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1.
Steroid hormones and pregnancy.
Noyola-Martínez, N, Halhali, A, Barrera, D
Gynecological endocrinology : the official journal of the International Society of Gynecological Endocrinology. 2019;(5):376-384
Abstract
Pregnancy is associated with physiological adjustments in order to allow adequate growth and fetal development. In particular, steroids are necessary to maintain in balance numerous functions during gestation. Steroidogenesis in the maternal, placental and fetal compartments and the biological effects of progestins and estrogens that play a pivotal role before and during pregnancy are described. Although it is well-known that androgens are considered as substrate for estrogens biosynthesis, their biosynthesis and functionality in placental and other tissues have been questioned. As compared with healthy pregnancy, steroid hormones levels have been found altered in complicated pregnancies and hormonal treatments have been used is some pathologies. Therefore, the aim of this work was to review the biosynthesis, function and regulation of progestins, androgens and estrogens during gestation. Furthermore, steroid hormones concentrations during healthy and complicated pregnancy as well hormonal therapies for the prevention of miscarriages and preterm deliveries are discussed in the present review.
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2.
Canonical and Noncanonical Androgen Metabolism and Activity.
Storbeck, KH, Mostaghel, EA
Advances in experimental medicine and biology. 2019;:239-277
Abstract
Androgens are critical drivers of prostate cancer. In this chapter we first discuss the canonical pathways of androgen metabolism and their alterations in prostate cancer progression, including the classical, backdoor and 5α-dione pathways, the role of pre-receptor DHT metabolism, and recent findings on oncogenic splicing of steroidogenic enzymes. Next, we discuss the activity and metabolism of non-canonical 11-oxygenated androgens that can activate wild-type AR and are less susceptible to glucuronidation and inactivation than the canonical androgens, thereby serving as an under-recognized reservoir of active ligands. We then discuss an emerging literature on the potential non-canonical role of androgen metabolizing enzymes in driving prostate cancer. We conclude by discussing the potential implications of these findings for prostate cancer progression, particularly in context of new agents such as abiraterone and enzalutamide, which target the AR-axis for prostate cancer therapy, including mechanisms of response and resistance and implications of these findings for future therapy.
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3.
Androgens in Congenital Adrenal Hyperplasia.
Pignatelli, D, Pereira, SS, Pasquali, R
Frontiers of hormone research. 2019;:65-76
Abstract
Congenital Adrenal Hyperplasias (CAH) are genetic diseases transmitted in an autosomal recessive way and these diseases affect many aspects of human health. The majority of CAH cases is due to a deficiency in 21-hydroxylase as a result of the existence of mutations in both alleles of the CYP21A2 gene. Since the identification of mild, non-classic forms of this disease, CAH has been recognized to be one of the most common genetic diseases in human beings. This disease is generally associated with elevated secretion of androgens, sometimes resulting in virilizing syndromes, including genital ambiguity, precocious puberty in both sexes, or milder syndromes of androgen excess like precocious pubarche or the occurrence of hirsutism and oligomenorrhea in women. Accumulating precursors like 17-hydroxypregnenolone and 17-hydroxyprogesterone (17OHP) are directed to the synthesis of androgens through the enzyme 17-hydroxylase/17,20 lyase leading to the production of dehydroepiandrosterone that is then converted to testosterone and dihydrotestosterone (DHT) at the gonads and at other peripheral tissues. 17OHP, the hallmark of 21-hydroxylase deficiency, can be converted to androstenedione (in a low efficiency molecular process) but can also be converted to DHT through an alternative pathway that becomes active due to the large amounts of accumulated 17OHP - the backdoor pathway. Another important pathway that becomes significant in this disease is the 11-oxyandrogens pathway through which androstenedione is converted to 11β-hydroxyandrostenedione at the adrenal and from there to 11-ketotestosterone and 11-ketoDHT. The elevated androgens levels affect the hypothalamic-pituitary-gonadal axis and, in some cases, the ovary resulting in chronic anovulation and infertility.
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4.
Understanding the Role of Androgen Action in Female Adipose Tissue.
