The effects of supraphysiologic doses of testosterone on muscle size and strength in normal men

Lived experiences of closeness to a person using Anabolic androgenic steroids a next of kin perspective

PURPOSE

Anabolic androgenic steroids (AAS) are used for their aesthetic and performance-enhancing effects and are associated with physical and psychological side effects. Behavioural changes/side effects as mood swings, aggressiveness, depression, potency problems, anxiety, and emotional coldness have been reported by next of kin to people using AAS.

METHODS

This phenomenological study is based on the reflective lifeworld research approach. Interviews were conducted with twelve next of kin about their experiences of living close to persons using AAS.

RESULTS

Next of kin to persons using AAS are particularly vulnerable because they experience little opportunity to influence their situation. Their given and safe context is lost, and their lives are circumscribed by feelings of insecurity, fear, powerlessness, and grief. Feelings of loneliness develop when their problems are not noticed by others and support is lacking from family and society.

CONCLUSIONS

Our research adds important knowledge on how the use of AAS affects next of kin. Understanding is required to approach the lifeworld of next of kin with flexibility and empathy in their difficulties and vulnerability. Healthcare professionals and other concerned professions need to be aware of next of kin existential needs to be able to meet and support them in their life situation.

Early Life Androgen Administration Attenuates Aging Related Declines in Muscle Protein Synthesis

PURPOSE

This study examined the acute and long-term effects of nandrolone decanoate (ND) on fractional synthetic rates (FSR).

METHODS

Male C57BL/6 mice were randomized into ND ( n = 20) or sham ( n = 20) groups. ND injections (10 g·kg -1 ·wk -1 ) started at 7 months of ages and continued for 6 wk. Ten animals from each group were randomly separated and examined 1 wk following drug cessation. The remaining animals were examined at 16 months of age. Animals were injected IP with 1.5 mL of deuterated water 24 h before euthanasia. The kidney, liver, heart, gastrocnemius, and soleus were extracted. Samples were analyzed for deuterated alanine enrichment in the bound protein and intracellular fraction by liquid chromatography tandem mass spectrometry to measure estimated FSR (fraction/day (F/D)) of mixed tissue.

RESULTS

One-way ANOVA, with treatment and age as fixed factors, indicated that kidney FSR was greater ( P = 0.027) in ND (0.41 ± 0.02 F/D) than sham (0.36 ± 0.014F/D) and higher ( P = 0.003) in young (0.42 ± 0.2 F/D) than old (0.35 ± 0.01 F/D). Liver and heart FSR values were greater ( P ≤ 0.001) in young (0.79 ± 0.06 F/D and 0.13 ± 0.01 F/D, respectively) compared with old (0.40 ± 0.01 F/D and 0.09 ± 0.01 F/D, respectively), but not between ND and sham. Gastrocnemius FSR was ( P ≤ 0.001) greater in young (0.06 ± 0.01 F/D) compared with old (0.03 ± 0.002 F/D), and greater ( P = 0.006) in ND (0.05 ± 0.01 F/D) compared with sham (0.04 ± 0.003 F/D). Soleus FSR rates were greater ( P = 0.050) in young (0.13 ± 0.01 F/D) compared with old (0.11 ± 0.003 F/D), but not between ND (0.12 ± 0.01 F/D) and sham (0.12 ± 0.01 F/D). Old animals who had received ND displayed elevated FSR in the gastrocnemius ( P = 0.054) and soleus ( P = 0.024).

CONCLUSIONS

ND use in young adult animals appeared to maintain long-term elevations in FSR in muscle during aging.

Ultraviolet spectra determination and computational analysis of 44 E/Z steroid isomers in dried blood spot

The dried blood spot (DBS) is a novel alternative matrix used in 2022 Beijing Winter Olympics and Paralympics. It is capable of distinguishing anabolic androgenic steroid (AAS) esters without the gas chromatography-combustion-isotope ratio mass spectrometry (GC-C-IRMS) confirmation. In this study, a method for detection of 22 anabolic steroid esters in DBS based on ultra-high liquid chromatography-mass spectrometry (UPLC-MS) with parallel reaction monitoring (PRM) was developed and validated. Methoxylamine was used as the derivatization reagent to improve the sensibility. Specificity, limit of detection (LOD), linearity, stability, robustness, and carryover were evaluated. Steroid esters are nine testosterone esters, six nandrolone esters, five boldenone esters, methenolone enanthate, and trenbolone acetate. UV spectra were determined by HPLC. And density functional theory (DFT) calculation methods could provide theoretical UV spectra data. Three basis set of B3LYP/6-31G(d), B3LYP/6-31+G(d, p), and WB97XD/6-31+G(d, p) were used for the geometry optimizations and TD-DFT calculation. The average deviation (%RD) of B3LYP/6-31+G(d) for all 44 ester oximes are less than 3.0%. This study for the first time provides a method to tentatively identify the 44 E/Z configurations of steroid oxime products.

NASA SPRINT exercise program efficacy for vastus lateralis and soleus skeletal muscle health during 70 days of simulated microgravity

The efficacy of the NASA SPRINT exercise countermeasures program for quadriceps (vastus lateralis) and triceps surae (soleus) skeletal muscle health was investigated during 70 days of simulated microgravity. Individuals completed 6° head-down-tilt bedrest (BR, n = 9), bedrest with resistance and aerobic exercise (BRE, n = 9), or bedrest with resistance and aerobic exercise and low-dose testosterone (BRE + T, n = 8). All groups were periodically tested for muscle (n = 9 times) and aerobic (n = 4 times) power during bedrest. In BR, surprisingly, the typical bedrest-induced decrements in vastus lateralis myofiber size and power were either blunted (myosin heavy chain, MHC I) or eliminated (MHC IIa), along with no change (P > 0.05) in %MHC distribution and blunted quadriceps atrophy. In BRE, MHC I (vastus lateralis and soleus) and IIa (vastus lateralis) contractile performance was maintained (P > 0.05) or increased (P < 0.05). Vastus lateralis hybrid fiber percentage was reduced (P < 0.05) and energy metabolism enzymes and capillarization were generally maintained (P > 0.05), while not all of these positive responses were observed in the soleus. Exercise offsets 100% of quadriceps and approximately two-thirds of soleus whole muscle mass loss. Testosterone (BRE + T) did not provide any benefit over exercise alone for either muscle and for some myocellular parameters appeared detrimental. In summary, the periodic testing likely provided a partial exercise countermeasure for the quadriceps in the bedrest group, which is a novel finding given the extremely low exercise dose. The SPRINT exercise program appears to be viable for the quadriceps; however, refinement is needed to completely protect triceps surae myocellular and whole muscle health for astronauts on long-duration spaceflights.NEW & NOTEWORTHY This study provides unique exercise countermeasures development information for astronauts on long-duration spaceflights. The NASA SPRINT program was protective for quadriceps myocellular and whole muscle health, whereas the triceps surae (soleus) was only partially protected as has been shown with other programs. The bedrest control group data may provide beneficial information for overall exercise dose and targeting fast-twitch muscle fibers. Other unique approaches for the triceps surae are needed to supplement existing exercise programs.

Selective Androgen Receptor Modulators-Transformative Drugs or Heralds of the Next Drug Epidemic?

This Viewpoint examines whether selective androgen receptor modulators have the potential to be transformative drugs or whether they herald the next drug epidemic.

Utilize multi-metabolic parameters as determinants for prediction of skeletal muscle mass quality in elderly type2 diabetic Chinese patients

BACKGROUND

Sarcopenia, an age-related disorder characterized by loss of skeletal muscle mass and function, is recently recognized as a complication in elderly patients with type 2 diabetes mellitus (T2DM). Skeletal muscles play a crucial role in glycemic metabolism, utilizing around 80% of blood glucose. Accordingly, we aimed to explore the relationship between glucose metabolism and muscle mass in T2DM.

METHODS

We employed the AWGS 2019 criteria for diagnosing low muscle mass and 1999 World Health Organization (WHO) diabetes diagnostic standards. This study included data of 191 individuals aged 60 and above with T2DM of Shanghai Pudong Hospital from November 2021 to November 2022. Fasting C-peptide (FPCP), fasting plasma glucose (FPG), 2-hour postprandial plasma glucose (PPG) and postprandial 2-hour C-peptide (PPCP), glycated hemoglobin A1c (HbA1c), glycated albumin (GA), serum lipids spectrum, renal and hepatic function, hemoglobin, and hormone were measured. Based on the findings of univariate analysis, logistic regression and receiver operating characteristic (ROC) curves were established.

RESULTS

Participants with low muscle mass had significantly lower alanine and aspartate aminotransferase, and both FPCP and PPCP levels (P < 0.05). Compared with those without low muscle mass, low muscle mass group had significantly higher FPG, HbA1c, GA levels (P < 0.05). Body fat (BF, OR = 1.181) was an independent risk factor for low muscle mass. PPCP (OR = 0.497), BMI (OR = 0.548), and female (OR = 0.050) were identified as protective factors for low skeletal muscle. The AUC of BMI was the highest, followed by the PPCP, gender and BF (0.810, 0.675, 0.647, and 0.639, respectively), and the AUC of the combination of the above four parameters reached 0.895.

CONCLUSIONS

In this cross-sectional study, BMI, Female, and PPCP associated with T2DM were protective factors for low muscle mass. BF was associated with T2DM and risk factor for low muscle mass.

