Effects of graded doses of testosterone on erythropoiesis in healthy young and older men

Cardiovascular phenotype of long-term anabolic-androgenic steroid abusers compared with strength-trained athletes

Introduction

Abuse of anabolic‐androgenic steroids (AAS) has been linked to a variety of different cardiovascular (CV) side effects, but still the clinical effects of AAS abuse on CV risk are not clear. The aim of this study was to assess the CV phenotype of a large cohort of men with long‐term AAS use compared with strength‐trained athletes without AAS use.

Methods

Fifty one strength‐trained men with ≥3 years of AAS use was compared with twenty one strength‐trained competing athletes. We verified substance abuse and non‐abuse by blood and urine analyses. The participants underwent comprehensive CV evaluation including laboratory analyses, 12‐lead ECG with measurement of QT dispersion, exercise ECG, 24 h ECG with analyses of heart rate variability, signal averaged ECG, basic transthoracic echocardiography, and coronary computed tomography angiography (CCTA).

Results

Hemoglobin levels and hematocrit were higher among the AAS users compared with non‐users (16.8 vs. 15.0 g/dl, and 0.50% vs. 0.44%, respectively, both p < 0.01) and HDL cholesterol significantly lower (0.69 vs. 1.25 mmol/L, p < 0.01). Maximal exercise capacity was 270 and 280 W in the AAS and the non‐user group, respectively (p = 0.04). Echocardiography showed thicker intraventricular septum and left ventricular (LV) posterior wall among AAS users (p < 0.01 for both), while LV ejection fraction was lower (50 vs. 54%, p = 0.02). Seven AAS users (17%) had evidence of coronary artery disease on CCTA. There were no differences in ECG measures between the groups.

Conclusions

A divergent CV phenotype dominated by increased CV risk, accelerated coronary artery disease, and concentric myocardial hypertrophy was revealed among the AAS users.

Relation of Testosterone, Dihydrotestosterone, and Estradiol With Changes in Outcomes Measures in the Testosterone Trials

CONTEXT

Many effects of testosterone are mediated through dihydrotestosterone (DHT) and estradiol.

OBJECTIVE

To determine the relative contributions of each hormone to the observed effects of testosterone treatment in older men with hypogonadism.

METHODS

Using data from the Testosterone Trials, we assessed the association of changes in total testosterone, estradiol, and DHT levels over 12 months of testosterone treatment with hemoglobin, high-density lipoprotein (HDL) cholesterol, volumetric bone mineral density (vBMD) of lumbar spine, sexual desire, and prostate-specific antigen (PSA). We used random forests to model the associations of predicted mean changes in outcomes with change in each hormone at low, mean, or high change in the other 2 hormones. Stepwise regression models were run to confirm the findings of random forests.

RESULT

Predicted increases in hemoglobin and sexual desire were greater with larger increases in estradiol and were larger with high change in DHT compared with low change in DHT. Greater increases in estradiol were associated with larger decreases in HDL cholesterol; this association did not vary according to changes in DHT or testosterone. Change in vBMD was most robustly associated with change in estradiol and was greater with high change in testosterone and DHT. There was no consistent relation between change in PSA and change in any hormone.

CONCLUSION

Change in estradiol level was the best predictor not only of the change in vBMD and sexual desire but also of the changes in hemoglobin and HDL cholesterol. Consideration of testosterone, estradiol, and DHT together offers a superior prediction of treatment response in older hypogonadal men than testosterone alone.

Role of Nuclear Receptors in Controlling Erythropoiesis

Nuclear receptors (NRs), are a wide family of ligand-regulated transcription factors sharing a common modular structure composed by an N-terminal domain and a ligand-binding domain connected by a short hinge linker to a DNA-binding domain. NRs are involved in many physiological processes, including metabolism, reproduction and development. Most of them respond to small lipophilic ligands, such as steroids, retinoids, and phospholipids, which act as conformational switches. Some NRs are still "orphan" and the search for their ligands is still ongoing. Upon DNA binding, NRs can act both as transcriptional activators or repressors of their target genes. Theoretically, the possibility to modulate NRs activity with small molecules makes them ideal therapeutic targets, although the complexity of their signaling makes drug design challenging. In this review, we discuss the role of NRs in erythropoiesis, in both homeostatic and stress conditions. This knowledge is important in view of modulating red blood cells production in disease conditions, such as anemias, and for the expansion of erythroid cells in culture for research purposes and for reaching the long-term goal of cultured blood for transfusion.

Monitoring of Testosterone Replacement Therapy to Optimize the Benefit-to-Risk Ratio

For hypogonadal men treated with testosterone, the goal is to ensure that benefits are optimized, risks are minimized, and any adverse effects are identified early and managed appropriately. This can best be achieved by careful patient selection, excluding men with contraindications and addressing any modifiable risk factors in those at increased risk. A standardized plan should be used for monitoring that includes evaluation of symptoms, side effects, adherence, and measurement of testosterone and hematocrit. Shared decision making should be used to determine whether to screen for prostate cancer and informed by age, baseline cancer risk, and patient preference.

Effects of long-term testosterone treatment on cardiovascular outcomes in men with hypogonadism: Rationale and design of the TRAVERSE study

BACKGROUND

Testosterone exerts some effects on the cardiovascular system that could be considered beneficial; some other effects may potentially increase the risk of cardiovascular (CV) events. Neither the long-term efficacy nor safety of testosterone treatment has been studied in an adequately-powered randomized trial.

METHODS

The Testosterone Replacement therapy for Assessment of long-term Vascular Events and efficacy ResponSE in hypogonadal men (TRAVERSE) study is a randomized, double-blind, placebo-controlled, parallel group, non-inferiority, multicenter study. Eligible participants are men, 45 to 80 years, with serum testosterone concentration <300 ng/dL and hypogonadal symptoms, who have evidence pre-existing CV disease or increased risk of CV disease. Approximately 6,000 subjects will be randomized to either 1.62% transdermal testosterone gel or a matching placebo gel daily for an anticipated duration of up to 5 years. The primary outcome is CV safety defined by the major adverse CV event composite of nonfatal myocardial infarction, nonfatal stroke, or death due to CV causes. The trial will continue until at least 256 adjudicated major adverse CV event endpoints have occurred to assess whether the 95% (2-sided) upper confidence limit for a hazard ratio of 1.5 can be ruled out. Secondary endpoints include prostate safety defined as the incidence of adjudicated high grade prostate cancer and efficacy in domains of sexual function, bone fractures, depression, anemia, and diabetes.

RESULTS

As of July 1, 2021, 5,076 subjects had been randomized.

CONCLUSIONS

The TRAVERSE study will determine the CV safety and long-term efficacy of testosterone treatment in middle-aged and older men with hypogonadism with or at increased risk of CV disease.

Sex-Specific Differences of Adenosine Triphosphate Levels in Red Blood Cells Isolated From ApoE/LDLR Double-Deficient Mice

In this study for the first time, we investigated the correlation between sex-specific differences in adenosine triphosphate (ATP) levels in red blood cells (RBCs) and their mechanical, biochemical, and morphological alterations during the progression of atherosclerosis in ApoE/LDLR double-deficient (ApoE/LDLR^−/−) mice. Our results indicate that both sex and age affect alterations in RBCs of both ApoE/LDLR^−/− and C57BL/6J mice. When compared with male RBCs, female RBCs were characterized by lower basal ATP and mean corpuscular hemoglobin concentration (MCHC), higher hemoglobin concentration (HGB), mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), deformability, and phosphatidylserine (PS) exposure levels, regardless of age in both, ApoE/LDLR^−/− and C57BL/6J mice. ApoE/LDLR^−/− mice compared with age-matched controls showed lower basal ATP levels regardless of age and sex. Intracellular ATP level of RBCs was decreased solely in senescent female C57BL/6J mice, while it was elevated in males. Basal extracellular ATP levels were 400 times lower than corresponding intracellular level. In conclusion, basal ATP levels, RBC morphology, deformability, PS exposure levels alterations are sex-dependent in mice. Changes in basal ATP levels were correlated with PS exposure and trends of changes in MCV. Trends of changes of the most RBC parameters were similar in both sexes of ApoE/LDLR^−/− mice compared with age-matched controls; however, their kinetics and levels vary greatly between different stages of disease progression.

