Remission of type 2 diabetes following long-term treatment with injectable testosterone undecanoate in patients with hypogonadism and type 2 diabetes: 11-year data from a real-world registry study

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.

Diabetes surpasses obesity as a risk factor for low serum testosterone level

BACKGROUND

Male obesity is one of the most associated factors with substandard testosterone levels. However, there is growing evidence linking low testosterone levels to insulin resistance and diabetic complications. We aimed to study the impact of diabetes mellitus on testosterone levels and to assess the correlation of various clinical and biochemical factors with hypogonadism.

SUBJECTS AND METHODS

This case-control study was conducted on 160 adult males categorized into four equal groups (40 each); Group A: lean men with T2DM, Group B: obese with T2DM, Group C: lean with normal glycemic profile, Group D: obese with normal glycemic profile. Serum total testosterone (TT), SHBG and HbA1c have been measured. Free testosterone (cFT) and HOMA-IR were calculated.

RESULTS

A significant negative correlation of serum TT and cFTwith BMI (r -0.16, p 0.04/ r -0.26, p < 0.001, respectively) and with waist circumference (WC) (r -0.23, p 0.003 and r -0.3, p < 0.001, respectively). A significant decrease in TT and cFT in the diabetes group versus the non-diabetes one (p < 0.001 for both). TT level was significantly lower in the diabetic lean group than in the non-diabetic lean (p < 0.001), and even significantly lower than in the non-diabetic obese (p < 0.001). TT level in the diabetic obese group was lower than in the non-diabetic obese (p < 0.001). The same for cFT level, lower in the diabetic lean group than in non-diabetic lean (p < 0.001) and lower in the diabetic obese than in the non-diabetic obese (p < 0.001). Concomitant significant reduction in SHBG in the diabetes group (p < 0.001). Linear regression analysis revealed that TT significantly correlated with HOMA-IR. HOMA-IR with WC, age and the duration of diabetes correlated significantly with cFT. In our model, HOMA-IR and HbA1c accounted for approximately 51.3% of TT variability (adjusted R-squared 0.513).

CONCLUSIONS

The impact of T2DM on serum testosterone levels was more significant than that of obesity. Our study showed a decrease in SHBG together with cFT among the diabetes group. Hypogonadism is significantly correlated to insulin resistance and poor glycemic control, which implies another perspective on the impact of suboptimal glycemic control on the development of hypogonadism.

Single-Cell RNA Sequencing Analysis of Steroidogenesis and Spermatogenesis Impairment in the Testis of db/db Mice

Objective

The mechanism of steroidogenesis and spermatogenesis impairment in men with type 2 diabetes remains unclear. We aimed to explore the local changes of steroidogenesis and spermatogenesis in the testis of db/db mice. Research Design and Methods. We performed single-cell RNA sequencing analysis in the testis of db/db and C57BL/6J mice. The differentially expressed genes were then confirmed by real-time PCR. The histopathological characteristics of testis in db/db mice and C57BL/6J control were also performed.

Results

The 20-week-old db/db mice had significantly higher blood glucose and body weight (both p < 0.001). The serum testosterone levels (4.4 ± 0.8 vs. 9.8 ± 0.7 ng/ml, p=0.001) and weight of the testis (0.16 ± 0.01 vs. 0.24 ± 0.01 g, p < 0.001) were significantly lower in db/db mice than that in C57BL/6J controls. db/db mice had a lower cross-sectional area of seminiferous tubules and thickness of the cell layer (both p < 0.05). The numbers of Sertoli cells and Leydig cells decreased in db/db mice (both p < 0.01). Single-cell RNA sequencing analysis showed that compared with the control group, the percentage of spermatogonia was significantly higher in the db/db mouse (p < 0.001), while the proportions of spermatocytes, round and elongating spermatids, and sperms were all lower in the db/db mouse (p all < 0.001). The most differentially expressed genes were found in round spermatids (n = 86), which were not found in spermatogonia, spermatocyte, and sperm. Igfbp5 was the most significantly decreased gene in Leydig cells of the db/db mouse, while the expression of Cd74, H2-Aa, and H2-Eb1 was elevated. Ccl7 and Ptgds were the most significantly increased and decreased genes in Sertoli cells of the db/db mouse.

Conclusions

The present study indicates spermiogenesis and steroidogenesis defects in db/db mice. The mechanism of steroidogenesis impairment in the testis of db/db mice deserves further investigation.

EMAS position statement: Testosterone replacement therapy in older men

INTRODUCTION

Late-onset hypogonadism is the clinical entity characterised by low testosterone concentrations associated with clinical symptoms in the absence of organic disease in ageing men. It has been associated with metabolic syndrome, reduced bone mineral density, and increased cardiovascular morbidity and mortality risk. Although testosterone replacement therapy (TRT) reverses most of these conditions in young hypogonadal men, the risk/benefit ratio of TRT in older men is debatable.

AIM

To update the 2015 EMAS statement on TRT in older men with new research on late-onset hypogonadism and TRT.

MATERIALS AND METHODS

Literature review and consensus of expert opinion.

SUMMARY RECOMMENDATIONS

TRT should be offered only to symptomatic older men with confirmed low testosterone concentrations after explaining the uncertainties regarding the long-term safety of this treatment. TRT may be offered to men with severe hypogonadism and erectile dysfunction to improve sexual desire, erectile, and orgasmic function. It should also be considered in hypogonadal men with severe insulin resistance or pre-diabetes mellitus. TRT may also be considered, in combination with proven treatment strategies, for osteoporosis, or for selected patients with persistent mild depressive symptoms and/or low self-perceived quality of life, combined with standard medical care for each condition. TRT is contraindicated in hypogonadal men actively seeking fertility treatment. Due to a lack of data, TRT should not be routinely used in older men to improve exercise capacity/physical function, improve cognitive function, or prevent cognitive decline. TRT must be avoided in older, frail men with known breast cancer or untreated prostate cancer and all men who have had myocardial infarction or stroke within the last four months, and those with severe or decompensated heart failure. The quality of evidence regarding patients with previous prostate cancer or cardiovascular disease is too low to draw definitive conclusions. Any limits on duration of use are arbitrary, and treatment should continue for as long as the man feels the benefits outweigh the risks for him, and decisions must be made on an individual basis. Withdrawal should be considered when hypogonadism is reversed after the resolution of underlying disorder. Short-acting transdermal preparations should be preferred for TRT initiation in older men, but injectable forms may be considered subsequently. Older men on TRT should be monitored at 3, 6, and 12 months after initiation and at least yearly thereafter, or earlier and more frequently if indicated. Evaluation should include assessment of the clinical response, and measurement of total testosterone, haematocrit, and prostate-specific antigen (PSA) concentrations. Bone density and/or quality should also be assessed. Obese and overweight patients should be encouraged to undergo lifestyle modifications, including exercise and weight loss, to increase endogenous testosterone.

Beyond apples and pears: sex-specific genetics of body fat percentage

Introduction

Biological sex influences both overall adiposity and fat distribution. Further, testosterone and sex hormone binding globulin (SHBG) influence adiposity and metabolic function, with differential effects of testosterone in men and women. Here, we aimed to perform sex-stratified genome-wide association studies (GWAS) of body fat percentage (BFPAdj) (adjusting for testosterone and sex hormone binding globulin (SHBG)) to increase statistical power.

Methods

GWAS were performed in white British individuals from the UK Biobank (157,937 males and 154,337 females). To avoid collider bias, loci associated with SHBG or testosterone were excluded. We investigated association of BFPAdj loci with high density cholesterol (HDL), triglyceride (TG), type 2 diabetes (T2D), coronary artery disease (CAD), and MRI-derived abdominal subcutaneous adipose tissue (ASAT), visceral adipose tissue (VAT) and gluteofemoral adipose tissue (GFAT) using publicly available data from large GWAS. We also performed 2-sample Mendelian Randomization (MR) using identified BFPAdj variants as instruments to investigate causal effect of BFPAdj on HDL, TG, T2D and CAD in males and females separately.