Comparing the Impacts of Testosterone and Exercise on Lean Body Mass, Strength and Aerobic Fitness in Aging Men

BACKGROUND

Based on the largely untested premise that it is a restorative hormone that may reverse the detrimental impacts of aging, prescription of testosterone (T) has increased in recent decades despite no new clinical indications. It is apparent that middle-aged and older men with low-normal serum T levels are considering T supplementation as an anti-aging strategy. At the same time, there is evidence that physical activity (PA) is at historical lows in the Western world. In this review, we compare the impacts of T treatment aimed at achieving physiological T concentrations in middle-aged and older men, alongside the impacts of ecologically relevant forms of exercise training. The independent, and possible combined, effects of T and exercise therapy on physiological outcomes such as aerobic fitness, body composition and muscular strength are addressed.

MAIN BODY

Our findings suggest that both T treatment and exercise improve lean body mass in healthy older men. If improvement in lean body mass is the primary aim, then T treatment could be considered, and the combination of T and exercise may be more beneficial than either in isolation. In terms of muscle strength in older age, an exercise program is likely to be more beneficial than T treatment (where the dose is aimed at achieving physiological concentrations), and the addition of such T treatment does not provide further benefit beyond that of exercise alone. For aerobic fitness, T at doses aimed at achieving physiological concentrations has relatively modest impacts, particularly in comparison to exercise training, and there is limited evidence as to additive effects. Whilst higher doses of T, particularly by intramuscular injection, may have larger impacts on lean body mass and strength, this must be balanced against potential risks.

CONCLUSION

Knowing the impacts of T treatment and exercise on variables such as body composition, strength and aerobic fitness extends our understanding of the relative benefits of physiological and pharmacological interventions in aging men. Our review suggests that T has impacts on strength, body composition and aerobic fitness outcomes that are dependent upon dose, route of administration, and formulation. T treatment aimed at achieving physiological T concentrations in middle-aged and older men can improve lean body mass, whilst exercise training enhances lean body mass, aerobic fitness and strength. Men who are physically able to exercise safely should be encouraged to do so, not only in terms of building lean body mass, strength and aerobic fitness, but for the myriad health benefits that exercise training confers.

Understanding the variation in exercise responses to guide personalized physical activity prescriptions

Understanding the factors that contribute to exercise response variation is the first step in achieving the goal of developing personalized exercise prescriptions. This review discusses the key molecular and other mechanistic factors, both extrinsic and intrinsic, that influence exercise responses and health outcomes. Extrinsic characteristics include the timing and dose of exercise, circadian rhythms, sleep habits, dietary interactions, and medication use, whereas intrinsic factors such as sex, age, hormonal status, race/ethnicity, and genetics are also integral. The molecular transducers of exercise (i.e., genomic/epigenomic, proteomic/post-translational, transcriptomic, metabolic/metabolomic, and lipidomic elements) are considered with respect to variability in physiological and health outcomes. Finally, this review highlights the current challenges that impede our ability to develop effective personalized exercise prescriptions. The Molecular Transducers of Physical Activity Consortium (MoTrPAC) aims to fill significant gaps in the understanding of exercise response variability, yet further investigations are needed to address additional health outcomes across all populations.

The dichotomy between health and drug abuse in bodybuilding

Aim: The aim of the present study was to investigate the expansion and prevalence of anabolic steroid use by examining the divergent effects between health and drug abuse and to create more awareness around the harmful consequences of these drugs when administered at abusive levels. Methods: A focused and concise literature search was conducted, and 101 high-quality articles were included in the review. Results: The findings underscore the adverse health risks of steroid abuse, emphasizing the stark contrast between health and drug abuse. Conclusions: While steroids and other performance-enhancing drugs can yield muscle growth, strength and even fat loss, abusing these substances can lead to adverse health outcomes. Furthermore, within the fitness subculture, particularly in the realm of bodybuilding, steroid abuse fosters an atmosphere of cheating and deception, frequently downplaying or ignoring the negative and sometimes deadly consequences it brings.

Advantage of ostarine over raloxifene and their combined treatments for muscle of estrogen-deficient rats

PURPOSE

Selective androgen (ostarine, OST) and estrogen (raloxifene, RAL) receptor modulators with improved tissue selectivity have been developed as alternatives to hormone replacement therapy. We investigated the combined effects of OST and RAL on muscle tissue in an estrogen-deficient rat model of postmenopausal conditions.

METHODS

Three-month-old Sprague Dawley rats were divided into groups: (1) untreated non-ovariectomized rats (Non-OVX), (2) untreated ovariectomized rats (OVX), (3) OVX rats treated with OST, (4) OVX rats treated with RAL, (5) OVX rats treated with OST and RAL. Both compounds were administered in the diet. The average dose received was 0.6 ± 0.1 mg for OST and 11.1 ± 1.2 mg for RAL per kg body weight/day. After thirteen weeks, rat activity, muscle weight, structure, gene expression, and serum markers were analyzed.

RESULTS

OST increased muscle weight, capillary ratio, insulin-like growth factor 1 (Igf-1) expression, serum phosphorus, uterine weight. RAL decreased muscle weight, capillary ratio, food intake, serum calcium and increased Igf-1 and Myostatin expression, serum follicle stimulating hormone (FSH). OST + RAL increased muscle nucleus ratio, uterine weight, serum phosphorus, FSH and luteinizing hormone and decreased body and muscle weight, serum calcium. Neither treatment changed muscle fiber size. OVX increased body and muscle weight, decreased uterine weight, serum calcium and magnesium.

CONCLUSION

OST had beneficial effects on muscle in OVX rats. Side effects of OST on the uterus and serum electrolytes should be considered before using it for therapeutic purposes. RAL and RAL + OST had less effect on muscle and showed endocrinological side effects on pituitary-gonadal axis.

Molecular and Structural Alterations of Skeletal Muscle Tissue Nuclei during Aging

Aging is accompanied by a progressive loss of skeletal muscle mass and strength. The mechanisms underlying this phenomenon are certainly multifactorial and still remain to be fully elucidated. Changes in the cell nucleus structure and function have been considered among the possible contributing causes. This review offers an overview of the current knowledge on skeletal muscle nuclei in aging, focusing on the impairment of nuclear pathways potentially involved in age-related muscle decline. In skeletal muscle two types of cells are present: fiber cells, constituting the contractile muscle mass and containing hundreds of myonuclei, and the satellite cells, i.e., the myogenic mononuclear stem cells occurring at the periphery of the fibers and responsible for muscle growth and repair. Research conducted on different experimental models and with different methodological approaches demonstrated that both the myonuclei and satellite cell nuclei of aged skeletal muscles undergo several structural and molecular alterations, affecting chromatin organization, gene expression, and transcriptional and post-transcriptional activities. These alterations play a key role in the impairment of muscle fiber homeostasis and regeneration, thus contributing to the age-related decrease in skeletal muscle mass and function.

Hypogonadism is frequent in very old men with multimorbidity and is associated with anemia and sarcopenia

BACKGROUND

Clinical data regarding hypogonadism in very old men with multimorbidity are rare. Hypogonadism can contribute to osteoporosis, anemia and sarcopenia and is therefore a relevant problem for geriatric patients.

METHODS

A total of 167 men aged 65-96 years (mean 81 ± 7 years) admitted to an acute geriatric ward were included in a cross-sectional study. Body composition derived from dual-energy X‑ray absorptiometry, bone mineral density, handgrip strength, multimorbidity, polypharmacy and laboratory values were obtained from the routine electronic clinical patient file.

RESULTS

Hypogonadism was present in 62% (n = 104) of the study participants, of whom 83% showed clinical manifestation of hypogonadism (hypogonadism in combination with anemia, sarcopenia and/or low T‑score). The subgroups showed a distribution of 52% primary and 48% secondary hypogonadism. Compared to the eugonadal patients, hypogonadal patients had reduced handgrip strength (p = 0.031) and lower hemoglobin levels (p = 0.043), even after adjustment for age, body mass index and glomerular filtration rate.

CONCLUSION

Hypogonadism is common in geriatric patients. If chronic anemia, sarcopenia, or osteoporosis are diagnosed, testosterone levels should be determined in geriatric settings.

Mechanisms of hepatic fatty acid oxidation and ketogenesis during fasting

Fasting is part of many weight management and health-boosting regimens. Fasting causes substantial metabolic adaptations in the liver that include the stimulation of fatty acid oxidation and ketogenesis. The induction of fatty acid oxidation and ketogenesis during fasting is mainly driven by interrelated changes in plasma levels of various hormones and an increase in plasma nonesterified fatty acid (NEFA) levels and is mediated transcriptionally by the peroxisome proliferator-activated receptor (PPAR)α, supported by CREB3L3 (cyclic AMP-responsive element-binding protein 3 like 3). Compared with men, women exhibit higher ketone levels during fasting, likely due to higher NEFA availability, suggesting that the metabolic response to fasting shows sexual dimorphism. Here, we synthesize the current molecular knowledge on the impact of fasting on hepatic fatty acid oxidation and ketogenesis.

In-depth mass spectrometry analysis of rhGH administration altered energy metabolism and steroidogenesis

Growth hormone, as a proteohormone, is primarily known of its dramatic effect on longitudinal growth. Recombinant DNA technology has provided a safe, abundant and comparatively cheap supply of human GH for growth hormone-deficient individuals. However, many healthy subjects, especially athletics, administrate GH for enhanced athletic performance or strength. A better and more comprehensive understanding of rhGH effect in healthy individuals is urgent and essential. In this study, we recruited 14 healthy young male and injected rhGH once. Untargeted LC-MS metabolomics profiling of serum and urine was performed before and after the rhGH injection. The GH-induced dysregulation of energy related pathways, such as amino acid metabolism, nucleotide metabolism, glycolysis and TCA cycle, was revealed. Moreover, individuals supplemented with micro-doses of rhGH exhibited significantly changed urinary steroidal profiles, suggesting a role of rhGH in both energy metabolism and steroidogenesis. We expect that our results will be helpful to provide new evidence on the effects of rhGH injection and provide potential biomarkers for rhGH administration.

