crossed over into the general community to become an endemic variant of drug abuse in sufficiently affluent communities that support an illicit drug industry geared to bodybuilding and aiming to create a hypermasculine body physique and image. This review focuses on the misuse of testosterone, defined as prescribing without valid clinical indications, and abuse of testosterone or synthetic androgens (androgen abuse), defined as the illicit use of androgens without prescription or valid indications, typically by athletes, bodybuilders and others for image-oriented, cosmetic, or occupational reasons.

Exercise Endocrinology: "What Comes Next?"

Endocrinology is a branch of physiology medical science that many exercise scientists are embracing in their research pursuits, so much so that “exercise endocrinology” is now viewed by many as a viable subdiscipline in the field [...]

Interaction between testosterone and obesity on hypertension: A population-based cross-sectional study

BACKGROUND AND AIMS

We aimed to evaluate the effects of serum testosterone, obesity and their interaction on blood pressure (BP) parameters and hypertension among Chinese rural adults.

METHODS

A total of 6199 adults were recruited from the Henan Rural Cohort Study. Serum testosterone was measured by liquid chromatography-tandem mass spectrometry. Logistic regression and linear regression were used to evaluate the association between testosterone, hypertension and BP parameters (including systolic blood pressure (SBP), diastolic blood pressure (DBP), pulse pressure (PP), and mean arterial pressure (MAP)). A generalized linear model was performed to identify the interactive effects of testosterone and obesity on hypertension.

RESULTS

High levels of serum testosterone were associated with a lower prevalence of hypertension in males (odds ratio (OR): 0.69, 95% confidence interval (CI): 0.53, 0.89). After stratification by obesity, observed associations were only found in non-obese males. Each one-unit increase in ln-testosterone was associated with a 1.23 mmHg decrease in SBP, 0.97 mmHg decrease in DBP, and 1.05 mmHg decrease in MAP among males. Moreover, interactive effects between testosterone and obesity on hypertension and BP parameters were found, indicating that protective effects of serum testosterone on hypertension and BP parameters were counteracted and accompanied by increased values of obesity-related indicators in males, and additional testosterone increased BP parameters and prevalence of hypertension at high levels of waist-to-hip ratio and waist-to-height ratio in females.

CONCLUSIONS

Elevated levels of serum testosterone were associated with decreased BP parameters and prevalent hypertension in males, and obesity modifying effects of serum testosterone on BP parameters and hypertension.

Performance Comparisons of Youth Weightlifters as a Function of Age Group and Sex

This study was designed to provide an overview of weightlifting performance as a function of age group and sex and evaluate the potential of countermovement jump height (CMJH) as a tool to gauge performance potential. Data from 130 youth athletes (female, n = 65 & male, n = 65) were used to examine progression of performance (Total and Sinclair total) and the relationship between CMJH and Sinclair total while considering interactions between CMJH and age and/or sex. ANOVAs with post hoc analyses revealed that both totals had a statistical first-order polynomial interaction effect between age group and sex and the difference between age groups of 12-13 and 14-15 years old was statistically greater for male than female. A linear model, developed to examine the relationship, revealed that CMJH and CMJH x sex x age rejected the null hypothesis. Our primary findings are that male youth weightlifters have a higher rate of performance progression, possibly owing to puberty, and CMJH may be a better gauging tool for older male youth weightlifters.

Haemoglobin thresholds to define anaemia in a national sample of healthy children and adolescents aged 1-19 years in India: a population-based study

BACKGROUND

WHO's haemoglobin cutoffs to define anemia were based on five studies of predominantly White adult populations, done over 50 years ago. Therefore, a general re-examination of the existing haemoglobin cutoffs is warranted for global application, in representative healthy populations of children and adults. Such data are scarce in low-income and middle-income countries; however, a 2019, large-scale, nationally representative survey of children and adolescents aged 0-19 years in India (Comprehensive National Nutrition Survey [CNNS]) offered an opportunity for this re-examination. Using this survey, we aimed to assess the age-specific and sex-specific percentiles of haemoglobin and cutoffs to define anaemia in the CNNS population.