Clinical characteristics and comorbidities associated with testosterone prescribing in men

OBJECTIVE

Testosterone replacement therapy (TRT) is recommended for the treatment of symptomatic hypogonadism in men. Data on prescription behaviours are, however, limited and conflicting. The objective of this study was to investigate clinical characteristics associated with the likelihood of being prescribed TRT by general practitioners (GP) in North-West London (NWL).

DESIGN

Retrospective cohort study using Discover database of GP-registered patients in NWL between 2015 and 2019.

PATIENTS

We identified 20,299 men aged ≥18 years with serum total testosterone measurement (TT) and without prior TRT prescription records.

MEASUREMENTS

We determined whether TRT was subsequently commenced, while analysing clinical characteristics related to hypogonadism.

RESULTS

Of all men having TT measurement, 19,583 (96.4%) were not commenced on TRT (Group A) and 716 (3.5%) men were commenced on TRT (Group B). Men prescribed TRT (Group B) had higher mean age, body mass index (BMI) and higher risks of hypertension, depression type 2 diabetes and ischaemic heart disease; conversely, men in Group B had lower mean pretreatment TT and were less likely to have prostate cancer. Four-hundred and thirty-six men (24.3%) with TT < 8 nmol/L and symptoms of low libido were not prescribed TRT.

CONCLUSIONS

Our study highlights several factors which may influence the decisions made by clinicians when initiating TRT in primary care. Clearer guidance for clinicians may help to improve the consistency of treatment of men with hypogonadism.

Society for Endocrinology guidelines for testosterone replacement therapy in male hypogonadism

Male hypogonadism (MH) is a common endocrine disorder. However, uncertainties and variations in its diagnosis and management exist. There are several current guidelines on testosterone replacement therapy that have been driven predominantly by single disciplines. The Society for Endocrinology commissioned this new guideline to provide all care providers with a multidisciplinary approach to treating patients with MH. This guideline has been compiled using expertise from endocrine (medical and nursing), primary care, clinical biochemistry, urology and reproductive medicine practices. These guidelines also provide a patient perspective to help clinicians best manage MH.

Prospective study on blood pressure, lipid metabolism and erythrocytosis during and after androgen abuse

Androgen abuse is associated with unfavourable changes in blood pressure, lipid metabolism and erythrocytosis. Most knowledge is based on cross-sectional studies sensitive to bias. We assessed the magnitude of these effects and their recovery in a prospective cohort study which included 100 men (≥18 years) performing an androgen cycle. Clinic visits took place before the cycle, at the end, 3 months after and 1 year after start of the cycle and included measurement of blood pressure, lipid parameters and haematocrit. During androgen use, systolic and diastolic blood pressure increased 6.87 (95% CI 4.34-9.40) and 3.17 mmHg (1.29-5.04) compared to baseline respectively. LDL cholesterol and ApoB increased 0.45 mmol/L (0.29-0.61) and 18.2 mg/dl (13.5-22.8) respectively, whereas HDL cholesterol, ApoA and Lp(a) decreased with 0.40 mmol/L (-0.45 to 0.35), 36.6 mg/dl (30.2-42.9) and 37.6% (13.9-61.3). ANGPTL3 increased 20.3% (7.38-33.2). Mean haematocrit increased 0.03 L/L (0.02-0.03). Three months after the cycle, and 1 year after the start, these parameters returned to baseline. In conclusion, androgen abuse induces small but clinically relevant adverse changes in blood pressure, lipid metabolism and erythrocytosis which are rapidly reversible after cessation. As follow-up was limited to 1 year, the impact of androgen abuse on cardiovascular disease remains uncertain.

Testosterone therapy and secondary erythrocytosis

Secondary erythrocytosis is one of the most common adverse events associated with testosterone therapy (TT). Upon encountering this, clinicians will often either adjust TT dosing, stop therapy, order a phlebotomy, or recommend a combination of these. Despite this, the evidence for secondary polycythemia causing harm during TT is scarce, and the hematocrit-based cutoffs present in multiple guidelines appear to be arbritrarily chosen. In this review, we present the pathophysiology behind TT and secondary erythrocytosis, the evidence connecting TT, secondary erythrocytosis and major adverse cardiovascular events (MACE), and the data supporting varying interventions upon diagnosis of secondary erythrocytosis.

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.

Long-term testosterone undecanoate treatment in the elderly testosterone deficient male: An observational cohort study

BACKGROUND

Quarterly intramuscular injections with long-acting testosterone undecanoate (TU) provide stable serum testosterone concentrations over time and are therefore preferred by many testosterone-deficient patients. However, the use of long-acting TU in elderly patients is limited due to lack of safety and feasibility studies.

OBJECTIVE

To investigate long-acting TU pharmacokinetics and assess differences in treatment regimens and risk of adverse outcomes in younger versus elderly testosterone-deficient patients.

MATERIALS AND METHODS

Single-center longitudinal observational study. Patients who initiated long-acting TU treatment between 2005 and 2010 were included. Elderly patients were born before 1956 and younger patients between 1965 and 1985. TU dose was adjusted yearly through shortening or prolongation of time between injections. Treatment targets were as follows: (1) free testosterone between 0 and -1 SD from the age-adjusted mean, (2) no symptoms of testosterone deficiency, and (3) hematocrit within the normal range.

RESULTS

The study population consisted of 63 elderly and 63 younger patients. Median follow-up time during testosterone replacement was 12.1 years. Increasing intervals between TU injections were performed 44% more often in the elderly compared to younger patients and time between TU injections were prolonged 4% more in the elderly patients. The hematocrit, as well as the hematocrit for a given serum testosterone (hematocrit: testosterone ratio), increased with treatment time but did not differ between age groups. During follow-up, 40% of patients-both elderly and younger-experienced polycythemia. Risk of polycythemia did not differ with age.

DISCUSSION AND CONCLUSION

An increased number of adjustments of TU dose are necessary in elderly patients in order to reach treatment targets. TU treatment in elderly testosterone-deficient patients is not associated with an increased risk of polycythemia compared to younger patients if age-adjusted treatment targets are reached.

The relationship between 2D:4D ratio and postpartum adult female variables in a Ghanaian population

OBJECTIVES

Postpartum hematological and anthropometric assessment is a requirement for optimal maternal and child health. The study aimed to determine the relationship between the 2D:4D ratio and postpartum hematological and anthropometric variables in adult females.

METHODS

The study was cross-sectional from December 2020 to April 2021 involving 272 postpartum adult females, aged between 18 and 36 years. The right (2D:4DR) and the left (2D:4DL) digit ratios were measured using computer-assisted analysis. Fasting venous samples were collected at a median (interquartile range) of 111 (44-210) days postpartum and analyzed for total testosterone (TT), estradiol, sex hormone-binding globulin, and complete blood count.

RESULTS

The mean ± standard deviation 2D:4DR and 2D:4DL were 0.94 ± 0.04 and 0.93 ± 0.04, respectively. As expected, the TT (r = -0.198, p = .015) and the free androgen index (FAI: r = -0.186, p = .019) were inversely correlated with the 2D:4DL while free testosterone (FT%: r = -0.157, p = .038) was inversely correlated with the 2D:4DR. The absolute basophile count (BASO: r = -0.124, p = .040) and the Platelet-lymphocyte ratio (PLR: r = -0.153, p = .016) were inversely correlated with the 2D:4DL and the 2D:4DR respectively. In addition, the mean cell volume was inversely correlated with the 2D:4DR (r = -0.139, p = .024) and the 2D:4DL (r = -0.122, p = .045). Moreover, the 2D:4DR was inversely correlated with height (r = -0.164, p = .007). Unexpectedly, the red blood cell count (RBC: r = 0.138, p = .025) was positively correlated with the 2D:4DR.