Results

We identified 195 and 174 loci explaining 3.35% and 2.60% of the variation in BFPAdj in males and females, respectively at genome-wide significance (GWS, p<5x10-8). Although the direction of effect at these loci was generally concordant in males and females, only 38 loci were common to both sexes at GWS. Seven loci in males and ten loci in females have not been associated with any adiposity/cardiometabolic traits previously. BFPAdj loci generally did not associate with cardiometabolic traits; several had paradoxically beneficial cardiometabolic effects with favourable fat distribution. MR analyses did not find convincing supportive evidence that increased BFPAdj has deleterious cardiometabolic effects in either sex with highly significant heterogeneity.

Conclusions

There was limited genetic overlap between BFPAdj in males and females at GWS. BFPAdj loci generally did not have adverse cardiometabolic effects which may reflect the effects of favourable fat distribution and cardiometabolic risk modulation by testosterone and SHBG.

Major cardiovascular disease risk in men with testosterone deficiency (hypogonadism): appraisal of short, medium and long-term testosterone therapy - a narrative review

INTRODUCTION

Low testosterone (T) levels are associated with obesity, metabolic syndrome, type 2 diabetes mellitus and altered lipid profiles, thus contributing to increased cardiovascular disease risk. Hence T deficiency has a detrimental effect on men's vascular health, quality of life and increased mortality.

OBJECTIVES

This review aims to present summary of data in the contemporary clinical literature pertaining to the benefits of T therapy in clinical studies with varying durations on vascular health in men with T deficiency.

METHODS

A Medline search using PubMed and EMBASE was performed using the following key words: "testosterone deficiency," "testosterone therapy," major cardiovascular adverse events", "cardiovascular disease". Relevant studies were extracted, evaluated, and analyzed. We evaluated findings from clinical trials, observational studies and systematic reviews and meta-analyses to develop a comprehensive account of the critical role of T in maintaining vascular health.

RESULTS

Considerable evidence beginning with studies published in 1940s concomitant with findings from the utmost recent clinical studies suggests a clinical value of T therapy in maintaining vascular health and reducing cardiovascular mortality. The current scientific and clinical evidence demonstrates strong relationship between low circulating T levels and risk of cardiovascular disease and T therapy is deemed safe in men with hypogonadism when given in the physiological range with no apparent harm.

CONCLUSION

What emerges from the current clinical literature is that, irrespective of the length of study durations, testosterone therapy provides significant health benefits and reduces risk of cardiovascular disease. More important is that data from many observational and registry studies, demonstrated that longer durations of testosterone therapy were associated with greater health benefits and reduced cardiovascular risk. T therapy in men with T deficiency reduces the incidence of major adverse cardiovascular events attributed to improving overall metabolic function.

Understanding human aging and the fundamental cell signaling link in age-related diseases: the middle-aging hypovascularity hypoxia hypothesis

Aging-related hypoxia, oxidative stress, and inflammation pathophysiology are closely associated with human age-related carcinogenesis and chronic diseases. However, the connection between hypoxia and hormonal cell signaling pathways is unclear, but such human age-related comorbid diseases do coincide with the middle-aging period of declining sex hormonal signaling. This scoping review evaluates the relevant interdisciplinary evidence to assess the systems biology of function, regulation, and homeostasis in order to discern and decipher the etiology of the connection between hypoxia and hormonal signaling in human age-related comorbid diseases. The hypothesis charts the accumulating evidence to support the development of a hypoxic milieu and oxidative stress-inflammation pathophysiology in middle-aged individuals, as well as the induction of amyloidosis, autophagy, and epithelial-to-mesenchymal transition in aging-related degeneration. Taken together, this new approach and strategy can provide the clarity of concepts and patterns to determine the causes of declining vascularity hemodynamics (blood flow) and physiological oxygenation perfusion (oxygen bioavailability) in relation to oxygen homeostasis and vascularity that cause hypoxia (hypovascularity hypoxia). The middle-aging hypovascularity hypoxia hypothesis could provide the mechanistic interface connecting the endocrine, nitric oxide, and oxygen homeostasis signaling that is closely linked to the progressive conditions of degenerative hypertrophy, atrophy, fibrosis, and neoplasm. An in-depth understanding of these intrinsic biological processes of the developing middle-aged hypoxia could provide potential new strategies for time-dependent therapies in maintaining healthspan for healthy lifestyle aging, medical cost savings, and health system sustainability.

Biomarkers to Be Used for Decision of Treatment of Hypogonadal Men with or without Insulin Resistance

Male hypogonadism is a result of low testosterone levels, but patients could be insulin-sensitive (IS) or insulin-resistant (IR), showing different impaired metabolic pathways. Thus, testosterone coadministration, which is commonly used to reestablish testosterone levels in hypogonadism, must take into account whether or not insulin is still active. By comparing metabolic cycles recorded in IS and IR plasma before and after testosterone therapy (TRT), it is possible to know what metabolic pathways can be reactivated in the two different groups upon testosterone recovery, and it is possible to understand if antagonism or synergy exists between these two hormones. IS hypogonadism uses glycolysis, while IR hypogonadism activates gluconeogenesis through the degradation of branched-chain amino acids (BCAAs). Upon administration of testosterone, acceptable improvements are observed in IS patients, wherein many metabolic pathways are restored, while in IR patients, a reprogramming of metabolic cycles is observed. However, in both subgroups, lactate and acetyl-CoA increases significantly. In IS patients, lactate is used through the glucose-lactate cycle to produce energy, while in IR patients, both lactate and acetyl-CoA are metabolized into ketone bodies, which are used to produce energy. Thus, in IR patients, an ancestral molecular mechanism is activated to produce energy, mimicking insulin effects. Regarding lipids, in both groups, the utilization of fatty acids for energy (β-oxidation) is blocked, even after TRT; free fatty acids (FFAs) increase in the blood in IS patients, while they are incorporated into triglycerides in those with IR. In both subgroups of hypogonadism, supplementation of useful chemicals is recommended during and after TRT when metabolites are not restored; they are listed in this review.

Voiding function improves under long-term testosterone treatment (TTh) in hypogonadal men, independent of prostate size

BACKGROUND

Functional hypogonadism is a condition in which some, but not all, older men have low testosterone levels. Rather than chronological age per se, the causality of hypogonadism includes obesity and impaired general health (e.g., metabolic syndrome). An association between testosterone deficiency and lower urinary tract symptoms (LUTS) has been reported, yet due to prostate safety concerns, men with severe LUTS (IPSS score > 19) have invariably been excluded from entering testosterone trials. Irrespective, exogenous testosterone has not been demonstrated to cause de novo or worsen mild to moderate LUTS.

OBJECTIVE

This study investigated whether long-term testosterone therapy (TTh) could have a protective effect on improving the symptoms of LUTS in hypogonadal men. However, the exact mechanism by which testosterone exerts is beneficial effect remains uncertain.

PATIENTS AND METHODS

In this study 321 hypogonadal patients with an average age of 58.9 ± 9.52 years received testosterone undecanoate in 12-week intervals for 12 years. One hundred and forty-seven of these males had the testosterone treatment interrupted for a mean of 16.9 months before it was resumed. Total testosterone, International Prostate Symptom Scale (IPSS), post-voiding residual bladder volume and aging male symptoms (AMS) were measured over the study period.

RESULTS

Prior to TTh interruption, it was observed that testosterone stimulation improved the men's IPSS, AMS and post-voiding residual bladder volume, while their prostate volume significantly increased. During the TTh interruption, there was a significant worsening in these parameters, although the increase in prostate volume continued. When TTh was resumed, these effects were reversed, implying that hypogonadism may require lifelong treatment.