METHODS

For this population-based study, we constructed age-specific and sex-specific haemoglobin percentiles from values reported for a defined healthy population in the CNNS, which used rigorous quality control measures during sample collection and in the laboratory analyses. To obtain a healthy population, we excluded participants with iron, folate, vitamin B12, and retinol deficiencies; inflammation; variant haemoglobins (haemoglobin A2 and haemoglobin S); and history of smoking. We considered age-specific and sex-specific 5th percentiles of haemoglobin derived for this healthy population as the study cutoff to define anaemia. We compared these with existing WHO cutoffs to assess significant differences between them at each year of age and sex for quantifying the prevalence of anaemia in the entire CNNS sample.

FINDINGS

Between Feb 24, 2016, and Oct 26, 2018, the CNNS survey collected blood samples from 49 486 individuals. 41 210 participants had a haemoglobin value, 8087 of whom were included in our study and comprised the primary analytical sample. Compared with existing WHO cutoffs, the study cutoffs for haemoglobin were lower at all ages, usually by 1-2 g/dL, but more so in children of both sexes aged 1-2 years and in girls aged 10 years or older. Aanemia prevalence with the study cutoffs was 19·2 percentage points lower than with WHO cutoffs in the entire CNNS sample with valid haemoglobin values across all ages and sexes (10·8% with study cutoffs vs 30·0% with WHO cutoffs).

INTERPRETATION

These findings support the re-examination of WHO haemoglobin cutoffs to define anaemia. Our haemoglobin reference percentiles, derived from healthy participants in a large representative Indian survey, are suitable for national use in India. Substantial variations in the 5th percentile of haemoglobin values across the 1-19 years age range and between sexes argue against constructing common cutoffs in stratified age groups for convenience.

FUNDING

None.

TRANSLATIONS

For the Hindi, Punjabi, Tamil and Kannada translations of the abstract see Supplementary Materials section.

Quantification of testosterone-dependent erythropoiesis during male puberty

NEW FINDINGS

What is the central question of this study? To what extent does testosterone influence haemoglobin formation during male puberty? What is the main finding and its importance? In boys, testosterone might be responsible for about 65% of the increase in haemoglobin mass during puberty. The underlying mechanisms are assumed to be twofold: (i) indirectly, mediated by the increase in lean body mass, and (ii) directly by immediate testosterone effects on erythropoiesis. Thereby, an increase in testosterone of 1 ng/ml is associated with an increase in haemoglobin mass of ∼65 g. These processes are likely to determine endurance performance in adulthood.

ABSTRACT

The amount of haemoglobin during puberty is related to endurance performance in adulthood. During male puberty, testosterone stimulates erythropoiesis and could therefore be used as a marker for later endurance performance. This cross-sectional study aimed to determine the relationship between serum testosterone concentration and haemoglobin mass (Hbmass) in both male and female children and adolescents and to evaluate the possible influences of altitude and training. Three-hundred and thirteen differentially trained boys and girls aged from 9 to 18 years and living at altitudes of 1000 and 2600 m above sea level entered the study. The stage of sexual maturation was determined according to the classification of Tanner. Testosterone was measured by ELISA. Hbmass was determined by CO-rebreathing. Haemoglobin concentration did not change during maturation in girls and was 11% higher during puberty in boys, while Hbmass was elevated by 33% in Tanner stage V compared to stage II in girls (498 ± 77 vs. 373 ± 88 g) and by 95% in boys (832 ± 143 vs. 428 ± 95 g). This difference can most likely be attributed to indirect testosterone influences through an increase in lean body mass (LBM) and to direct testosterone effects on erythropoiesis, which increase the Hbmass by ∼65 g per 1 ng/ml. Altitude and training statuses were not associated with testosterone, but with an increase in Hbmass (altitude by 1.1 g/kg LBM, training by 0.8 g/kg LBM). Changes in Hbmass are closely related to testosterone levels during male puberty. Further studies will show whether testosterone and Hbmass during childhood and adolescence can be used as diagnostic tools for endurance talents.

