Testosterone replacement therapy: current trends and future directions

Dichloroacetic acid and trichloroacetic acid as disinfection by-products in drinking water are endocrine-disrupting chemicals

Dichloroacetic acid (DCAA) and trichloroacetic acid (TCAA) are two typical non-volatile disinfection by-products (DBPs) found in drinking water. Increasing evidence has demonstrated that they show reproductive toxicity. However, whether they might have endocrine disrupting properties remains largely unknown. To discover this, we treated male mice or pregnant mice with 0, 1-, 102-, 103-, 104-, or 5 × 104-fold maximal concentration level (MCL) of DCAA or TCAA in drinking water. In male mice, the levels of testosterone in serum and androgen receptor (AR) in testis were declined with ≥ 103-fold MCL of DCAA (26.4 mg/kg/d) or TCAA (52.7 mg/kg/d). In pregnant mice, miscarriage rates were increased with ≥ 104-fold MCL of DCAA (264 mg/kg/d) or ≥ 103-fold MCL of TCAA. The levels of FSH in serum were increased and those of estradiol and progesterone were reduced with ≥ 103-fold MCL of DCAA or TCAA. The protein levels of estrogen receptors (ERα and ERβ) in ovary were reduced with ≥ 102-fold MCL of DCAA (2.64 mg/kg/d) or TCAA (5.27 mg/kg/d). Exposure to some certain fold MCL of DCAA or TCAA also altered the protein levels of ERα and ERβ in uterus and placenta. Exposure to 5 × 104-fold MCL of both DCAA and TCAA showed the combined effects. Therefore, both DCAA and TCAA could be considered as novel reproductive endocrine disrupting chemicals, which might be helpful for further assessment of the toxicological effects of DCAA and TCAA and the awareness of reproductive endocrine disrupting properties caused by DCAA and TCAA in drinking water.

Stability and detectability of testosterone esters in dried blood spots after intramuscular injections

While misuse of testosterone esters is widespread in elite and recreational sports, direct detection of intact testosterone esters in doping control samples is hampered by the rapid hydrolysis by esterases present in the blood. With dried blood spot (DBS) as sample matrix, continued degradation of the esters is avoided due to inactivation of the hydrolase enzymes in dried blood. Here, we have developed the method further for detection of testosterone esters in DBS with focus on robustness and applicability in doping control. To demonstrate the method's feasibility, DBS samples from men receiving two intramuscular injections of Sustanon® 250 (n = 9) or placebo (n = 10) were collected, transported, and stored prior to analysis, to mimic a doping control scenario. The presented nanoLC-HRMS/MS method appeared reliable and suitable for direct detection of four testosterone esters (testosterone decanoate, isocaproate, phenylpropionate, and propionate) after extraction from DBS. Sustanon® was detected in all subjects for at least 5 days, with detection window up to 14 days for three of the esters. Evaluation of analyte stability showed that while storage at room temperature is tolerated well for a few days, testosterone esters are highly stable (>18 months) in DBS when stored in frozen conditions. Collectively, these findings demonstrate the applicability of DBS sampling in doping control for detection of steroid esters. The fast collection and reduced shipment costs of DBS compared with urine and standard blood samples, respectively, will allow more frequent and/or large-scale testing to increase detection and deterrence.

The correlation between testosterone, inflammation and cytokine status in type-2 diabetes men

Type 2 diabetes mellitus (T2DM) is believed to cause hypogonadism through increasing pro-inflammatory cytokines. Tumour necrosis factor-α (TNF-α) is a primary cytokine associated with T2DM. The study explored the association between total testosterone (TT) level and cytokines status in 53 adult males, 27 T2DM (T2DM group) and 26 non-T2DM (control group). Blood samples evaluated fasting plasma glucose, HbA1c, insulin, HOMA-IR, FSH, LH, TT, prolactin, estradiol, cortisol, cortisol-binding globulin, C-reactive protein and eight cytokines (Interferon-gamma, IL-10, IL-13, IL-17A, IL-4, IL-23, IL-6, TNF-α). Data are presented as a median with interquartile interval. TT concentration was lower in the T2DM group [10.9 nmol/L (7.1-12.2) vs. 12.3 nmol/L (10.7-14.9) in control, p = 0.008]. CRP and cortisol in T2DM patients were higher than in control (p = 0.031 and 0.041 respectively). TT was negatively correlated with HOMA-IR, body mass index (BMI) and FSH (p = 0.028, 0.019 and 0.006 respectively). Multiple linear regression models showed that lower TT values were predictable by a linear combination of the independent variables: TNF-α, BMI and T2DM (p = 0.047, 0.023 and 0.019 respectively). High CRP and cortisol levels in T2DM patients suggest an inflammatory state. TT levels associated with TNF-α suggest a role of this cytokine in the aetiology of hypogonadism in T2DM patients.

Ficus natalensis extract alleviates Cadmium chloride-induced testicular disruptions in albino rats

BACKGROUND

Cadmium is a potential environmental pollutant with worldwide health problems. Many Ficus species are reported to have an extensive diversity of traditional uses, among them the treatment of reproductive toxicity.

OBJECTIVES

This study set out to evaluate the effect of Ficus natalensis extract on the testicular impairments induced by cadmium chloride (CdCl₂) and investigated the potential mechanisms associated with its treatment.

METHODS

Thus, 40 male albino rats were categorized into 4 groups (n = 10); group I (control), group II (cadmium-treated group) orally received 5 mg/kg/day CdCl₂ for one month, group III (cadmium + Ficus natalensis extract) orally received 5 mg/kg/day CdCl₂ for one month plus 200 mg/kg/day Ficus natalensis extract for another month, and group IV (cadmium + reference drug (mesterolone) orally received 5 mg/kg/day CdCl₂ for one month plus 4.16 mg/kg/day mesterolone for another month.

RESULTS

At the end of experiment, CdCl₂ administration markedly induced histological and histo-morphometric changes with a substantial (p < 0.05) decrease in the sperm count, sperm motility, serum TAC, serum testosterone, downregulation in the mRNA expression levels of testicular 17β-HSD and StAR, in addition to a significant increase in serum TNF-α and testicular MDA level compared to the control group. Conversely, the treatment with Ficus natalensis methanolic extract as well as the reference drug significantly ameliorated the above-mentioned adverse effects induced by CdCl₂.

CONCLUSIONS

Our results suggested that Ficus natalensis extract can attenuate the CdCl₂-induced testicular impairments via inhibiting the oxidative cell damage and inflammation that contributed to CdCl₂ toxicity.