Treatment with Testosterone Therapy in Type 2 Diabetic Hypogonadal Adult Males: A Systematic Review and Meta-Analysis

Testosterone replacement therapy (TRT) has been used to treat hypogonadal males with type 2 diabetes mellitus (T2DM) for a long time, despite variable results. This meta-analysis examines TRT's role in hypogonadal males with T2DM. The databases PubMed, Embase, and Google Scholar were searched for relevant RCTs and observational studies. Estimated pooled mean differences (MDs) and relative risks with 95% confidence intervals were used to measure the effects of TRT (CIs). When compared to the placebo, TRT improves glycemic management by significantly reducing glycated hemoglobin (HBA1c) levels (WMD = -0.29 [-0.57, -0.02] p = 0.04; I2 = 89.8%). Additionally, it reduces the homeostatic model assessment levels of insulin resistance (WMD = -1.47 [-3.14, 0.19]; p = 0.08; I2 = 56.3%), fasting glucose (WMD = -0.30 [-0.75, 0.15]; p = 0.19; I2 = 84.4%), and fasting insulin (WMD = -2.95 [-8.64, 2.74]; however, these results are non-significant. On the other hand, HBA1c levels are significantly reduced with TRT; in addition, total testosterone levels significantly increase with testosterone replacement therapy (WMD = 4.51 [2.40, 6.61] p = 0.0001; I2 = 96.3%). Based on our results, we hypothesize that TRT can improve glycemic control and hormone levels, as well as lower total cholesterol, triglyceride, and LDL cholesterol levels while raising HDL cholesterol in hypogonadal type 2 diabetes patients. To this end, we recommend TRT for these patients in addition to standard diabetes care.

Cardiometabolic indices predict hypogonadism in male patients with type 2 diabetes

PURPOSE

To evaluate in men with type 2 diabetes the association of cardiometabolic indices [Visceral Adiposity Index (VAI), Triglyceride Glucose Index (TyG), and lipid accumulation product (LAP)] with total testosterone (TT) levels, and their predictive cut-off values in identifying hypogonadism.

METHODS

265 consecutive men aged 40-70 years with type 2 diabetes performed an andrological evaluation; metabolic parameters and TT were determined. Receiver operating characteristic (ROC) curves were used to identify cut-off values of cardiometabolic indices in predicting low testosterone (TT < 12 nmol/l).

RESULTS

VAI, TyG, and LAP were negatively associated with TT levels. The prevalence of hypogonadism in men in the fourth quartiles of VAI, TyG, and LAP was ~ 70.0-75.0% compared to ~ 10.0-17.0% in men in the first quartiles (p < 0.001). The sensitivity and specificity of the three cardiometabolic indices in predicting TT < 12 nmol/l were significantly higher concerning BMI, waist circumference, lipid profile and HbA1c. Cut off values of VAI ≥ 3.985, TyG ≥ 4.925, and LAP ≥ 51.645 predict hypogonadism with good sensitivity and specificity.

CONCLUSION

This is the first study evaluating the association of VAI, TyG, and LAP with hypogonadism in men with type 2 diabetes. Alterations in these indices should direct the patients to andrological evaluation.

Interaction between gut microbiota and sex hormones and their relation to sexual dimorphism in metabolic diseases

Metabolic diseases, such as obesity, metabolic syndrome (MetS) and type 2 diabetes (T2D), are now a widespread pandemic in the developed world. These pathologies show sex differences in their development and prevalence, and sex steroids, mainly estrogen and testosterone, are thought to play a prominent role in this sexual dimorphism. The influence of sex hormones on these pathologies is not only reflected in differences between men and women, but also between women themselves, depending on the hormonal changes associated with the menopause. The observed sex differences in gut microbiota composition have led to multiple studies highlighting the interaction between steroid hormones and the gut microbiota and its influence on metabolic diseases, ultimately pointing to a new therapy for these diseases based on the manipulation of the gut microbiota. This review aims to shed light on the role of sexual hormones in sex differences in the development and prevalence of metabolic diseases, focusing on obesity, MetS and T2D. We focus also the interaction between sex hormones and the gut microbiota, and in particular the role of microbiota in aspects such as gut barrier integrity, inflammatory status, and the gut-brain axis, given the relevance of these factors in the development of metabolic diseases.

Very low-calorie ketogenic diet rapidly augments testosterone levels in non-diabetic obese subjects

BACKGROUND

The very low-calorie ketogenic diet (VLCKD) represents an opportunity to attain clinically relevant weight loss in obese patients. Functional hypogonadism represents a frequent hormonal disorder associated with obesity and visceral fat accumulation characterised by low testosterone levels and subnormal luteinising hormone (LH) levels.

AIM

To evaluate the early effects of VLCKD on serum total testosterone (TT) levels in non-diabetic obese patients.

METHODS

Twenty-two obese male patients (mean age 39.3 ± 11.7 years, mean body mass index (BMI) 38.2 ± 6.4 kg/m² ) were enrolled and treated for 28 days with VLCKD. Anthropometric and hormonal variables were assessed before, during and after diet intervention.

RESULTS

After 7 and 28 days on a VLCKD, a significant and persistent reduction in body weight, BMI, fat mass, blood glucose, insulin and homeostasis model assessment index was observed compared with baseline. TT significantly increased after 7 days (+35 ± 64 ng/dl) and 28 days (+74 ± 97 ng/dl) on a VLCKD. In addition to TT, a significant increase in serum sex hormone-binding globulin levels was observed after 7 (+2.1 ± 4.1) and 28 days (+7.7 ± 10.0). However, both calculated free testosterone and LH did not change after 7 or 28 days of VLCKD. Following cessation of VLCKD, hypogonadal subjects achieved a higher percentage of total weight loss (8.5% ± 1.5%), a greater reduction in weight (-9.94 ± 1.66 kg), fat mass (-7 ± 2.1 kg) and waist circumference (-6.31 ± 2.65 cm) and a greater improvement in glycaemia (-8.75 ± 10.92 mg/dl) as compared with eugonadal subjects. Furthermore, hypogonadal subjects exhibited a trend of higher TT increase (+98.12 ± 71.51 ng/dl) as compared with eugonadal subjects.

CONCLUSIONS

VLCKD results in rapid improvements in TT levels associated with weight loss in male obese non-diabetic subjects, particularly in the presence of obesity-related hypogonadism.

Metformin and testosterone replacement therapy inversely associated with hormone-associated cancers (prostate, colorectal and male breast cancers) among older White and Black men

BACKGROUND

The independent and joint association of metformin and testosterone replacement therapy (TTh) with the incidence of prostate, colorectal, and male breast cancers remain poorly understood, including the investigation of the risk of these cancers combined (HRCs, hormone-associated cancers) among men of different racial and ethnic background.

METHODS

In 143,035 men (≥ 65 yrs old) of SEER-Medicare 2007-2015, we identified White (N = 110,430), Black (N = 13,520) and Other Race (N = 19,085) men diagnosed with incident HRC. Pre-diagnostic prescription of metformin and TTh was ascertained for this analysis. Weighted multivariable-adjusted conditional logistic and Cox proportional hazards models were conducted.

RESULTS

We found independent and joint associations of metformin and TTh with incident prostate (odds ratio [OR]joint  = 0.44, 95% confidence interval [CI]: 0.36-0.54) and colorectal cancers (ORjoint  = 0.47, 95% CI: 0.34-0.64), but not with male breast cancer. There were also inversed joint associations of metformin and TTh with HRCs (ORjoint  = 0.45, 95% CI: 0.38-0.54). Similar reduced associations with HRCs were identified among White, Black, and Other Race men.

CONCLUSION

Pre-diagnostic use of metformin and TTh were, independently and jointly, inversely associated with incident prostate and colorectal cancers. The risk of HRCs was also reduced among White, Black and Other Race men. Greatest reduced associations of prostate and colorectal cancers and HRCs were mainly observed in combination of metformin and TTh. Larger studies are needed to confirm the independent and joint association of metformin plus TTh with these cancers in understudied and underserved populations.