Frequency and type of adverse analytical findings in athletics: Differences among disciplines

Athletics is a highly diverse sport that contains a set of disciplines grouped into jumps, throws, races of varying distances, and combined events. From a physiological standpoint, the physical capabilities linked to success are quite different among disciplines, with varying involvements of muscle strength, muscle power, and endurance. Thus, the use of banned substances in athletics might be dictated by physical dimensions of each discipline. Thus, the aim of this investigation was to analyse the number and distribution of adverse analytical findings per drug class in athletic disciplines. The data included in this investigation were gathered from the Anti-Doping Testing Figure Report made available by the World Anti-Doping Agency (from 2016 to 2018). Interestingly, there were no differences in the frequency of adverse findings (overall,~0.95%, range from 0.77 to 1.70%) among disciplines despite long distance runners having the highest number of samples analysed per year (~9812 samples/year). Sprinters and throwers presented abnormally high proportions of adverse analytical findings within the group of anabolic agents (p < 0.01); middle- and long-distance runners presented atypically high proportions of findings related to peptide hormones and growth factors (p < 0.01); racewalkers presented atypically high proportions of banned diuretics and masking agents (p = 0.05). These results suggest that the proportion of athletes that are using banned substances is similar among the different disciplines of athletics. However, there are substantial differences in the class of drugs more commonly used in each discipline. This information can be used to effectively enhance anti-doping testing protocols in athletics.

Sarcopenic Characteristics of Active Older Adults: a Cross-Sectional Exploration

BACKGROUND

Ageing is associated with a decline in skeletal muscle mass and function (strength and power), known as sarcopenia. Inadequate dietary protein and inactivity have been shown to accelerate sarcopenia outcomes, occurring at different rates in males and females. Regardless, active older adults who often exceed the exercise guidelines still show signs of sarcopenia. This study aimed to explore the link between age, physical activity, protein intake, and biological sex with skeletal muscle mass, strength, power, and physical capacity/performance in active older adults. Fifty-four active older adults were recruited from this trial and grouped according to age (middle aged: 50-59 years, and older age: ≥ 60 years), exercise volume (low: ≥ 90-149 min/week, moderate: ≥ 150-299 min/week, and high: ≥ 300 min/week), protein intake (low: < 0.8 g/kg body mass (BM), moderate: ≥ 0.8-1.19g /kg BM, and high: ≥ 1.2 g/kg BM), and biological sex (males and females). Skeletal muscle and fat mass (dual X-ray absorptiometry), strength (1-repetition maximum using leg press, chest press, lateral pull down, and hand grip), power (counter movement jump), and general fitness (cardiorespiratory capacity and gait speed) were assessed. Data were grouped based on variables, and a general linear model (ANCOVA) or an independent t test was used to determine between group differences.

RESULTS

Fifty three of the total participants' data were analysed. The middle-aged group had 18%, 11%, and 10% higher leg press, chest press, and lateral pull down, respectively, compared to the older-aged group (p < .05). There were no significant differences between different levels of training volume and any of the outcomes. Higher protein intakes were associated with significantly less body fat mass (p = .005) and a trend towards a higher leg press (p = .053) and higher relative power (W/kg) (p = .056) compared with the moderate and low protein intake groups. Significant differences based on biological sex were observed for all outcomes except for gait speed (p = .611) and cardiorespiratory fitness (p = .147).

CONCLUSIONS

Contributions of age, physical activity, daily protein intake, and biological sex can explain the individual variation in outcomes related to changes in body composition, strength, power, and/or cardiorespiratory fitness in a cohort of active older adults. The preprint version of this work is available on Research Square: https://www.researchsquare.com/article/rs-51873/v1 .

TRIAL REGISTRATION

This trial is registered in the ANZCTR.org.au, no. ACTRN12618001088235 ( https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=375286 ).

