Androgens and male aging: Current evidence of safety and efficacy

Association between cardiometabolic index and testosterone among adult males: a cross-sectional analysis from National Health and Nutrition Examination Survey 2013-2016

Background

Cardiometabolic index (CMI) is a well-promising indicator for predicting obesity-related diseases. Testosterone decline and deficiency importantly affect men's health, and may be associated with obesity and excessive deposition of visceral adipose tissue. We aimed to explore the association between CMI and serum testosterone in US adult males.

Methods

The present cross-sectional study was conducted among adult males with complete data about CMI and testosterone in 2013-2016 National Health and Nutrition Examination Survey (NHANES). CMI was calculated as follows: triglyceride (TG) (mmol/L)/high-density lipid-cholesterol (HDL-C) (mmol/L) × waist-to-height ratio (WHtR). Multivariable regression and subgroup analyses were conducted to explore the association between CMI and testosterone.

Results

We included 2,209 male participants for the final analysis. After adjusting for confounders, CMI was found to show a negative correlation between testosterone [minimally adjusted model: β=-10.56, 95% confidence interval (CI): -12.76, -8.36, P<0.001, fully adjusted model: β=-0.04 (-4.88, 4.81), P=0.99]. Multivariate-adjusted beta also showed testosterone levels were significantly lower in the two highest CMI groups (Q3, Q4) compared to the lowest group (Q1). In the subgroup populations, the relationship between CMI and testosterone was affected by age, race, education level, hypertension, and smoking status (P-interaction <0.05). Furthermore, receiver operating characteristic (ROC) curve analysis indicated that triglyceride-glucose-body mass index (TyG-BMI) (0.67, 95% CI: 0.65, 0.70) was the best predictor of low testosterone (results), although CMI was comparable in its predictive value (0.68, 95% CI: 0.65, 0.71).

Conclusions

Higher CMI scores were associated with lower testosterone levels in adult males in the United States, with this correlation being influenced by factors such as age, race, education level, hypertension, and smoking status. CMI was comparable to other metabolic indexes for predicting testosterone deficiency, although TyG-BMI was the best overall predictor.

Testosterone Inhibits Lipid Accumulation in Porcine Preadipocytes by Regulating ELOVL3

Castration is commonly used to reduce stink during boar production. In porcine adipose tissue, castration reduces androgen levels resulting in metabolic disorders and excessive fat deposition. However, the underlying detailed mechanism remains unclear. In this study, we constructed porcine preadipocyte models with and without androgen by adding testosterone exogenously. The fluorescence intensity of lipid droplet (LD) staining and the fatty acid synthetase (FASN) mRNA levels were lower in the testosterone-treated cells than in the untreated control cells. In contrast, the mRNA levels of adipose triglycerides lipase (ATGL) and androgen receptor (AR) were higher than in the testosterone-treated cells than in the control cells. Subsequently, transcriptomic sequencing of porcine preadipocytes incubated with and without testosterone showed that the mRNA expression levels of very long-chain fatty acid elongase 3 (ELOVL3), a key enzyme involved in fatty acids synthesis and metabolism, were high in control cells. The siRNA-mediated knockdown of ELOVL3 reduced LD accumulation and the mRNA levels of FASN and increased the mRNA levels of ATGL. Next, we conducted dual-luciferase reporter assays using wild-type and mutant ELOVL3 promoter reporters, which showed that the ELOVL3 promoter contained an androgen response element (ARE); furthermore, its transcription was negatively regulated by AR overexpression. In conclusion, our study reveals that testosterone inhibits fat deposition in porcine preadipocytes by suppressing ELOVL3 expression. Moreover, our study provides a theoretical basis for further studies on the mechanisms of fat deposition caused by castration.