Neo-Natal Castration Leads to Subtle Differences in Porcine Anterior Cruciate Ligament Morphology and Function in Adolescence

Female adolescent athletes are at a higher risk of tearing their anterior cruciate ligament (ACL) than male counterparts. While most work related to hormones has focused on the effects of estrogen to understand the increased risk of ACL injury, there are other understudied factors, including testosterone. The purpose of this study was to determine how surgical castration in the male porcine model influences ACL size and function across skeletal growth. Thirty-six male Yorkshire crossbreed pigs were raised to 3 (juvenile), 4.5 (early adolescent), and 6 months (adolescent) of age. Animals were either castrated (barrows) within 2 weeks after birth or were left intact (boars). Posteuthanasia, joint and ACL size were assessed via MRI, and biomechanics were assessed via a robotic testing system. Joint size increased throughout age, yet barrows had smaller joints than boars. ACL cross-sectional area (CSA), length, volume, and in situ stiffness increased with age, as did the percent contribution of the ACL anteromedial (AM) bundle to resisting loads. Boar ACL, AM bundle, and PL bundle volumes were 19%, 25%, and 15% larger than barrows across ages. However, ACL CSA, in situ stiffness, and bundle contribution were similar between boars and barrows. The barrows had smaller temporal increases in AM bundle function than boars, but these data were highly variable. Early and sustained loss in testosterone leads to subtle differences in ACL morphology but may not influence measures associated with increased injury risk, such as CSA or bundle forces in response to applied loads.

Up to the maximum-testosterone dose-dependent effects on anabolic and androgen responsive tissues in orchiectomized rats

BACKGROUND

Despite the high number of synthetic androgenic-anabolic steroids, testosterone is still misused for doping in amateur and professional sports. However, only few studies investigated the dose-response effects of testosterone beyond its physiological concentrations and in over 90 years of research, no saturation dosage has been experimentally described for exogenous testosterone administration.

OBJECTIVES

We want to elucidate the physiological and pathophysiological effects of supra-physiological testosterone application and close this gap in testosterone dose-response data.

MATERIALS AND METHODS

Male orchiectomized rats were treated with different testosterone doses ranging from 0.1 to 50 mg/kg body weight for 3 weeks. Several physiological endpoints (e.g., body weight, organ and muscle weight, muscle strength, muscle fiber size) were examined during and after the termination of the treatment with an adjusted Hershberger assay, open-field-test, and (immuno-)histologic.

RESULTS

The wet weights of androgen responsive organs (penis, prostate, seminal vesicle) showed a significant increase in a dose-dependent manner. Histological evaluation of the prostate showed a significant higher percentage of KI67 positive prostate nuclei in the highest dosage group and an increasing hyperplasia with increasing testosterone administered. A significant anabolic effect was only observed in Levator ani wet weight, and to minor degree for the cardiac muscle. Regarding other skeletal muscles (Musculus soleus and Musculus gastrognemicus), no significant testosterone effects were observed. We showed a significant increasing dosage-response effect for testosterone in androgen responsive organs with saturation at the two highest concentration of 10 and 50 mg/kg body weight.

DISCUSSION AND CONCLUSION

The dose-dependent androgenic effects of testosterone were well observable and the anabolic effects on muscle tissue were visible although to a lesser degree, without the support of aerobic exercise and a protein rich diet. Future studies should investigate a combinatorial effect of testosterone and training. Nevertheless, with the chosen range of applied testosterone, we showed a saturation of testosterone effects in prostate, seminal vesicle, penis, and Levator ani.

The Plateau in Muscle Growth with Resistance Training: An Exploration of Possible Mechanisms

It is hypothesized that there is likely a finite ability for muscular adaptation. While it is difficult to distinguish between a true plateau following a long-term training period and short-term stalling in muscle growth, a plateau in muscle growth has been attributed to reaching a genetic potential, with limited discussion on what might physiologically contribute to this muscle growth plateau. The present paper explores potential physiological factors that may drive the decline in muscle growth after prolonged resistance training. Overall, with chronic training, the anabolic signaling pathways may become more refractory to loading. While measures of anabolic markers may have some predictive capabilities regarding muscle growth adaptation, they do not always demonstrate a clear connection. Catabolic processes may also constrain the ability to achieve further muscle growth, which is influenced by energy balance. Although speculative, muscle cells may also possess cell scaling mechanisms that sense and regulate their own size, along with molecular brakes that hinder growth rate over time. When considering muscle growth over the lifespan, there comes a point when the anabolic response is attenuated by aging, regardless of whether or not individuals approach their muscle growth potential. Our goal is that the current review opens avenues for future experimental studies to further elucidate potential mechanisms to explain why muscle growth may plateau.

Higher Myonuclei Density in Muscle Fibers Persists Among Former Users of Anabolic Androgenic Steroids

CONTEXT

No information exists on the long-lasting effects of supraphysiological anabolic androgenic steroids (AASs) usage on the myocellular properties of human skeletal muscle in previous AAS users.

OBJECTIVE

We hypothesized that former AAS users would demonstrate smaller myonuclei domains (ie, higher myonuclei density) than matched controls.

METHODS

A community-based cross-sectional study in men aged 18-50 years engaged in recreational strength training. Muscle biopsies were obtained from the m. vastus lateralis. Immunofluorescence analyses were performed to quantify myonuclei density and myofiber size.

RESULTS

Twenty-five males were included: 8 current and 7 previous AAS users and 10 controls. Median (25th-75th percentiles) accumulated duration of AAS use was 174 (101-206) and 140 (24-260) weeks in current and former AAS users, respectively (P = .482). Geometric mean (95% CI) elapsed duration since AAS cessation was 4.0 (1.2; 12.7) years among former AAS users. Type II muscle fibers in former AAS users displayed higher myonuclei density and DNA to cytoplasm ratio than controls, corresponding to smaller myonuclei domains (P = .013). Longer accumulated AAS use (weeks, log2) was associated with smaller myonuclei domains in previous AAS users: beta-coefficient (95% CI) -94 (-169; -18), P = .024. Type I fibers in current AAS users exhibited a higher amount of satellite cells per myofiber (P = .031) than controls.

CONCLUSION

Muscle fibers in former AAS users demonstrated persistently higher myonuclei density and DNA to cytoplasm ratio 4 years after AAS cessation suggestive of enhanced retraining capacity.

Online information and availability of three doping substances (anabolic agents) in sports: role of pharmacies

Background: The Internet has become an important source for easy access to doping substances, where people and athletes may acquire, outside pharmacies and without a (medical) prescription. These online websites do not always offer quality-assured products, and are outside the regular distribution channels of medicines. The aim of this study was to estimate the availability and accessible information on the Internet about the sale of three doping substances (oxandrolone, DHEA, androstenedione). Methods: Cross-sectional exploratory study, being an observation at a point in time of the online availability of these three doping substances (WADA S1 category: anabolic agents), purchased from Spain, Puerto Rico, Canada, United States, Ukraine and Russia. The characteristics of the websites, the countries the webs sold to, the pharmaceutical forms offered and the recommendations for its use were analyzed by using a computer tool designed ad hoc. Results: There were significant differences between countries in the number of webpages that sold the products (Chi-square test, p < 0.05). Oxandrolone was available for purchase mainly when buying from Spain (27.12%) and Ukraine (26.58%), in websites dedicated to sports (77.26%). For DHEA, most of the pages offered it if the search was done from Canada (23.34%) and Russia (21.44%). Products containing androstenedione or DHEA are claimed to enhance sports performance or for sports use without providing details. Compared to the total number of websites checked, the proportion of pharmacies offering these products was low, ranging from 4.86% for DHEA to 15.79% for androstenedione. Conclusion: The three substances selected are easily available without control through the Internet. Only a small number of websites offering them were online pharmacies, and requested a prescription. Most of the doping substances are purchased from the country where they are requested. Product information described benefits for sports performance, but did not do the same with their side effects. It would be advisable for these products to be sold through pharmacies, to guarantee their quality and provide evidence-based information on their safe use, benefits and risks, and only with a prescription. Athletes should be encouraged to consult health professionals about those supplements suitable for their type of training and sports objectives.

Filamin A cooperates with the androgen receptor in preventing skeletal muscle senescence

Aging induces a slow and progressive decrease in muscle mass and function, causing sarcopenia. Androgens control muscle trophism and exert important anabolic functions through the binding to the androgen receptor. Therefore, analysis of the androgen receptor-mediated actions in skeletal muscle might provide new hints for a better understanding of sarcopenia pathogenesis. In this study, we report that expression of the androgen receptor in skeletal muscle biopsies from 20 subjects is higher in young, as compared with old subjects. Co-immunoprecipitation experiments reveal that the androgen receptor is complexed with filamin A mainly in young, that in old subjects. Therefore, we have in depth analyzed the role of such complex using C2C12 myoblasts that express a significant amount of the androgen receptor. In these cells, hormone stimulation rapidly triggers the assembly of the androgen receptor/filamin A complex. Such complex prevents the senescence induced by oxidative stress in C2C12 cells, as disruption of the androgen receptor/filamin A complex by Rh-2025u stapled peptide re-establishes the senescent phenotype in C2C12 cells. Simultaneously, androgen stimulation of C2C12 cells rapidly triggers the activation of various signaling effectors, including Rac1, focal adhesion kinase, and mitogen-activated kinases. Androgen receptor blockade by bicalutamide or perturbation of androgen receptor/filamin A complex by Rh-2025u stapled peptide both reverse the hormone activation of signaling effectors. These findings further reinforce the role of the androgen receptor and its extranuclear partners in the rapid hormone signaling that controls the functions of C2C12 cells. Further investigations are needed to promote clinical interventions that might ameliorate muscle cell function as well the clinical outcome of age-related frailty.