Current Concept Review: Inclusion and Analysis of Diverse Study Populations in Orthopaedic Research

As disparities in healthcare access and outcomes have been increasingly identified across medical specialties, the importance of recognizing and understanding the diversity of our patient populations and the influence of individual characteristics such as age, sex, gender, race, and ethnicity on clinical outcomes has been emphasized. Orthopaedic literature has advanced dramatically in the quality and quantity of research generated over the past 25 years, yet a consistent, sustained focus on studying musculoskeletal health in the context of these unique patient-specific variables has not been maintained. The result of this inattention may be the provision of orthopaedic care that is ill-suited for the individual patient whose biologic characteristics, life experiences, and cultural constructs differ from that of the typical research subject. The recent proliferation of meta-analyses-whose intention is to optimize statistical power-likely compounds the problem because improper, inconsistent, or absent categorization of patients in research articles precludes meaningful subgroup analysis. This article describes the current variability in demographic reporting in the orthopaedic literature, highlights the importance of complete, consistent demographic reporting and subgroup analysis, and reviews specific examples of orthopaedic conditions that illustrate how clinical outcomes may be affected by patient-specific variables such as age, sex, gender, race, and ethnicity.

Sex and Age-Group Differences in Strength, Jump, Speed, Flexibility, and Endurance Performances of Swedish Elite Gymnasts Competing in TeamGym

Purpose: To analyze sex and age group differences in strength, jump, speed, flexibility, and endurance performances of TeamGym athletes. Methods: A total of 91 Swedish elite gymnasts (junior female, n = 26, age = 15.4 y; senior female, n = 23, age = 20.0 y; junior male, n = 19, age = 15.6 y; senior male, n = 23, age = 20.6 y) participated in three testing sessions on three separate days. These were: (1) a series of flexibility tests for the lower- and upper-body; (2) strength tests for the lower- and upper-body; and (3) various types of jumps, a 20-m sprint-run, and a 3,000-m run test. Results: Males were 24% stronger in the back squat one-repetition maximum (relative to body mass) compared to females (P < 0.001, H g = 1.35). In the pull-ups and dips, 2.4 and 2.3 times more repetitions were completed by the males compared to the females (both P < 0.001, 0.70 ≤ R ≤ 0.77). However, females were similarly strong as males in the hanging sit-ups test (P = 0.724). The males jumped 29, 34, 33, and 17% higher in the squat jump (SJ), countermovement jump (CMJ), countermovement jump with arm swing (CMJa), and drop jump (DJ), respectively, compared to the females (all P ≤ 0.002, 0.14 ≤η p 2   ≤ 0.60). In the 20-m sprint run, males were 4% faster than females (P < 0.001, R = 0.40). Moreover, the females had significantly better flexibility than the males in the trunk forward bending, front split, and side split tests (all P < 0.001, 0.24 ≤η p 2 ≤ 0.54). In the 3,000-m run test, males were 11% faster than females (P < 0.001,η p 2 ≤ 0.54). Compared to junior athletes, seniors performed better in the pull-ups, dips, SJ, CMJ, CMJa, and 20-m sprint-run tests (all P ≤ 0.012, 0.31 ≤ R ≤ 0.56, 0.16 ≤η p 2 ≤ 0.25), with separate within-sex age-group differences (i.e., juniors vs. seniors) that were significant for the males but not for the females in the SJ, CMJ, CMJa, and 20-m sprint-run tests (males: all P < 0.001, 0.67 ≤ R ≤ 0.69, 1.37 ≤ H g ≤ 2.01; females: all P = 0.298-732). Conclusions: Large sex and age-group differences were observed for most physical performance metrics with specific within-sex age-group differences only observed for male athletes, with male seniors performing better than juniors in the SJ, CMJ, CMJa, and 20-m sprint-run tests.