JATENZO®: Challenges in the development of oral testosterone

Testosterone therapy (TT) for the treatment of testosterone deficiency (TD) can be administered via several routes of administration. Due to a variety of concerns such as hepatotoxicity, an oral formulation has long been absent in the United States. Recently, JATENZO® (testosterone undecanoate) oral capsules was approved by the US FDA as an oral option for men suffering from TD. In this article, we will discuss the history and challenges in the development of a viable oral formulation of exogeneous TT and examine how JATENZO® addresses these concerns.

Late-onset hypogonadism: Clinical evidence, biological aspects and evolutionary considerations

The growing life expectancy in modern societies has raised scientific interest in identifying medical interventions to alleviate age-associated pathologies such as vascular calcification, cognitive decline, sarcopenia, osteoporosis and sexual dysfunction. Although no such single treatment has thus far been established in humans, some clinicians and patients have set their hopes on testosterone replacement therapy (TRT) as a potential "fountain of youth" for aging men. While TRT has proven effective in ameliorating distinct symptoms of late-onset hypogonadism (LOH), its safety remains to be demonstrated. Besides humans, multiple other species exhibit age-related reductions in circulating testosterone levels, raising the question whether such changes are an inherent, pathological feature of growing organismal age or rather reflect an adaptive response. In this manuscript, we apply key principles of evolutionary medicine to testosterone biology and LOH to provide a novel perspective on these two fields. Additionally, we discuss insightful data derived from the animal kingdom to illustrate the plasticity of individual testosterone trajectories across the lifespan, outline cost-benefit-considerations of TRT in LOH and highlight potential caveats of such therapies.

Exogenous testosterone replacement therapy versus raising endogenous testosterone levels: current and future prospects

Testosterone replacement therapy is an important treatment option for men with low testosterone and symptomatic hypogonadism. Various formulations of exogenous testosterone replacement therapy exist, including oral, buccal, intramuscular, transdermal, subdermal, and nasal preparations. However, exogenous testosterone replacement therapy is a double-edged sword, posing risks to fertility due to negative feedback mechanisms on the hypothalamic-pituitary-gonadal (HPG) axis, which is the main regulator of testosterone production and spermatogenesis in males. Alternative pharmacologic therapies are being used to increase endogenous testosterone levels while attempting to preserve fertility and function of the HPG axis. These include selective estrogen receptor modulators, gonadotropins, and aromatase inhibitors. This review focuses on overviewing and comparing the currently available methods of exogenous testosterone replacement therapy, alternative treatments to increasing endogenous testosterone, and novel treatments that are currently under investigation to normalize testosterone levels while preserving the function of the HPG axis. In conclusion, reports suggest that, though Testosterone replacement therapy is an important way to restore testosterone levels and reduce symptoms associated with low testosterone, it is often difficult to decide which treatment to select for patients with testosterone deficiency. Several factors need to be considered to decide on optimal therapy option for the patient which include but are not limited to safety, efficacy, cost-effectiveness, dosing flexibility, and side effects. Alternative approaches which aim to improve endogenous testosterone production and preserve fertility are promising but still are at their initial stages of development. Ultimately, patient-centered decision making is paramount to appropriate treatment selection.

Low bone mineral density is associated with hypogonadism and cranial irradiation in male childhood cancer survivors

We investigated if bone mineral density was related to testosterone deficiency and/or previous cancer treatment in men who were childhood cancer survivors. Men with untreated testosterone deficiency or previous treatment with cranial irradiation were at increased risk of impaired bone health. Prevention of osteoporosis should be considered in their follow-up.

INTRODUCTION

Childhood cancer survivors (CCS) are at increased risk of hypogonadism. Reduced bone mineral density (BMD) has been reported in CCS but it is unclear whether this is due to hypogonadism or a direct effect of cancer therapy. This study investigated BMD in CCS, and association with hypogonadism, previous treatment and cancer type.

METHODS

Investigation of 125 CCS (median age 33.7 at inclusion; 9.6 at diagnosis) and 125 age-matched population controls. Serum testosterone and luteinizing hormone were assayed and BMD at total hip and lumbar spine L1-L4 measured. The mean difference in BMD (g/cm2; 95% CI) between CCS and controls was analysed. Odds ratios (OR; 95% CI) for low BMD were also calculated.

RESULTS

Overall, BMD in the CCS cohort did not significantly differ from controls. However, compared with eugonadal CCS, the CCS with untreated hypogonadism had lower BMD at the hip (mean difference - 0.139 (- 0.210; - 0.067); p < 0.001) and spine (- 0.102 (- 0.174; - 0.030); p = 0.006). They also had a higher risk of low hip BMD (OR 4.1 (1.3; 14); p = 0.018). CCS treated with cranial irradiation also had lower BMD (hip - 0.076 (- 0.133; - 0.019); p = 0.009; spine - 0.071 (- 0.124; - 0.018); p = 0.009) compared with controls. The latter associations remained statistically significant after adjustment for hypogonadism.

CONCLUSIONS

CCS with hypogonadism or previously treated with cranial irradiation are at increased risk of impaired bone health. Prevention of osteoporosis should be considered as an important part in future follow-up of these men.

Hypogonadism, Type-2 Diabetes Mellitus, and Bone Health: A Narrative Review

One of the complications from chronic hyperglycemia and insulin resistance due to type 2 diabetes mellitus (T2DM) on the hypothalamic-pituitary-gonadal axis in men is the high prevalence of hypogonadotropic hypogonadism (HH). Both T2DM and hypogonadism are associated with impaired bone health and increased fracture risk but whether the combination results in even worse bone disease than either one alone is not well-studied. It is possible that having both conditions predisposes men to an even greater risk for fracture than either one alone. Given the common occurrence of HH or hypogonadism in general in T2DM, a significant number of men could be at risk. To date, there is very little information on the bone health men with both hypogonadism and T2DM. Insulin resistance, which is the primary defect in T2DM, is associated with low testosterone (T) levels in men and may play a role in the bidirectional relationship between these two conditions, which together may portend a worse outcome for bone. The present manuscript aims to review the available evidences on the effect of the combination of hypogonadism and T2DM on bone health and metabolic profile, highlights the possible metabolic role of the skeleton, and examines the pathways involved in the interplay between bone, insulin resistance, and gonadal steroids.

Testosterone, testosterone therapy and prostate cancer

With prostate cancer not observed in eunuchs and total androgen suppression by castration an effective first-line treatment for advanced prostate cancer, the dramatic regression seen in tumour symptoms after castration, lead to the theory that high levels of circulating androgens were a risk factor for prostate cancer. This theory however, ignored the effects testosterone variations within a physiologic range could have on early tumour events and since the early 2000s, clinical evidence discounting testosterone as a linear mechanistic cause of prostate cancer growth mounted, with alternative mechanistic hypotheses such as the saturation model being proposed. Together with a growing understanding of the negative health effects and decreased quality of life in men with testosterone deficiency or hypogonadism, a paradigm shift away from testosterone as a prostate cancer inducer occurred allowing clinicians to use testosterone therapy as potential treatment for men with difficult and symptomatic hypogonadism that had been previously treated for prostate cancer. In this review we contextualise the idea of testosterone as a risk factor for prostate cancer inducement and compile the most current literature with regards to the influence of testosterone and testosterone therapy in prostate cancer.