Schiffer, L, Arlt, W, O'Reilly, MW
Frontiers of hormone research. 2019;:33-49
Abstract
Adipose tissue is an important target of androgen action in humans. Androgens exert important effects on adipose tissue biology, including fat mass expansion and distribution, insulin signalling and lipid metabolism. In conditions of female androgen excess such as polycystic ovary syndrome (PCOS), androgens exert metabolically deleterious effects on adipose tissue function in a depot-specific manner. Androgen excess in women is metabolically deleterious, and adverse metabolic effects may be mediated by effects on preadipocyte differentiation and adipocyte hypertrophy. Circulating androgen burden correlates with adiposity in women, and drives visceral fat mass accumulation. Adipose tissue is also an important organ of pre-receptor androgen metabolism, and is host to a complex network of androgen activating and inactivating enzymes. Adipose androgen generation is increased in subcutaneous (SC) adipose tissue in women with PCOS, and intra-adipose concentrations of potent androgens may exceed those measured in peripheral circulation. Increased expression of the key androgen-activating enzyme aldo-ketoreductase type 1C3 in PCOS SC adipose tissue leads to high concentrations of testosterone and dihydrotestosterone. Enhanced local androgen generation may further contribute to the adverse metabolic profile of women with PCOS by exerting lipotoxic effects on local adipose biology.
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5.
A Clinical Perspective of Sleep and Andrological Health: Assessment, Treatment Considerations, and Future Research.
Liu, PY
The Journal of clinical endocrinology and metabolism. 2019;(10):4398-4417
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Abstract
CONTEXT Sleep that is insufficient, misaligned, or disrupted causes hypersomnolence and neuropsychological deficits, adversely affects cardiometabolic health, and is increasingly recognized to impair other biological processes that lead to conditions important to men, such as hypogonadism, erectile dysfunction, and infertility. EVIDENCE ACQUISITION Literature review from 1970 to December 2018. EVIDENCE SYNTHESIS High-quality and complementary epidemiological and interventional studies establish that abnormal sleep is associated with increased mortality, hypertension, and other cardiometabolic disorders (insufficient, disrupted, and misaligned sleep), as well as reduced fecundity and total sperm count (insufficient sleep), erectile dysfunction (disrupted sleep), and low testosterone (both). Circadian misalignment shifts the peak of testosterone's diurnal rhythm to occur soon after waking up, irrespective of the biological clock time, but it does not change the mean concentration. Preliminary studies show that extending sleep in individuals who are chronically sleep deprived may become a strategy to reduce insulin resistance and hypertension. Continuous positive airway pressure therapy can improve erectile function, and possibly systemic testosterone exposure, but only when used adherently by men with obstructive sleep apnea. Both high-dose and replacement-dose testosterone therapies modestly worsen sleep-disordered breathing, but they also improve cardiometabolic function and sexual desire. Persistence of either the adverse or beneficial outcomes over the longer term requires further investigation. CONCLUSIONS Sleep is increasingly recognized to be essential for healthy living. Establishing the effect of abnormal sleep, and of improving sleep, on andrological issues of prime interest to men will promote prioritization of sleep, and may thereby improve overall long-term health outcomes.
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6.
Androgens and the Regulation of Adiposity and Body Fat Distribution in Humans.
Tchernof, A, Brochu, D, Maltais-Payette, I, Mansour, MF, Marchand, GB, Carreau, AM, Kapeluto, J
Comprehensive Physiology. 2018;(4):1253-1290
Abstract
The sexual dimorphism in human body fat distribution suggests a causal role for sex hormones. This is of particular importance when considering the role of excess visceral adipose tissue accumulation as a critical determinant of obesity-related cardiometabolic alterations. Scientific literature on the modulation of body fat distribution by androgens in humans is abundant, remarkably inconsistent and difficult to summarize. We reviewed relevant literature on this topic, with a particular emphasis on androgen replacement, androgen effects on selected parameters of adipose tissue function and adipose tissue steroid-converting enzymes. In men, low androgenic status mostly reflected by reduced total testosterone is a frequent feature of visceral obesity and the metabolic syndrome. Regarding testosterone therapy, however, studies must be appreciated in the context of current controversies on their cardiovascular effects. Analyses of available studies suggest that decreases in waist circumference in response to testosterone are more likely observed in men with low levels of testosterone and high BMI at study onset. In women with androgen excess, higher testosterone and free testosterone levels are fairly consistent predictors of increased abdominal and/or visceral adipose tissue accumulation, which is not the case in nonhyperandrogenic women. Regarding mechanisms, androgens decrease adipogenesis and markers of lipid storage in vitro in men and women. Evidence also suggest that local steroid transformations by adipose tissue steroid-converting enzymes expressed in a depot-specific fashion may play a role in androgen-mediated modulation of body fat distribution. Accumulating evidence shows that androgens are critical modulators of body fat distribution in both men and women. © 2018 American Physiological Society. Compr Physiol 8:1253-1290, 2018.