Sex-based limits to running speed in the human, horse and dog: The role of sexual dimorphisms

Elite performing men continue to record faster record times in running events compared to women. These sex-based differences in running speed and endurance in humans are expected based on sexual dimorphisms that contribute to differences in the determinants of aerobic performance. Comparatively, the sexual dimorphisms contributing to sex-based differences in elite aerobic performance are not ubiquitous across other species that compete in running events. The purpose of this review is to offer a framework and model for ongoing discussions of the physiological determinants and ultimately limits of physical performance. The records for average running speed of champion athletes were delineated by sex for thoroughbred horses, greyhound dogs, and humans. Male and female performances within each of these species are being optimized by training, nutrition, and financial incentives, and are approaching a performance maximum. For horses and greyhounds breeding also plays a role. Analysis of athletic records shows that there is a sex-related difference of ~10% or more in elite athletic performance for humans; however, the upper limit of performance does not appear to be different between sexes for thoroughbred horses and greyhound dogs. In the context of the nil sex differences in running performance in thoroughbreds and greyhounds, we discuss the physiological role of sexual dimorphisms on sex-specific limits to running performance. We highlight that studies on both human and animal performance in athletic events stimulate critical physiological questions and drive novel research.

Mood States and Performance in Elite Canoe Polo Players: The Mediating Role of Stress

Sport performance is characterized by competitive stressful conditions that elicit emotional states. The purpose of the study was to examine whether stress mediated the relationship between mood states and performance. Thirty-two elite canoe polo players from four different Italian teams (16 senior males and 16 senior females), aged between 29 and 38 years old (M = 32.3, SD = 2.71), participated in the study. Measures included level of psychological stress, six mood dimensions, and performance outcome. We also detected the digit ratio-the lower second-to-fourth digit length (2D:4D) ratio-as it was demonstrated to be correlated to high sports performance. The assessment took place one day before the first game of the national competition "ITALY CUP". Male athletes reported lower scores on dysfunctional emotion-related states and on 2D:4D ratio than female athletes. The results of the mediation analysis showed that psychological stress plays a mediating role between moods and performance. Overall, given the limited literature, the findings supported an integrative approach to the study of the linkage between emotion and action in canoe polo.

An Abductive Inference Approach to Assess the Performance-Enhancing Effects of Drugs Included on the World Anti-Doping Agency Prohibited List

Some have questioned the evidence for performance-enhancing effects of several substances included on the World Anti-Doping Agency's Prohibited List due to the divergent or inconclusive findings in randomized controlled trials (RCTs). However, inductive statistical inference based on RCTs-only may result in biased conclusions because of the scarcity of studies, inter-study heterogeneity, too few outcome events, or insufficient power. An abductive inference approach, where the body of evidence is evaluated beyond considerations of statistical significance, may serve as a tool to assess the plausibility of performance-enhancing effects of substances by also considering observations and facts not solely obtained from RCTs. Herein, we explored the applicability of an abductive inference approach as a tool to assess the performance-enhancing effects of substances included on the Prohibited List. We applied an abductive inference approach to make inferences on debated issues pertaining to the ergogenic effects of recombinant human erythropoietin (rHuEPO), beta₂-agonists and anabolic androgenic steroids (AAS), and extended the approach to more controversial drug classes where RCTs are limited. We report that an abductive inference approach is a useful tool to assess the ergogenic effect of substances included on the Prohibited List-particularly for substances where inductive inference is inconclusive. Specifically, a systematic abductive inference approach can aid researchers in assessing the effects of doping substances, either by leading to suggestions of causal relationships or identifying the need for additional research.

Does lunar cycle affect biological parameters in young healthy men?

This study aimed to assess the effects of the lunar cycle on diurnal variation of biological, i.e, hormonal, biochemical, and hematological, profiles of diurnally active healthy men. Blood samples of 20 males were collected on four occasions [full moon (FM) and new moon (NM), in the morning (06:00-07:00 h) and evening (19:00-20:00 h)]. The results showed that melatonin and testosterone levels and neutrophils count were lower during the FM as compared to the NM in the morning (p < .001; d = 4.13, p < .001; d = 3.84, p < .01; d = 0.77, respectively) and evening (p < .001; d = 6.36, p < .001; d = 4.03, p < .05; d = 1.07, respectively) samples. However, cortisol level was higher during the FM compared to the NM, in the morning (p < .001; d = 0.74) and evening (p < .001; d = 3.54). Hemoglobinemia was higher only in the evening during the FM compared to the evening of the NM (p < .01; d = 1.22). In summary, this study confirmed that lunar cycle can affect human biological parameters independently of time of day.