Late-onset hypogonadism: a concept comes of age

The term Late-onset hypogonadism (LOH) was coined in 2002 and defined as a disease entity in the ISA, ISSAM, EAU, EAA and ASA endorsed Recommendations for Investigation, Treatment and Monitoring of LOH (2005 and 2008) as 'a clinical and biochemical syndrome associated with advancing age, characterized by symptoms and a deficiency in serum testosterone (T)'. LOH was classified as a combined primary and secondary hypogonadism since the endocrine capacity of the testes and the pituitary are impaired. Symptoms of LOH include loss of libido, erectile dysfunction, loss of muscle mass, increased body fat, anemia, osteoporosis, depressed mood, decreased vitality, sweating, and hot flushes. Since these symptoms may also have origins other than LOH, exclusion of other disease entities and subnormal serum T levels are considered prerequisites for the diagnosis and possible treatment of LOH. However, during following years these guidelines were often neglected and, especially in the USA, indiscriminate prescribing of T was widely practised so that the US FDA warned against such irresponsible behavior. In Europe, T prescribing remained largely restricted to LOH as defined above. Nevertheless, a discussion started whether LOH really exists or is only a consequence of age-related comorbidities. Numerous studies have helped to clarify the situation, in particular, the European Male Aging Study (EMAS) and the US-initiated 7 T trials. Consequently, the newest US Endocrine Society Practice Guideline on T treatment (2018) includes advanced age as a cause of organic hypogonadism and recommends that 'in men >65 years who have symptoms or conditions suggestive of T deficiency … and consistently and unequivocally low morning T concentrations we suggest that clinicians offer T therapy on an individualised basis after explicit discussion of the potential risks and benefits'. Thus, the concept of LOH as conceived two decades ago has weathered criticism and survived the times.

Androgen Deficiency and Phosphodiesterase Type 5 Expression Changes in Aging Male: Therapeutic Implications

The age-related decline of serum T occurs in ~20-30% of adult men and it is today defined as late-onset hypogonadism (LOH). In the elderly, such decline becomes more prevalent (up to 60%) and shows-up with erectile dysfunction (ED) and hypoactive sexual desire. A large body of experimental evidences have shown that the combination of T replacement therapy (TRT) and phosphodiesterase type 5 inhibitors (PDE5i) is, usually, effective in restoring erectile function in patients with LOH and ED who have not responded to monotherapy for sexual disturbances. In fact, PDE5is potentiate the action of nitric oxide (NO) produced by endothelial cells, resulting in a vasodilator effect, while T facilitates PDE5i effects by increasing the expression of PDE5 in corpora cavernosa. Meta-analytic data have recognized to PDE5i a protective role on the cardiovascular health in patients with decreased left ventricular ejection fraction. In addition, several studies have shown pleiotropic beneficial effects of these drugs throughout the body (i.e., on bones, urogenital tract and cerebral, metabolic, and cardiovascular levels). TRT itself is able to decrease endothelial dysfunction, oxidative stress and inflammation, thus lowering the cardiovascular risk. Furthermore, untreated hypogonadism could be the cause of PDE5i ineffectiveness especially in the elderly. For these reasons, aging men complaining ED who have LOH should undergo TRT before or at the moment when PDE5i treatment is started.

Sport, doping and male fertility

It is universally accepted that lifestyle interventions are the first step towards a good overall, reproductive and sexual health. Cessation of unhealthy habits, such as tobacco, alcohol and drug use, poor nutrition and sedentary behavior, is suggested in order to preserve/improve fertility in humans. However, the possible risks of physical exercise per se or sports on male fertility are less known. Being "fit" does not only improve the sense of well-being, but also has beneficial effects on general health: in fact physical exercise is by all means a low-cost, high-efficacy method for preventing or treating several conditions, ranging from purely physical (diabetes and obesity) to psychological (depression and anxiety), highly influencing male reproduction. If male sexual and reproductive health could be positively affected by a proper physical activity, inadequate bouts of strength - both excessive intensity and duration of exercise training - are more likely to have detrimental effects. In addition, the illicit use of prohibited drugs (i.e. doping) has reached pandemic proportions, and their actions, unfortunately very often underestimated by both amateur and professional athletes, are known to disrupt at different levels and throughout various mechanisms the male hypothalamic-pituitary-gonadal axis, resulting in hypogonadism and infertility.

Potential risks related to anabolic steroids use on nervous, cardiovascular and reproductive systems disorders in men

Anabolic steroids (AS) have been a subject of intensive research for the last several decades. Due to wide use of AS in pharmacological treatment and in professional and amateur sport, it is, hence, worthwhile to describe the biochemical mechanism of the effects of AS usage in humans and its potential health risks. In this work, the relationship between diet and its effect on the level of testosterone in blood is described. Testosterone affects the nervous system, however, there is need for further researches to examine the influence of AS therapy on emotional and cognitive functioning. AS therapy has known negative effects on the cardiovascular system: cardiac hypertrophy can occur, blood pressure can vastly increased, thrombotic complications can come about. These effects are observed not only in patients who are treated with AS, but also in athletes. The paper also describes the relationship between AS and reproductive system diseases. Decreased libido and erectile dysfunction are only some of the many side effects of an incorrect AS treatment.

The complex association between metabolic syndrome and male hypogonadism

BACKGROUND

The complex association between metabolic syndrome (MetS) and male hypogonadism is well established. A number of observational studies show that low testosterone is associated with insulin resistance and an increased risk for diabetes mellitus and MetS in men.

AIMS

To elucidate the association between MetS and male hypogonadism, present epidemiological data on the co-existence of the two comorbidities, enlighten the underlying pathophysiology and appraise the effects of testosterone supplementation therapy (TTh) and lifestyle modifications on MetS and body composition in men.

MATERIALS AND METHODS

Systematic search to PubMed and Medline databases for publications reporting data on association between MetS and male hypogonadism.

RESULTS

Both MetS and male hypogonadism have a high prevalence in the general population and are frequently co-existing e.g. in males with diabetes. Accumulating evidence from animal and human studies suggests that MetS is involved in the pathogenesis of hypogonadism in males as well as the other way around. On the other hand, there is evidence for a favorable effect of testosterone supplementation in testosterone deficient men with MetS and/or diabetes mellitus.