Recent advances in reproductive research in Australia and New Zealand: highlights from the Annual Meeting of the Society for Reproductive Biology, 2022

In 2022, the Society for Reproductive Biology came together in Christchurch New Zealand (NZ), for its first face-to-face meeting since the global COVID-19 pandemic. The meeting showcased recent advancements in reproductive research across a diverse range of themes relevant to human health and fertility, exotic species conservation, and agricultural breeding practices. Here, we highlight the key advances presented across the main themes of the meeting, including advances in addressing opportunities and challenges in reproductive health related to First Nations people in Australia and NZ; increasing conservation success of exotic species, including ethical management of invasive species; improvements in our understanding of developmental biology, specifically seminal fluid signalling, ovarian development and effects of environmental impacts such as endocrine-disrupting chemicals; and leveraging scientific breakthroughs in reproductive engineering to drive solutions for fertility, including in assisted reproductive technologies in humans and agricultural industries, and for regenerative medicine.

Understanding Sleep Disturbances in Prostate Cancer-A Scientometric Analysis of Sleep Assessment, Aetiology, and Its Impact on Quality of Life

Prostate cancer is the most commonly diagnosed cancer in the United Kingdom. While androgen-deprivation therapy is the most common treatment for prostate cancer, patients undergoing this treatment typically experience side effects in terms of sleep disturbances. However, the relation between prostate cancer and sleep and the way in which sleep interventions may benefit oncological patients is underinvestigated in the literature. The current study aims to review in a data-driven approach the existing literature on the field of prostate cancer and sleep to identify impactful documents and major thematic domains. To do so, a sample of 1547 documents was downloaded from Scopus, and a document co-citation analysis was conducted on CiteSpace software. In the literature, 12 main research domains were identified as well as 26 impactful documents. Research domains were examined regarding the link between prostate cancer and sleep, by taking into account variations in hormonal levels. A major gap in the literature was identified in the lack of use of objective assessment of sleep quality in patients with prostate cancer.

Inflammatory signals from fatty bone marrow support DNMT3A driven clonal hematopoiesis

Both fatty bone marrow (FBM) and somatic mutations in hematopoietic stem cells (HSCs), also termed clonal hematopoiesis (CH) accumulate with human aging. However it remains unclear whether FBM can modify the evolution of CH. To address this question, we herein present the interaction between CH and FBM in two preclinical male mouse models: after sub-lethal irradiation or after castration. An adipogenesis inhibitor (PPARγ inhibitor) is used in both models as a control. A significant increase in self-renewal can be detected in both human and rodent DNMT3A^Mut-HSCs when exposed to FBM. DNMT3A^Mut-HSCs derived from older mice interacting with FBM have even higher self-renewal in comparison to DNMT3A^Mut-HSCs derived from younger mice. Single cell RNA-sequencing on rodent HSCs after exposing them to FBM reveal a 6-10 fold increase in DNMT3A^Mut-HSCs and an activated inflammatory signaling. Cytokine analysis of BM fluid and BM derived adipocytes grown in vitro demonstrates an increased IL-6 levels under FBM conditions. Anti-IL-6 neutralizing antibodies significantly reduce the selective advantage of DNMT3A^Mut-HSCs exposed to FBM. Overall, paracrine FBM inflammatory signals promote DNMT3A-driven clonal hematopoiesis, which can be inhibited by blocking the IL-6 pathway.

Testosterone replacement relieves ligature-induced periodontitis by mitigating inflammation, increasing pro-resolving markers and promoting angiogenesis in rats: A preclinical study

OBJECTIVES

This study aimed to evaluate the inflammatory profile as well as the resolution of inflammation in a ligature-induced periodontal inflammation in rats with depletion and/or supraphysiological testosterone replacement.

DESIGN

Sixty male rats (Holtzman) were used in the present study. Study groups were created as following: (1) Sham (no testicle removal); (2) Orchiectomy (OCX), 3) OCX + Testosterone (OCX + T); (4) Sham + Ligature (SH + L); (5) OCX+L; and 6) OCX + T + L. The surgeries were performed on day 1, and testosterone was administered weekly since day 1. On day 15, a cotton ligature was placed around the lower first molars and maintained for 15 days. Morphological changes in periodontal tissues were determined by histopathological analysis. Immunohistochemistry (factor VIII) and immunoenzymatic assay were performed to evaluate angiogenesis process and (pro- and anti-) inflammatory markers, respectively.