Integrating Transwomen and Female Athletes with Differences of Sex Development (DSD) into Elite Competition: The FIMS 2021 Consensus Statement

Sport is historically designated by the binary categorization of male and female that conflicts with modern society. Sport’s governing bodies should consider reviewing rules determining the eligibility of athletes in the female category as there may be lasting advantages of previously high testosterone concentrations for transwomen athletes and currently high testosterone concentrations in differences in sex development (DSD) athletes. The use of serum testosterone concentrations to regulate the inclusion of such athletes into the elite female category is currently the objective biomarker that is supported by most available scientific literature, but it has limitations due to the lack of sports performance data before, during or after testosterone suppression. Innovative research studies are needed to identify other biomarkers of testosterone sensitivity/responsiveness, including molecular tools to determine the functional status of androgen receptors. The scientific community also needs to conduct longitudinal studies with specific control groups to generate the biological and sports performance data for individual sports to inform the fair inclusion or exclusion of these athletes. Eligibility of each athlete to a sport-specific policy needs to be based on peer-reviewed scientific evidence made available to policymakers from all scientific communities. However, even the most evidence-based regulations are unlikely to eliminate all differences in performance between cisgender women with and without DSD and transwomen athletes. Any remaining advantage held by transwomen or DSD women could be considered as part of the athlete’s unique makeup.

Association of Serum Testosterone and Luteinizing Hormone With Blood Pressure and Risk of Cardiovascular Disease in Middle-Aged and Elderly Men

Background

The age‐related decline in testosterone levels is thought to be of great importance for male aging and cardiovascular diseases. However, data are controversial on whether abnormal sex hormones are linked to the presence of cardiovascular diseases and it is also uncertain how blood pressure modifies the association between testosterone levels and major cardiovascular diseases.

Methods and Results

This is a multicenter, population‐based, cross‐sectional study of 6296 men conducted between 2013 and 2016. Basic information and clinical symptoms were obtained by questionnaires. Blood pressure and plasma levels of total testosterone, sex hormone–binding globulin, luteinizing hormone, and free testosterone were determined in men in a multistage random, cluster sampling in 6 provinces of China. There were 5786 Chinese men (mean [SD] age 55.0 [10.1] years) included after exclusion criteria were applied; 37.2% (2150) of them were diagnosed with hypertension. Total testosterone, free testosterone, and sex hormone–binding globulin were inversely associated with the prevalence of hypertension. Age >65 years or body mass index ≥24 negatively impacted the inverse correlation between testosterone levels and hypertension, whereas smoking and family history of hypertension strengthened the correlation. In participants with grade 2 hypertension, total testosterone was positively associated with the presence of stroke, and luteinizing hormone was also positively correlated with cardiovascular and cerebrovascular diseases.

Conclusions

Lower total testosterone could be a promising risk marker for prevalent hypertension. Both low and high levels of testosterone are associated with greater cardiovascular risk. Primary hypogonadism may be a risk marker for major cardiovascular diseases in men with severe hypertension.

Functional performance of older adults: A comparison between men and women

The objective of this study was to compare the functional performance of community-dwelling older adults of both sexes and investigate the possible mediation aspects that may influence the sex differences regarding socioeconomic and anthropometric characteristics, health status, and quadriceps muscle strength. 233 Brazilian older adults were assessed, and men's and women's sociodemographic data, physical activity level, quadriceps muscle strength, functional performance (gait speed and the SPPB), and history of falls were compared. Sex differences in functional performance were observed even after statistically adjusting the model (age, body mass, income, physical activity level, and occurrence of falls). When quadriceps muscle strength was included in the adjusted model, the sex difference remained only for gait speed. When stature was included in the adjusted model, the sex difference in gait speed disappeared. Our results suggest that the sex difference in functional performance assessed by the SPPB can be explained due to the fact that men are stronger than women. In addition, the sex difference regarding gait speed was explained by the sex difference in stature. Public actions that encourage older women to practice physical activities that promote increased muscle strength can positively interfere with their best functional performance for as long as possible.

