Obesity, type 2 diabetes, and testosterone in ageing men

Novel perspectives of testosterone therapy in men with functional hypogonadism: traversing the gaps of knowledge

INTRODUCTION

In the past decade, there has been a significant augmentation in the corpus of evidence pertaining to functional hypogonadism. Despite this, prevailing clinical guidelines continue to advise against the universal screening for hypogonadism in middle-aged and elderly males.

FINDINGS

Numerous randomized controlled trials have scrutinized the effects of testosterone therapy in males afflicted with type 2 diabetes and/or obesity. However, these guidelines uniformly assert that lifestyle modifications and weight reduction should be the primary intervention strategies in overweight and obese males, relegating testosterone therapy to a secondary, selective option. It is extensively documented that testosterone therapy can yield substantial improvements in various metabolic parameters as well as ameliorate symptoms of erectile dysfunction. Moreover, recent studies have demonstrated the potential of testosterone therapy in reversing type 2 diabetes in males with low-normal testosterone levels who are at elevated risk for this condition, in comparison to the outcomes achievable through lifestyle modifications alone.

CONCLUSION

This focused review article aims to present a comprehensive update on the latest data concerning the innovative aspects of testosterone therapy in males with functional hypogonadism, particularly in the context of type 2 diabetes and/or obesity. Additionally, it will delve into the cardiovascular safety of such interventions within this high-risk demographic, with a special emphasis on insights gleaned from the TRAVERSE trial.

Changes in plasma metabolite concentrations and enzyme activities in aging riding horses

In older horses, basal metabolic rate decreases, and plasma metabolite and hormone concentrations related to energy metabolism change. The occurrence of age-related diseases, which increases in old animals, may enhance inflammatory reactivity (inflammaging). Finding the appropriate treatment for inflammaging at an early stage may prevent various age-related diseases. Changes in metabolite and hormone concentrations and enzyme activities involved in energy metabolism in the plasma of clinically healthy riding horses of various ages were measured to identify biomarkers of inflammaging (persistent low-grade inflammation that occurs with aging). All horses were clinically healthy, and their body condition scores (BCSs) were 4 or 5 (9-point scale). Plasma triglyceride (TG), total cholesterol (T-Cho), blood urea nitrogen (BUN), insulin concentrations, malondialdehyde (MDA), and serum amyloid A (SAA) concentrations generally increased with age. Adiponectin concentrations, plasma superoxide dismutase (SOD), and leukocyte AMP-activated protein kinase (AMPK) activities decreased, while plasma aspartate aminotransferase (AST), alanine aminotransferase (ALT), and glutathione peroxidase (GPx) remained unchanged as horses aged. Although riding horses that partake in continuous exercise seems to be less likely to develop inflammaging, horses over 17 years of age tend to show proinflammatory signs with disordered lipid metabolism. In riding horses, SAA, in combination with other markers, may be a useful biomarker for inflammaging and dysregulated lipid metabolism in aging horses.

Multi-omics reveals the testosterone promotion effect mechanism of Cordyceps Sobolifera on Leydig cells

ETHNOPHARMACOLOGICAL RELEVANCE

Cordyceps sobolifera (CS) has been traditionally utilized as an ethnic remedy for various health conditions, including chronic kidney diseases, anti-fatigue interventions, and management of chronic inflammation. Notably, CS is recognized for its substantial content of bioactive compounds, among which nucleosides prominently feature as constituents with diverse therapeutic advantages.

AIM OF THE STUDY

This study aims to investigate the effects of CS on testosterone secretion in Leydig cells and explore the underlying mechanism.

MATERIALS AND METHODS

Leydig cells were isolated from rat testes to establish a primary rat Leydig cells model. Cell proliferation and testosterone secretion were assessed via the methyl-piperidino-pyrazole (MTT) assay and enzyme-linked immunosorbent assay (ELISA), respectively. Samples earmarked for RNA sequencing (RNA-Seq) analysis facilitated the identification of significantly differentially expressed genes (DEGs), and we conducted Gene Ontology (GO)/Kyoto Encyclopedia of Genes and Genomes (KEGG) functional annotation and enrichment analyses. The veracity of our findings was validated through quantitative real time polymerase chain reaction (qRT-PCR) and western blotting.