Correlates of testosterone change as men age

Objective: The literature on testosterone (T) in men reports diverse correlates of T, some with minimal empirical support and most with little indication of how they change with advancing age. We test eight putative correlations across age.Method: Correlations were tested on a large sample of British men.Results: Seven of eight correlations replicated. Most change across men's life courses. The diurnal cycle of T is considerably weaker among older than younger men. Single men have higher T than married men of the same age; however, this difference lessens as men get older. Elevated T among smokers is less pronounced as men age. The inverse relationship between obesity and T is sustained across the adult age range. The lessening of T with age is well established, however there is disagreement about the course of decline. We find T having a steep decline around age 30, with possibly a rebound around age 50, after which levels remain roughly constant. Correlations involving health become stronger among older men. After age 30 or 40, the inverse relationships between T and HbA1c, diabetes, and metabolic syndrome all become increasingly significant, though not necessarily strong in magnitude.Conclusion: Most putative correlates of T are replicated. There is a basis here for the generalization that among older men, those healthy have higher T than those who are not, but not a lot higher.

Obesity, type 2 diabetes, and testosterone in ageing men

In the absence of obesity, adverse lifestyle behaviours, and use of medication such as opioids serum testosterone concentrations decrease by only a minimal amount at least until very advanced age in most men. Obesity is heterogeneous in its phenotype, and it is the accumulation of excess adipose tissue viscerally associated with insulin resistance, dyslipidaemia, inflammation, hypothalamic leptin resistance and gliosis that underpins the functional hypogonadism of obesity. Both central (hypothalamic) and peripheral mechanisms are involved resulting in a low serum total testosterone concentration, while LH and FSH are typically in the normal range. Peripherally a decrease in serum sex hormone binding globulin (SHBG) concentration only partially explains the decrease in testosterone and there is increasing evidence for direct effects in the testis. Men with obesity associated functional hypogonadism and serum testosterone concentrations below 16 nmol/L are at increased risk of incident type 2 diabetes (T2D); high testosterone concentrations are protective. The magnitude of weight loss is linearly associated with an increase in serum testosterone concentration and with the likelihood of preventing T2D or reverting newly diagnosed disease; treatment with testosterone for 2 years increases the probability of a positive outcome from a lifestyle intervention alone by approximately 40%. Whether the additional favourable benefits of testosterone treatment on muscle mass and strength and bone density and quality in the long-term remains to be determined.

On the Need to Distinguish between Insulin-Normal and Insulin-Resistant Patients in Testosterone Therapy

Male hypogonadism is a disorder characterized by low levels of the hormone testosterone and patients may also have insulin sensitivity (IS) or insulin resistance (IR), such that they show different clinical complications and different metabolic pathways. In this review, we compare metabonomic differences observed between these two groups before and after testosterone therapy (TRT) in order to obtain information on whether the two hormones testosterone and insulin are synergistic or antagonistic. IS hypogonadism uses glucose as the main biofuel, while IR activates gluconeogenesis by the degradation of branched-chain amino acids. The Krebs (TCA) cycle is active in IS but connected with glutaminolysis, while in IR the TCA cycle stops at citrate, which is used for lipogenesis. In both cases, the utilization of fatty acids for energy (β-oxidation) is hampered by lower amounts of acetylcarnitine, although it is favored by the absence of insulin in IR. Increased free fatty acids (FFAs) are free in the blood in IS, while they are partially incorporated in triglycerides in IR. Thus, upon TRT, the utilization of glucose is increased more in IS than in IR, revealing that in IR there is a switch from preferential glucose oxidation to lipid oxidation. However, in both cases, a high production of lactate and acetyl-CoA is the final result, with these levels being much higher in IR. Lactate is used in IS in the glucose–lactate cycle between the liver and muscle to produce energy, while in IR lactate and acetyl-CoA are biotransformed into ketone bodies, resulting in ketonuria. In conclusion, the restoration of testosterone values in hypogonadism gives better results in IS than in IR patients: in IS, TRT restores most of the metabolic pathways, while in IR TRT impairs insulin, and when insulin is inactive TRT activates an ancestral molecular mechanism to produce energy. This evidence supports the hypothesis that, over time, hypogonadism switches from IS to IR, and in the latter case most of the insulin-related metabolisms are not reactivated, at least within 60 days of TRT. However, testosterone therapy in both IS and IR might be of benefit given supplementation with metabolites that are not completely restored upon TRT, in order to help restore physiological metabolisms. This review underlines the importance of using a systems biology approach to shed light on the molecular mechanisms of related biochemical pathways involving insulin and testosterone.

Effects of gender-affirming hormone therapy on cardiovascular risk factors focusing on glucose metabolism in an Austrian transgender cohort

Objective

We aimed to investigate the effect of gender-affirming hormone therapy (GAHT) on cardiovascular disease risk factors focusing on glucose tolerance.

Patients and Methods

This primarily translational study enrolled 16 transgender persons assigned female at birth (AFAB), 22 assigned male at birth (AMAB), and 33 age- and BMI-matched cisgender controls at the Medical University of Vienna from 2013 to 2020. A 3-Tesla MRI scan to measure intramyocardial, pancreatic, hepatic fat content and subcutaneous-to-visceral adipose tissue ratio (SAT/VAT-ratio), an oral glucose tolerance test (oGTT), bloodwork including brain natriuretic peptide (pro-BNP), sex hormones and two glucose-metabolism related biomarkers (adiponectin, betatrophin) were performed.

Results

Estrogen intake was associated with higher fasting insulin (p = 0.034) and Homeostatic Model Assessment for Insulin Resistance (HOMA-IR) (p = 0.037), however, lower HbA1c levels (p = 0.031) in AMAB than cisgender males. Adiponectin (p = 0.001) and betatrophin (p = 0.034) levels were higher in AMAB than cisgender males, but similar to cisgender females. Compared to cisgender females, AFAB displayed no differences in glucose metabolism or SAT/VAT-ratio. AFAB had lower pro-BNP levels (p = 0.014), higher liver enzymes (AST: p = 0.011; ALT: p = 0.012) and lower HDL levels (p = 0.017) than cisgender females, but comparable levels to cisgender males. AMAB showed an increased heart rate (p < 0.001) and pro-BNP (p = 0.002) levels, but a more favorable SAT/VAT-ratio (p = 0.013) and lower creatine kinase (CK) (p = 0.001) than cisgender males. There were no relevant differences in organ fat content between transgender persons and their respective cisgender controls.

Conclusion

In AMAB, most investigated parameters adapted to levels seen in cisgender females except for parameters related to fasted insulin resistance. AMAB should be monitored with respect to the development of insulin resistance.

Glycemic Variability in Subjects with Diabetes and Hypogonadism during Testosterone Replacement Treatment: A Pilot Study

Background: This is a proof of concept, as a pilot study, with the aim to evaluate continuous glucose monitoring metrics (CGM) in subjects with type 2 diabetes (T2DM), treated with nutritional therapy and metformin, before and after testosterone replacement therapy (TRT). Methods: In this longitudinal observational study, subjects affected by T2DM and starting TRT for documented ED and hypogonadism were enrolled. All subjects mounted a CGM system during the v0 visit, one week before the beginning of the TRT (week−1), during v2, four weeks after the start of TRT (week 4), and v4 (week 12). CGM was worn for about 144 h after each visit. Results: A total of seven patients, referring to our clinic for erectile dysfunction (ED), were studied (aged 63.3 ± 2.3 years). Mean (± standard deviation) total testosterone level was 2.3 ± 0.6 ng/mL at baseline. After TRT, total testosterone level was 4.6 ± 3.04 ng/mL at week 4 and 3.93 ± 4.67 ng/mL at week 12. No significant differences were observed in TIR, TAR, TBR, estimated HbA1c, AUC below, and AUC above limit during the intervention period. Conclusions: This is the first study evaluating the effects of TRT on daily glucose excursions in subjects with T2DM and hypogonadism. Though we did not find any significant difference in key CGM metrics during the 12 weeks of TRT, this study confirms the glycometabolic safety of the TRT even on the most novel standardized glycemic targets.

