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Mechanisms of Ageing and Development Apr 2004The aging process is accompanied by significant changes in body composition characterized by decreased fat free mass and increased and redistributed fat mass. Muscle... (Review)
Review
The aging process is accompanied by significant changes in body composition characterized by decreased fat free mass and increased and redistributed fat mass. Muscle loss results from the atrophy of muscle fibers and decreased synthesis of muscle proteins. Increased number of adipocytes and fat accumulation in non-adipose tissue leads to adiposity. These changes can impose functional limitations and increase morbidity. In men, declining testosterone levels that occur with aging can be a contributing factor to these changes. Studies in hypogonadal men have shown that testosterone replacement is effective in increasing muscle mass and strength and decreasing fat mass. The molecular mechanisms of testosterone's influence on muscle and adipose are not fully elucidated. However, testosterone appears to stimulate IGF-1 expression directly and indirectly leading to increased muscle protein synthesis and growth. It may also counter the inhibitory effects of myostatin, cytokines, and glucocorticoids. The predominant effects of testosterone on fat mass are increased lipolysis and decreased adipogenesis. Current evidence suggests that testosterone replacement may be effective in reversing age-dependent body composition changes and associated morbidity. However, hypogonadism must be diagnosed carefully, and therapy should be monitored regularly in order to avoid the adverse effects associated with testosterone supplementation.
Topics: Aging; Body Composition; Humans; Hypogonadism; Male; Risk Factors; Testosterone
PubMed: 15063106
DOI: 10.1016/j.mad.2004.01.004 -
The Medical Letter on Drugs and... Mar 2019
Topics: Drug Administration Schedule; Hormone Replacement Therapy; Humans; Hypogonadism; Injections, Subcutaneous; Male; Self Administration; Testosterone
PubMed: 30845097
DOI: No ID Found -
Journal of Endocrinological... Mar 2000There is increasing evidence that androgen therapy in men may be effectively applied in several conditions to improve well being and health. Classical indications for... (Review)
Review
There is increasing evidence that androgen therapy in men may be effectively applied in several conditions to improve well being and health. Classical indications for androgen therapy in males are represented by primary or secondary hypogonadism, delayed puberty, aplastic anemia and that secondary to chronic renal failure, protein wasting diseases such as trauma, burns, tumors and infectious diseases. Androgen innovating applications in men are represented by aging and visceral obesity associated with the metabolic syndrome. In addition, it is clear that appropriate testosterone treatment can be adequately used in male contraception, provided spermatogenesis is abolished and tolerability is adequate. Due to unphysiological hormone levels achieved by currently available testosterone preparations, new delivery systems have been produced to achieve more physiological and sustained hormone levels and improve tolerability and action at the levels of target tissues. Some of them are now available in several countries and new formulas are under development.
Topics: Aging; Humans; Hypogonadism; Male; Testosterone
PubMed: 10803480
DOI: 10.1007/BF03343707 -
The American Journal of Nursing Aug 2019
Topics: Administration, Oral; Adult; Aged; Aged, 80 and over; Humans; Male; Middle Aged; Testosterone; United States; United States Food and Drug Administration
PubMed: 31356324
DOI: 10.1097/01.NAJ.0000577424.31609.23 -
Rejuvenation Research Oct 2012Abstract Testosterone replacement therapy is often equated with the macho male physique and virility and is viewed by some as an antiaging tonic. The growth in... (Review)
Review
Abstract Testosterone replacement therapy is often equated with the macho male physique and virility and is viewed by some as an antiaging tonic. The growth in testosterone's reputation and its increased use by men of all ages has seemed to outpace the scientific evidences. This review will aim to examine the uncertainty regarding the nature and the clinical importance of the age-related reduction in the testosterone levels. Considerations will be given both to clinical symptoms, biochemical and clinical diagnostic criteria, and to the risk-to-benefit ratio of reversing late-onset hypogonadism in aging and older men.
Topics: Aging; Androgens; Andropause; Body Composition; Hormone Replacement Therapy; Humans; Hypogonadism; Male; Risk Assessment; Testosterone
PubMed: 22656862
DOI: 10.1089/rej.2012.1316 -
MMW Fortschritte Der Medizin Jun 2017
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Behavioural Brain Research Jun 2020The marked increase in adolescent reward-seeking behavior has important implications for adaptive and maladaptive development. Reward-seeking is linked to increased...
The marked increase in adolescent reward-seeking behavior has important implications for adaptive and maladaptive development. Reward-seeking is linked to increased testosterone and increased neural responses to reward cues. How acute testosterone changes modulate neural reward systems remains unclear. Based on previous work, adolescents, particularly males, showing an increase in endogenous testosterone reactivity were hypothesized to show increased neural response to reward in ventromedial prefrontal cortex, ventral striatum, and posterior cingulate cortex. Sixty-one healthy adolescents aged 10-13 (38 female, mean age = 12.01 [SD = 1.00]) completed a reward-cue processing task during fMRI. Saliva samples to be assayed for testosterone were collected immediately before and after scanning. Acute testosterone changes were not associated with variation in behavioral performance. Within ventromedial prefrontal and posterior cingulate cortices, increased acute testosterone change was associated with reduced discrimination between rewarded and un-rewarded trials. Results suggest that increasing levels of testosterone may result in reduced attention to/salience of task irrelevant information. In contrast to previous studies that found a positive association between testosterone and neural response to reward, the reward information in the current paradigm was irrelevant to success in task performance. These results are consistent with theoretical conceptualization of testosterone's role in reproduction, which involves a shift in salience to short-term relative to long-term goals. These data further emphasized the need to consider context in the study of hormones; specific behaviors will be up- or down-regulated by a hormone based on the fit of the behavior with the broader contextual goal being orchestrated by the hormone.