CONCLUSION

There are significant relationships between the 2D:4D ratio and postpartum female variables. These findings are useful preliminary reference data for postpartum research and subsequent 2D:4D ratio studies.

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.

Harm Reduction in Male Patients Actively Using Anabolic Androgenic Steroids (AAS) and Performance-Enhancing Drugs (PEDs): a Review

Anabolic androgenic steroid (AAS) and performance-enhancing drug (PED) use is a prevalent medical issue, especially among men, with an estimated 2.9-4 million Americans using AAS in their lifetime. Prior studies of AAS use reveal an association with polycythemia, dyslipidemia, infertility, hypertension, left ventricular hypertrophy, and multiple behavioral disorders. AAS withdrawal syndrome, a state of depression, anhedonia, and sexual dysfunction after discontinuing AAS use, is a common barrier to successful cessation. Clinical resources for these patients and training of physicians on management of the patient using AAS are limited. Many men are hesitant to seek traditional medical care due to fear of judgment and lack of confidence in physician knowledge base regarding AAS. While proposed approaches to weaning patients off AAS are published, guidance on harm reduction for actively using patients remains sparse. Medical education regarding the management of AAS use disorder is paramount to improving care of this currently underserved patient population. Management of these patients must be non-judgmental and focus on patient education, harm reduction, and support for cessation. The approach to harm reduction should be guided by the specific AAS/PEDs used.

Androgen Treatment in Adolescent Males With Hypogonadism

During adolescence, androgens are responsible for the development of secondary sexual characteristics, pubertal growth, and the anabolic effects on bone and muscle mass. Testosterone is the most abundant testicular androgen, but some effects are mediated by its conversion to the more potent androgen dihydrotestosterone (DHT) or to estradiol. Androgen deficiency, requiring replacement therapy, may occur due to a primary testicular failure or secondary to a hypothalamic–pituitary disorder. A very frequent condition characterized by a late activation of the gonadal axis that may also need androgen treatment is constitutional delay of puberty. Of the several testosterone or DHT formulations commercially available, very few are employed, and none is marketed for its use in adolescents. The most frequently used androgen therapy is based on the intramuscular administration of testosterone enanthate or cypionate every 3 to 4 weeks, with initially low doses. These are progressively increased during several months or years, in order to mimic the physiology of puberty, until adult doses are attained. Scarce experience exists with oral or transdermal formulations. Preparations containing DHT, which are not widely available, are preferred in specific conditions. Oxandrolone, a non-aromatizable drug with higher anabolic than androgenic effects, has been used in adolescents with preserved testosterone production, like Klinefelter syndrome, with positive effects on cardiometabolic health and visual, motor, and psychosocial functions. The usual protocols applied for androgen therapy in boys and adolescents are discussed.

Receptor-Mediated Muscle Homeostasis as a Target for Sarcopenia Therapeutics

Sarcopenia is a disease characterized by age-related decline of skeletal muscle mass and function. The molecular mechanisms of the pathophysiology of sarcopenia form a complex network due to the involvement of multiple interconnected signaling pathways. Therefore, signaling receptors are major targets in pharmacological strategies in general. To provide a rationale for pharmacological interventions for sarcopenia, we herein describe several druggable signaling receptors based on their role in skeletal muscle homeostasis and changes in their activity with aging. A brief overview is presented of the efficacy of corresponding drug candidates under clinical trials. Strategies targeting the androgen receptor, vitamin D receptor, Insulin-like growth factor-1 receptor, and ghrelin receptor primarily focus on promoting anabolic action using natural ligands or mimetics. Strategies involving activin receptors and angiotensin receptors focus on inhibiting catabolic action. This review may help to select specific targets or combinations of targets in the future.

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.

Erythrocytosis in a Large Cohort of Trans Men Using Testosterone: A Long-Term Follow-Up Study on Prevalence, Determinants, and Exposure Years

CONTEXT

Erythrocytosis is a known side effect of testosterone therapy that can increase the risk of thromboembolic events.

OBJECTIVES

To study the prevalence and determinants in the development of erythrocytosis in trans men using testosterone.

METHODS

A 20-year follow-up study in adult trans men who started testosterone therapy and had monitoring of hematocrit at our center (n = 1073).

RESULTS

Erythrocytosis occurred in 11% (hematocrit > 0.50 L/L), 3.7% (hematocrit > 0.52 L/L), and 0.5% (hematocrit > 0.54 L/L) of trans men. Tobacco use (odds ratio [OR] 2.2; 95% CI, 1.6-3.3), long-acting undecanoate injections (OR 2.9; 95% CI, 1.7-5.0), age at initiation of hormone therapy (OR 5.9; 95% CI, 2.8-12.3), body mass index (BMI) (OR 3.7; 95% CI, 2.2-6.2), and pulmonary conditions associated with erythrocytosis and polycythemia vera (OR 2.5; 95% CI, 1.4-4.4) were associated with hematocrit > 0.50 L/L. In the first year of testosterone therapy hematocrit increased most: 0.39 L/L at baseline to 0.45 L/L after 1 year. Although there was only a slight continuation of this increase in the following 20 years, the probability of developing erythrocytosis still increased (10% after 1 year, 38% after 10 years).

CONCLUSION

Erythrocytosis occurs in trans men using testosterone. The largest increase in hematocrit was seen in the first year, but also after the first years a substantial number of people present with hematocrit > 0.50 L/L. A reasonable first step in the care for trans men with erythrocytosis while on testosterone is to advise them to quit smoking, to switch to a transdermal administration route, and if BMI is high, to lose weight.

Testosterone and exercise: effects on fitness, body composition, and strength in middle-to-older aged men with low-normal serum testosterone levels

As men age, serum testosterone (T) concentrations decrease, as do fitness, strength, and lean mass. Whether testosterone treatment confers additive benefit to reverse these changes when combined with exercise training in middle-to-older aged men remains unclear. We assessed the effects of T treatment and exercise, alone and in combination, on aerobic capacity (V̇o₂peak), body composition, and muscular strength in men 50-70 yr, waist circumference ≥95 cm and low-normal serum T (6-14 nmol·L^-1). Participants (n = 80) were randomized to AndroForte5 (testosterone 5.0% wt/vol, 100 mg/2 mL) cream (T), or matching placebo (P), applied transdermally daily, and supervised center-based exercise (Ex) or no additional exercise (NEx), for 12-wk. Exercise increased V̇o_2peak and strength versus nonexercise (V̇o_2peak: T + Ex: +2.5 mL·kg^-1·min^-1, P + Ex: +3.2 mL·kg^-1·min^-1, P < 0.001; leg press: T + Ex: +31 kg, P + Ex: +24 kg, P = 0.006). T treatment did not affect V̇o_2peak or strength. Exercise decreased total (T + Ex: -1.7, P + Ex: -2.3 kg, P < 0.001) and visceral fat (T + Ex: -0.1 kg, P + Ex: -0.3 kg, P = 0.003), and increased total (T + Ex: +1.4 kg, P + Ex: +0.7 kg, P = 0.008) and arm lean mass (T + Ex: +0.5 kg, P + Ex: +0.3 kg, P = 0.024). T treatment did not affect total or visceral fat, but increased total (T + Ex: +1.4 kg, T + NEx: +0.7 kg, P = 0.015), leg (T + Ex: +0.3 kg, T + NEx: +0.2 kg, P = 0.024), and arm lean mass (T + Ex: +0.5 kg, T + NEx: +0.2 kg, P = 0.046). T + Ex increased arm lean mass (T + Ex: +0.5 kg vs. P + NEx: -0.0 kg, P = 0.001) and leg strength (T + Ex: +31 kg vs. P + NEx: +12 kg, P = 0.032) compared with P + NEx, with no other additive effects. Exercise training was more effective than T treatment in increasing aerobic capacity and decreasing total and visceral fat mass. T treatment at therapeutic doses increased lean mass but conferred limited additional benefit when combined with exercise. Exercise should be evaluated as an antiaging intervention in preference to testosterone treatment in men.NEW & NOTEWORTHY We illustrate that exercise training generates superior outcomes to testosterone treatment for improving aerobic fitness, muscular strength, and total and visceral fat mass in men 50-70 yr with low-normal serum testosterone concentrations. Adding testosterone treatment to exercise did not provide any additive benefit for these variables. Testosterone treatment alone and exercise alone had similar impacts on lean mass. Therefore, men unable to exercise may obtain benefit from testosterone treatment alone to improve lean mass.