Extracts of Phyllostachys pubescens Leaves Represses Human Steroid 5-Alpha Reductase Type 2 Promoter Activity in BHP-1 Cells and Ameliorates Testosterone-Induced Benign Prostatic Hyperplasia in Rat Model

Benign prostatic hyperplasia (BPH) is the most common symptomatic abnormality of the human prostate characterized by uncontrolled proliferation of the prostate gland. In this study, we investigated the effect of bamboo, Phyllostachys pubescens, leaves extract (PPE) on human 5α-reductase type 2 (SRD5A2) gene promoter activity in human prostate cell lines and the protective effect of PPE on a testosterone-induced BPH rat model. PPE repressed human SRD5A2 promoter activity and its mRNA expression. The rats treated with PPE for 4 weeks showed a significantly attenuated prostate weight compared to vehicle control. PPE-treated rats also showed reduced serum dihydrotestosterone, testosterone, prostate-specific antigen, and SRD5A2 levels by testosterone injection. Quantitative real-time polymerase chain reaction showed that PPE treatment significantly decreased mRNA expression of SRD5A2, androgen receptor (AR), proliferating cell nuclear antigen (PCNA), and fibroblast growth factor 2 compared with the vehicle-treated, testosterone-injected rats in the prostate. Furthermore, PPE treatment showed reduced AR, PCNA, and tumor necrosis factor alpha expression in the prostate via immunohistofluorescence staining. In conclusion, oral administration of PPE prevented and inhibited the development and progression of enlarged prostate lesions in testosterone-induced animal models through various anti-proliferative and anti-inflammatory pharmacological effects and induced suppression of SRD5A2 gene expression.

Research gaps in medical treatment of transgender/nonbinary people

With the growing number of transgender and gender-nonbinary individuals who are becoming visible, it is clear that there is a need to develop a rigorous evidence base to inform care practice. Transgender health research is often limited to HIV/AIDS or mental health research and is typically subsumed in larger studies with general LGBTQ focus. Although the number of knowledgeable health care providers remains modest, the model for the medical approach to transgender health is shifting owing to growing social awareness and an appreciation of a biological component. Gender-affirming medicine facilitates aligning the body of the transgender person with the gender identity; typical treatment regimens include hormone therapy and/or surgical interventions. While broadly safe, hormone treatments require some monitoring for safety. Exogenous estrogens are associated with a dose-dependent increase in venous thromboembolic risk, and androgens stimulate erythropoiesis. The degree to which progressing gender-affirming hormone treatment changes cancer risk, cardiac heart disease risk, and/or bone health remains unknown. Guidelines referencing the potential exacerbation of cancer, heart disease, or other disease risk often rely on physiology models, because conclusive clinical data do not exist. Dedicated research infrastructure and funding are needed to address the knowledge gap in the field.

Transgender Women in the Female Category of Sport: Perspectives on Testosterone Suppression and Performance Advantage

Males enjoy physical performance advantages over females within competitive sport. The sex-based segregation into male and female sporting categories does not account for transgender persons who experience incongruence between their biological sex and their experienced gender identity. Accordingly, the International Olympic Committee (IOC) determined criteria by which a transgender woman may be eligible to compete in the female category, requiring total serum testosterone levels to be suppressed below 10 nmol/L for at least 12 months prior to and during competition. Whether this regulation removes the male performance advantage has not been scrutinized. Here, we review how differences in biological characteristics between biological males and females affect sporting performance and assess whether evidence exists to support the assumption that testosterone suppression in transgender women removes the male performance advantage and thus delivers fair and safe competition. We report that the performance gap between males and females becomes significant at puberty and often amounts to 10-50% depending on sport. The performance gap is more pronounced in sporting activities relying on muscle mass and explosive strength, particularly in the upper body. Longitudinal studies examining the effects of testosterone suppression on muscle mass and strength in transgender women consistently show very modest changes, where the loss of lean body mass, muscle area and strength typically amounts to approximately 5% after 12 months of treatment. Thus, the muscular advantage enjoyed by transgender women is only minimally reduced when testosterone is suppressed. Sports organizations should consider this evidence when reassessing current policies regarding participation of transgender women in the female category of sport.