CONCLUSIONS

Studies with superior methodological characteristics are needed in order to establish a role for testosterone supplementation in men with MetS and/or diabetes mellitus.

Klinefelter Syndrome: Integrating Genetics, Neuropsychology, and Endocrinology

Although first identified over 70 years ago, Klinefelter syndrome (KS) continues to pose substantial diagnostic challenges, as many patients are still misdiagnosed, or remain undiagnosed. In fact, as few as 25% of patients with KS are accurately diagnosed and most of these diagnoses are not made until adulthood. Classic characteristics of KS include small testes, infertility, hypergonadothropic hypogonadism, and cognitive impairment. However, the pathophysiology behind KS is not well understood, although genetic effects are also thought to play a role. For example, recent developments in genetics and genomics point to a fundamental change in our understanding of KS, with global epigenetic and RNA expression changes playing a central role for the phenotype. KS is also associated with more general health markers, including higher morbidity and mortality rates and lower socioeconomic status (which likely affect both morbidity and mortality). In addition, hypogonadism is associated with greater risk of metabolic syndrome, type 2 diabetes, cardiovascular disease, breast cancer, and extragonadal germ cell tumors. Medical treatment typically focuses on testosterone replacement therapy (TRT), although the effects of this therapy have not been studied rigorously, and future studies need to evaluate the effects of TRT on metabolic risk and neurocognitive outcomes. This review presents a comprehensive interdisciplinary examination of recent developments in genetic, endocrine, and neurocognitive science, including the study of animal models. It provides a number of recommendations for improving the effectiveness of research and clinical practice, including neonatal KS screening programs, and a multidisciplinary approach to KS treatment from childhood until senescence.

Antibacterial steroidal alkaloids from Holarrhena antidysenteriaca

Two new steroidal alkaloids, isoconkuressine and N-formylconessimine, together with 6 known steroidal alkaloids including conkuressine, conessine, isoconessimine, conimine, conarrhimine, and funtudienine, were isolated from the seeds of Holarrhena antidysenteriaca Wall.ex A.DC. Their intrinsic antibacterial activities and synergistic effects with penicillin and vancomycin were analyzed in methicillin sensitive staphylococcus aureus (MSSA) and methicillin resistant staphylococcus aureus (MRSA). Two of the steroidal alkaloids including one new compound (N-formylconessimine) showed potential antibacterial activity and possessed synergistic effects with penicillin and vancomycin, respectively.

MOSH Syndrome (Male Obesity Secondary Hypogonadism): Clinical Assessment and Possible Therapeutic Approaches

Male obesity secondary hypogonadism (MOSH) impairs fertility, sexual function, bone mineralization, fat metabolism, cognitive function, deteriorates muscle mass and alters body composition. The aim of this pilot study was to evaluate the effect of dietary intervention and physical activity on the MOSH patient’s hormonal profile after a 10% weight loss compared to baseline. Fourteen male patients were enrolled. Hormonal, lipid, glycemic profiles and body composition were determined at baseline and after a 10% weight loss. Aging Male Symptoms Scale (AMS) and Yale Food Addiction Scale (YFAS) were administered to patients in order to investigate hypogonadal symptoms and food addiction. Compared to baseline, a significant increase of Total Testosterone (TT) (300.2 ± 79.5 ng/dL vs. 408.3 ± 125.9 ng/dL, p = 0.002, 95% CI 26.8; 167.7) and a reduction of 17-Beta Estradiol level (48.3 ± 14.9 pg/mL vs. 39.2 ± 15.2 pg/mL, p = 0.049, 95% CI 3.1; 0.0) were observed. Total Fat Mass (FM) percentage, android and gynoid fat mass percentage (39.2 ± 6.4% vs. 36.2 ± 5.8%, p = 0.0001, 95% CI 22.5; 62.3; 51.5 ± 6.8% vs. 47.6 ± 6.8%, p = 0.001, 95% CI 0.6; 1.8, vs. 39.2 ± 6.2% vs. 36.5 ± 6.3% p = 0.0001, 95% CI 0.9; 2.0 respectively) were significantly decreased after nutritional intervention. In addition, total Fat Free Mass (FFM) in kg was significantly reduced after 10% weight loss (62.3 ± 2.8 kg vs. 60.3 ± 7.7 kg, p = 0.002, 95% CI 45.0; 93.0). Lifestyle changes, specifically dietotherapy and physical activity, induce positive effects on hypogonadism due to obesity.

High risk of hypogonadism in young male cancer survivors

OBJECTIVE

Cancer and its treatment in childhood and young adulthood can cause hypogonadism, leading to increased risk of long-term morbidity and mortality. The aim of this study was to evaluate the risk of presenting with biochemical signs of hypogonadism in testicular cancer survivors (TCS) and male childhood cancer survivors (CCS) in relation to the type of treatment given.

DESIGN

Case-control study.

PATIENTS

Ninety-two TCS, 125 CCS (mean age 40 and median age 34 years, respectively; mean follow-up time 9.2 and 24 years, respectively) and a corresponding number of age-matched controls.

MEASUREMENTS

Fasting morning blood samples were analysed for total testosterone (TT), follicle-stimulating hormone (FSH) and luteinizing hormone (LH). The odds ratios (OR) for hypogonadism, defined as primary, secondary, compensated or ongoing androgen replacement, were calculated for TCS and CCS and for subgroups defined by diagnosis and treatment.

RESULTS

Hypogonadism was found in 26% of CCS and 36% of TCS, respectively (OR: 2.1, P = .025 and OR = 2.3, P = .021). Among CCS, the OR was further increased in those given testicular irradiation (OR = 28, P = .004). Radiotherapy other than cranial or testicular irradiation plus chemotherapy, or cranial irradiation without chemotherapy, associated also with increased ORs (OR = 3.7, P = .013, and OR = 4.4, P = .038, respectively). Among TCS, those receiving >4 cycles of cisplatin-based chemotherapy had OR = 17, P = .015.

CONCLUSIONS

Biochemical signs of testosterone deficiency are recognized as markers of decreased life expectancy. Thus, the risk of hypogonadism in TCS and CCS should be recognized and emphasizes the need of long-term follow-up for these men.