How does hormone transition in transgender women change body composition, muscle strength and haemoglobin? Systematic review with a focus on the implications for sport participation

Objectives

We systemically reviewed the literature to assess how long-term testosterone suppressing gender-affirming hormone therapy influenced lean body mass (LBM), muscular area, muscular strength and haemoglobin (Hgb)/haematocrit (HCT).

Design

Systematic review.

Data sources

Four databases (BioMed Central, PubMed, Scopus and Web of Science) were searched in April 2020 for papers from 1999 to 2020.

Eligibility criteria for selecting studies

Eligible studies were those that measured at least one of the variables of interest, included transwomen and were written in English.

Results

Twenty-four studies were identified and reviewed. Transwomen experienced significant decreases in all parameters measured, with different time courses noted. After 4 months of hormone therapy, transwomen have Hgb/HCT levels equivalent to those of cisgender women. After 12 months of hormone therapy, significant decreases in measures of strength, LBM and muscle area are observed. The effects of longer duration therapy (36 months) in eliciting further decrements in these measures are unclear due to paucity of data. Notwithstanding, values for strength, LBM and muscle area in transwomen remain above those of cisgender women, even after 36 months of hormone therapy.

Conclusion

In transwomen, hormone therapy rapidly reduces Hgb to levels seen in cisgender women. In contrast, hormone therapy decreases strength, LBM and muscle area, yet values remain above that observed in cisgender women, even after 36 months. These findings suggest that strength may be well preserved in transwomen during the first 3 years of hormone therapy.

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.

[ADVERSE EFFECTS OF ANDROGEN DEPRIVATION THERAPY ON PATIENTS WITH PROSTATE CANCER AND ITS EFFECT ON OVERALL SURVIVAL]

(Background) Patients with prostate cancer, which progresses slowly compared with other cancers, are generally older, and not a few are solely treated with androgen-deprivation therapy (ADT). The physical effects of ADT on bone health, body composition, and hematological parameters must be carefully considered. (Methods) We collected the clinical records of 185 men with pathologically diagnosed prostate cancer who were treated with ADT at our hospital. The primary aim of the study was to determine the prevalence and severity of adverse effects caused by ADT. The second aim was to analyze the effect of fluctuation in the rate of these adverse effects on overall survival (OS). (Results) The median age of patients was 75 years. After ADT for 1 or 2 years, evaluation of bone mineral density revealed median losses of 3% and 6%, respectively. After ADT for 1 year, body mass index was significantly increased by a median 2.1%, and total cholesterol and hemoglobin levels were significantly increased and decreased, respectively. The local and systemic symptoms of subcutaneous granuloma and hot flashes were experienced by 39% and 21.6% patients, respectively. Mono- and multivariate analysis revealed that significant fluctuation in the rate of adverse events after 1-year ADT did not affect OS. (Conclusion) Prevalence and severity of adverse effects caused by ADT were acceptable and almost all patients could be treated in the outpatient clinic, and significant fluctuation in the rate of adverse effects had no effect on OS.

Testosterone treatment to prevent or revert type 2 diabetes in men enrolled in a lifestyle programme (T4DM): a randomised, double-blind, placebo-controlled, 2-year, phase 3b trial

BACKGROUND

Men who are overweight or obese frequently have low serum testosterone concentrations, which are associated with increased risk of type 2 diabetes. We aimed to determine whether testosterone treatment prevents progression to or reverses early type 2 diabetes, beyond the effects of a community-based lifestyle programme.

METHODS

T4DM was a randomised, double-blind, placebo-controlled, 2-year, phase 3b trial done at six Australian tertiary care centres. Men aged 50-74 years, with a waist circumference of 95 cm or higher, a serum testosterone concentration of 14·0 nmol/L or lower but without pathological hypogonadism, and impaired glucose tolerance (oral glucose tolerance test [OGTT] 2-h glucose 7·8-11·0 mmol/L) or newly diagnosed type 2 diabetes (provided OGTT 2-h glucose ≤15·0 mmol/L) were enrolled in a lifestyle programme and randomly assigned (1:1) to receive an intramuscular injection of testosterone undecanoate (1000 mg) or placebo at baseline, 6 weeks, and then every 3 months for 2 years. Randomisation was done centrally, including stratification by centre, age group, waist circumference, 2-h OGTT glucose, smoking, and first-degree family history of type 2 diabetes. The primary outcomes at 2 years were type 2 diabetes (2-h OGTT glucose ≥11·1 mmol/L) and mean change from baseline in 2-h OGTT glucose, assessed by intention to treat. For safety assessment, we did a masked monitoring of haematocrit and prostate-specific antigen, and analysed prespecified serious adverse events. This study is registered with the Australian New Zealand Clinical Trials Registry, ACTRN12612000287831.

FINDINGS

Between Feb 5, 2013, and Feb 27, 2017, of 19 022 men who were pre-screened, 1007 (5%) were randomly assigned to the placebo (n=503) and testosterone (n=504) groups. At 2 years, 2-h glucose of 11·1 mmol/L or higher on OGTT was reported in 87 (21%) of 413 participants with available data in the placebo group and 55 (12%) of 443 participants in the testosterone group (relative risk 0·59, 95% CI 0·43 to 0·80; p=0·0007). The mean change from baseline 2-h glucose was -0·95 mmol/L (SD 2·78) in the placebo group and -1·70 mmol/L (SD 2·47) in the testosterone group (mean difference -0·75 mmol/L, -1·10 to -0·40; p<0·0001). The treatment effect was independent of baseline serum testosterone. A safety trigger for haematocrit greater than 54% occurred in six (1%) of 484 participants in the placebo group and 106 (22%) of 491 participants in the testosterone group, and a trigger for an increase of 0·75 μg/mL or more in prostate-specific antigen occurred in 87 (19%) of 468 participants in the placebo group and 109 (23%) of 480 participants in the testosterone group. Prespecified serious adverse events occurred in 37 (7·4%, 95% CI 5·4 to 10·0) of 503 patients in the placebo group and 55 (10·9%, 8·5 to 13·9) of 504 patients in the testosterone group. There were two deaths in each group.

INTERPRETATION

Testosterone treatment for 2 years reduced the proportion of participants with type 2 diabetes beyond the effects of a lifestyle programme. Increases in haematocrit might be treatment limiting. Longer-term durability, safety, and cardiovascular effects of the intervention remain to be further investigated.

FUNDING

Australian National Health and Medical Research Council, Bayer, Eli Lilly, University of Adelaide, and WW (formerly Weight Watchers).

Characteristics and Attitudes of Men Using Anabolic Androgenic Steroids (AAS): A Survey of 2385 Men

Additional characterization of patients using anabolic androgenic steroids (AAS) is needed to improve harm reduction and cessation resources for patients. Our group sought to expand upon the currently limited data regarding AAS use by performing a web-based survey assessing experiences of males using AAS. Participants included men over the age of 18 with history of AAS use within the past 5 years. Data were collected between August 2019 and April 2020. Primary outcome measures included age when starting AAS, dose of AAS, motivations for use, experiences with health-care professionals, and rate of successful cessation. The survey was accessed 3640 times, resulting in 2385 completed surveys meeting the inclusion criteria (68.93% participation rate).