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Randomized controlled trials - mechanistic studies of testosterone and the cardiovascular system.
Jones, TH, Kelly, DM
Asian journal of andrology. 2018;(2):120-130
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Abstract
Testosterone deficiency is common in men with cardiovascular disease (CVD), and randomized placebo-controlled trials (RCTs) have reported beneficial effects of testosterone therapy on exercise-induced cardiac ischemia in chronic stable angina, functional exercise capacity, maximum oxygen consumption during exercise (VO2max) and muscle strength in chronic heart failure (CHF), shortening of the Q-T interval, and improvement of some cardiovascular risk factors. Testosterone deficiency is associated with an adverse CV risk profile and mortality. Clinical and scientific studies have provided mechanistic evidence to support and explain the findings of the RCTs. Testosterone is a rapid-onset arterial vasodilator within the coronary circulation and other vascular beds including the pulmonary vasculature and can reduce the overall peripheral systemic vascular resistance. Evidence has demonstrated that testosterone mediates this effect on vascular reactivity through calcium channel blockade (L-calcium channel) and stimulates potassium channel opening by direct nongenomic mechanisms. Testosterone also stimulates repolarization of cardiac myocytes by stimulating the ultra-rapid potassium channel-operated current. Testosterone improves cardiac output, functional exercise capacity, VO2maxand vagally mediated arterial baroreceptor cardiac reflex sensitivity in CHF, and other mechanisms. Independent of the benefit of testosterone on cardiac function, testosterone substitution may also increase skeletal muscle glucose metabolism and enhance muscular strength, both factors that could contribute to the improvement in functional exercise capacity may include improved glucose metabolism and muscle strength. Testosterone improves metabolic CV risk factors including body composition, insulin resistance, and hypercholesterolemia by improving both glucose utilization and lipid metabolism by a combination of genomic and nongenomic actions of glucose uptake and utilization expression of the insulin receptor, glucose transporters, and expression on regulatory enzymes of key metabolic pathways. The effect on high-density lipoprotein-cholesterol (HDL-C) differs between studies in that it has been found to fall, rise, or have no change in levels. Testosterone replacement can suppress the levels of circulating pro-inflammatory cytokines and stimulate the production of interleukin-10 (IL-10) which has anti-inflammatory and anti-atherogenic actions in men with CVD. No effect on C-reactive protein has been detected. No adverse effects on clotting factors have been detected. RCTs have not clearly demonstrated any significant evidence that testosterone improves or adversely affects the surrogate markers of atherosclerosis such as reduction in carotid intima thickness or coronary calcium deposition. Any effect of testosterone on prevention or amelioration of atherosclerosis is likely to occur over years as shown in statin therapy trials and not months as used in testosterone RCTs. The weight of evidence from long-term epidemiological studies supports a protective effect as evidenced by a reduction in major adverse CV events (MACEs) and mortality in studies which have treated men with testosterone deficiency. No RCT where testosterone has been replaced to the normal healthy range has reported a significant benefit or adverse effect on MACE nor has any recent meta-analysis.
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Source and amount of carbohydrate in the diet and inflammation in women with polycystic ovary syndrome.