Effectiveness and tolerability of parenteral testosterone undecanoate: a post-marketing surveillance study

This observational post-marketing study of parenteral testosterone undecanoate (TU) in a non-selected population aimed to: examine the effectiveness of TU as treatment of hypogonadism; record adverse drug reactions (ADR) quantitatively particularly regarding polycythemia, prostate safety and cardiovascular-related metabolic risk factors; and verify whether recommended injection intervals apply to routine clinical practice. Eight hundred and seventy subjects from 259 outpatient units scheduled to visit the clinic six times were included. Effectiveness and tolerability of TU administration were assessed on a 4-point scale. Body weight, waist girth, blood pressure, hemoglobin levels, hematocrit, prostate-specific antigen (PSA), and digital rectal prostate examination were assessed. Over 90% of subjects completed the observational duration of 52.8 ± 9.7 weeks (mean ± SD) and 56% judged effectiveness as very good, 30.8% as good. 63.1% judged tolerability as very good, and 24.4% as good. No adverse effects on indicators of cardiovascular risk were observed. Polycythemia occurred in one subject and a supranormal hematocrit in one subject. Four subjects developed supranormal PSA levels. Prostate carcinoma was found in one subject, one subject had recurrence of a previously surgically treated prostate carcinoma, and the other two showed no indication of malignancy. Parenteral TU is safe, effective, and well-tolerated in clinical practice proving a good therapeutic option for hypogonadism.

Transplanted human p75-positive stem Leydig cells replace disrupted Leydig cells for testosterone production

Previous studies have demonstrated that rodent stem Leydig cell (SLC) transplantation can partially restore testosterone production in Leydig cell (LC)-disrupted or senescent animal models, which provides a promising approach for the treatment of hypogonadism. Here, we isolated human SLCs prospectively and explored the potential therapeutic benefits of human SLC transplantation for hypogonadism treatment. In adult human testes, p75 neurotrophin receptor positive (p75⁺) cells expressed the known SLC marker nestin, but not the LC lineage marker hydroxysteroid dehydrogenase-3β (HSD3β). The p75⁺ cells which were sorted by flow cytometry from human adult testes could expand in vitro and exhibited clonogenic self-renewal capacity. The p75⁺ cells had multi-lineage differentiation potential into multiple mesodermal cell lineages and testosterone-producing LCs in vitro. After transplantation into the testes of ethane dimethane sulfonate (EDS)-treated LC-disrupted rat models, the p75⁺ cells differentiated into LCs in vivo and secreted testosterone in a physiological pattern. Moreover, p75⁺ cell transplantation accelerated the recovery of serum testosterone levels, spermatogenesis and reproductive organ weights. Taken together, we reported a method for the identification and isolation of human SLCs on the basis of p75 expression, and demonstrated that transplanted human p75⁺ SLCs could replace disrupted LCs for testosterone production. These findings provide the groundwork for further clinical application of human SLCs for hypogonadism.

Risk of low bone mineral density in testicular germ cell cancer survivors: association with hypogonadism and treatment modality

The cure rate of testicular cancer exceeds 95%, but testicular cancer survivors (TCS) are at increased risk of hypogonadism (HG). It has been suggested that TCS have reduced bone mineral density (BMD), but it is unclear whether this is related to HG or a direct effect of cancer therapy. The aim of this study was to evaluate whether TCS have decreased BMD, and if BMD is related to HG and/or the cancer treatment given. We investigated 91 TCS (mean age at diagnosis: 31 years; mean 9.3 years follow-up) and equal number of age matched controls (mean age at inclusion 40.3 years and 41.2 years, respectively). Total testosterone and LH were measured. BMD was determined using dual-energy X-ray absorptiometry (DXA). Low BMD (LBD) was defined as Z-score <-1. Compared to eugonadal TCS, both TCS with untreated HG (mean difference: -0.063 g/cm² ; 95% CI: -0.122; -0.004 p = 0.037) and TCS receiving androgen replacement (mean difference -0.085 g/cm² ; 95% CI: -0.168; -0.003; p = 0.043) presented with statistically significantly 6-8% lower hip BMD. At the spine, L1-L4, an 8% difference reached the level of statistical significance only for those with untreated HG (mean difference: -0.097 g/cm² ; 95% CI: -0.179; -0.014; p = 0.022). TCS with untreated HG had significantly increased OR for spine L1-L4 LBD (OR = 4.1; 95% CI: 1.3; 13; p = 0.020). The associations between the treatment given and BMD were statistically non-significant, both with and without adjustment for HG. In conclusion, TCS with HG are at increased risk of impaired bone health. Prevention of osteoporosis should be considered as an important part in future follow up of these men.

Assessment of Hypogonadism in Men With Type 2 Diabetes: A Cross-Sectional Study From Saudi Arabia

BACKGROUND/OBJECTIVES

A high incidence of hypogonadism in men with type 2 diabetes (T2D) has been globally reported. This study aimed to determining the frequency of hypogonadism and related risk factors among men with T2D in a single-site hospital in Saudi Arabia.

DESIGN AND METHODS

A cross-sectional study was performed on 157 men with T2D (between 30 and 70 years of age). Using a prestructured questionnaire, the demographic features of these patients were gathered and their medical records were referred to gather information regarding the duration of the diabetes, smoking habits, and the presence of retinopathy, neuropathy, and nephropathy. Besides these, the biochemical parameters, total testosterone (TT), free testosterone, sex hormone-binding globulin, follicle-stimulating hormone, luteinizing hormone, prolactin, serum lipids, and glycosylated hemoglobin were also recorded. All the patients submitted the fully completed Androgen Deficiency in Aging Male (ADAM) questionnaire. The combination of symptoms (positive ADAM score) plus a TT level ⩽8 nmol/L constituted the condition of hypogonadism.

RESULTS

The total frequency of hypogonadism was 22.9% (36/157). Of the 157 total patients, 123 (78.3%) were shown to be ADAM positive, and of these, 90 (73.2%) exhibited decreased libido, 116 (94.3%) had weak erections, and 99 (80.5%) reported more than 3 symptoms of ADAM. Of these hypogonadic patients, 22.2% (n = 8) revealed primary hypogonadism, whereas 77.8% (n = 28) showed secondary hypogonadism. From the univariate analysis conducted, significant relationship was observed between treatment type, body mass index (BMI), and hypogonadism. The regression analysis showed BMI acting an independent risk factor of hypogonadism.

CONCLUSIONS

Saudi men with T2D revealed a high incidence of hypogonadism. Body mass index was identified as an independent risk factor for hypogonadism.