Average participant age was 31.69 ± 10.09 years. Over half of respondents were from the United States (n = 1271, 53.3%). Motives to use AAS included improving appearance (n = 1959, 82.2%), strength gain (n = 1192, 50%), and self-esteem/body image issues (n = 712, 29.87%). Participants rated physicians poorly, regarding knowledge of AAS (4.08 ± 2.23). Most participants did not reveal AAS use to their health-care providers (n = 1338, 56.1%); of those that did, 55.30% (n = 579) reported feeling discriminated against for their use. Of 46.16% (n = 1101) attempting AAS cessation, 60.22% (n = 663) were unsuccessful. Challenges in the management of AAS use include early onset of use, supraphysiologic doses used, and frequently present body image disorders stress. Distrust of health-care providers, poor cessation rates, and lack of physician training further exacerbate this. These findings should serve to reinforce previous calls to action for further research on the treatment of AAS use disorder.

Testosterone Therapy and Cardiovascular Risk: A Critical Analysis of Studies Reporting Increased Risk

BACKGROUND

Treatment of "adult-onset hypogonadism" (AOH) with exogenous testosterone therapy (TTh) to raise serum testosterone (T) levels may influence cardiovascular (CV) risk factors in patients with AOH, whereas low endogenous T levels are associated with an increased CV risk and mortality.

AIM

To critically evaluate studies reporting increased CV risk associated with TTh and to provide an overview of the risks and benefits of restoring T levels through exogenous TTh.

METHODS

A review of publications focusing on the association between TTh and increased CV risk was conducted, and the study methodologies and conclusions of each were critically evaluated. Further, recent clinical and epidemiological studies associating AOH or TTh with a change in CV risk, and pertinent hematologic and vascular effects noted in animal studies and in vitro, as well as in clinical practice were also reviewed.

OUTCOMES

A review of the literature shows that untreated testosterone deficiency and/or low T is associated with an increase in CV risk and adverse outcomes, with numerous studies and meta-analyses to support a positive association between exogenous TTh and an improvement in CV risk factors in men with AOH.

RESULTS

Numerous studies in the literature demonstrate the positive benefits of using TTh; however, since 2013, some publications have suggested a link to increased CV risk associated with TTh. A number of these studies retrospectively analyzed insurance claims databases using diagnosis codes, procedures codes, and prescription information. Many reviews published since have pointed out the methodological flaws and debatable conclusions of these studies.

CLINICAL IMPLICATIONS

A careful assessment of the patient's current health status and CV risk factors should be weighed against the benefits and possible risks resulting from TTh, and consideration should be given to deferring treatment pending resolution or stabilization of CV disease or risk factors.

STRENGTHS & LIMITATIONS

In this review, we provide an in-depth analysis of studies reporting increased CV risk with TTh. Many of the studies were not well-designed, randomized, double-blind, prospective clinical trials but rather post hoc analyses of cohort data. These studies may reflect bias in how treatment and nontreatment decisions are made or reflect conclusions based on widely cited methodological flaws.

CONCLUSION

Appropriate patient selection supported by low pre-treatment T levels and monitoring T levels during treatment with the goal of achieving and maintaining physiologic levels all contribute to the safe and effective use of TTh in men with AOH. Khera M, Miner M, Jaffe J, et al. Testosterone Therapy and Cardiovascular Risk: A Critical Analysis of Studies Reporting Increased Risk. J Sex med 2021;18:83-98.

Hypogonadism and cancer survivorship

PURPOSE OF REVIEW

Hypogonadism is highly prevalent among not only patients with a history of prior treatment for cancer, but also among those patients with a new oncologic diagnosis who have not yet received any cancer therapy. Hypogonadism can cause a wide array of signs and symptoms including: deceased muscle mass; increased fat mass; decreased energy, mood, and overall sense of well being; diminished bone mineral density; infertility; and impaired libido and sexual function. This purpose of this manuscript is to review the mechanisms by which cancer and oncologic treatment regimens can adversely affect the hypothalamic pituitary gonadal axis, resulting in hypogonadism. Risks and benefits associated with the treatment of testosterone deficiency are also discussed, which are important considerations for clinicians caring for affected patients.

RECENT FINDINGS

Hypogonadism has a high prevalence in the setting of cancer and is an important survivorship issue. Recent randomized controlled trials confirm testosterone's therapeutic benefits in terms of sexual function, mood body composition, and bone health, but the specific benefits in terms of quality of life are less clear.

SUMMARY

More prospective studies are needed to further delineate the risks, benefits, and overall outcomes of testosterone replacement therapy in patients with cancer and cancer survivors.

Longitudinal Changes in Hematologic Parameters Among Transgender People Receiving Hormone Therapy

CONTEXT

The effect of gender-affirming hormone therapy (HT) on erythropoiesis is an area of priority in transgender health research.

OBJECTIVE

To compare changes in hematologic parameters and rates of erythrocytosis and anemia among transgender people to those of cisgender controls.

DESIGN

Longitudinal observational study.

PARTICIPANTS AND SETTING

We compared 559 transfeminine (TF) and 424 transmasculine (TM) people enrolled in 3 integrated health care systems to matched cisgender referents.

INTERVENTIONS AND OUTCOME

Hormone therapy receipt was ascertained from filled prescriptions. Hemoglobin (Hb) and hematocrit (Hct) levels were examined from the first blood test to HT initiation, and from the start of HT to the most recent blood test. Rates of erythrocytosis and anemia in transgender participants and referents were compared by calculating adjusted hazard ratios and 95% confidence intervals (CI).

RESULTS

In the TF group, there was a downward trend for both Hb and Hct. The corresponding changes in the TM cohort were in the opposite direction. TM study participants experienced a 7-fold higher rate (95% CI: 4.1-13.4) of erythrocytosis relative to matched cisgender males, and an 83-fold higher rate (95% CI: 36.1-191.2) compared to cisgender females. The corresponding rates for anemia were elevated in TF subjects but primarily relative to cisgender males (hazard ratio 5.9; 95% CI: 4.6-7.5).

CONCLUSIONS

Our results support previous recommendations that hematological parameters of transgender people receiving HT should be interpreted based on their affirmed gender, rather than their sex documented at birth. The clinical significance of erythrocytosis following testosterone therapy, as well as anemia following feminizing HT, requires further investigation.

Diurnal variation in red blood cell variables in athletes after single and repeated bouts of exercise

BACKGROUND

The aim of this study was to examine the diurnal and exercise-related changes in red blood cell variables which serve as indirect markers of doping in sports.

METHODS

Ten men and 7 women, all undoped highly trained endurance athletes aged 19-34 years, were included in the study. Before and on the day with single and repeated bouts of exercise, blood samples were collected at 07:00, 09:00, 13:00, 18:00, and 21:00, at least 2 hours after exercise. Hemoglobin (Hb), hematocrit (Hct), and the reticulocytes % (Ret%) were determined by flow cytometry. Changes in OFF-hr score were also calculated and repeated-measures ANOVA was used to compare diurnal differences.

RESULTS

In overall, the mean Hb decreased continuously by 4.5 and 3.3% (all P<0.001) over the day with single and repeated bouts of exercise, respectively. Corresponding values for the decline in Hct were 4.2 and 5.9% (all P<0.001). In contrast, the Ret% showed no apparent diurnal rhythm but single and repeated bouts of exercise increased the relative Ret% in the evening by 12.4 and 16.7% (P<0.01), respectively. Then the calculated OFF-hr score was reduced by 6.2 and 9.8% (all P<0.01) at the end of the day.

CONCLUSIONS

These results confirmed the normal diurnal pattern in the examined red blood cell variables in response to exercise in highly trained athletes. Furthermore, they showed noticeable between-subject variability and the possible risk of a false suspicion of blood doping in undoped athletes after repeated bouts of exercise.