RESULTS

Ligature promoted a marked inflammatory gingival infiltrate and bone loss (P < 0.05). Supraphysiological testosterone treatment increased the percentage of blood vessels, extracellular matrix and fibroblasts in the presence and absence of periodontal inflammation (P < 0.05). A high dose of testosterone increased factor VIII+ blood vessels and IL-10 expression in inflamed gingival tissue, while PGE₂, LXA₄ and MPO were reduced as a result of supraphysiological testosterone administration (P < 0.05).

CONCLUSIONS

These results, in our experimental model, suggest that supraphysiological testosterone treatment stimulated gingival tissue repair during ligature-induced periodontitis, and it seems to be related to an anti-inflammatory and pro-resolutive mechanism resulting by the modulatory effect on PGE₂ and IL-10 related to an enhanced angiogenesis.

Testofen, a specialised Trigonella foenum-graecum seed extract reduces age-related symptoms of androgen decrease, increases testosterone levels and improves sexual function in healthy aging males in a double-blind randomised clinical study

This study examined the effect of Testofen, a specialised Trigonella foenum-graecum seed extract on the symptoms of possible androgen deficiency, sexual function and serum androgen concentrations in healthy aging males. This was a double-blind, randomised, placebo-controlled trial involving 120 healthy men aged between 43 and 70 years of age. The active treatment was standardised Trigonella foenum-graecum seed extract at a dose of 600 mg/day for 12 weeks. The primary outcome measure was the change in the Aging Male Symptom questionnaire (AMS), a measure of possible androgen deficiency symptoms; secondary outcome measures were sexual function and serum testosterone. There was a significant decrease in AMS score over time and between the active and placebo groups. Sexual function improved, including number of morning erections and frequency of sexual activity. Both total serum testosterone and free testosterone increased compared to placebo after 12 weeks of active treatment. Trigonella foenum-graecum seed extract is a safe and effective treatment for reducing symptoms of possible androgen deficiency, improves sexual function and increases serum testosterone in healthy middle-aged and older men.

"Linearity assessment methods for sex steroid hormones and carrier proteins among men in the National Health and Nutrition Examination Survey (NHANES III)"

INTRODUCTION

It has been hypothesized that racial disparities among several diseases are explained by differences in testosterone (T), 17-β estradiol (E), sex hormone binding globulin (SHBG) and albumin (A) levels, yet epidemiologic results have been mixed. Statistical advice regarding appropriate adjustment methods for carrier proteins of sex steroid hormones in the literature is scant. Therefore, we investigated different adjustment methods for carrier proteins.

METHODS

Data for 1496 men, >17 years from the Third National Health and Nutrition Examination Survey (NHANES III) 1988-91 were used to analyze linearity between sex hormones and carrier proteins by examining correlation, plots, and regression models. The statistical importance of age, body mass index (BMI), and race/ethnicity were examined for changes in results by the adjustment method.

RESULTS

T was weakly correlated with SHBG and A (r-squared, 0.25, 0.13, respectively) and E was weakly negatively correlated with A (p<0.0001), but not SHBG (p<0.1799). Based on the model residual plots and r-squared, the categorical model performed better than linear models. Regression coefficients for age, BMI, and race/ethnicity groups using quotient (e.g., T/A and E/A) models differed from continuous and categorical models.

CONCLUSION

Choosing an appropriate adjustment for carrier proteins is important to prevent bias in analyses and inconsistency in findings across studies. Linearity between variables should not be assumed when adjusting models, and should be conducted and reported. An independent categorical carrier protein variable is recommended in analysis exploring factors predicting sex hormone levels, although statistical testing should always be employed.

Anabolic steroid-induced hypogonadism: diagnosis and treatment

OBJECTIVE

To develop an understanding of hypogonadal men with a history of anabolic-androgenic steroid (AAS) use and to outline recommendations for management.

DESIGN

Review of published literature and expert opinions. Intended as a meta-analysis, but no quality studies met the inclusion criteria.

SETTING

Not applicable.

PATIENT(S)

Men seeking treatment for symptomatic hypogonadism who have used nonprescribed AAS.