RESULTS

The results showed that CS and guanosine could promote Leydig cell proliferation and bolster testosterone secretion. Our integrative analysis of metabolomics and transcriptomics has unveiled the potential mechanisms governing testosterone synthesis. Specifically, metabolomics has illuminated striking correlations within cholesterol metabolism, and bile secretion. Concurrently, transcriptomics has underscored the pivotal roles played by the cyclic adenosine monophosphate (cAMP) signaling pathway and steroid hormone biosynthesis. Furthermore, our investigation has demonstrated CS's aptitude in elevating the expression of proteins and genes. Notably, our findings have elucidated that these effects can be mitigated by protein kinase A (PKA) and adenylate cyclase (AC) specific inhibitors.

CONCLUSION

This study delineates the cAMP-PKA pathways as plausible mechanisms underpinning the testosterone-enhancing properties of CS, with guanosine emerging as a fundamental bioactive constituent.

Structural analysis of polysaccharide from Inonotus obliquus and investigate combined impact on the sex hormones, intestinal microbiota and metabolism in SPF male mice

The dysregulation of sex hormone levels is associated with metabolic disorders such as obesity. Inonotus obliquus polysaccharide (IOP) exhibits a promising therapeutic effect on conditions like obesity and diabetes, potentially linked to its influence on intestinal microbiota and metabolism. The exact cause and mechanisms that link sex hormones, gut microbiota and metabolism are still unknown. In this research, we examined the molecular weight, monosaccharide composition, and glycosidic bond type of IOP. We found that IOP mostly consists of alpha-structured 6‑carbon glucopyranose, with a predominant (1 → 4) linkage to monosaccharides and a uniform distribution. Following this, we administered two different concentrations of IOP to mice through gavage. The results of the enzyme-linked immunosorbent assay (ELISA) demonstrated a significant increase in testosterone (T) levels in the IOP group as compared to the control group. Additionally, the results of tissue immunofluorescence indicated that increased IOP led to a decrease in adiponectin content and an increase in SET protein expression. The study also revealed changes in the intestinal microbiota and metabolic changes in mice through 16S rRNA data and non-targeted LC-MS data, respectively. The study also found that IOP mainly affects pathways linked to glycerophospholipid metabolism. In addition, it has been observed that there is an increase in the number of beneficial bacteria, such as the Eubacterium coprostanoligenes group and g.Lachnospiraceae NK4A136 group, while the levels of metabolites that are linked to obesity or diabetes, such as 1,5-anhydrosorbitol, are reduced. Furthermore, biomarker screening has revealed that the main microorganism responsible for the differences between the three groups is g.Erysipelatoclostridiaceae. In summary, these findings suggest that IOP exerts its therapeutic effects through a synergistic interplay between sex hormones, gut microbiome composition, and metabolic processes.

Evaluation of the Incidence of Low Testosterone Levels in Young Male Adults with Moderate to Severe Obesity-Single-Centre Study from India

PURPOSE

With the increase in obesity epidemic among Asians, it is necessary to evaluate the impact of obesity on this population. Low testosterone levels are known to be associated with obesity. This is the 1st study from Asia to evaluate incidence and magnitude of hypotestosteronemia in young adults with BMI more than 32.5 kg/m2 defined as moderate to severe obesity in Asians.

MATERIALS AND METHODS

One hundred thirty-four male patients with BMI more than 32.5 kg/m2, between 18 and 30 years old who visited a single bariatric facility between 2017 and 2020, were evaluated with BMI, total and free testosterone levels and clinical features of gynecomastia, hypogonadism, and thinning of pubic and armpit hair. Statistical analysis was performed using SPSS, Spearman's correlation coefficient, and ANOVA test.

RESULTS

60.4% of patients (84/134) had low testosterone levels (< 300 ng/dl) and 23.9% (32/134) had levels between 300 and 400 ng/dl. 89.6% patients (120/134 had gynecomastia, 60.4% (81/134) had thinning of pubic and arm pit hair, and 62.7% (84/134) had hypogonadism. Testosterone levels showed a decreasing trend with increasing BMI, but it was not statistically significant.