EMAS position statement: Testosterone replacement therapy in older men

INTRODUCTION

Late-onset hypogonadism is the clinical entity characterised by low testosterone concentrations associated with clinical symptoms in the absence of organic disease in ageing men. It has been associated with metabolic syndrome, reduced bone mineral density, and increased cardiovascular morbidity and mortality risk. Although testosterone replacement therapy (TRT) reverses most of these conditions in young hypogonadal men, the risk/benefit ratio of TRT in older men is debatable.

AIM

To update the 2015 EMAS statement on TRT in older men with new research on late-onset hypogonadism and TRT.

MATERIALS AND METHODS

Literature review and consensus of expert opinion.

SUMMARY RECOMMENDATIONS

TRT should be offered only to symptomatic older men with confirmed low testosterone concentrations after explaining the uncertainties regarding the long-term safety of this treatment. TRT may be offered to men with severe hypogonadism and erectile dysfunction to improve sexual desire, erectile, and orgasmic function. It should also be considered in hypogonadal men with severe insulin resistance or pre-diabetes mellitus. TRT may also be considered, in combination with proven treatment strategies, for osteoporosis, or for selected patients with persistent mild depressive symptoms and/or low self-perceived quality of life, combined with standard medical care for each condition. TRT is contraindicated in hypogonadal men actively seeking fertility treatment. Due to a lack of data, TRT should not be routinely used in older men to improve exercise capacity/physical function, improve cognitive function, or prevent cognitive decline. TRT must be avoided in older, frail men with known breast cancer or untreated prostate cancer and all men who have had myocardial infarction or stroke within the last four months, and those with severe or decompensated heart failure. The quality of evidence regarding patients with previous prostate cancer or cardiovascular disease is too low to draw definitive conclusions. Any limits on duration of use are arbitrary, and treatment should continue for as long as the man feels the benefits outweigh the risks for him, and decisions must be made on an individual basis. Withdrawal should be considered when hypogonadism is reversed after the resolution of underlying disorder. Short-acting transdermal preparations should be preferred for TRT initiation in older men, but injectable forms may be considered subsequently. Older men on TRT should be monitored at 3, 6, and 12 months after initiation and at least yearly thereafter, or earlier and more frequently if indicated. Evaluation should include assessment of the clinical response, and measurement of total testosterone, haematocrit, and prostate-specific antigen (PSA) concentrations. Bone density and/or quality should also be assessed. Obese and overweight patients should be encouraged to undergo lifestyle modifications, including exercise and weight loss, to increase endogenous testosterone.

Familial Correlation and Heritability of Hand Grip Strength in Korean Adults (Korea National Health and Nutrition Examination Survey 2014 to 2019)

BACKGRUOUND

The onset and progression of sarcopenia are highly variable among individuals owing to genetic and environmental factors. However, there are a limited number of studies measuring the heritability of muscle strength in large numbers of parent-adult offspring pairs. We aimed to investigate the familial correlation and heritability of hand grip strength (HGS) among Korean adults.

METHODS

This family-based cohort study on data from the Korea National Health and Nutrition Examination Survey (2014 to 2019) included 5,004 Koreans aged ≥19 years from 1,527 families. HGS was measured using a digital grip strength dynamometer. Familial correlations of HGS were calculated in different pairs of relatives. Variance component methods were used to estimate heritability.

RESULTS

The heritability estimate of HGS among Korean adults was 0.154 (standard error, 0.066). Correlation coefficient estimates for HGS between parent-offspring, sibling, and spouse pairs were significant at 0.07, 0.10, and 0.23 (P<0.001, P=0.041, and P<0.001, respectively). The total variance in the HGS phenotype was explained by additive genetic (15.4%), shared environmental (11.0%), and unique environmental (73.6%) influences. The odds of weak HGS significantly increased in the offspring of parents with weak HGS (odds ratio [OR], 1.69-3.10; P=0.027-0.038), especially in daughters (OR, 2.04-4.64; P=0.029-0.034).

CONCLUSION

HGS exhibits a familial correlation and significant heritable tendency in Korean adults. Therefore, Asian adults, especially women, who have parents with weak HGS, need to pay special attention to their muscle health with the help of healthy environmental stimuli.

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

ABSTRACT

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

Potential application of anti-osteoporotic therapy to relieve sarcopenia in the elderly

Sarcopenia is a progressive and systemic skeletal muscle disorder associated with aging that usually occurs with age in the elderly. Sarcopenia currently lacks effective pharmacological treatment modalities. Multiple pharmacological intervention modalities are available for osteoporosis, a comprehensive disease characterized by decreased systemic bone mass, degradation of bone microarchitecture, and increased bone fragility. Several recent studies have shown an extremely strong correlation between sarcopenia and osteoporosis, leading to the concept of "osteosarcopenia". Therefore, it is possible to alleviate sarcopenia simultaneously by improving osteoporosis.

Impact of biological sex and sex hormones on molecular signatures of skeletal muscle at rest and in response to distinct exercise training modes

Substantial divergence in cardio-metabolic risk, muscle size, and performance exists between men and women. Considering the pivotal role of skeletal muscle in human physiology, we investigated and found, based on RNA sequencing (RNA-seq), that differences in the muscle transcriptome between men and women are largely related to testosterone and estradiol and much less related to genes located on the Y chromosome. We demonstrate inherent unique, sex-dependent differences in muscle transcriptional responses to aerobic, resistance, and combined exercise training in young and older cohorts. The hormonal changes with age likely explain age-related differential expression of transcripts. Furthermore, in primary human myotubes we demonstrate the profound but distinct effects of testosterone and estradiol on amino acid incorporation to multiple individual proteins with specific functions. These results clearly highlight the potential of designing exercise programs tailored specifically to men and women and have implications for people who change gender by altering their hormone profile.

Energetic costs of testosterone in two subsistence populations

OBJECTIVE

Testosterone plays a role in mediating energetic trade-offs between growth, maintenance, and reproduction. Investments in a high testosterone phenotype trade-off against other functions, particularly survival-enhancing immune function and cellular repair; thus only individuals in good condition can maintain both a high testosterone phenotype and somatic maintenance. While these effects are observed in experimental manipulations, they are difficult to demonstrate in free-living animals, particularly in humans. We hypothesize that individuals with higher testosterone will have higher energetic expenditures than those with lower testosterone.

METHODS

Total energetic expenditure (TEE) was quantified using doubly labeled water in n = 40 Tsimane forager-horticulturalists (50% male, 18-87 years) and n = 11 Hadza hunter-gatherers (100% male, 18-65 years), two populations living subsistence lifestyles, high levels of physical activity, and high infectious burden. Urinary testosterone, TEE, body composition, and physical activity were measured to assess potential physical and behavioral costs associated with a high testosterone phenotype.

RESULTS

Endogenous male testosterone was significantly associated with energetic expenditure, controlling for fat free mass; a one standard deviation increase in testosterone is associated with the expenditure of an additional 96-240 calories per day.

DISCUSSION

These results suggest that a high testosterone phenotype, while beneficial for male reproduction, is also energetically expensive and likely only possible to maintain in healthy males in robust condition.

The effect of supraphysiological dose of nandrolone decanoate administration on the inflammatory, neurotrophin and behavioral response in adult and old male mice

This study examined the effect of 6 weeks of supraphysiological nandrolone decanoate (ND) administration in adult mice (7 months) on cognitive function and neuroinflammation during aging. Male C57BL/6 mice were randomized into ND (10 mg·kg-1·wk-1) or control (CTL) groups. Half of the mice were tested at a young (Y) age (ND-Y and CTL-Y), 1 week following final ND administration, while the remaining mice were tested at 16 months (O) (ND-O and CTL-O). Learning and memory were better in young mice compared to older mice, regardless of treatment. ND-O displayed decreased anxiety as compared to all other groups. TNFα and IL1β expression were higher in older mice, regardless of treatment. ND administration in young mice appeared to attenuate the neuroinflammatory response in aging mice as evidenced by decreased COX2, IL-4 and increased IL-10 expression in ND-O compared to CTL-O. BDNF AR and ER expression increased in ND-O compared to CTL-O. Results of the study indicated that supraphysiological ND administration had no negative effect on learning and memory but may attenuate anxiety in older mice. In addition, ND administration in young adult mice may attenuate the inflammatory response during aging, which may be related to elevations in both AR and ER expression.

Use of Anabolic-Androgenic Steroids and Male Fertility: A Systematic Review and Meta-analysis

Background

Anabolic-androgenic steroids (AASs) are often used by men for bodybuilding and to improve sports performance. The use is not limited to professional competitive athletes, but many amateur men.

Objective

The objective of this study was to assess and systematically review the effects of AAS on male fertility parameters, spermiogram, testosterone, follicle-stimulating hormone (FSH) and luteinising hormone (LH) and to review reversibility and other morbidity impacting fertility.