INTERVENTION(S)

History and physical examination followed by medical intervention if necessary.

MAIN OUTCOME MEASURES(S)

Serum testosterone and gonadotropin levels, symptoms, and fertility restoration.

RESULT(S)

Symptomatic hypogonadism is a potential consequence of AAS use and may depend on dose, duration, and type of AAS used. Complete endocrine and metabolic assessment should be conducted. Management strategies for anabolic steroid-associated hypogonadism (ASIH) include judicious use of testosterone replacement therapy, hCG, and selective estrogen receptor modulators.

CONCLUSION(S)

Although complications of AAS use are variable and patient specific, they can be successfully managed. Treatment of ASIH depends on the type and duration of AAS use. Specific details regarding a patient's AAS cycle are important in medical management.

Physiological testosterone retards cardiomyocyte aging in Tfm mice via androgen receptor-independent pathway

OBJECTIVE

To determine whether testosterone modulates markers of cardiomyocytes aging via its classic androgen receptor (AR)-dependent pathway or conversion to estradiol.

METHODS

Male littermates and testicular feminized (Tfm) mice were randomly separated into 4 experimental groups littermate controls (n=8), Tfm mice (n=7), testosterone-treated Tfm mice (n=8), and Tfm mice treated with testosterone in combination with the aromatase inhibitor anastrazole (n=7). Cardiomyocytes were isolated from mouse left ventricles, the activity of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px), and the amount of malondialdehyde (MDA) were measured using colorimetry method, and expression of p16(INK4α) and retinoblastoma (Rb) proteins were detected by Western blotting.

RESULTS

The SOD and GSH-Px enzyme activities of cardiomyocytes were decreased, and the MDA levels and the expression of p16(INK4α) and Rb proteins were increased in Tfm mice compared with control mice. An increase was observed in the activities of SOD and GSH-Px enzyme as well as a decrease in MDA levels and the expression of p16(INK4α) and Rb proteins in the testosterone-treated Tfm mice. After co-treatment with anastrazole in Tfm mice, these improvement were partly inhibited.

CONCLUSION

Physiological testosterone replacement can delay cardiomyocyte aging in Tfm mice, an effect that is independent of the AR pathway and in part conversion to estradiol.

A randomized, double-blind, placebo-controlled trial of testosterone gel on body composition and health-related quality-of-life in men with hypogonadal to low-normal levels of serum testosterone and symptoms of androgen deficiency over 6 months with 12 months open-label follow-up

INTRODUCTION

The clinical significance of low to low-normal testosterone (T) levels in men remains debated.

AIM

To analyze the effects of raising serum T on lean body mass (LBM), fat mass (FM), total body mass, and health-related quality-of-life (HRQoL).

METHODS

Randomized, double-blind, placebo-controlled study. Men, aged 50-80 years, with serum total T<15 nmol/L and bioavailable T < 6.68 nmol/L, and a Aging Males' Symptoms (AMS) total score >36, received 6 months treatment with transdermal 1% T gel (5-7.5 mg/day; n =183) or placebo gel (n =179), followed by 12 months open-label with T in all.

RESULTS

After 6 months, LBM increased in T- treated patients by 1.28 ± 0.15 kg (mean ± SE) and FM decreased by 1.16 ± 0.16 kg, with minor changes with placebo (LBM +0.02 ± 0.10 kg and FM -0.14 ± 0.12 kg; all p < 0.001, T group vs. placebo). Changes were largely similar across subgroups of age, baseline total testosterone, and baseline BMI. Total HRQoL improved compared with placebo (p < 0.05, T group vs. placebo).

CONCLUSIONS

Six months 1% T gel improved body composition and HRQoL in symptomatic men with low to low-normal T, with further improvements over the following 12 months.

The effect of supra- and subphysiologic testosterone levels on ligature-induced bone loss in rats--a radiographic and histologic pilot study

BACKGROUND

Testosterone is the primary male sexual hormone, and varying concentrations of the hormone mediated by physiologic, pathologic, or pharmacologic mechanisms may induce large variations in the body. Data regarding the general role of testosterone in mediating inflammation are still inconclusive. Therefore, the purpose of this study is to assess the consequences of supra- and subphysiologic levels of testosterone on ligature-induced bone loss in rats.