Eurycoma Longifolia as a potential adoptogen of male sexual health: a systematic review on clinical studies

Eurycoma longifolia (EL) has been well recognized as a booster of male sexual health. Over the past few decades, numerous in vivo animal studies and human clinical trials have been conducted across the globe to explore the promising role of EL in managing various male sexual disorders, which include erectile dysfunction, male infertility, low libido, and downregulated testosterone levels. The aim of the present review is to analyze and summarize the literature on human clinical trials which revealed the clinical significance and therapeutic feasibility of EL in improving male sexual health. This systematic review is focused on the following databases: Medline, Wiley Online Library, BioMed Central, Hindawi, Web of Knowledge, PubMed Central and Google Scholar, using search terms such as "Eurycoma longifolia", "EL", "Tongkat Ali", "male sexual health", "sexual infertility", "erectile dysfunction", "male libido", and "testosterone levels". Notably, only human clinical studies published between 2000 and 2014 were selected and thoroughly reviewed for relevant citations. Out of 150 articles, 11 met the inclusion criteria. The majority of articles included were randomized placebo-controlled trials, multiple cohort studies, or pilot trials. All these studies demonstrated considerable effects of EL on male sexual health disorders. Among them, 7 studies revealed remarkable association between the use of EL and the efficacy in the treatment of male sexual disorders, and remaining 4 studies failed to demonstrate sufficient effects on male sexual health. In summary, there is convincing evidence for the prominence of EL in improving the male sexual health. The review also substantiates the use of current methodology in the development of novel and more rationale natural herbal medicines for the management of male sexual disorders.

Transplantation of CD51+ Stem Leydig Cells: A New Strategy for the Treatment of Testosterone Deficiency

Stem Leydig cell (SLC) transplantation could provide a new strategy for treating the testosterone deficiency. Our previous study demonstrated that CD51 (also called integrin αv) might be a putative cell surface marker for SLCs, but the physiological function and efficacy of CD51⁺ SLCs treatment remain unclear. Here, we explore the potential therapeutic benefits of CD51⁺ SLCs transplantation and whether these transplanted cells can be regulated by the hypothalamic-pituitary-gonadal (HPG) axis. CD51⁺ cells were isolated from the testes of 12-weeks-old C57BL/6 mice, and we showed that such cells expressed SLC markers and that they were capable of self-renewal, extensive proliferation, and differentiation into multiple mesenchymal cell lineages and LCs in vitro. As a specific cytotoxin that eliminates Leydig cells (LCs) in adult rats, ethane dimethanesulfonate (EDS) was used to ablate LCs before the SLC transplantation. After being transplanted into the testes of EDS-treated rats, the CD51⁺ cells differentiated into mature LCs, and the recipient rats showed a partial recovery of testosterone production and spermatogenesis. Notably, a testosterone analysis revealed a circadian rhythm of testosterone secretion in cell-transplanted rats, and these testosterone secretions could be suppressed by decapeptyl (a luteinizing hormone-releasing hormone agonist), suggesting that the transplanted cells might be regulated by the HPG axis. This study is the first to demonstrate that CD51⁺ SLCs can restore the neuroendocrine regulation of testicular function by physiologically recovering the expected episodic changes in diurnal testosterone serum levels and that SLC transplantation may provide a new tool for the studies of testosterone deficiency treatment. Stem Cells 2017;35:1222-1232.

Effect of short-term androgen deficiency on bladder contractility and urothelial mediator release

In men, testosterone levels decline by 1% per year after the age of 40. Reduced androgen levels may directly contribute to lower urinary tract symptoms and bladder dysfunction, although the mechanisms are unclear. This study examined the effect of low testosterone and testosterone replacement on key mechanisms involved in local bladder function. Intraluminal release of the mediators ATP and ACh in response to bladder distension was measured in whole bladders from rats 8 weeks following castration, whilst bladder contractility was assessed using isolated strips. Human urothelial cells were cultured under low, physiological and supra-physiological testosterone conditions for 24 h or 5 days, and stretch-induced release of ATP and ACh was measured. Phasic contractile activity of bladder strips, agonist-induced reponses to carbachol and isoprenaline and nerve-evoked contractions were unaffected by castration. The acetylcholinesterase inhibitor neostigmine significantly increased amplitude of phasic activity only in bladder strips following castration, and this was prevented by testosterone replacement. Intraluminal ACh release following bladder distension was significantly reduced following castration, whilst ATP release was unaffected. In contrast, stretch-induced ATP release from urothelial cells was significantly enhanced in low testosterone conditions, whilst ACh release was unaltered. Testosterone-replacement to physiological levels prevented these changes. Whilst androgen deficiency of 8 weeks does not directly affect contractility of bladder smooth muscle, urothelial mediator release is sensitive to changes in testosterone. These changes in mediator release may be an early effect of the decline in testosterone and could affect sensory pathways in the longer term, contributing to the urinary symptoms and bladder dysfunction seen in androgen-deficient men.

[Abdominal pain and hypertension in a 55-year-old male patient]

A 55-year-old male patient under permanent testosterone therapy for hypogonadism presented with abdominal pain and increased blood pressure values. In the physical examination a plethora was noted and laboratory examinations revealed polyglobulia. In the subsequent diagnostic process polycythemia vera and cancer could be excluded as the cause. A secondary polyglobulia due to testosterone substitution was diagnosed. Unphysiologically high testosterone levels represent a rare cause of secondary polyglobulia and with an appropriate medical history should be taken into account at an early stage.

Pharmacology of testosterone replacement therapy preparations

The goal of testosterone replacement therapy (TRT) is to return serum testosterone levels to within physiologic range and improve symptoms in hypogonadal men. Some of the symptoms aimed to improve upon include decreased libido, erectile dysfunction, infertility, hot flashes, depressed mood, and loss of muscle mass or hair. Clinical use of testosterone for replacement therapy began approximately 70 years ago. Over the decades, numerous preparations and formulations have been developed primarily focusing on different routes of delivery and thus pharmacokinetics (PKs). Currently the routes of delivery approved for use by the United States Food and Drug Administration encompasses buccal, nasal, subdermal, transdermal, and intramuscular (IM). Many factors must be considered when a clinician is choosing the most correct formulation for a patient. As this decision depends highly on the patient, active patient participation is important for effective selection. The aim of this review is to describe and compare all testosterone preparations currently available and approved by the United States Food and Drug Administration. Areas of focus will include pharmacology, PKs, adverse effects, and specifics related to individual delivery routes.

Enhancement of dopaminergic activity and region-specific activation of Nrf2-ARE pathway by intranasal supplements of testosterone propionate in aged male rats

The potential influence of intranasal testosterone propionate (InTP) supplements on mesodopaminergic system in aged male rats was investigated by analyzing the exploratory and motor behaviors as well as dopamine neurobiochemical indices. Meanwhile, oxidative stress parameters and pathway of nuclear factor erythroid 2-related factor 2 (Nrf2)-binding antioxidant response elements (Nrf2-ARE) were examined to check whether the Nrf2-ARE pathway was involved in the InTP-induced alteration of mesodopaminergic system in aged male rats. The exploratory and motor behavioral deficits, as well as the reduced expression of dopamine, tyrosine hydroxylase, and dopamine transporter, which indicated the declined activity of mesodopaminergic system, were ameliorated in rats administered with 12-week InTP. The results indicated that chronic InTP supplements could effectively influence the brain function activity in a way opposite to the effect of aging on the mesodopaminergic system of rats. The increased levels of Nrf2, heme oxygenase-1, and

NAD(P)H

quinone oxidoreductase-1 in the substantia nigra and ventral tegmental area, but not in the hippocampus of InTP-administered aged male rats, indicated that the ameliorative effect of InTP supplements on mesodopaminergic system might be related to the region-specific activation of the Nrf2-ARE pathway.