Methods

Eligibility criteria - We included studies mentioning data about adult males using supraphysiologic doses of AAS for sports performance or appearance enhancement, with comparison data from general population or matched controls if available reporting fertility parameters and sexual performance. Information sources - A systematic literature search was performed using PubMed, MEDLINE, EMBASE, Google Scholar and World of Science. Controlled clinical trials randomised or nonrandomised (if available), case series with or without matched controls, case reports, cross-sectional surveys, reports on follow-up of subjects caught in doping test and their fertility parameters when reported. Risk of bias/quality assessment - The quality assessment of the included studies was performed using the Newcastle-Ottawa Scale.

Results

Included studies - Thirty-two studies were included. There were 12 cohort studies, 5 case-control studies, 9 cross-sectional surveys and 6 case reports. The study population comprised 9371 individuals, of which 2671 were AAS users. Synthesis of results - AAS users had reduced levels of FSH and LH than the naïve population. These levels remained low for 3-6 months after stopping AAS. One year after stopping AAS, the users and naïve population had insignificant differences in FSH and LH values. The total testosterone (TT) levels were comparable in users and naïve populations at baseline, 3 months and 6 months after stopping, but at 1 year, TT values were lower in AAS users. Sperm concentration in AAS users and naïve population was similar, but sperm motility was lower in AAS users. The testicular size was lower in AAS users. The erectile function improved with AAS use, but on withdrawal, there was decreased libido and erectile dysfunction. Most AAS users need additional medications to mitigate detrimental effects on fertility. Description of the effect - AAS use negatively impacted the gonadotrophin levels and had lower sperm motility and testicular size. Strength - Comprehensive review of 32 publications, study population of 9371 individuals, of which 2671 were AAS users, meta-analysis of reproductive hormones, semen parameters and testis size.

Limitations

The limitations are small sample size of most of the studies, polypharmacy, lack of information on dosing and high heterogeneity.

Interpretation

AAS use is detrimental for sperm motility and has a partially reversible negative impact on male fertility. Users must be cautioned about its negative impact on libido and erectile function.Registration: PROSPERO Registration No. CRD42023411294.

Androgen action on myogenesis throughout the lifespan; comparison with neurogenesis

Androgens' pleiotropic actions in promoting sex differences present not only a challenge to providing a comprehensive account of their function, but also an opportunity to gain insights by comparing androgenic actions across organ systems. Although often overlooked by neuroscientists, skeletal muscle is another androgen-responsive organ system which shares with the nervous system properties of electrochemical excitability, behavioral relevance, and remarkable capacity for adaptive plasticity. Here we review androgenic regulation of mitogenic plasticity in skeletal muscle with the goal of identifying areas of interest to those researching androgenic mechanisms mediating sexual differentiation of neurogenesis. We use an organizational-activational framework to relate broad areas of similarity and difference between androgen effects on mitogenesis in muscle and brain throughout the lifespan, from early organogenesis, through pubertal organization, adult activation, and aging. The focus of the review is androgenic regulation of muscle-specific stem cells (satellite cells), which share with neural stem cells essential functions in development, plasticity, and repair, albeit with distinct, muscle-specific features. Also considered are areas of paracrine and endocrine interaction between androgen action on muscle and nervous system, including mediation of neural plasticity of innervating and distal neural populations by muscle-produced trophic factors.

Mechanisms of mechanical overload-induced skeletal muscle hypertrophy: current understanding and future directions

Mechanisms underlying mechanical overload-induced skeletal muscle hypertrophy have been extensively researched since the landmark report by Morpurgo (1897) of "work-induced hypertrophy" in dogs that were treadmill trained. Much of the preclinical rodent and human resistance training research to date supports that involved mechanisms include enhanced mammalian/mechanistic target of rapamycin complex 1 (mTORC1) signaling, an expansion in translational capacity through ribosome biogenesis, increased satellite cell abundance and myonuclear accretion, and postexercise elevations in muscle protein synthesis rates. However, several lines of past and emerging evidence suggest that additional mechanisms that feed into or are independent of these processes are also involved. This review first provides a historical account of how mechanistic research into skeletal muscle hypertrophy has progressed. A comprehensive list of mechanisms associated with skeletal muscle hypertrophy is then outlined, and areas of disagreement involving these mechanisms are presented. Finally, future research directions involving many of the discussed mechanisms are proposed.

Hormonal, immune, and oxidative stress responses to blood flow-restricted exercise

INTRODUCTION

Heavy-load free-flow resistance exercise (HL-FFRE) is a widely used training modality. Recently, low-load blood-flow restricted resistance exercise (LL-BFRRE) has gained attention in both athletic and clinical settings as an alternative when conventional HL-FFRE is contraindicated or not tolerated. LL-BFRRE has been shown to result in physiological adaptations in muscle and connective tissue that are comparable to those induced by HL-FFRE. The underlying mechanisms remain unclear; however, evidence suggests that LL-BFRRE involves elevated metabolic stress compared to conventional free-flow resistance exercise (FFRE).

AIM

The aim was to evaluate the initial (<10 min post-exercise), intermediate (10-20 min), and late (>30 min) hormonal, immune, and oxidative stress responses observed following acute sessions of LL-BFRRE compared to FFRE in healthy adults.

METHODS

A systematic literature search of randomized and non-randomized studies was conducted in PubMed, Embase, Cochrane Central, CINAHL, and SPORTDiscus. The Cochrane Risk of Bias (RoB2, ROBINS-1) and TESTEX were used to evaluate risk of bias and study quality. Data extractions were based on mean change within groups.

RESULTS

A total of 12525 hits were identified, of which 29 articles were included. LL-BFRRE demonstrated greater acute increases in growth hormone responses when compared to overall FFRE at intermediate (SMD 2.04; 95% CI 0.87, 3.22) and late (SMD 2.64; 95% CI 1.13, 4.16) post-exercise phases. LL-BFRRE also demonstrated greater increase in testosterone responses compared to late LL-FFRE.

CONCLUSION

These results indicate that LL-BFRRE can induce increased or similar hormone and immune responses compared to LL-FFRE and HL-FFRE along with attenuated oxidative stress responses compared to HL-FFRE.

Beneficial Effects of Asparagus officinalis Extract Supplementation on Muscle Mass and Strength following Resistance Training and Detraining in Healthy Males

The phytoecdysteroid 20-hydroxyecdysone (20E) is widely used for resistance training (RT). Little is known about its potential ergogenic value and detraining effects post-RT. This study aimed to examine the effects of 20E extracted from Asparagus officinalis (A. officinalis) on muscle strength and mass, as well as anabolic and catabolic hormones following RT and detraining. Twenty males, aged 20.1 ± 1.1 years, were matched and randomly assigned to consume double-blind supplements containing either a placebo (PLA) or 30 mg/day of 20E for 12 weeks of RT and detraining. Before and after RT and detraining, muscle strength and mass and anabolic and catabolic hormones were measured. This study found that 20E reduced cortisol levels significantly (p < 0.05) compared to the PLA, yet no effect was observed on muscle mass, strength, or anabolic hormones after RT. Subsequent to 6 weeks of detraining, the 20E demonstrated a lower percentage change in 1RM bench press/FFM than the PLA (p < 0.05). Compared to the PLA, detraining throughout the 12 weeks resulted in a lower percentage change in thigh (p < 0.05) and chest (p < 0.01) circumferences, as well as reduced cortisol levels (p < 0.01), with 20E. Our findings demonstrate that 20E supplementation is a promising way to maintain muscle mass and strength during detraining. Accordingly, 20E may prevent muscle mass and strength loss due to detraining by lowering catabolic hormone levels.

Update on the treatment of cancer cachexia

Cancer cachexia is a complex multifaceted syndrome involving functional impairment and changes in body composition that cannot be reversed by nutritional support. Cancer cachexia is characterized by decreased skeletal muscle mass, increased lipolysis, and decreased food intake. Cancer cachexia decreases chemotherapy tolerance as well as quality of life. However, because no fully effective interventions are available, cancer cachexia remains an unmet need in cancer treatment. In recent years, several discoveries and treatments for cancer cachexia have been studied, and guidelines have been published. We believe that the development of effective strategies for the diagnosis and treatment of cancer cachexia will lead to breakthroughs in cancer treatment.

The MMAAS Project: An Observational Human Study Investigating the Effect of Anabolic Androgenic Steroid Use on Gene Expression and the Molecular Mechanism of Muscle Memory

OBJECTIVE

It remains unknown whether myonuclei remain elevated post anabolic-androgenic steroid (AAS) usage in humans. Limited data exist on AAS-induced changes in gene expression.

DESIGN

Cross-sectional/longitudinal.

SETTING

University.

PARTICIPANTS

Fifty-six men aged 20 to 42 years.

INDEPENDENT VARIABLES

Non-resistance-trained (C) or resistance-trained (RT), RT currently using AAS (RT-AS), of which if AAS usage ceased for ≥18 weeks resampled as Returning Participants (RP) or RT previously using AAS (PREV).

MAIN OUTCOME MEASURES

Myonuclei per fiber and cross-sectional area (CSA) of trapezius muscle fibers.