METHODS

Three male adult Holtzman rats were used to observe the course of serum testosterone concentration following orchiectomy (Ocx) and testosterone injections. Another 60 rats were randomly assigned to the following groups: (1) sham-operation controls (n = 10); (2) sham-operation and ligature-induced bone loss (n = 10); (3) orchiectomy without ligature (Ocx; n = 10); (4) Ocx and ligature (n = 10); (5) Ocx plus 250 mg/kg body weight intramuscular testosterone esters injection without ligature (Ocx+T; n = 10); and (6) Ocx, T, and ligature (n = 10). The ligatures were placed 30 days postorchiectomy (or sham-operation) and maintained for 15 days. Thereafter, the rats were sacrificed, and their hemimandibles were used for radiographic evaluation of bone loss along with histologic and histometric analyses of gingival tissue.

RESULTS

The results indicated a significant increase in bone loss in the Ocx and Ocx+T groups in the presence and absence of inflammation, respectively. In addition, the Ocx and Ocx+T groups presented increased gingival area accompanying ligature-induced bone loss.

CONCLUSIONS

Both sub- and supraphysiologic testosterone levels may influence bone metabolism, but only subphysiologic levels significantly increase ligature-induced bone loss. Moreover, testosterone has a regulatory effect on the gingival area.

Physical health problems in adults with Prader-Willi syndrome

Prader-Willi syndrome (PWS) is a genetic disorder which is characterized by severe hypotonia and feeding problems in early infancy. In later childhood and adolescence, this is followed by hyperphagia and extreme obesity if the diet is not strictly controlled. Data on physical health problems in adults with PWS are scarce. We report on the prevalence of physical health problems in a Dutch cohort of adults with PWS in relation to age, BMI, and genetic subtype. Participants (n = 102) were retrieved via the Dutch Prader-Willi Parent Association and through physicians specializing in persons with intellectual disabilities (ID). Details regarding physical health problem spanning the participants' lifespan were collected from caretakers through semi-structured interviews. Cardiovascular problems included diabetes mellitus, hypertension, and cerebrovascular accidents. Respiratory infections were frequent in adulthood. In males, cryptorchidism was almost universal, for which 28/48 males had a history of surgery, mostly orchidopexy. None of the women had a regular menstrual cycle. Sixteen individuals had a diagnosis of osteoporosis. Spinal deformation, hip dysplasia, and foot abnormalities were common. Skinpicking, leg edema, and erysipelas were frequent dermatological problems. The findings in our group support the notion that the prevalence of physical health problems is underestimated. This underscores the importance of developing monitoring programs which would help to recognize physical health problems at an early stage.

The influence of age on bioavailable and free testosterone is independent of body mass index and glucose levels

PURPOSE

To evaluate the influence of age on serum levels of total testosterone (TT), bioavailable testosterone (BT), free testosterone (FT), and sex-hormone binding globulin (SHBG), considering the presence of fasting blood glucose levels and body mass index (BMI) in a selected male population.

METHODS

A total of 428 men were analyzed. Anthropometry was taken from all, considering BMI as general obesity indicative variable. Fasting blood samples were drawn for determination of plasma glucose levels and serum levels of albumin, TT, and SHBG. The values of BT and FT were calculated from TT, SHBG, and albumin, by Vermeulen's equation. Statistical significance was set at P ≤ 0.05.

RESULTS

Age was negatively correlated to BT (r = -0.301; P < 0.001) and FT (r = -0.273; P < 0.001), but not to TT levels (r = 0.002, P = 0.974). Age was positively correlated to SHBG (r = 0.376; P < 0.001). Age was independently associated with the occurrence of high SHBG levels (OR = 1.07, 95%CI = 1.05-1.10, P < 0.001) and of low BT (OR = 1.04, 95%CI = 1.02-1.07, P < 0.001) and FT levels (OR = 1.05, 95%CI = 1.03-1.08, P < 0.001), but not with low levels of TT (P = 0.08).