Topics: Adolescent; Attention; Brain; Brain Mapping; Child; Choice Behavior; Cues; Female; Gyrus Cinguli; Humans; Magnetic Resonance Imaging; Male; Prefrontal Cortex; Reward; Testosterone; Ventral Striatum
PubMed: 32194193
DOI: 10.1016/j.bbr.2020.112593 -
Neuropsychopharmacology : Official... Sep 2023Humans are strategically more prosocial when their actions are being watched by others than when they act alone. Using a psychopharmacogenetic approach, we investigated... (Clinical Trial)
Clinical Trial
Humans are strategically more prosocial when their actions are being watched by others than when they act alone. Using a psychopharmacogenetic approach, we investigated the endocrinological and computational mechanisms of such audience-driven prosociality. One hundred and ninety-two male participants received either a single dose of testosterone (150 mg) or a placebo and performed a prosocial and self-benefitting reinforcement learning task. Crucially, the task was performed either in private or when being watched. Rival theories suggest that the hormone might either diminish or strengthen audience-dependent prosociality. We show that exogenous testosterone fully eliminated strategic, i.e., feigned, prosociality and thus decreased submission to audience expectations. We next performed reinforcement-learning drift-diffusion computational modeling to elucidate which latent aspects of decision-making testosterone acted on. The modeling revealed that testosterone compared to placebo did not deteriorate reinforcement learning per se. Rather, when being watched, the hormone altered the degree to which the learned information on choice value translated to action selection. Taken together, our study provides novel evidence of testosterone's effects on implicit reward processing, through which it counteracts conformity and deceptive reputation strategies.
Topics: Humans; Male; Altruism; Choice Behavior; Reinforcement, Psychology; Reward; Social Behavior; Testosterone
PubMed: 37012404
DOI: 10.1038/s41386-023-01570-y -
Acta Medica Portuguesa Nov 2018Female sexual dysfunction is a common problem, affecting more than 1/3 of women during their lives. The aim of this review is to review the evidence for the... (Review)
Review
INTRODUCTION
Female sexual dysfunction is a common problem, affecting more than 1/3 of women during their lives. The aim of this review is to review the evidence for the effectiveness of testosterone in sexual dysfunction in postmenopausal women, particularly in the improvement of sexual desire.
MATERIAL AND METHODS
The authors searched in international databases National Guidelines Clearinghouse, Guidelines Finder, Cochrane Library and MEDLINE/PubMed, for guidelines, systematic reviews, meta-analysis and randomized controlled trials, published between January 2005 and February 2017, using the MeSH terms 'testosterone', 'androgens', 'libido', 'sexual dysfunctions' and 'menopause'.
RESULTS
From a pool of 506 articles, 11 were selected: three guidelines, one systematic review with meta-analysis and seven randomized controlled trials. The selected articles showed testosterone's efficacy on global sexual function and improvement of sexual desire in postmenopausal women, when both are used in monotherapy or in association with other hormones. No study showed changes in hepatic enzymes or serious adverse effects.
DISCUSSION
The small sample size and short follow-up used in the included studies limits the ability to assess testosterone's long-term benefits and effects.
CONCLUSION
At short-term, testosterone seems to improve sexual function in postmenopausal women, particularly sexual desire. Nevertheless, more studies with larger sample size and longer follow-up are needed to understand its long-term safety and effectiveness.
Topics: Androgens; Diagnostic and Statistical Manual of Mental Disorders; Evidence-Based Medicine; Female; Humans; Libido; Middle Aged; Postmenopause; Practice Guidelines as Topic; Randomized Controlled Trials as Topic; Sexual Dysfunctions, Psychological; Systematic Reviews as Topic; Testosterone
PubMed: 30521462
DOI: 10.20344/amp.9277 -
Der Urologe. Ausg. A Jan 2010About 15% of men and women in their reproductive years remain childless; in 50% of cases the reasons can be found in the male partner. It is important to define as...
About 15% of men and women in their reproductive years remain childless; in 50% of cases the reasons can be found in the male partner. It is important to define as exactly as possible the reasons for infertility to select those men who can be treated by a causal treatment option and to find the optimum treatment strategy. While FSH is the key hormone for intact spermatogenesis, testosterone as an important modifier of quantitative normal sperm production may sometimes be underestimated. Exogenous substitution with testosterone will suppress spermatogenesis and is thus not indicated in hypogonadal males with hypogonadism and infertility at the same time. In males with normal to elevated gonadotrophins and symptomatic testosterone deficiency, treatment is difficult and evidence-based recommendations are missing. The situation in males presenting with secondary hypogonadotropic hypogonadism exhibiting one of the clearly defined and treatable reasons of male infertility is totally different. To stimulate the gonadal function in secondary hypogonadal patients wishing to father a child, pulsatile GnRH or subcutaneous gonadotrophin treatment are used. They stimulate both testosterone production and spermatogenesis. After the end of successful fertility treatment, substitution is continued by exogenous testosterone treatment with oral, transdermal or intramuscular physiological preparations.
Topics: Hormone Replacement Therapy; Humans; Hypogonadism; Infertility, Male; Male; Testosterone; Treatment Outcome
PubMed: 20063086
DOI: 10.1007/s00120-009-2195-x