CONCLUSION

Obesity is one of the important etiologies of hypotestosteronemia and its manifestations in young adults. The actual incidence may be significantly higher than what is reported in the literature. High-quality research is required to address questions of diagnosis and best treatment options.

Men treated with BEACOPP for Hodgkin lymphoma may be at increased risk of testosterone deficiency

In the current study, we report the prevalence of male testosterone deficiency in a cohort of 60 male long-term survivors of malignant lymphoma with normal total testosterone but in the lower part of the reference level. Testosterone deficiency was defined as subnormal concentrations of total testosterone or subnormal concentrations of calculated free testosterone. The aim was to clarify whether total testosterone was sufficient for identification of testosterone deficiency in male survivors of malignant lymphoma. Hormonal analyses taken at follow-up were compared with samples taken at diagnosis for a subgroup of 20 survivors, for evaluation of changes in hormones over time. Another group of 83 similar survivors of malignant lymphoma with testosterone in the high end of reference levels were also used for comparison, to identify groups of increased risk of testosterone deficiency. A total group of 143 survivors were therefore included in the study. Our findings indicate that for screening purposes an initial total testosterone is sufficient in some survivors because sexual hormone binding globulin concentration was found stable over time. However, 15% were found with subnormal calculated free testosterone. Survivors intensely treated for Hodgkin lymphoma and older survivors were identified as high-risk groups for testosterone deficiency necessitating endocrinological attention during follow-up. Some evidence of pituitary downregulation was also found, because of uncompensated decreases in testosterone concentration over time. In conclusion, longitudinal measurements of total testosterone alone do not seem adequate for the screening of testosterone deficiency for all long-term lymphoma survivors.

Does an increase in adipose tissue 'weight' affect male fertility? A systematic review and meta-analysis based on semen analysis performed using the WHO 2010 criteria

INTRODUCTION

Obesity negatively impact on the metabolism of sex hormones, leading to reduced testosterone serum levels. However, how the obesity could negatively impact on the overall gonadal function, particularly on male fertility, remained unclear so far.

OBJECTIVE

To systematically review evidences regarding the influence of body weight excess on the sperm production.

METHODS

A meta-analysis was conducted, searching all prospective and retrospective observational studies reporting male subjects older than 18 years old, with body weight excess from overweight to severe obesity were considered. Only studies using the V edition of the World Health Organization (WHO) manual for semen analysis interpretation were considered. No specific interventions were considered. Search was focused on studies comparing overweight/obese to normal weight subjects.

RESULTS

Twenty-eight studies were considered. Total sperm count and sperm progressive motility were significantly lower in overweight compared to normal weight subjects. Meta-regression analyses demonstrated that patients' age impacted on sperm parameters. Similarly, obese men showed lower sperm concentration, total sperm number, progressive and total motilities, and normal morphology lower than normal weight subjects. Reduced sperm concentration in obese men was influenced by age, smoking habit, varicocele, and total testosterone serum levels at meta-regression analyses.

CONCLUSIONS

The male potential fertility is reduced in subjects with increased body weight, compared to normal weight men. The higher was the increased body weight, the worst was the sperm quantity/quality. This result comprehensively included obesity among non-communicable risk factor for male infertility, shedding new lights on the negative impact of increased body weight on overall gonadal function.

Testosterone and aging male, a perspective from a developing country

PURPOSE

Hypogonadism is associated with a wide range of physical and psychological symptoms that can affect the overall health of men. However, in a developing country, there are several imposing challenges in the diagnosis and treatment of hypogonadism, including a lack of awareness and understanding of the condition among healthcare providers and patients, limited resources and the high cost of treatment. This review aimed to examine the potential benefits and risks of testosterone replacement therapy (TRT) and provides a perspective of a developing country on the topic.