Barrea, L, Marzullo, P, Muscogiuri, G, Di Somma, C, Scacchi, M, Orio, F, Aimaretti, G, Colao, A, Savastano, S
Nutrition research reviews. 2018;(2):291-301
Abstract
High carbohydrate intake and low-grade inflammation cooperate with insulin resistance and hyperandrogenism to constitute an interactive continuum acting on the pathophysiology of polycystic ovary syndrome (PCOS), the most common endocrine disorder in women of reproductive age characterised by oligo-anovulatory infertility and cardiometabolic disorders. The role of insulin in PCOS is pivotal both in regulating the activity of ovarian and liver enzymes, respectively involved in androgen production and in triggering low-grade inflammation usually reported to be associated with an insulin resistance, dyslipidaemia and cardiometabolic diseases. Although an acute hyperglycaemia induced by oral glucose loading may increase inflammation and oxidative stress by generating reactive oxygen species through different mechanisms, the postprandial glucose increment, commonly associated with the Western diet, represents the major contributor of chronic sustained hyperglycaemia and pro-inflammatory state. Together with hyperinsulinaemia, hyperandrogenism and low-grade inflammation, unhealthy diet should be viewed as a key component of the 'deadly quartet' of metabolic risk factors associated with PCOS pathophysiology. The identification of a tight diet-inflammation-health association makes the adoption of healthy nutritional approaches a primary preventive and therapeutic tool in women with PCOS, weakening insulin resistance and eventually promoting improvements of reproductive life and endocrine outcomes. The intriguing nutritional-endocrine connections operating in PCOS underline the role of expert nutritionists in the management of this syndrome. The aim of the present review is to provide an at-a-glance overview of the possible bi-directional mechanisms linking inflammation, androgen excess and carbohydrate intake in women with PCOS.
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9.
Practical Use of Pharmacotherapy for Obesity.
Igel, LI, Kumar, RB, Saunders, KH, Aronne, LJ
Gastroenterology. 2017;(7):1765-1779
Abstract
Obesity management requires a multidisciplinary approach, as there are many factors that contribute to the development of obesity, as well as the preservation of excess weight once it has been gained. Diet, exercise, and behavior modification are key components of treatment. In addition to lifestyle changes, weight gain secondary to medications is an important modifiable risk factor. Even after appropriate lifestyle modification, and medication adjustments (where possible) to avoid agents that can contribute to weight gain, many patients are still unable to achieve clinically meaningful weight loss. Pharmacotherapy for obesity management can fill an important role for these patients. This article will review medications that can lead to weight gain and potential alternatives, currently approved anti-obesity medications and best practices to individualize the selection process, and the use of testosterone in men with hypogonadism and obesity.
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A Perspective on Middle-Aged and Older Men With Functional Hypogonadism: Focus on Holistic Management.
Grossmann, M, Matsumoto, AM
The Journal of clinical endocrinology and metabolism. 2017;(3):1067-1075
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CONTEXT Middle-aged and older men (≥50 years), especially those who are obese and suffer from comorbidities, not uncommonly present with clinical features consistent with androgen deficiency and modestly reduced testosterone levels. Commonly, such men do not demonstrate anatomical hypothalamic-pituitary-testicular axis pathology but have functional hypogonadism that is potentially reversible. EVIDENCE ACQUISITION Literature review from 1970 to October 2016. EVIDENCE SYNTHESIS Although definitive randomized controlled trials are lacking, evidence suggests that in such men, lifestyle measures to achieve weight loss and optimization of comorbidities, including discontinuation of offending medications, lead to clinical improvement and a modest increase in testosterone. Also, androgen deficiency-like symptoms and end-organ deficits respond to targeted treatments (such as phosphodiesterase-5 inhibitors for erectile dysfunction) without evidence that hypogonadal men are refractory. Unfortunately, lifestyle interventions remain difficult and may be insufficient even if successful. Testosterone therapy should be considered primarily for men who have significant clinical features of androgen deficiency and unequivocally low testosterone levels. Testosterone should be initiated either concomitantly with a trial of lifestyle measures, or after such a trial fails, after a tailored diagnostic work-up, exclusion of contraindications, and appropriate counseling. CONCLUSIONS There is modest evidence that functional hypogonadism responds to lifestyle measures and optimization of comorbidities. If achievable, these interventions may have demonstrable health benefits beyond the potential for increasing testosterone levels. Therefore, treatment of underlying causes of functional hypogonadism and of symptoms should be used either as an initial or adjunctive approach to testosterone therapy.