The Effect of Testosterone on Men With Andropause

BACKGROUND

Andropause is the gradual reduction of the male sex hormone (testosterone) with increasing age. Its symptoms are sexual dysfunction, weakness, fatigue, insomnia, loss of motivation, mood disorders and reduction of bone density. Treatment of andropause with testosterone has been recently considered.

OBJECTIVES

The aim of this study was to evaluate the effect of testosterone in the treatment of andropause in men.

PATIENTS AND METHODS

For men who met the inclusion criteria (50 years of age and older) laboratory tests and clinical examinations were conducted by an urologist in order to diagnose prostate cancer, prostate disease, urinary tract infection and active urinary retention. After obtaining consent, the patients were enrolled in the study. Data were analyzed using SPSS version 20. Descriptive statistics (frequency and percentage, mean, standard deviation) and the paired t-test were used to compare levels of testosterone. To determine the correlation between age and testosterone levels, the Pearson correlation was used. Finally, to compare the treatment processes during the treatment period the repeated measures ANOVA was used.

RESULTS

The mean age of patients was 56.57 ± 3.21 years. A total of 31 patients (39%) were smokers, among them 30% smoked daily, 2.5% weekly and 6% smoked for fun. The mean testosterone level before treatment was 240.6 ± 125.4 and at 1, 3 and 6 months after treatment the level was raised, so that at the end of the sixth months it was 578.7 ± 141.7. The level of increase was statistically significant (P = 0.0001).

CONCLUSIONS

Treatment with testosterone in men over 50 years with andropause will increase testosterone levels and also quality of life, sexual desire, erection, energy levels, ability to exercise and feel the joy of life more than before. Depression was decreased and they had sleepy feelings after dinner.

Association Between Testosterone Supplementation Therapy and Thrombotic Events in Elderly Men

OBJECTIVE

To determine the prevalence of thrombotic events and all-cause mortality in men older than 65 years with hypogonadism treated with testosterone therapy (TST).

PATIENTS AND METHODS

We retrospectively reviewed the charts of 217 hypogonadal men >65 years. We compared men who received TST (n = 153) to hypogonadal men (n = 64) who did not receive TST. We evaluated all-cause mortality, prevalence of myocardial infarction (MI), transient ischemic attack (TIA), cerebrovascular accident (CVA or "stroke"), and deep vein thrombosis/pulmonary embolism (DVT/PE). All events were verified by contacting patients. We excluded men with previous thrombotic events, men previously on androgen deprivation therapy, and men who had used TST before age of 65 years.

RESULTS

Median age and Charlson Comorbidity Index of men on TST (74y; 5.1) was similar to hypogonadal men not on TST (73y, P = .48; 5.3, P = .36). Median follow-up was 3.8 vs 3.5 years (TST vs no TST). No man on TST died, whereas 5 hypogonadal men who did not receive TST died (P = .007). There were 4 thrombotic events (1 MI, 2 CVA/TIA, and 1 PE) in men who received TST and 1 event (CVA/TIA) among men who did not receive TST (P = .8). All events (1 death, 6-month follow-up) occurred at least after 2 years of follow-up.

CONCLUSION

There was increased all-cause mortality in hypogonadal men not treated with testosterone compared to men who received TST. There was no difference in prevalence of MI, TIA/CVA, or PE between patients treated with testosterone and hypogonadal men not treated with testosterone.

Androgen Deficiency and Erectile Dysfunction in Patients with Type 2 Diabetes

BACKGROUND

The association between type 2 diabetes mellitus (T2DM) and low total serum testosterone (LST) has been identified in several cross-sectional studies.

OBJECTIVES

To assess the prevalence of androgen deficiency and erectile dysfunction (ED) and their relation to glycemic control within a sample of Egyptian men with T2DM.

RESEARCH DESIGN AND METHODS

A cross-sectional study including 70 men having T2DM. Their ages ranged from 30 to 50 years. They were evaluated for symptoms of androgen deficiency and ED, using a validated Arabic-translated Androgen Deficiency in Aging Males questionnaire and five-items version of the International Index of Erectile Function-5, respectively. Total testosterone (TT), glycated hemoglobin (HbA1c), follicle-stimulating hormone (FSH), luteinizing hormone (LH), and prolactin were measured for all study subjects. Penile hemodynamics was assessed using penile duplex study for subjects who gave history of ED.

RESULTS

LST was found in 40% of studied men, and 92.9% of them reported overt symptoms of androgen deficiency. ED was detected in 85.7% of those with LST, as opposed to 31.0% of those with normal TT (P < 0.000). TT was lower in diabetic men with ED compared to those without ED (12.04 ± 5.36 vs 17.11 ± 7.11 nmol/L, P < 0.001). Significant negative correlation was found between TT and age, body mass index, waist circumference, systolic and diastolic blood pressures, and HBA1c (P < 0.00). FSH, LH, and prolactin levels were within the normal reference range in all subjects. HbA1c was higher in patients who had LST with ED, compared to those with normal TT and without ED. However, multivariate logistic regression analysis did not reveal a significant association between HBA1c and LST levels.

CONCLUSION

LST, symptoms of androgen deficiency, and ED are common in the studied sample of Egyptian men with T2DM. Inappropriately normal FSH and LH in face of LST may denote a state of hypogonadotropic hypogonadism. HBA1c was found to be more significantly associated with ED than with LST.

Study of Sex Hormone-binding Globulin Gene Polymorphism and Risk of Type 2 Diabetes Mellitus in Egyptian Men

OBJECTIVES

Conditions of hypoandrogenism in men have been linked to insulin resistance, suggesting that alterations in normal sex steroid physiology could play a role in the pathogenesis of Type 2 diabetes mellitus (T2DM). Sex hormone-binding globulin (SHBG) gene polymorphisms may be the cause of sex steroid alteration. The aim of this work is to study the effect of SHBG gene polymorphisms on the risk of T2DM through its impact on testosterone and oestradiol level in Egyptian men.