MATERIALS AND METHODS

A comprehensive literature review was conducted to gather relevant information on the impact of testosterone deficiency on ageing males and the effectiveness of TRT for treating hypogonadism. Published peer-reviewed articles were analyzed to evaluate the benefits and risks of TRT. Additionally, the unique challenges faced in the diagnosis and treatment of hypogonadism in a developing country were considered.

RESULTS

Testosterone replacement therapy has been shown to be an effective treatment for hypogonadism, particularly in symptomatic men with low testosterone levels. It offers potential benefits such as improvements in symptoms and overall quality of life. However, there are associated risks and side effects that need to be considered. In a developing country, challenges such as limited awareness and understanding of hypogonadism, resource constraints, and high treatment costs pose additional barriers to accessing TRT and comprehensive care.

CONCLUSION

In conclusion, TRT holds promise as a treatment for hypogonadism, but its implementation and accessibility face significant challenges in a developing country. Addressing these challenges, including raising awareness, allocating resources, and finding cost-effective solutions, is crucial for ensuring that men with hypogonadism in such settings receive appropriate diagnosis and treatment. Further research and efforts are needed to improve the management of hypogonadism in developing countries and optimize the potential benefits of TRT for affected individuals.

Body composition and testosterone in men: a Mendelian randomization study

Background

Testosterone is an essential sex hormone that plays a vital role in the overall health and development of males. It is well known that obesity decreases testosterone levels, but it is difficult to determine the causal relationship between body composition and testosterone.

Methods

To investigate potential causal associations between body composition and testosterone levels by a first time application of Mendelian randomization methods. Exposure variables in men included body composition (fat mass, fat-free mass, and body mass index). In addition to whole body fat and fat-free mass, we examined fat and fat-free mass for each body part (e.g., trunk, left arm, right arm, left leg and right leg) as exposures. Instrumental variables were defined using genome-wide association study data from the UK Biobank. Outcome variables in men included testosterone levels (total testosterone [TT], bioavailable testosterone [BT], and sex hormone-binding globulin [SHBG]). A one-sample Mendelian randomization analysis of inverse-variance weighted and weighted median was performed.

Results

The number of genetic instruments for the 13 exposure traits related to body composition ranged from 156 to 540. Genetically predicted whole body fat mass was negatively associated with TT (β=-0.24, P=5.2×10-33), BT (β=-0.18, P=5.8×10-20) and SHBG (β=-0.06, P=8.0×10-9). Genetically predicted whole body fat-free mass was negatively associated with BT (β=-0.04, P=2.1×10-4), but not with TT and SHBG, after multiple testing corrections. When comparing the causal effect on testosterone levels, there was a consistent trend that the effect of fat mass was more potent than that of fat-free mass. There were no differences between body parts.

Conclusion

These results show that reducing fat mass may increase testosterone levels.

A Drosophila model targets Eiger/TNFα to alleviate obesity-related insulin resistance and macrophage infiltration

Obesity is associated with various metabolic disorders, such as insulin resistance and adipose tissue inflammation (ATM), characterized by macrophage infiltration into adipose cells. This study presents a new Drosophila model to investigate the mechanisms underlying these obesity-related pathologies. We employed genetic manipulation to reduce ecdysone levels to prolong the larval stage. These animals are hyperphagic and exhibit features resembling obesity in mammals, including increased lipid storage, adipocyte hypertrophy and high circulating glucose levels. Moreover, we observed significant infiltration of immune cells (hemocytes) into the fat bodies, accompanied by insulin resistance. We found that attenuation of Eiger/TNFα signaling reduced ATM and improved insulin sensitivity. Furthermore, using metformin and the antioxidants anthocyanins, we ameliorated both phenotypes. Our data highlight evolutionarily conserved mechanisms allowing the development of Drosophila models for discovering therapeutic pathways in adipose tissue immune cell infiltration and insulin resistance. Our model can also provide a platform to perform genetic screens or test the efficacy of therapeutic interventions for diseases such as obesity, type 2 diabetes and non-alcoholic fatty liver disease.