RESULTS

There were no significant differences between C (n = 5), RT (n = 15), RT-AS (n = 17), and PREV (n = 6) for myonuclei per fiber. Three of 5 returning participants (RP1-3) were biopsied twice. Before visit 1, RP1 ceased AAS usage 34 weeks before, RP2 and RP3 ceased AAS usage ≤2 weeks before, and all had 28 weeks between visits. Fiber CSA decreased for RP1 and RP2 between visits (7566 vs 6629 μm 2 ; 7854 vs 5677 μm 2 ) while myonuclei per fiber remained similar (3.5 vs 3.4; 2.5 vs 2.6). Respectively, these values increased for RP3 between visits (7167 vs 7889 μm 2 ; 2.6 vs 3.3).

CONCLUSIONS

This cohort of past AAS users did not have elevated myonuclei per fiber values, unlike previous research, but reported AAS usage was much lower. Training and AAS usage history also varied widely among participants. Comparable myonuclei per fiber numbers despite decrements in fiber CSA postexposure adheres with the muscle memory mechanism, but there is variation in usage relative to sampling date and low numbers of returning participants.

Retaining Race in Chronic Kidney Disease Diagnosis and Treatment

The best overall measure of kidney function is glomerular filtration rate (GFR) as commonly estimated from serum creatinine concentrations (eGFRcr) using formulas that correct for the higher average creatinine concentrations in Blacks. After two decades of use, these formulas have come under scrutiny for estimating GFR differently in Blacks and non-Blacks. Discussions of whether to include race (Black vs. non-Black) in the calculation of eGFRcr fail to acknowledge that the original race-based eGFRcr provided the same CKD treatment recommendations for Blacks and non-Blacks based on directly (exogenously) measured GFR. Nevertheless, the National Kidney Foundation and the American Society of Nephrology Task Force on Reassessing the Inclusion of Race in Diagnosing Kidney Disease removed race in CKD treatment guidelines and pushed for the immediate adoption of a race-free eGFRcr formula by physicians and clinical laboratories. This formula is projected to negate CKD in 5.51 million White and other non-Black adults and reclassify CKD to less severe stages in another 4.59 million non-Blacks, in order to expand treatment eligibility to 434,000 Blacks not previously diagnosed and to 584,000 Blacks previously diagnosed with less severe CKD. This review examines: 1) the validity of the arguments for removing the original race correction, and 2) the performance of the proposed replacement formula. Excluding race in the derivation of eGFRcr changed the statistical bias from +3.7 to -3.6 ml/min/1.73m2 in Blacks and from +0.5 to +3.9 in non-Blacks, i.e., promoting CKD diagnosis in Blacks at the cost of restricting diagnosis in non-Blacks. By doing so, the revised eGFRcr greatly exaggerates the purported racial disparity in CKD burden. Claims that the revised formulas identify heretofore undiagnosed CKD in Blacks are not supported when studies that used kidney failure replacement therapy and mortality are interpreted as proxies for baseline CKD. Alternatively, a race-stratified eGFRcr (i.e., separate equations for Blacks and non-Blacks) would provide the least biased eGFRcr for both Blacks and non-Blacks and the best medical treatment for all patients.

Adjuvant pharmacological strategies for the musculoskeletal system during long-term space missions

Despite 2 h of daily exercise training, muscle wasting and bone loss are still present after 6-month missions to the international space station. Some crew members lose bone much faster than others. In preparation for missions to the Moon and Mars, space agencies are therefore reviewing their countermeasure portfolios. Here, we discuss the potential of current pharmacological strategies. Bone loss in space is fuelled by bone resorption. Alendronate, an oral bisphosphonate, reduced bone losses in experimental bed rest and space. However, gastrointestinal side effects precluded its further utilization in space. Zoledronate (a potent bisphosphonate), denosumab (RANKL antagonist) and romosozumab (sclerostin antagonist) are all administered via injection. They effectively suppress bone resorption and are routinely prescribed against osteoporosis. Their serious adverse effects, namely, osteonecrosis of the jaw and atypical femur fractures occur very rarely when the usage is limited to 1 or 2 years. Hence, utilization of one of these compounds may outweigh the bone risks of space travelling, in particular in those with high bone resorption rates. Muscle wasting in space is likely due to hampered muscle protein synthesis. Even though this might theoretically be countered by the synthesis-boosting effects of anabolic steroids, the practical grounds for such recommendation are currently weak. Moreover, they reveal their full potential only when combined with an anabolic exercise stimulus, for example, via strength training. It therefore seems that a combination of exercise and pharmacological countermeasures should be considered for musculoskeletal health on the way to the Moon and Mars and back.

Optimizing the Design of Clinical Trials to Evaluate the Efficacy of Function-Promoting Therapies

BACKGROUND

Several candidate molecules that may have application in treating physical limitations associated with aging and chronic diseases are in development. Challenges in the framing of indications, eligibility criteria, and endpoints and the lack of regulatory guidance have hindered the development of function-promoting therapies.

METHODS

Experts from academia, pharmaceutical industry, National Institutes of Health (NIH), and Food and Drug Administration (FDA) discussed optimization of trial design including the framing of indications, eligibility criteria, and endpoints.

RESULTS

Mobility disability associated with aging and chronic diseases is an attractive indication because it is recognized by geriatricians as a common condition associated with adverse outcomes, and it can be ascertained reliably. Other conditions associated with functional limitation in older adults include hospitalization for acute illnesses, cancer cachexia, and fall injuries. Efforts are underway to harmonize definitions of sarcopenia and frailty. Eligibility criteria should reconcile the goals of selecting participants with the condition and ensuring generalizability and ease of recruitment. An accurate measure of muscle mass (eg, D3 creatine dilution) could be a good biomarker in early-phase trials. Performance-based and patient-reported measures of physical function are needed to demonstrate whether treatment improves how a person lives, functions, or feels. Multicomponent functional training that integrates training in balance, stability, strength, and functional tasks with cognitive and behavioral strategies may be needed to translate drug-induced muscle mass gains into functional improvements.

CONCLUSIONS

Collaborations among academic investigators, NIH, FDA, pharmaceutical industry, patients, and professional societies are needed to conduct well-designed trials of function-promoting pharmacological agents with and without multicomponent functional training.

Androgens and Selective Androgen Receptor Modulators to Treat Functional Limitations Associated With Aging and Chronic Disease

Testosterone, many steroidal androgens, and nonsteroidal ligands that bind to androgen receptor and exert tissue-specific transcriptional activity (selective androgen receptor modulators [SARMs]) are being developed as function-promoting therapies to treat functional limitations associated with aging and chronic diseases. This narrative review describes preclinical studies, mechanisms, and randomized trials of testosterone, other androgens, and nonsteroidal SARMs. Sex differences in muscle mass and strength and empiric use of anabolic steroids by athletes to increase muscularity and athletic performance provide supportive evidence of testosterone's anabolic effects. In randomized trials, testosterone treatment increases lean body mass, muscle strength, leg power, aerobic capacity, and self-reported mobility. These anabolic effects have been reported in healthy men, hypogonadal men, older men with mobility limitation and chronic diseases, menopausal women, and HIV-infected women with weight loss. Testosterone has not consistently improved walking speed. Testosterone treatment increases volumetric and areal bone mineral density, and estimated bone strength; improves sexual desire, erectile function, and sexual activity; modestly improves depressive symptoms; and corrects unexplained anemia in older men with low testosterone levels. Prior studies have not been of sufficient size or duration to determine testosterone's cardiovascular and prostate safety. The efficacy of testosterone in reducing physical limitations, fractures, falls, progression to diabetes, and correcting late-onset persistent depressive disorder remains to be established. Strategies to translate androgen-induced muscle mass and strength gains into functional improvements are needed. Future studies should evaluate the efficacy of combined administration of testosterone (or a SARM) plus multidimensional functional exercise to induce neuromuscular adaptations required for meaningful functional improvements.

A Validation Study of a Deep Learning-Based Doping Drug Text Recognition System to Ensure Safe Drug Use among Athletes

This study aimed to develop an English version of a doping drug-recognition system using deep learning-based optical character recognition (OCR) technology. A database of 336 banned substances was built based on the World Anti-Doping Agency's International Standard Prohibited List and the Korean Pharmaceutical Information Center's Drug Substance Information. For accuracy and validity analysis, 886 drug substance images, including 152 images of prescriptions and drug substance labels collected using data augmentation, were used. The developed hybrid system, based on the Tesseract OCR model, can be accessed by both a smartphone and website. A total of 5379 words were extracted, and the system showed character recognition errors regarding 91 words, showing high accuracy (98.3%). The system correctly classified all 624 images for acceptable substances, 218 images for banned substances, and incorrectly recognized 44 of the banned substances as acceptable. The validity analysis showed a high level of accuracy (0.95), sensitivity (1.00), and specificity (0.93), suggesting system validity. The system has the potential of allowing athletes who lack knowledge about doping to quickly and accurately check whether they are taking banned substances. It may also serve as an efficient option to support the development of a fair and healthy sports culture.

Evidence of use and users of image- and performance-enhancing drugs in sports in Switzerland: a scoping literature review and implications for Swiss drug policy

BACKGROUND

"Image- and performance-enhancing drugs" are widely used in sports worldwide to improve body image and performance goals. In view of the growing research interest and use of these substances, and the paucity of data on the situation in Switzerland, we conducted a scoping literature review on evidence of the use and users of these substances in Switzerland.

METHODS

A scoping review was conducted following the Preferred Reporting Items for Systematic reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR) statement. We searched PubMed/Medline, Embase and Google Scholar for articles published before August 2022. Primary outcomes were evidence of the use and users of image- and performance enhancing drugs in Switzerland. We used a narrative synthesis approach for data analysis.