A 2-year longitudinal follow-up of performance characteristics in Chinese male elite youth athletes from swimming and racket sports

Training in elite sport aims at the optimization of the athletic performance, and to control the athletes`progress in physiological, anthropometrical and motor performance prerequisites. However, in most sports, the value of longitudinal testing is unclear. This study evaluates the longitudinal development and the influence of intense training over 2-years on specific physiological performance prerequisites, as well as certain body dimensions and motor abilities in elite youth athletes. Recruited between 11-13 years of age at Shanghai Elite Sport school, the sample of student-athletes (N = 21) was categorized as the swimming group (10 athletes), and the racket sports group (11 players: 7 table tennis and 4 badminton players). The performance monitoring took place over two years between September 2016 and September 2018 and included 5 test waves. In all the test waves, the athletes were assessed by means of three physiological measurements (vital capacity, hemoglobin concentration, heart rate at rest), three anthropometric parameters (body height, body weight, chest girth), and two motor tests (back strength, complex reaction speed). Seven out of eight diagnostic methods exhibit medium to high validity to discriminate between the different levels of performance development in the two sports groups. The investigated development of the performance characteristics is attributed partly to the inherited athletic disposition as well as to the different sport-specific training regimens of the two sports groups.

Testosterone supplementation upregulates androgen receptor expression and translational capacity during severe energy deficit

Testosterone supplementation during energy deficit promotes whole body lean mass accretion, but the mechanisms underlying that effect remain unclear. To elucidate those mechanisms, skeletal muscle molecular adaptations were assessed from muscle biopsies collected before, 1 h, and 6 h after exercise and a mixed meal (40 g protein, 1 h postexercise) following 14 days of weight maintenance (WM) and 28 days of an exercise- and diet-induced 55% energy deficit (ED) in 50 physically active nonobese men treated with 200 mg testosterone enanthate/wk (TEST) or placebo (PLA) during the ED. Participants (n = 10/group) exhibiting substantial increases in leg lean mass and total testosterone (TEST) were compared with those exhibiting decreases in both of these measures (PLA). Resting androgen receptor (AR) protein content was higher and fibroblast growth factor-inducible 14 (Fn14), IL-6 receptor (IL-6R), and muscle ring-finger protein-1 gene expression was lower in TEST vs. PLA during ED relative to WM (P < 0.05). Changes in inflammatory, myogenic, and proteolytic gene expression did not differ between groups after exercise and recovery feeding. Mechanistic target of rapamycin signaling (i.e., translational efficiency) was also similar between groups at rest and after exercise and the mixed meal. Muscle total RNA content (i.e., translational capacity) increased more during ED in TEST than PLA (P < 0.05). These findings indicate that attenuated proteolysis at rest, possibly downstream of AR, Fn14, and IL-6R signaling, and increased translational capacity, not efficiency, may drive lean mass accretion with testosterone administration during energy deficit.

Peripheral hematological parameters in women with polycystic ovary syndrome

OBJECTIVE

There have been few studies on hematological parameters (e.g., hemoglobin, red cell distribution width, white blood cells, and mean platelet volume), and polycystic ovary syndrome (PCOS). This study aimed to compare hematological parameters between women with PCOS and controls.

METHODS

We performed an age-matched case-control study in Faisal bin Mishal Center for Infertility, Buraidah (Kingdom of Saudi Arabia). The cases were women with PCOS and an equal number of healthy women were enrolled as controls. The basic gynecological history was recorded and blood samples were analyzed for blood parameters using an automated hematology analyzer.

RESULTS

The two groups (60 women in each arm of the study) were similar in age. However, body mass index was significantly higher in women with PCOs compared with controls. There were no significant differences in any of the hematological parameters (hemoglobin, red blood cells, red cell distribution width, white blood cells, platelets, and mean platelet volume) between the two groups.

CONCLUSION

There does not appear to be a significant difference in hematological parameters in Saudi women with PCOS and healthy controls. A larger study on this issue is required in the future.

Differential effects of testosterone on circulating neutrophils, monocytes, and platelets in men: Findings from two trials

BACKGROUND

Testosterone treatment increases erythrocytes in men, but its effects on leukocyte and platelet counts are unknown and could affect its safety.

OBJECTIVE

To determine whether testosterone affects circulating leukocytes and platelets in men.

METHODS

Secondary analyses of two randomized testosterone trials were performed: the 5α-reductase (5aR) and OPTIMEN trials. In 5aR trial, 102 healthy men, 21-50 years (mean age 38), received a long-acting GnRH agonist, and 50, 125, 300, or 600 mg/week testosterone enanthate (TE) plus placebo or 2.5 mg/ day dutasteride for 20 weeks. In OPTIMEN, 78 functionally limited men, ≥65 years (mean age 72) with protein intake ≤ 0.83 g kg-1  day-1 , were randomized to controlled diets with 0.8 g kg-1  day-1 protein or 1.3 g kg-1  day-1 protein plus placebo or TE (100 mg/week) for 6 months. Changes from baseline in total and differential leukocyte count, and platelet count were evaluated.

RESULTS

In 5aR, testosterone administration was associated with increases in total leukocyte (estimated change from baseline 40, 490, 1230, and 1280 cells/µL, P < .001), neutrophil (65.1, 436.1, 1177.2, and 1192.2 cells/µL, P < .001), monocyte (-20.2, 24.5, 90.6, and 143.9 cells/µL, P < .001), platelet (-7.3, 8.4, 8.7, and 8.9 × 103 cells/µL, P = .033), and erythrocyte counts. Testosterone did not affect absolute lymphocyte count. Similar increase in total leukocyte count was observed with testosterone treatment in OPTIMEN (change 0.77 × 103 cells/µL, P vs placebo = 0.004).

CONCLUSIONS

Testosterone administration in men differentially increases neutrophil and monocyte counts. These findings, together with its erythropoietic effects, suggest that testosterone promotes the differentiation of hematopoietic progenitors into the myeloid lineage. These findings have potential mechanistic, therapeutic, and safety implications.

Late-onset hypogonadism: Reductio ad absurdum of the cardiovascular risk-benefit of testosterone replacement therapy

BACKGROUND

Low testosterone (T) level is considered a marker of poor cardiovascular health. Ten years ago, the Testosterone in Older Men with Mobility Limitations (TOM) trial was discontinued due to a higher number of adverse events in men receiving T compared with placebo. Since then, several studies have investigated the risks of T replacement therapy (TRT) in late-onset hypogonadism (LOH).

OBJECTIVE

To review the mechanism by which TRT could damage the cardiovascular system.

MATERIALS AND METHODS

Comprehensive literature search of recent clinical and experimental studies.

RESULTS

The mechanisms of T-mediated coronary vasodilation were reviewed with emphasis on calcium-activated and ATP-sensitive potassium ion channels. We showed how T regulates endothelial nitric oxide synthase (eNOS) and phosphoinositide 3-kinase/protein kinase B/eNOS signaling pathways in vessel walls and its direct effects on cardiomyocytes via β1-adrenergic and ryanodine receptors and provided data on myocardial infarction and heart failure. Vascular smooth muscle senescence could be explained by the modulation of growth factors, matrix metalloproteinase-2, and angiotensin II by T. Furthermore, leukocyte trafficking, facilitated by changes in TNF-α, could explain some of the effects of T on atheromatous plaques. Conflicting data on prothrombotic risk linked to platelet aggregation inhibition via NO-triggered arachidonate synthesis or increased aggregability due to enhanced thromboxane A in human platelets provide evidence regarding the hypotheses on plaque maturation and rupture risk. The effects of T on cardiac electrophysiology and oxygen delivery were also reviewed.

DISCUSSION

The effects of TRT on the cardiovascular system are complex. Although molecular studies suggest a potential benefit, several clinical observations reveal neutral or occasionally detrimental effects, mostly due to confounding factors.

CONCLUSIONS

Attempts to demonstrate that TRT damages the cardiovascular system via systematic analysis of the putative mechanisms led to the contradiction of the initial hypothesis. Current evidence indicates that TRT is safe once other comorbidities are addressed.