Endoscopic sleeve gastroplasty for treatment of class 1 and 2 obesity (MERIT): a prospective, multicentre, randomised trial

BACKGROUND

Endoscopic sleeve gastroplasty (ESG) is an endolumenal, organ-sparing therapy for obesity, with wide global adoption. We aimed to explore the efficacy and safety of ESG with lifestyle modifications compared with lifestyle modifications alone.

METHODS

We conducted a randomised clinical trial at nine US centres, enrolling individuals aged 21-65 years with class 1 or class 2 obesity and who agreed to comply with lifelong dietary restrictions. Participants were randomly assigned (1:1·5; with stratified permuted blocks) to ESG with lifestyle modifications (ESG group) or lifestyle modifications alone (control group), with potential retightening or crossover to ESG, respectively, at 52 weeks. Lifestyle modifications included a low-calorie diet and physical activity. Participants in the primary ESG group were followed up for 104 weeks. The primary endpoint at 52 weeks was the percentage of excess weight loss (EWL), with excess weight being that over the ideal weight for a BMI of 25 kg/m². Secondary endpoints included change in metabolic comorbidities between the groups. We used multiple imputed intention-to-treat analyses with mixed-effects models. Our analyses were done on a per-protocol basis and a modified intention-to-treat basis. The safety population was defined as all participants who underwent ESG (both primary and crossover ESG) up to 52 weeks.

FINDINGS

Between Dec 20, 2017, and June 14, 2019, 209 participants were randomly assigned to ESG (n=85) or to control (n=124). At 52 weeks, the primary endpoint of mean percentage of EWL was 49·2% (SD 32·0) for the ESG group and 3·2% (18·6) for the control group (p<0·0001). Mean percentage of total bodyweight loss was 13·6% (8·0) for the ESG group and 0·8% (5·0) for the control group (p<0·0001), and 59 (77%) of 77 participants in the ESG group reached 25% or more of EWL at 52 weeks compared with 13 (12%) of 110 in the control group (p<0·0001). At 52 weeks, 41 (80%) of 51 participants in the ESG group had an improvement in one or more metabolic comorbidities, whereas six (12%) worsened, compared with the control group in which 28 (45%) of 62 participants had similar improvement, whereas 31 (50%) worsened. At 104 weeks, 41 (68%) of 60 participants in the ESG group maintained 25% or more of EWL. ESG-related serious adverse events occurred in three (2%) of 131 participants, without mortality or need for intensive care or surgery.

INTERPRETATION

ESG is a safe intervention that resulted in significant weight loss, maintained at 104 weeks, with important improvements in metabolic comorbidities. ESG should be considered as a synergistic weight loss intervention for patients with class 1 or class 2 obesity. This trial is registered with ClinicalTrials.gov, NCT03406975.

FUNDING

Apollo Endosurgery, Mayo Clinic.

Plasma Metabonomics in Insulin-Resistant Hypogonadic Patients Induced by Testosterone Treatment

Hypogonadic subjects with insulin resistance (IR) showed different metabonomic profiles compared to normo-insulinemic subjects (IS). Testosterone replacement therapy (TRT) may have a different impact on the metabolisms of those with the presence or absence of insulin resistance. We evaluated the changes in the metabolism of IR hypogonadic patients before and after 60 days of TRT. The metabonomic plasma profiles from 20 IR hypogonadal patients were recorded using ultra-high-performance liquid chromatography (UHPLC) and high-resolution mass spectrometry (HRMS). Plasma metabolites, before and after 60 days of TRT, were compared. In hypogonadic patients, carnosine, which is important for improving performance during exercise, increased. Conversely, proline and lysine—amino acids involved in the synthesis of collagen—reduced. Triglycerides decreased and fatty acids (FFAs) increased in the blood as a consequence of reduced FFA β-oxidation. Glycolysis slightly improved, while the Krebs cycle was not activated. Gluconeogenesis (which is the main energy source for hypogonadal IR before TRT) stopped after treatment. As a consequence, lactate and acetyl CoA increased significantly. Both lactate and acetyl CoA were metabolized into ketone bodies which increased greatly, also due to leucine/isoleucine degradation. Ketone bodies were derived predominantly from acetyl CoA because the reaction of acetyl CoA into ketone bodies is catalyzed by mtHMGCoA synthase. This enzyme is inhibited by insulin, which is absent in IR patients but overexpressed following testosterone administration. Ketosis is an alternative route for energy supply and provides the same metabolic effects as insulin but at the metabolic or primitive control level, which bypasses the complex signaling pathway of insulin. After treatment, the hypogonadic patients showed clinical symptoms related to ketonuria. They presented similarly to those following a ketogenic diet, the so-called ‘keto flu’. This must be taken into account before the administration of TRT to hypogonadic patients.

Ageing male (part 2): Management of functional hypogonadism in older men, a patient-centric holistic approach

The diagnosis of functional hypogonadism should prompt a thorough assessment and optimization of general health, including lifestyle changes, weight reduction, care of comorbidities and cessation of offending medications, some of which can lead to meaningful gains in endogenous testosterone (T) concentrations. Having excluded or addressed reversible causes and contra-indications, patients with functional hypogonadism can be offered a trial of testosterone replacement therapy (TRT) after full discussion on the anticipated benefits and potential risks. T treatment improves libido but may be less effective for erectile dysfunction (ED). T treatment can also have modest positive effects on insulin resistance, bone strength, some measures of physical strength, and mild depressive symptoms but the clinical significance of these relatively short-term improvements remain uncertain in terms of longer-term patient-important outcomes. Initiation of TRT is a joint decision between patient and clinician since longer-term benefits and risks have not been adequately defined.

The role of the androgen receptor in the pathogenesis of obesity and its utility as a target for obesity treatments

Obesity is associated with hypothalamic-pituitary-testicular axis dysregulation in males. Here, we summarize recent evidence derived from clinical trials and studies in preclinical animal models regarding the role of androgen receptor (AR) signaling in the pathophysiology of males with obesity. We also discuss therapeutic strategies targeting the AR for the treatment of obesity and their limitations and provide insight into the future research necessary to advance this field.

Testosterone supplementation and bone parameters: a systematic review and meta-analysis study

BACKGROUND

The role of testosterone (T) replacement therapy (TRT) in subjects with late onset hypogonadism is still the object of an intense debate.

METHODS

All observational studies and placebo-controlled or -uncontrolled randomized trials (RCTs) comparing the effect of TRT on different bone parameters were considered.

RESULTS

Out of 349 articles, 36 were considered, including 3103 individuals with a mean trial duration of 66.6 weeks. TRT improves areal bone mineral density (aBMD) at the spine and femoral neck levels in observational studies, whereas placebo-controlled RTCs showed a positive effect of TRT only at lumber spine and when trials included only hypogonadal patients at baseline (total testosterone < 12 nM). The effects on aBMD were more evident in subjects with lower T levels at baseline and increased as a function of trial duration and a higher prevalence of diabetic subjects. Either T or estradiol increase at endpoint contributed to aBMD improvement. TRT was associated with a significant reduction of bone resorption markers in observational but not in controlled studies.

CONCLUSION

TRT is able to inhibit bone resorption and increase bone mass, particularly at the lumbar spine level and when the duration is long enough to allow the anabolic effect of T and estrogens on bone metabolism to take place.