SUBJECTS AND METHODS

A case control study was performed in the diabetes clinic at Zagazig University Hospital on 185 males with Type 2 diabetes and their matched healthy controls. Two polymorphisms (rs6257 and rs6259) of the gene encoding SHBG were genotyped and serum levels of SHBG, testosterone and oestradiol were measured by enzyme-linked immunosorbent assay (ELISA).

RESULTS

Carriers of rs6257 variant allele (CC or CT) and carriers of rs6259 wild allele (GG) appear to have a high risk of diabetes than carriers of other alleles (OR 2.241, 1.585 and 2.391, respectively). They also showed a significant decrease in plasma level of both SHBG and testosterone and a significant increase in oestradiol blood level compared with carriers of other alleles.

CONCLUSIONS

Sex hormone-binding globulin gene polymorphisms at position rs6257 and rs6259 are associated with higher risk of T2DM in Egyptian men, through lowering circulating levels of SHBG and consequently, lowering testosterone and elevating oestradiol level.

Increase in Bcl2 expression of penile and prostate cells of Sprague Dawley male rats following treatment with buceng (combination of Pimpinella alpina molk with Eurycoma longifolia Jack)

Background: Treatment with buceng combination of Eurycoma longifolia Jack and Pimpinella alpine Molk has been proven to increase testosterone level, decrease apoptosis and caspase3 expression. Bcl2 is an antiapoptotic protein found in cytoplasm which inhibits cells apoptosis. This study was aimed to investigate the effect of buceng on Bcl2 expression on penile and prostate tissues of the rats. Methods: In this experimental study, 24 male Sprague Dawley rats of 90 days old, weighing ± 300 grams, were randomly assigned into four groups. Group A, normal rats. Group B, castrated rats and treated with buceng 100 mg/day, per oral (Cast-Bcg); Group C, castrated rats and treated with 2 ml of water as placebo against buceng (Cast-Plac). Group D, castrated rats, treated with mesterolone 6.75 mg/day, per oral, as exogenous testosterone (Cast-Mest). All rats were treated for 30 days. Manova test was used to analyze the different expression of Bcl2 among groups with significance level at p ≤ 0.05. Results: Castration was associated with significant decrease of Bcl2 expression in the penile and prostate tissues (53.0 and 50.9%, respectively) compared to normal rats (82.6 and 84.2%, respectively, p < 0.001). Treatment with mesterolone reversed Bcl2 expression (77.1 and 78.1%) to a near normal level. The same level of Bcl2 expression was also observed with buceng treatment (73.8 and 78.2%).Conclusion: The treatment with buceng could enhance Bcl2 expression in penile and prostate tissues, comparable to normal rats and mesterolone treated rats.

Testosterone replacement therapy: who to evaluate, what to use, how to follow, and who is at risk?

BACKGROUND

Hypogonadism, defined as a low serum testosterone in the presence of signs and symptoms, is common, particularly in aging men. Testosterone supplementation therapy (TST) is the standard treatment for male hypogonadism. It has been demonstrated to have a significant impact on the signs and symptoms of hypogonadism, but there are concerns about the increase in TST and its potential adverse effects, particularly cardiovascular effects.

OBJECTIVE

This review presents health care providers with current information regarding the prevalence and impact of hypogonadism, as well as the diagnosis, evaluation, and treatment of hypogonadism. The beneficial and potential adverse effects are reviewed with a discussion on the current cardiovascular controversy.

METHODS

We reviewed current and "landmark" articles in the English-language literature pertaining to hypogonadism, its prevalence, etiologies, presentation, evaluation, and treatment.

RESULTS

Authorities in the field have offered guidelines and recommendations regarding the diagnosis, evaluation, and management of hypogonadism. Although there is a consensus as to the definition of hypogonadism as the presence of a low serum testosterone with signs and symptoms of hypogonadism, there is variability in the definition of "low testosterone." Various testosterone formulations exist, differing in route and frequency of administration as well as in side-effect profiles. Testosterone supplementation therapy should be continued in individuals demonstrating an improvement in signs and symptoms, which may take 3 months to a year for maximum response. Individuals treated with TST require monitoring for adverse effects. Further studies are needed to determine the impact of TST on cardiovascular health.

CONCLUSION

Hypogonadism is common, particularly in aging men. Symptomatic individuals who have no contraindications to TST should be offered treatment. A careful assessment of treatment response after adequate titration and duration of therapy as well as monitoring for adverse effects is essential in treating patients for hypogonadism. Although hypogonadism is associated with increased all-cause and cardiovascular-related mortality, controversy exists regarding the impact of TST on cardiovascular risk, highlighting the need for further studies.

Current topics in testosterone replacement of hypogonadal men

All forms of hypogonadism - primary, secondary and late-onset - require testosterone substitution. The indication is given when the patient presents with symptoms of androgen deficiency and the serum testosterone levels are below normal. Several testosterone preparations and modes of application are available of which those producing physiologic serum levels should be preferred e.g. preferentially transdermal gels and long-acting intramuscular testosterone undecanoate. Testosterone substitution must be monitored at regular intervals, best at 3, 6 and 12 months after initiation and then annually. Parameters for surveillance include well-being, libido and sexual activity, measurement of serum testosterone levels, haemoglobin and haematocrit, PSA and digital rectal examination, and, biannually, bone mineral density. Testosterone has positive effects on comorbidities such as obesity, metabolic syndrome, diabetes type II, cardiovascular diseases and osteoporosis.

Directed mouse embryonic stem cells into leydig-like cells rescue testosterone-deficient male rats in vivo

The primary function of Leydig cells is to secrete testosterone, which is critical in the regulation of male reproduction and development. Low levels of testosterone will lead to male hypogonadism. Stem cell-derived Leydig cell transplantation may be a promising alternative therapy for male hypogonadism. Thus far, others have reported that Leydig-like cells can be derived from mesenchymal stem cells, embryonic stem cells (ESCs), and induced pluripotent stem cells. However, the efficiency of the differentiating Leydig cells remains low, and progress toward generating functional adult Leydig cells (ALCs) is limited. Herein, we describe a robust method of directing differentiation of mouse embryonic stem cells (mESCs) into Leydig-like cells in vitro by overexpression of the transcription factor steroidogenic factor-1 (SF-1) and treatment with a combination of 8-Bromoadenosine-3',5'-cyclic monophosphate and forskolin. These differentiated cells express mRNA encoding the steroidogenic enzymes and produce progesterone and testosterone. Importantly, when transplanted into male rats that had their original Leydig cells selectively eliminated by ethylene dimethanesulfonate, these in vitro-derived Leydig-like cells further developed into functional ALCs that rescued serum testosterone levels. These data provide evidence that mESCs can be induced to differentiate into Leydig-like cells in vitro, which can develop in the in vivo microenvironment.