Retinoic acid receptor antagonists for male contraception: current status†

Retinoic acid receptor alpha (RARA), a nuclear receptor protein, has been validated as a target for male contraception by gene knockout studies and also pharmacologically using a pan-retinoic acid receptor antagonist. Retinoic acid receptor alpha activity is indispensable for the spermatogenic process, and therefore its antagonists have potential as male contraceptive agents. This review discusses the effects of systematic dosing regimen modifications of the orally bioavailable and reversible pan-antagonist BMS-189453 as well as studies with the alpha-selective antagonists BMS-189532 and BMS-189614 in a murine model. We also provide an overview of structure-activity studies of retinoic acid receptor alpha antagonists that provide insight for the design of novel alpha-selective ligands.

A cross-sectional comparison of secondary polycythemia in testosterone-deficient men treated with nasal testosterone gel vs. intramuscular testosterone cypionate

INTRODUCTION

Secondary polycythemia is a known adverse effect of testosterone replacement therapy (TRT). Different testosterone formulations are available, with significantly different half-lives, which have varying influences on the development of secondary polycythemia. Herein, we compared the prevalence of secondary polycythemia in testosterone-deficient men treated with intranasal testosterone gel (Natesto^®) vs. intramuscular testosterone cypionate (TC) therapy.

METHODS

We performed a cross-sectional analysis of secondary polycythemia (hematocrit [Hct] ≥54%) in men who received TRT. We included a total of 60 men: 30 men who received Natesto (4.5% testosterone gel [tid, 5.5 mg/nostril, 11 mg/dose, 33 mg/day]), and 30 who received TC (between 0.5 and 1.0 mL or 100-200 mg intramuscularly weekly). A univariable and multiple regression analysis was performed considering last Hct measurement as the main outcome. The analyzed variables included were age, body mass index (BMI), smoking history, treatment group, and testosterone levels on followup.

RESULTS

We identified polycythemia (Hct ≥54%) in 10% (3/30) of men who received TC. Additionally, in men treated with TC, 33.3% (10/30) had a Hct ≥50% during therapy. None of the men who received Natesto had a Hct ≥50% during therapy. On multivariable linear regression analysis, we demonstrated that the use of TC increased Hct by 3.24% (95% confidence interval [CI] 0.74-5.73%, p=0.012) compared to Natesto.

CONCLUSIONS

The prevalence of polycythemia in men treated with Natesto was markedly lower compared to the men who received TC therapy.

Hematologic Markers and Prostate Cancer Risk: A Prospective Analysis in UK Biobank

BACKGROUND

Risk factors for prostate cancer are not well understood. Red blood cell, platelet, and white blood cell indices may be markers of a range of exposures that might be related to prostate cancer risk. Therefore, we examined the associations of hematologic parameters with prostate cancer risk.

METHODS

Complete blood count data from 209,686 male UK Biobank participants who were free from cancer at study baseline were analyzed. Participants were followed up via data linkage. After a mean follow-up of 6.8 years, 5,723 men were diagnosed with prostate cancer and 323 men died from prostate cancer. Multivariable-adjusted Cox regression was used to estimate adjusted HRs and 95% confidence intervals (CI) for prostate cancer incidence and mortality by hematologic parameters, and corrected for regression dilution bias.

RESULTS

Higher red blood cell (HR per 1 SD increase = 1.09, 95% CI, 1.05-1.13) and platelet counts (HR = 1.07, 1.04-1.11) were associated with an increased risk of prostate cancer. Higher mean corpuscular volume (HR = 0.90, 0.87-0.93), mean corpuscular hemoglobin (HR = 0.90, 0.87-0.93), mean corpuscular hemoglobin concentration (HR = 0.87, 0.77-0.97), and mean sphered cell volume (HR = 0.91, 0.87-0.94) were associated with a lower prostate cancer risk. Higher white blood cell (HR = 1.14, 1.05-1.24) and neutrophil count (HR = 1.27, 1.09-1.48) were associated with prostate cancer mortality.

CONCLUSIONS

These associations of blood indices of prostate cancer risk and mortality may implicate shared common causes, including testosterone, nutrition, and inflammation/infection among several others in prostate cancer development and/or progression.

IMPACT

These associations provide insights into prostate cancer development and progression.

The role of iron in mediating testosterone's effects on erythropoiesis in mice

Testosterone stimulates iron-dependent erythropoiesis and suppresses hepcidin. To clarify the role of iron in mediating testosterone's effects on erythropoiesis, we induced iron deficiency in mice by feeding low iron diet. Iron-replete and iron-deficient mice were treated weekly with testosterone propionate or vehicle for 3 weeks. Testosterone treatment increased red cell count in iron-replete mice, but, surprisingly, testosterone reduced red cell count in iron-deficient mice. Splenic stress erythropoiesis was stimulated in iron-deficient mice relative to iron-replete mice, and further increased by testosterone treatment, as indicated by the increase in red pulp area, the number of nucleated erythroblasts, and expression levels of TfR1, GATA1, and other erythroid genes. Testosterone treatment of iron-deficient mice increased the ratio of early-to-late erythroblasts in the spleen and bone marrow, and serum LDH level, consistent with ineffective erythropoiesis. In iron-deficient mice, erythropoietin levels were higher but erythropoietin-regulated genes were generally downregulated relative to iron-replete mice, suggesting erythropoietin resistance. Conclusion: Testosterone treatment stimulates splenic stress erythropoiesis in iron-replete as well as iron-deficient mice. However, testosterone worsens anemia in iron-deficient mice because of ineffective erythropoiesis possibly due to erythropoietin resistance associated with iron deficiency. Iron plays an important role in mediating testosterone's effects on erythropoiesis.

Therapeutic Phlebotomy for Testosterone-Induced Polycythemia

OBJECTIVES

To evaluate therapeutic phlebotomy (TP) requests for testosterone replacement therapy (TRT) and to highlight the impact to a blood center (BC) or service that provides TP for individuals on TRT.

METHODS

Review of TP requests for individuals on TRT at our BC over a 3-year period from 2014 through 2016, as well as the total number of TP collections.

RESULTS

Total TPs during 2014, 2015, and 2016 were 475, 500, and 569, respectively. Annual TP collections for patients on TRT were 193, 212, and 239, respectively. TRT patients with TP orders increased 71.4% during this period. After discontinuation of TP services for TRT at our BC, 32% continued to donate as volunteer blood donors at our BC.

CONCLUSIONS

Our BC observed increased TP requests for patients on TRT from 2014 through 2016. Our findings suggest that individuals on TRT may be presenting to BCs as volunteer blood donors to avoid charges for TP.

Testosterone Therapy in Adolescent Boys: The Need for a Structured Approach

BACKGROUND

In adolescents, testosterone may have several effects including promotion of secondary sexual characteristics and pubertal growth, attainment of optimal muscle mass and peak bone mass, optimization of the metabolic profile, and psychosocial maturation and well-being.

SUMMARY

Testosterone therapy is a cornerstone of the management of hypogonadism in boys. Since the initial report of the chemical synthesis of testosterone, several formulations have continued to develop, and although many of these have been used in boys, none of them have been studied in detail in this age group. Given the wide ranging effects of testosterone, the level of evidence for their effects in boys and the heterogeneity of conditions that lead to early-onset hypogonadism, a standardized protocol for monitoring testosterone replacement in this age group is needed. Key Messages: In this review, we focus on the perceived benefits of androgen replacement in boys affected by pubertal delay and highlight the need to improve the health monitoring of boys who receive androgen replacement therapy, proposing different approaches based on the underlying pathophysiology.

Androgens stimulate erythropoiesis through the DNA-binding activity of the androgen receptor in non-hematopoietic cells

BACKGROUND

Androgens function through DNA and non-DNA binding-dependent signalling of the androgen receptor (AR). How androgens promote erythropoiesis is not fully understood.

DESIGN AND METHODS

To identify the androgen signalling pathway, we treated male mice lacking the second zinc finger of the DNA-binding domain of the AR (AR^ΔZF2 ) with non-aromatizable 5α-dihydrotestosterone (5α-DHT) or aromatizable testosterone. To distinguish direct hematopoietic and non-hematopoietic mechanisms, we performed bone marrow reconstitution experiments.