Anabolic-Androgenic Steroids and Exercise Training: Breaking the Myths and Dealing With Better Outcome in Sarcopenia

Sarcopenia is an emerging clinical condition determined by the reduction in physical function and muscle mass, being a health concern since it impairs quality of life and survival. Exercise training is a well-known approach to improve physical capacities and body composition, hence managing sarcopenia progression and worsening. However, it may be an ineffective treatment for many elderly with exercise-intolerant conditions. Thus, the use of anabolic-androgenic steroids (AAS) may be a plausible strategy, since these drugs can increase physical function and muscle mass. The decision to initiate AAS treatment should be guided by an evidence-based patient-centric perspective, once the balance between risks and benefits may change depending on the clinical condition coexisting with sarcopenia. This mini-review points out a critical appraisal of evidence and limitation of exercise training and AAS to treat sarcopenia.

Sexual Dysfunction in Men and Women with Diabetes: A Reflection of their Complications?

BACKGROUND

Diabetes mellitus (DM), one of the worldwide leading causes of death, is associated with a plethora of micro- and macro-vascular complications which should be carefully investigated and, in case, treated in order to improve quality of life and reduce the risk of premature mortality.

OBJECTIVE

The study aimed to investigate and report current evidence with regard to the association between sexual dysfunction and diabetes.

METHODS

A detailed analysis of current literature has been performed on PubMed and Scholar in order to retrieve the most relevant findings pertaining to the study topic.

RESULTS

Female and male sexual dysfunction often occurs in diabetes; while cardiovascular complications are clearly involved, psychosexological factors, endocrine complications, and endothelial dysfunction all contribute to the pathogenesis of sexual dysfunctions. Psychological symptoms are seldom investigated, yet they should not be overlooked by the clinician; in fact, an interplay between sexual dysfunctions and depressive symptoms has been reported, and beneficial effects in both conditions might be obtained by adequate psychological support. Sexual dysfunctions can also act as early biomarkers of cardiovascular disease, a phenomenon frequently reported in men, in which erectile dysfunction predicts the development of coronary artery disease. Additionally, drug therapies can act in both directions, with treatments for diabetes possibly improving male sexual function and exerting beneficial effects for cardiovascular health being reported for pro-erectile drugs.

CONCLUSION

Sexual dysfunctions often occur in men and women with diabetes. Investigating micro- and macro-vascular complications might not be enough to prevent the development or worsening of any sexual dysfunction; endocrine and psychological assessments are therefore needed to provide the best chances for adequate treatment.

The Sexual Long COVID (SLC): Erectile Dysfunction as a Biomarker of Systemic Complications for COVID-19 Long Haulers

Introduction

Long term complications of COVID-19, the disease caused by the SARS-CoV-2, involve many organ systems, dramatically worsening the quality of life, and finally contributing to impaired physical functioning. Despite the presence of well-identified pathogenetic mechanisms, the effect of “Long COVID” on sexual health has been only marginally addressed.

Objectives

To provide coverage of the current literature on long COVID, its epidemiology, pathophysiology, and relevance for erectile function. Methods. Comprehensive review of literature pertaining to the epidemiology and pathophysiology of long COVID, and its relevance for erectile function.

Results

Symptoms of long COVID are highly prevalent and involve almost all systems of the human body, with a plethora of clinical manifestations which range from minor nuisances to life-threatening conditions. “Brain fog” and fatigue are the most common complaints, although other neuropsychiatric complications, including sensory dysfunctions, anxiety, depression, and cerebrovascular events have also been reported. The respiratory and cardiovascular systems are also affected, with dyspnea, pulmonary fibrosis, endothelial dysfunction, and myocarditis occurring in some COVID long haulers. A subset of patients might develop endocrine manifestations, including onset of diabetes, thyroid dysfunction, and hypogonadism. Overall, long COVID features many complications which can impair erectile function by multiple pathogenetic mechanisms, and which could require tailored treatment: (i) careful investigation and management from the sexual medicine expert are therefore much needed, (ii) and future research on this topic is warranted.

Conclusion

in COVID-19 long haulers, several complications can adversely affect erectile function which, upon future tailored studies, could be used as biomarker for the severity of the long COVID disease and for its follow-up.

Sansone A, Mollaioli D, Limoncin E et al. The Sexual Long COVID (SLC): Erectile Dysfunction as a Biomarker of Systemic Complications for COVID-19 Long Haulers. Sex Med Rev 2022;10:271–285.

Erectile Dysfunction in Diabetic Patients: From Etiology to Management

Diabetes mellitus (DM) is a widespread chronic disease with a prevalence that is expected to further increase in the near future. The classical management of DM includes the normalization of the glycometabolic profile and the evaluation of cardiac and cerebral vascular health by the intervention of an array of different specialists. However, so far, sexual dysfunctions are still a neglected complication in patients with DM, although there is an elevated prevalence of this long-term complication in male and female patients. Furthermore, some of them may represent a sign of vascular alteration and/or hypogonadism and require timely management to prevent the onset of major adverse cardiac events. This narrative review briefly summarizes the current evidence on epidemiology, pathogenesis, diagnosis, and therapy of erectile dysfunction in male patients with DM to support diabetologists in clinical practice.

The genetics of testosterone contributes to "femaleness/maleness" of cardiometabolic traits and type 2 diabetes

The genetic architecture of testosterone is highly distinct between sexes. Moreover, obesity is associated with higher testosterone in females but lower testosterone in males. Here, we ask whether male-specific testosterone variants are associated with a male pattern of obesity and type 2 diabetes (T2D) in females, and vice versa. In the UK Biobank, we conducted sex-specific genome-wide association studies and computed polygenic scores for total (PGS_TT) and bioavailable testosterone (PGS_BT). We tested sex-congruent and sex-incongruent associations between sex-specific PGS_Ts and metabolic traits, as well as T2D diagnosis. Female-specific PGS_BT was associated with an elevated cardiometabolic risk and probability of T2D, in both sexes. Male-specific PGS_TT was associated with traits conferring a lower cardiometabolic risk and probability of T2D, in both sexes. We demonstrate the value in considering polygenic testosterone as sex-related continuous traits, in each sex.

European Association of Urology Guidelines on Sexual and Reproductive Health-2021 Update: Male Sexual Dysfunction

CONTEXT

The present summary of the European Association of Urology (EAU) guidelines is based on the latest guidelines on male sexual health published in March 2021, with a last comprehensive update in January 2021.

OBJECTIVE

To present a summary of the 2021 version of the EAU guidelines on sexual and reproductive health.

EVIDENCE ACQUISITION

A literature review was performed up to January 2021. The guidelines were updated, and a strength rating for each recommendation was included based on either a systematic review of the evidence or a consensus opinion from the expert panel.

EVIDENCE SYNTHESIS

Late-onset hypogonadism is a clinical condition in the ageing male combining low levels of circulating testosterone and specific symptoms associated with impaired hormone production and/or action. A comprehensive diagnostic and therapeutic work-up, along with screening recommendations and contraindications, is provided. Erectile dysfunction (ED) is the persistent inability to attain and maintain an erection sufficient to permit satisfactory sexual performance. Along with a detailed basic and advanced diagnostic approach, a novel decision-making algorithm for treating ED in order to better tailor therapy to individual patients is provided. The EAU guidelines have adopted the definition of premature ejaculation (PE), which has been developed by the International Society for Sexual Medicine. After the subtype of PE has been defined, patient's expectations should be discussed thoroughly and pharmacotherapy must be considered as the first-line treatment for patients with lifelong PE, whereas treating the underlying cause must be the initial goal for patients with acquired PE. Haemospermia is defined as the appearance of blood in the ejaculate. Several reasons of haemospermia have been acknowledged; the primary goal over the management work-up is to exclude malignant conditions and treat any other underlying cause.

CONCLUSIONS

The 2021 guidelines on sexual and reproductive health summarise the most recent findings, and advise in terms of diagnosis and treatment of male hypogonadism and sexual dysfunction for their use in clinical practice. These guidelines reflect the multidisciplinary nature of their management.

PATIENT SUMMARY

Updated European Association of Urology guidelines on sexual and reproductive health are presented, addressing the diagnosis and treatment of the most prevalent conditions in men. Patients must be fully informed of all relevant diagnostic and therapeutic options and, together with their treating physicians, decide on optimal personalised management strategies.