RESULTS

Overall, 18 studies were reviewed, which in total comprised 11,401 survey participants, 140 interviews and 1368 toxicologically analysed substances. Articles were mostly peer-reviewed (83%) and mostly included evidence from professional athletes (43%). The mean publication year was 2011. In most articles both outcomes (78%) were evaluated simultaneously. We demonstrate that image- and performance-enhancing drugs appear to be prevalent among athletes and non-athletes in Switzerland. A wide variety of substances exist, and the type of substances used varied by age, motivation, sex and sports discipline. The main motivations for using these substances were, among others, image- and performance enhancement. The main route of acquisition of these substances was the Internet. Furthermore, we demonstrated that substantial proportions of these substances, as well as supplements, may be counterfeit. Information on image- and performance-enhancing drug use was acquired from different sources.

CONCLUSIONS

Although evidence of image- and performance-enhancing drug use and its users in Switzerland is scarce and there are major gaps, we demonstrate that these substances are also prevalent among athletes and non-athletes in Switzerland. Furthermore, high proportions of substances acquired from unregulated drug markets are counterfeit, which puts users in a situation of unpredictable risk when consuming them. Overall, the use of these substances may pose a substantial risk to individual and public health in this possibly growing and often insufficiently informed and medically neglected user community in Switzerland. There is a great need for future research, as well as prevention, harm-reduction and treatment programmes for this hard-to-reach user community. Doping policies in Switzerland should be critically reviewed as simple medical care and evidence-based treatment for non-athlete image- and performance-enhancing drug users is excessively criminalized under the current legislature, leaving possibly over 200,000 image- and performance-enhancing drug users in Switzerland with inadequate medical care.

Clustering psychopathology in male anabolic-androgenic steroid users and nonusing weightlifters

INTRODUCTION

Prior research has demonstrated that personality disorders and clinical psychiatric syndromes are common among users of anabolic-androgenic steroids (AAS). However, the prevalence, expression, and severity of psychopathology differ among AAS users and remain poorly understood. In this study, we examine the existence of potential clinically coherent psychopathology subgroups, using cluster procedures.

METHODS

A sample of 118 male AAS users and 97 weightlifting nonusers was assessed using the Millon Clinical Multiaxial Inventory-III (MCMI-III), measuring personality disorders and clinical syndromes. Group differences in MCMI-III scales were assessed using Wilcoxon-Mann-Whitney tests and Fisher's exact test. Agglomerative hierarchical clustering was used to identify clusters based on MCMI-III scale scores from the whole sample.

RESULTS

AAS users displayed significantly higher scores on all personality disorder (except narcissistic) and clinical syndrome scales compared to nonusing weightlifters. The clustering analysis found four separate clusters with different levels and patterns of psychopathology. The "no psychopathology" cluster was most common among nonusing weightlifters, while the three other clusters were more common among AAS users: "severe multipathology," "low multipathology," and "mild externalizing." The "severe multipathology" cluster was found almost exclusively among AAS users. AAS users also displayed the highest scores on drug and alcohol dependence syndromes.

CONCLUSIONS

AAS users in our sample demonstrated greater psychopathology than the nonusing weightlifters, with many exhibiting multipathology. This may pose a significant challenge to clinical care for AAS users, particularly as there appears to be significant variation in psychopathology in this population. Individual psychiatric profiles should be taken into consideration when providing treatment to this group.

SIGNIFICANT OUTCOMES

As a group, AAS users displayed markedly greater psychopathology than nonusing weightlifters. Multipathology was common among AAS users. Four different subgroups of personality profiles were identified with distinct patterns of pathology and severity.

LIMITATIONS

The cross-sectional nature of the study precludes inferences about causality. The study is limited by possible selection bias, as participants choosing to be involved in research may not be entirely representative for the group as a whole. The study is vulnerable to information bias, as the results are based on self-report measures and interviews.

An observational human study investigating the effect of anabolic androgenic steroid use on the transcriptome of skeletal muscle and whole blood using RNA-Seq

BACKGROUND

The effects of Anabolic Androgenic Steroids (AAS) are largely illustrated through Androgen Receptor induced gene transcription, yet RNA-Seq has yet to be conducted on human whole blood and skeletal muscle. Investigating the transcriptional signature of AAS in blood may aid AAS detection and in muscle further understanding of AAS induced hypertrophy.

METHODS

Males aged 20-42 were recruited and sampled once: sedentary controls (C), resistance trained lifters (RT) and resistance trained current AAS users (RT-AS) who ceased exposure ≤ 2 or ≥ 10 weeks prior to sampling. RT-AS were sampled twice as Returning Participants (RP) if AAS usage ceased for ≥ 18 weeks. RNA was extracted from whole blood and trapezius muscle samples. RNA libraries were sequenced twice, for validation purposes, on the DNBSEQ-G400RS with either standard or CoolMPS PE100 reagents following MGI protocols. Genes were considered differentially expressed with FDR < 0.05 and a 1.2- fold change.

RESULTS

Cross-comparison of both standard reagent whole blood (N = 55: C = 7, RT = 20, RT-AS ≤ 2 = 14, RT-AS ≥ 10 = 10, RP = 4; N = 46: C = 6, RT = 17, RT-AS ≤ 2 = 12, RT-AS ≥ 10 = 8, RP = 3) sequencing datasets, showed that no genes or gene sets/pathways were differentially expressed between time points for RP or between group comparisons of RT-AS ≤ 2 vs. C, RT, or RT-AS ≥ 10. Cross-comparison of both muscle (N = 51, C = 5, RT = 17, RT-AS ≤ 2 = 15, RT-AS ≥ 10 = 11, RP = 3) sequencing (one standard & one CoolMPS reagent) datasets, showed one gene, CHRDL1, which has atrophying potential, was upregulated in RP visit two. In both muscle sequencing datasets, nine differentially expressed genes, overlapped with RT-AS ≤ 2 vs. RT and RT-AS ≤ 2 vs. C, but were not differentially expressed with RT vs. C, possibly suggesting they are from acute doping alone. No genes seemed to be differentially expressed in muscle after the long-term cessation of AAS, whereas a previous study found long term proteomic changes.

CONCLUSION

A whole blood transcriptional signature of AAS doping was not identified. However, RNA-Seq of muscle has identified numerous differentially expressed genes with known impacts on hypertrophic processes that may further our understanding on AAS induced hypertrophy. Differences in training regimens in participant groupings may have influenced results. Future studies should focus on longitudinal sampling pre, during and post-AAS exposure to better control for confounding variables.

Human skeletal muscle-specific atrophy with aging: a comprehensive review

Age-related skeletal muscle atrophy appears to be a muscle group-specific process, yet only a few specific muscles have been investigated and our understanding in this area is limited. This review provides a comprehensive summary of the available information on age-related skeletal muscle atrophy in a muscle-specific manner, nearly half of which comes from the quadriceps. Decline in muscle-specific size over ∼50 yr of aging was determined from 47 cross-sectional studies of 982 young (∼25 yr) and 1,003 old (∼75 yr) individuals and nine muscle groups: elbow extensors (-20%, -0.39%/yr), elbow flexors (-19%, -0.38%/yr), paraspinals (-24%, -0.47%/yr), psoas (-29%, -0.58%/yr), hip adductors (-13%, -0.27%/yr), hamstrings (-19%, -0.39%/yr), quadriceps (-27%, -0.53%/yr), dorsiflexors (-9%, -0.19%/yr), and triceps surae (-14%, -0.28%/yr). Muscle-specific atrophy rate was also determined for each of the subcomponent muscles in the hamstrings, quadriceps, and triceps surae. Of all the muscles included in this review, there was more than a fivefold difference between the least (-6%, -0.13%/yr, soleus) to the most (-33%, -0.66%/yr, rectus femoris) atrophying muscles. Muscle activity level, muscle fiber type, sex, and timeline of the aging process all appeared to have some influence on muscle-specific atrophy. Given the large range of muscle-specific atrophy and the large number of muscles that have not been investigated, more muscle-specific information could expand our understanding of functional deficits that develop with aging and help guide muscle-specific interventions to improve the quality of life of aging women and men.

Misadventures in Toxicology: Concentration Matters for Testosterone-Induced Neurotoxicity

Testosterone is the predominant androgen in men and has important physiological functions. Due to declining testosterone levels from a variety of causes, testosterone replacement therapy (TRT) is increasingly utilized, while testosterone is also abused for aesthetic and performance-enhancing purposes. It has been increasingly speculated that aside from more well-established side effects, testosterone may cause neurological damage. However, the in vitro data utilized to support such claims is limited due to the high concentrations used, lack of consideration of tissue distribution, and species differences in sensitivity to testosterone. In most cases, the concentrations studied in vitro are unlikely to be reached in the human brain. Observational data in humans concerning the potential for deleterious changes in brain structure and function are limited by their inherent design as well as significant potential confounders. More research is needed as the currently available data are limited; however, what is available provides rather weak evidence to suggest that testosterone use or abuse has neurotoxic potential in humans.