RESULTS

In wild-type mice, 5α-DHT had greater erythroid activity than testosterone, which can be aromatized to estradiol. The erythroid response in wild-type mice following 5α-DHT treatment was associated with increased serum erythropoietin (EPO) and its downstream target erythroferrone, and hepcidin suppression. 5α-DHT had no erythroid activity in AR^ΔZF2 mice, proving the importance of DNA binding by the AR. Paradoxically, testosterone, but not 5α-DHT, suppressed EPO levels in AR^ΔZF2 mice, suggesting testosterone following aromatization may oppose the erythroid-stimulating effects of androgens. Female wild-type mice reconstituted with AR^ΔZF2 bone marrow cells remained responsive to 5α-DHT. In contrast, AR^ΔZF2 mice reconstituted with female wild-type bone marrow cells showed no response to 5α-DHT.

CONCLUSION

Erythroid promoting effects of androgens are mediated through DNA binding-dependent actions of the AR in non-hematopoietic cells, including stimulating EPO expression.

Obstructive Sleep Apnea Is Associated With Polycythemia in Hypogonadal Men on Testosterone Replacement Therapy

BACKGROUND

Polycythemia (erythrocytosis) is a known side effect of testosterone (T) replacement therapy (TRT) and appears to correlate with maximum T levels. There is also a well-established association between obstructive sleep apnea (OSA) and the development of polycythemia, which confers additional long-term cardiovascular morbidity. Synergy between TRT and OSA in the development of polycythemia remains poorly understood.

AIM

The objective of this study was to retrospectively assess the relationship of OSA and secondary polycythemia in hypogonadal men receiving TRT.

METHODS

We performed a retrospective chart review of all men treated by a single provider from 2015 to 2019 for the diagnosis of hypogonadism. Patients who developed a hematocrit of 52% or greater were classified as having polycythemia. OSA was identified via clinical documentation or use of nocturnal continuous positive airway pressure. Demographics, laboratory values, treatment details, and comorbidities were recorded. Data were reported as mean ± SD for parametric variables and median [interquartile range] for non-parametric values.

OUTCOME

The primary outcome of this study was the association between OSA and polycythemia in hypogonadal men on TRT.

RESULTS

474 men were included in this study. 62/474 (13.1%) men met the criteria for the diagnosis of polycythemia with a median hematocrit of 53.6 [interquartile range 52.6, 55.5]. Univariate analysis demonstrated a strong positive association between polycythemia and the concomitant diagnosis of OSA in hypogonadal men (P = .002). Even after correcting for age, body mass index (BMI), and peak T levels in the multivariate analysis (P = .01), this relationship remained significant with an odds ratio of 2.09 [95% CI 1.17, 3.76]. 37 men on TRT with polycythemia and OSA were included in the final cohort with a mean age of 59.2 ± 11.4 years, mean BMI of 32.4 ± 6.0, and median time from TRT initiation to polycythemia diagnosis of 3 years. All patients diagnosed with OSA were prescribed continuous positive airway pressure with poor compliance noted in 52.8% of men. 37.8% were managed via phlebotomy and 59.5% were managed via dose de-escalation of TRT. In hypogonadal men on TRT with polycythemia, BMI was the only risk factor strongly associated with OSA (P = .013).

CLINICAL TRANSLATION

In hypogonadal men (particularly those with elevated BMI) on TRT who develop secondary polycythemia, a diagnosis of OSA should be strongly considered.

STRENGTHS & LIMITATIONS

This is a single provider retrospective study and further studies are needed to assess generalizability.

CONCLUSIONS

In this retrospective single-center cohort, the development of polycythemia in hypogonadal men on TRT was associated with an increased prevalence of OSA. Lundy SD, Parekh NV, Shoskes DA. Obstructive Sleep Apnea Is Associated With Polycythemia in Hypogonadal Men on Testosterone Replacement Therapy. J Sex Med 2020;17:1297-1303.

Testosterone Administration During Energy Deficit Suppresses Hepcidin and Increases Iron Availability for Erythropoiesis

CONTEXT

Severe energy deprivation markedly inhibits erythropoiesis by restricting iron availability for hemoglobin synthesis.

OBJECTIVE

The objective of this study was to determine whether testosterone supplementation during energy deficit increased indicators of iron turnover and attenuated the decline in erythropoiesis compared to placebo.

DESIGN

This was a 3-phase, randomized, double-blind, placebo-controlled trial.

SETTING

The study was conducted at the Pennington Biomedical Research Center.

PATIENTS OR OTHER PARTICIPANTS

Fifty healthy young males.

INTERVENTION(S)

Phase 1 was a 14-day free-living eucaloric controlled-feeding phase; phase 2 was a 28-day inpatient phase where participants were randomized to 200 mg testosterone enanthate/week or an isovolumetric placebo/week during an energy deficit of 55% of total daily energy expenditure; phase 3 was a 14-day free-living, ad libitum recovery period.

MAIN OUTCOME MEASURE(S)

Indices of erythropoiesis, iron status, and hepcidin and erythroferrone were determined.

RESULTS

Hepcidin declined by 41%, indicators of iron turnover increased, and functional iron stores were reduced with testosterone administration during energy deficit compared to placebo. Testosterone administration during energy deficit increased circulating concentrations of erythropoietin and maintained erythropoiesis, as indicated by an attenuation in the decline in hemoglobin and hematocrit with placebo. Erythroferrone did not differ between groups, suggesting that the reduction in hepcidin with testosterone occurs through an erythroferrone-independent mechanism.

CONCLUSION

These findings indicate that testosterone suppresses hepcidin, through either direct or indirect mechanisms, to increase iron turnover and maintain erythropoiesis during severe energy deficit. This trial was registered at www.clinicaltrials.gov as #NCT02734238.

Low testosterone is associated with frailty, muscle wasting and physical dysfunction among men receiving hemodialysis: a longitudinal analysis

BACKGROUND

Despite the high prevalence of frailty among patients receiving hemodialysis, few preventable or treatable contributing causes have been identified. Hypogonadism is also common in this population and low serum testosterone concentrations share several clinical phenotypes with frailty. We hypothesized that low serum testosterone concentrations would be associated with frailty and several of its individual components.

METHODS

We used data from 440 men from A Cohort Study To Investigate the Value of Exercise in ESRD/Analysis Designed to Investigate the Paradox of Obesity and Survival in ESRD, a longitudinal study that recruited participants from 14 dialysis centers in Atlanta, GA and the San Francisco, CA Bay Area from 2009 to 2011. We assessed frailty using the Fried Frailty Phenotype. We examined the association between free testosterone (as a continuous and dichotomous variable) and frailty, individual frailty components, sarcopenia, lower extremity function and muscle mass estimation by creatinine and body impedance spectroscopy over 12 months using generalized estimating equations.

RESULTS

The mean age was 56.1 ± 14.2 years and 27% were white. A 50% lower concentration of free testosterone was associated with 1.40-fold higher odds of being frail [95% confidence interval (CI) 1.05-1.53] and 1.40-fold higher odds of becoming frail over 12 months (95% CI 1.07-1.73). This association was mainly due to an association with two components of frailty: grip strength and gait speed. In addition, 50% lower free testosterone concentration was associated with a 1.55-fold higher odds of having sarcopenia (95% CI 1.09-2.02) and 1.72-fold higher odds for developing sarcopenia (95% CI 1.13-2.33) as well as with lower muscle mass and a decrease in muscle mass over 12 months as estimated by serum creatinine and by bioelectrical impedance spectroscopy.

CONCLUSION

Serum free testosterone concentration was associated with frailty, physical function, sarcopenia and muscle mass as well as with changes in these outcomes over 12 months. Testosterone replacement may be a feasible therapeutic target toward prevention of frailty, although clinical trials are needed to test this possibility.