CONCLUSIONS

Age was significantly associated to high levels of SHBG and to low levels of BT and FT, without significant association to TT. This pattern was independent of BMI and glucose levels.

Identification of serum biomarkers for aging and anabolic response

OBJECTIVE

With the progressive aging of the human population, there is an inexorable decline in muscle mass, strength and function. Anabolic supplementation with testosterone has been shown to effectively restore muscle mass in both young and elderly men. In this study, we were interested in identifying serum factors that change with age in two distinct age groups of healthy men, and whether these factors were affected by testosterone supplementation.

METHODS

We measured the protein levels of a number of serum biomarkers using a combination of banked serum samples from older men (60 to 75 years) and younger men (ages 18 to 35), as well as new serum specimens obtained through collaboration. We compared baseline levels of all biomarkers between young and older men. In addition, we evaluated potential changes in these biomarker levels in association with testosterone dose (low dose defined as 125 mg per week or below compared to high dose defined as 300 mg per week or above) in our banked specimens.

RESULTS

We identified nine serum biomarkers that differed between the young and older subjects. These age-associated biomarkers included: insulin-like growth factor (IGF1), N-terminal propeptide of type III collagen (PIIINP), monokine induced by gamma interferon (MIG), epithelial-derived neutrophil-activating peptide 78 (ENA78), interleukin 7 (IL-7), p40 subunit of interleukin 12 (IL-12p40), macrophage inflammatory protein 1β (MIP-1β), platelet derived growth factor β (PDGFβ) and interferon-inducible protein 10 (IP-10). We further observed testosterone dose-associated changes in some but not all age related markers: IGF1, PIIINP, leptin, MIG and ENA78. Gains in lean mass were confirmed by dual energy X-ray absorptiometry (DEXA).

CONCLUSIONS

Results from this study suggest that there are potential phenotypic biomarkers in serum that can be associated with healthy aging and that some but not all of these biomarkers reflect gains in muscle mass upon testosterone administration.

Low-dose testosterone treatment decreases oxidative damage in TM3 Leydig cells

Testosterone replacement therapy has benefits for aging men and those with hypogonadism. However, the effects of exogenous testosterone on Leydig cells are still unclear and need to be clarified. In this report, we demonstrate that testosterone supplementation can reduce oxidative damage in Leydig cells. The TM3 Leydig cell line was used as an in vitro cell model in this study. Cytoprotective effects were identified with 100-nmol l⁻¹ testosterone treatment, but cytotoxic effects were found with ≥ 500-nmol l⁻¹ testosterone supplementation. Significantly reduced reactive oxygen species (ROS) generation, lipid peroxide contents and hypoxia induction factor (HIF)-1α stabilization and activation were found with 100-nmol l⁻¹ testosterone treatment. There was a 1.72-fold increase in ROS generation in the 500-nmol l⁻¹ compared to the 100-nmol l⁻¹ testosterone treatment. A 1.58-fold increase in steroidogenic acute regulatory protein (StAR) expression was found in 50-nmol l⁻¹ testosterone-treated cells (P < 0.01). Chemically induced hypoxia was attenuated by testosterone supplementation. Leydig cells treated with low-dose testosterone supplementation showed cytoprotection by decreasing ROS and lipid peroxides, increasing StAR expression and relieving hypoxia stress as demonstrated by HIF-1α stabilization. Increased oxidative damage was found with ≥ 500-nmol l⁻¹ testosterone manipulation. The mechanism governing the differential dose effects of testosterone on Leydig cells needs further investigation in order to shed light on testosterone replacement therapy.

Late onset hypogonadism, sexuality and fertility

The numerous and varying effects of androgen deficiency in males cause an array of symptoms and complaints any of which can be the trigger for a medical consultation. It is, therefore, important to consider the possibility of late onset hypogonadism (LOH) in a patient who is presenting with any such symptoms. This review describes LOH and the current guidelines for its treatment and management. Also discussed are the normal changes undergone by men as they age and the effects that are expected due to this change. The relationship between LOH and its effects on both sexuality and fertility are also considered.