Neo-natal castration leads to subtle differences in porcine anterior cruciate ligament morphology and function in adolescence

Female adolescent athletes are at a higher risk of tearing their anterior cruciate ligament (ACL) than male counterparts. While most work related to hormones has focused on the effects of estrogen to understand the increased risk of ACL injury, there are other understudied factors, including testosterone. The purpose of this study was to determine how surgical castration in the male porcine model influences ACL size and function across skeletal growth. Thirty-six male Yorkshire crossbreed pigs were raised to 3 (juvenile), 4.5 (early adolescent), and 6 months (adolescent) of age. Animals were either castrated (barrows) within 1-2 weeks after birth or were left intact (boars). Post-euthanasia, joint and ACL size were assessed via MRI, and biomechanics were assessed via a robotic testing system. Joint size increased throughout age, yet barrows had smaller joints than boars (p<0.001 for all measures). ACL cross-sectional area (CSA), length, volume, and stiffness increased with age (p<0.0001), as did ACL anteromedial (AM) bundle percent contribution to resisting loads (p=0.012). Boar ACL, AM bundle, and PL bundle volumes were 19% (p=0.002), 25% (p=0.003), and 15% (p=0.04) larger than barrows across ages. However, CSA, stiffness, and bundle contribution were similar between boars and barrows (p>0.05). The barrows had smaller temporal increases in AM bundle percent function than boars, but these data were highly variable. Thus, early and sustained loss in testosterone leads to subtle differences in ACL morphology, but may not influence measures associated with increased injury risk, such as CSA or bundle forces in response to applied loads.

Investigation of in vitro generated metabolites of GLPG0492 using equine liver microsomes for doping control

An effective alternative to testosterone therapy is selective androgen receptor modulators, a class of compounds that has a tissue-specific effect on muscle and bone. These drugs, which enhance performance, pose a severe abuse risk in competitive sports. GLPG0492 is one of the selective androgen receptor modulators discovered in recent decades. This compound has a unique tissue-specific action for muscle and bone against steroid receptors and acts as a partial agonist for androgen receptors. This study examined GLPG0492 and its metabolites in vitro using equine liver microsomes. Liquid chromatography-high-resolution mass spectrometry was utilized to determine the probable structures of detected metabolites. This study identified 39 metabolites of GLPG0492 (21 phase I and 18 phase II). The hydroxylation of GLPG0492 results in monohydroxylated and dihydroxylated metabolites. Additionally, the study detected dissociated side chains (3-methyl and 4-(hydroxymethyl)) and corresponding hydroxylated metabolites. A series of glucuronic acid- and sulfonic acid-conjugated analogs of GLPG0492 were detected during phase II of the study. The findings might help in the detection of GLPG0492 and the elucidation of its illegal use in equestrian sports.

Genetic analyses implicate complex links between adult testosterone levels and health and disease

BACKGROUND

Testosterone levels are linked with diverse characteristics of human health, yet, whether these associations reflect correlation or causation remains debated. Here, we provide a broad perspective on the role of genetically determined testosterone on complex diseases in both sexes.

METHODS

Leveraging genetic and health registry data from the UK Biobank and FinnGen (total N = 625,650), we constructed polygenic scores (PGS) for total testosterone, sex-hormone binding globulin (SHBG) and free testosterone, associating these with 36 endpoints across different disease categories in the FinnGen. These analyses were combined with Mendelian Randomization (MR) and cross-sex PGS analyses to address causality.

RESULTS

We show testosterone and SHBG levels are intricately tied to metabolic health, but report lack of causality behind most associations, including type 2 diabetes (T2D). Across other disease domains, including 13 behavioral and neurological diseases, we similarly find little evidence for a substantial contribution from normal variation in testosterone levels. We nonetheless find genetically predicted testosterone affects many sex-specific traits, with a pronounced impact on female reproductive health, including causal contribution to PCOS-related traits like hirsutism and post-menopausal bleeding (PMB). We also illustrate how testosterone levels associate with antagonistic effects on stroke risk and reproductive endpoints between the sexes.

CONCLUSIONS

Overall, these findings provide insight into how genetically determined testosterone correlates with several health parameters in both sexes. Yet the lack of evidence for a causal contribution to most traits beyond sex-specific health underscores the complexity of the mechanisms linking testosterone levels to disease risk and sex differences.

A comprehensive normative reference database of muscle morphology in typically developing children aged 3-18 years-a cross-sectional ultrasound study

During childhood, muscle growth is stimulated by a gradual increase in bone length and body mass, as well as by other factors, such as physical activity, nutrition, metabolic, hormonal, and genetic factors. Muscle characteristics, such as muscle volume, anatomical cross-sectional area, and muscle belly length, need to continuously adapt to meet the daily functional demands. Pediatric neurological and neuromuscular disorders, like cerebral palsy and Duchenne muscular dystrophy, are characterized by impaired muscle growth, which requires treatment and close follow-up. Nowadays ultrasonography is a commonly used technique to evaluate muscle morphology in both pediatric pathologies and typically developing children, as it is a quick, easy applicable, and painless method. However, large normative datasets including different muscles and a large age range are lacking, making it challenging to monitor muscle over time and estimate the level of pathology. Moreover, in order to compare individuals with different body sizes as a result of age differences or pathology, muscle morphology is often normalized to body size. Yet, the usefulness and practicality of different normalization techniques are still unknown, and clear recommendations for normalization are lacking. In this cross-sectional cohort study, muscle morphology of four lower limb muscles (medial gastrocnemius, tibialis anterior, the distal compartment of the semitendinosus, rectus femoris) was assessed by 3D-freehand ultrasound in 118 typically developing children (mean age 10.35 ± 4.49 years) between 3 and 18 years of age. The development of muscle morphology was studied over the full age range, as well as separately for the pre-pubertal (3-10 years) and pubertal (11-18 years) cohorts. The assumptions of a simple linear regression were checked. If these assumptions were fulfilled, the cross-sectional growth curves were described by a simple linear regression equation. Additional ANCOVA analyses were performed to evaluate muscle- or gender-specific differences in muscle development. Furthermore, different scaling methods, to normalize muscle morphology parameters, were explored. The most appropriate scaling method was selected based on the smallest slope of the morphology parameter with respect to age, with a non-significant correlation coefficient. Additionally, correlation coefficients were compared by a Steiger's Z-test to identify the most efficient scaling technique. The current results revealed that it is valid to describe muscle volume (with exception of the rectus femoris muscle) and muscle belly length alterations over age by a simple linear regression equation till the age of 11 years. Normalizing muscle morphology data by allometric scaling was found to be most useful for comparing muscle volumes of different pediatric populations. For muscle lengths, normalization can be achieved by either allometric and ratio scaling. This study provides a unique normative database of four lower limb muscles in typically developing children between the age of 3 and 18 years. These data can be used as a reference database for pediatric populations and may also serve as a reference frame to better understand both physiological and pathological muscle development.

Testosterone replacement in prostate cancer survivors with testosterone deficiency: Study protocol of a randomized controlled trial

BACKGROUND

Most men diagnosed with prostate cancer today have organ-confined disease and low risk of disease recurrence after radical prostatectomy. Testosterone deficiency in prostate cancer survivors contributes to impaired health-related quality of life but testosterone treatment is viewed as a contraindication in this population.

OBJECTIVES

We describe the design of the first randomized trial to determine the safety and efficacy of testosterone treatment in men who have undergone prostatectomy for non-aggressive prostate cancer and have symptomatic testosterone deficiency.

METHODS

Surviving Prostate cancer while Improving quality of life through Rehabilitation with Testosterone Trial is a randomized, placebo-controlled, double-blind, parallel group trial in 142 men, ≥ 40 years, who have undergone radical prostatectomy for organ-confined prostate cancer, Gleason score ≤ 7 (3+4), Stage pT2, N0, M0 lesions and have symptomatic testosterone deficiency and undetectable prostate specific antigen for > 2 years after surgery. Eligible participants are randomized to weekly intramuscular injections of 100-mg testosterone cypionate or placebo for 12 weeks and followed for another 12 weeks. Primary endpoint is change from baseline in sexual activity. Secondary outcomes include change in sexual desire, erectile function, energy, lean and fat mass, physical and cognitive performance. Safety is assessed by monitoring prostate-specific antigen, lower urinary tract symptoms, hemoglobin, and adverse events.

RESULTS

The trial is being conducted at two trial sites in Boston, MA and Baltimore, MD. As of July 30, 2022, 42 participants have been randomized. No prostate-specific antigen or clinical recurrence has been noted to-date.

DISCUSSION

Recruitment was slowed by coronavirus disease 2019-related closures, slow subsequent ramp-up of research activities, and patient concerns about safety of testosterone treatment. Despite these challenges, participant retention has been high.

CONCLUSION

The Surviving Prostate cancer while Improving quality of life through Rehabilitation with Testosterone Trial, a placebo-controlled, randomized trial, will determine whether testosterone replacement therapy is safe and efficacious in correcting symptoms of testosterone deficiency in prostate cancer survivors, and potentially inform clinical practice.

Anabolic-androgenic steroids: How do they work and what are the risks?

Anabolic-androgenic steroids (AAS) are a class of hormones that are widely abused for their muscle-building and strength-increasing properties in high, nontherapeutic, dosages. This review provides an up-to-date and comprehensive overview on how these hormones work and what side effects they might elicit. We discuss how AAS are absorbed into the circulation after intramuscular injection or oral ingestion and how they are subsequently transported to the tissues, where they will move into the extravascular compartment and diffuse into their target cells. Inside these cells, AAS can biotransform into different metabolites or bind to their cognate receptor: the androgen receptor. AAS and their metabolites can cause side effects such as acne vulgaris, hypertension, hepatotoxicity, dyslipidemia, testosterone deficiency, erectile dysfunction, gynecomastia, and cardiomyopathy. Where applicable, we mention treatment options and self-medication practices of AAS users to counteract these side effects. Clinicians may use this review as a guide for understanding how AAS use can impact health and to assist in patient education and, in some cases, the management of side effects.