The Etiology and Pathophysiology Genesis of Benign Prostatic Hyperplasia and Prostate Cancer: A New Perspective

Background: The etiology of benign prostatic hyperplasia and prostate cancer are unknown, with ageing being the greatness risk factor. Methods: This new perspective evaluates the available interdisciplinary evidence regarding prostate ageing in terms of the cell biology of regulation and homeostasis, which could explain the timeline of evolutionary cancer biology as degenerative, inflammatory and neoplasm progressions in these multifactorial and heterogeneous prostatic diseases. Results: This prostate ageing degeneration hypothesis encompasses the testosterone-vascular-inflamm-ageing triad, along with the cell biology regulation of amyloidosis and autophagy within an evolutionary tumorigenesis microenvironment. Conclusions: An understanding of these biological processes of prostate ageing can provide potential strategies for early prevention and could contribute to maintaining quality of life for the ageing individual along with substantial medical cost savings.

Can conditions of skeletal muscle loss be improved by combining exercise with anabolic-androgenic steroids? A systematic review and meta-analysis of testosterone-based interventions

Sarcopenia, cachexia, and atrophy due to inactivity and disease states are characterized by a loss of skeletal muscle mass, often accompanied by reduced levels of anabolic hormones (e.g. testosterone). These conditions are associated with an increase in mortality, hospitalization and worsening in quality of life. Both physical exercise (EX) and anabolic-androgenic steroid (AAS) administration can improve the prognosis of patients as they increase physical functionality. However, there is a gap in the literature as to the impact of these therapies on the gains in strength and muscle mass and their implications for patient safety. Accordingly, we performed a random-effects meta-analysis to elucidate the effects of AAS and/or EX interventions on lean body mass (LBM) and muscle strength in conditions involving muscle loss. A systematic search for relevant clinical trials was conducted in MEDLINE, EMBASE, SCOPUS, Web of Science, and SPORTDiscus. Comparisons included AAS vs. Control, EX vs. Control, AAS vs. EX, AAS + EX vs. AAS and AAS + EX vs. EX. A total of 1114 individuals were analyzed. AAS increased LBM (effect size [ES]: 0.46; 95% CI: 0.25, 0.68, P = 0.00) and muscle strength (ES: 0.31; 95% CI: 0.08, 0.53, P = 0.01) when compared to a control group. EX promoted an increase in muscular strength (ES: 0.89; 95% CI: 0.53, 1.25, P = 0.00), with no effect on LBM when compared to the control group (ES: 0.15; 95% CI: -0.07, 0.38, P = 0.17). AAS did not demonstrate statistically significant differences when compared to EX for LBM and muscle strength. The combination of EX + AAS promoted a greater increase in LBM and muscular strength when compared to AAS or EX in isolation. Qualitatively, AAS administration had relatively few side effects. Significant heterogeneity was found in some analyses, which may be explained by the use of different AAS types and EX protocols. Our findings suggest that AAS administration in cachectic and sarcopenic conditions may be a viable interventional strategy to enhance muscle function when exercise is not a possible approach. Moreover, combining AAS with exercise may enhance positive outcomes in this population.

Testosterone therapy for prevention and reversal of type 2 diabetes in men with low testosterone

Men with obesity and/or type 2 diabetes (T2D) have a high prevalence of testosterone deficiency (TD). Similarly, men with TD have an increased risk of developing obesity and/or T2D, and further body fat accumulation and deterioration of glycemic control create a vicious cycle. The landmark testosterone for diabetes mellitus trial, the largest randomized controlled trial of testosterone therapy (TTh) to date, confirms the beneficial effects of TTh on fat loss and gain in muscle mass, and that TTh for 2 years significantly reduces the risk of incident T2D, and may also reverse T2D. The testosterone for diabetes mellitus trial suggests that TTh reduces the risk of T2D and results in greater improvement in sexual function and wellbeing, beyond lifestyle intervention alone.

Association of gonadal hormones and sex hormone binding globulin with risk of diabetes: A cohort study in middle-aged and elderly Chinese males

AIM

Late-onset hypogonadism in men is related to the development of diabetes. The association of gonadal hormones, sex hormone binding globulin with diabetes has been studied in various studies. However, there is no cohort study on the relationship between gonadal hormone, sex hormone binding globulin and diabetes in Chinese. We aimed to provide an insight into the possible association in middle-aged and elderly Chinese males.

METHODS

We included a population sample of 673 subjects aged 40 years or older. Total testosterone (TT), sex hormone binding globulin (SHBG), follicle-stimulating hormone (FSH) and luteinising hormone (LH) were detected. The homeostasis model assessment of insulin resistance (HOMA-IR) was calculated to estimate insulin sensitivity. Diabetes was diagnosed according to the 2010 American Diabetes Association criteria.

RESULTS

With an average follow-up time of 3.2 ± 0.5 years, 9.8% of participants had developed diabetes. The prevalence of diabetes was decreased according to increasing SHBG quartiles (Q1:13.1%, Q2: 12.0%, Q3: 11.2%, Q4: 3.0%, P for trend < .0001) and TT (Q1:16.0%, Q2: 7.9%, Q3: 9.0%, Q4: 6.4%, P for trend < .0001). The ORs of diabetes for increasing SHBG quartiles were 4.52 (95% CI 1.40-14.57), 4.32 (95% CI 1.33-14.06), 3.89 (95% CI 1.21-12.50) and 1.00 (reference) respectively. But the odds of prevalent diabetes were not increased in different quartiles of TT, FSH and LH. In subgroup analyses, the relationship between SHBG and risk of incident diabetes was significantly increased in the population aged over 60, without insulin resistance and with eGFR < 90 mL/min per 1.73 m² .

CONCLUSIONS

Compared with gonadal hormones, a lower level of SHBG is independently associated with the risk of diabetes in middle-aged and elderly Chinese males.

Glycemic benefits with adherence to testosterone therapy in men with hypogonadism and type 2 diabetes mellitus

BACKGROUND

While previous studies have demonstrated testosterone's beneficial effects on glycemic control in men with hypogonadism and Type 2 Diabetes, the extent to which these improvements are observed based on the degree of treatment adherence has been unclear.

OBJECTIVES

To evaluate the effects of long-term testosterone therapy in A1C levels in men with Type 2 Diabetes Mellitus and hypogonadism, controlling for BMI, pre-treatment A1C, and age among different testosterone therapy adherence groups.

MATERIALS AND METHODS

We performed a retrospective analysis of 1737 men with diabetes and hypogonadism on testosterone therapy for 5 years of data from 2008-2018, isolating A1C, lipid panels, and BMI results for analysis. Subjects were categorized into adherence groups based on quartiles of the proportion of days covered (> 75% of days, 51-75% of days, 26-50% of days and 0-25% of days), with >75% of days covered considered adherent to therapy.

RESULTS

Pre-treatment median A1C was 6.8%. Post-treatment median A1C was 7.1%. The adherent group, >75%, was the only group notable for a decrease in A1C, with a median decrease of -0.2 (p = 0.0022). BMI improvement was associated with improved post-treatment A1C (p = 0.007). When controlling for BMI, age, and pre-treatment A1C, the >75% adherence group was associated with improved post-treatment A1C (p < 0.001).

DISCUSSION

When controlling for all studied variables, testosterone adherence was associated with improved post-treatment A1C. The higher the initial A1C at the initiation of therapy, the higher the potential for lowering the patient's A1C with >75% adherence. Further, all groups showed some reduction in BMI, which may indicate that testosterone therapy may affect A1C independent of weight loss.

CONCLUSION

Even when controlling for improved BMI, pre-treatment A1C, and age, testosterone positively impacted glycemic control in diabetes patients with hypogonadism, with the most benefit noted in those most adherent to therapy (>75%).