Examining the associations between testosterone and biomarkers as men age

OBJECTIVES

Testosterone concentrations in men decline with advancing age. However, the cause of the decline is yet to be fully elucidated. Therefore, the aims of this study were to examine the associations between chronic diseases such as obesity and type 2 diabetes mellitus (T2DM) with total testosterone (TT) and sex hormone-binding globulin (SHBG), using a large nationally-representative data set (National Health and Nutrition Examination Survey; NHANES).

METHODS

NHANES is a cross-sectional survey, physical examination, and laboratory evaluation of a nationally-representative sample of a non-institutionalized United States population. Male participants aged ≥18 years during the NHANES 2013-2014 and NHANES 2015-2016 survey periods were selected for this analysis. The analysis included the following data: body mass index (BMI), oral glucose tolerance test (OGTT), homeostatic model assessment of insulin resistance (HOMA-IR), insulin, glucose, and age.

RESULTS

An overweight or obese condition was significantly inversely associated with TT and SHBG, even after adjusting for other variables. Several variables associated with T2DM (OGTT, HOMA-IR, insulin, and glucose) were also inversely associated with TT; however, only the associations between OGTT and insulin with TT remained significant after adjusting for the other variables. Insulin and HOMA-IR levels were significantly inversely associated with SHBG; however, only the association between SHBG and pre-diabetic HOMA-IR levels remained significant after adjusting for the other variables. OGTT became significantly associated with SHBG after adjusting for the other variables. Age was significantly inversely associated with TT, but positively associated with SHBG, even after adjusting for other variables.

CONCLUSION

The results of the present study, which is the largest to date, indicate that a marker of obesity, BMI, and some markers of T2DM are both independently and significantly inversely associated with TT and SHBG.

Lifestyle Can Exert a Significant Impact on the Development of Metabolic Complications and Quality Life in Patients with Inflammatory Bowel Disease

Inflammatory bowel diseases (IBDs) are associated with an increased risk of metabolic comorbidities. There is a lack of data regarding the relationship between lifestyle and metabolic diseases in IBD patients. A cross-sectional study on consecutive IBD outpatients was conducted. Adherence to the Mediterranean diet (MD) was assessed using a 14-item questionnaire from the PREDIMED study, and physical activity was evaluated using the GODIN-Leisure score. Body composition was studied based on body mass index and waist-hip ratio (WHR), while quality of life was assessed using a nine-item short questionnaire. Among the 688 evaluated IBD patients, 66% were overweight or obese, 72.7% did not lead an active lifestyle and 70.1% did not adhere to the MD. Metabolic syndrome was associated with age (OR = 1.07, p = 0.019), overweight/obesity (OR = 12.987, p < 0.001) and the inflammatory behavior of Crohn's disease (OR = 6.172, p = 0.001). Type 2 diabetes mellitus or prediabetes was associated with age (OR = 1.063 p = 0.016), overweight/obesity (OR = 3.861, p < 0.001) and the inflammatory behavior of Crohn's disease (OR = 4.716, p = 0.001). Overweight /obesity (OR = 5.494, p < 0.001), a high WHR (OR = 2.564, p = 0.005) and a non-active lifestyle (OR = 2.202, p = 0.0003) were associated with metabolic dysfunction-associated steatotic liver disease. Lifestyle, body composition and not solely systemic inflammation might exert a significant influence on the emergence of metabolic comorbidities such as MASLD, type 2 diabetes mellitus and metabolic syndrome in patients with IBD.

Pharmacotherapy of male hypogonadism

Hypogonadism is frequent with a prevalence of 2% in the general population. Hypogonadism may derive from any condition able to disrupt the hypothalamic-pituitary-testis (HPT) axis at one or more levels. Hypogonadism may be classified according to the age of onset, its potential reversibility and level of the HPT axis damage. The latter categorization is useful to decide on the treatment. Damages to the hypothalamus-pituitary may benefit from either GnRH, gonadotropin or T therapy with the former carrying the advantage of stimulating spermatogenesis. Conversely, when the testis is damaged, T therapy is the only option and restoration of spermatogenesis is not possible. Therefore, the choice of therapy is primarily based on the diagnosis and patients' needs and both should be carefully considered.