Aging and sex hormones in males

Over the past two decades several large cohort studies have been performed to disclose the changes of sex hormone in elderly and their clinical significance. Beyond the decline of total testosterone, aging is accompanied by a sex hormone binding globulin (SHBG) increase, a steeper free testosterone decline, while gonadotropins may be increased or inappropriately normal, with important contribution of comorbidities (e.g., obesity) to these changes. Actually, it has become firm the concept that the biochemical finding of testosterone deficiency alone is not sufficient for diagnosing hypogonadism in older men. The definition of late-onset hypogonadism (LOH) includes low serum testosterone levels coupled with signs and symptoms related to hypogonadism. Indeed, the combination of multiple factors all contributing to the testosterone decline, with other concurrent comorbidities further overlapping, makes the clinical correlates of LOH highly heterogeneous. For all these reasons both the diagnosis and the therapeutic management of LOH, especially the decision about starting testosterone replacement treatment, remain challenging.

Mechanisms underlying the metabolic actions of testosterone in humans: A narrative review

The role of testosterone in improving sexual symptoms in men with hypogonadism is well known. However, recent studies indicate that testosterone plays an important role in several metabolic functions in males. Multiple PubMed searches were conducted with the use of the terms testosterone, insulin sensitivity, obesity, type 2 diabetes, anaemia, bone density, osteoporosis, fat mass, lean mass and body composition. This narrative review is focused on detailing the mechanisms that underlie the metabolic aspects of testosterone therapy in humans. Testosterone enhances insulin sensitivity in obese men with hypogonadism by decreasing fat mass, increasing lean mass, decreasing free fatty acids and suppressing inflammation. At a cellular level, testosterone increases the expression of insulin receptor β subunit, insulin receptor substrate-1, protein kinase B and glucose transporter type 4 in adipose tissue and adenosine 5'-monophosphate-activated protein kinase expression and activity in skeletal muscle. Observational studies show that long-term therapy with testosterone prevents progression from prediabetes to diabetes and improves HbA1c. Testosterone increases skeletal muscle satellite cell activator, fibroblast growth factor-2 and decreases expression of the muscle growth suppressors, myostatin and myogenic regulatory factor 4. Testosterone increases haematocrit by suppressing hepcidin and increasing expression of ferroportin along with that of transferrin receptor and plasma transferrin concentrations. Testosterone also increases serum osteocalcin concentrations, which may account for its anabolic actions on bone. In conclusion, testosterone exerts a series of potent metabolic effects, which include insulin sensitization, maintenance and growth of the skeletal muscle, suppression of adipose tissue growth and maintenance of erythropoiesis and haematocrit.

Effect of Metformin on Testosterone Levels in Male Patients With Type 2 Diabetes Mellitus Treated With Insulin

AIM

To explore the chronic effects of metformin on testosterone levels in men with type 2 diabetes mellitus (T2DM).

METHODS

This is a secondary analysis of a real-world study evaluating the efficacy and safety of premixed insulin treatment in patients with T2DM via 3-month intermittent flash glucose monitoring. Male patients aged 18-60 who were using metformin during the 3-month study period were included as the metformin group. The control group included males without metformin therapy by propensity score matching analysis with age as a covariate. Testosterone levels were measured at baseline and after 3-month treatment.

RESULTS

After 3-month treatment, the control group had higher levels of total testosterone, free and bioavailable testosterone than those at baseline (P<0.05). Compared with the control group, the change of total (-0.82 ± 0.59 vs. 0.99 ± 0.59 nmol/L) and bioavailable (-0.13 ± 0.16 vs. 0.36 ± 0.16 nmol/L) testosterone levels in the metformin group significantly decreased (P=0.036 and 0.029, respectively). In Glycated Albumin (GA) improved subgroup, the TT, FT, and Bio-T levels in the control subgroup were higher than their baseline levels (P < 0.05). Compared with the metformin subgroup, TT level in the control subgroup also increased significantly (P=0.044). In GA unimproved subgroup, the change of TT level in the metformin subgroup was significantly lower than that in the control subgroup (P=0.040).

CONCLUSION

In men with T2DM, 3-month metformin therapy can reduce testosterone levels, and counteract the testosterone elevation that accompanied with the improvement of blood glucose.

CLINICAL TRIAL REGISTRATION

https://www.clinicaltrials.gov/ct2/show/NCT04847219?term=04847219&draw=2&rank=1.

Testosterone treatment longer than 1 year shows more effects on functional hypogonadism and related metabolic, vascular, diabetic and obesity parameters (results of the 2-year clinical trial)

OBJECTIVE

We evaluated long-term effects of testosterone undecanoate on glycemic control, metabolic syndrome, vascular function and morphology in obese men with functional hypogonadism (FH) and type 2 diabetes (T2D) in a 2-year prospective clinical trial.

METHODS

A total of 55 participants were enrolled in this study; group P (n = 27) received placebo during first and testosterone therapy (TTh) during second year, group T (n = 28) received TTh both years. We pooled results after 1 year of TTh to obtain more statistical power. Results for group T after 2 years of TTh are also presented. We evaluated wide assortment of biochemical (fasting plasma glucose-FPG, glycated hemoglobin-HbA1c and lipid profile), hormonal, vascular (flow-mediated dilatation-FMD and intima-media thickness-IMT), anthropometrical and derived parameters (BMI, HOMA-IR, non-HDL cholesterol, bioavailable and calculated free testosterone). Quality of life was assessed using Aging Males' Symptoms (AMS) questionnaire.

RESULTS

FPG, HbA₁c, HOMA-IR and IMT decreased, FMD increased, lipid profile and AMS sexual sub-score improved, and testosterone levels fully normalized after 2 years of TTh.

CONCLUSIONS

Two-year of TTh resulted in normalized serum testosterone levels, improved glycemia, endothelial function, lipids and insulin sensitivity, and quelled the symptoms of hypogonadism, potentially reducing cardiovascular risk in obese men with FH and T2D.

Testosterone deficiency in men infected with COVID ‐19

As our understanding of the SARS‐CoV‐2 virus develops, recent research has highlighted the potential role of testosterone in the severity of illness. Here, the authors explain the role of testosterone in men infected with COVID‐19.

Remission of type 2 diabetes following long-term treatment with injectable testosterone undecanoate in patients with hypogonadism and type 2 diabetes: 11-year data from a real-world registry study

AIMS

To investigate whether testosterone therapy (TTh) in men with hypogonadism and type 2 diabetes mellitus (T2DM) improves glycaemic control and insulin sensitivity, and results in remission of T2DM.

MATERIAL AND METHODS

A total of 356 men who had total testosterone levels ≤12.1 nmol/L (350 ng/dL) and symptoms of hypogonadism were included in the study and followed up for 11 years. All patients received standard diabetes treatment and 178 patients additionally received parenteral testosterone undecanoate 1000 mg every 12 weeks following an initial 6-week interval. A control group comprised 178 hypogonadal patients who opted not to receive TTh.

RESULTS

Patients with hypogonadism and T2DM treated with testosterone had significant progressive and sustained reductions in fasting glucose, glycated haemoglobin (HbA1c) and fasting insulin over the treatment period. In the control group, fasting glucose, HbA1c and fasting insulin increased. Among the patients treated with testosterone 34.3% achieved remission of their diabetes and 46.6% of patients achieved normal glucose regulation. Of the testosterone-treated group, 83.1% reached the HbA1c target of 47.5 mmol/mol (6.5%) and 90% achieved the HbA1c target of 53.0 mmol/mol (7%). In contrast, no remission of diabetes or reductions in glucose or HbA1c levels were noted in the control group. There were fewer deaths, myocardial infarctions, strokes and diabetic complications in the testosterone-treated group.

CONCLUSIONS

Long-term TTh in men with T2DM and hypogonadism improves glycaemic control and insulin resistance. Remission of diabetes occurred in one-third of the patients. TTh is potentially a novel additional therapy for men with T2DM and hypogonadism.