Lowered testosterone in male obesity: mechanisms, morbidity and management

Testosterone therapy for functional hypogonadism in middle-aged and elderly males: current evidence and future perspectives

Population aging is a global phenomenon driving research focus toward preventing and managing age-related disorders. Functional hypogonadism (FH) has been defined as the combination of low testosterone levels, typically serum total testosterone below 300-350 ng/dL, together with manifestations of hypogonadism, in the absence of an intrinsic pathology of the hypothalamic-pituitary-testicular (HPT) axis. It is usually seen in middle-aged or elderly males as a product of aging and multimorbidity. This age-related decline in testosterone levels has been associated with numerous adverse outcomes. Testosterone therapy (TTh) is the mainstay of treatment for organic hypogonadism with an identifiable intrinsic pathology of the HPT axis. Current guidelines generally make weak recommendations for TTh in patients with FH, mostly in the presence of sexual dysfunction. Concerns about long-term safety have historically limited TTh use in middle-aged and elderly males with FH. However, recent randomized controlled trials and meta-analyses have demonstrated safe long-term outcomes regarding prostatic and cardiovascular health, together with decreases in all-cause mortality and improvements in various domains, including sexual function, body composition, physical strength, bone density, and hematopoiesis. Furthermore, there are numerous insightful studies suggesting additional benefits of TTh, for instance in cardio-renal-metabolic conditions. Specifically, future trials should investigate the role of TTh in improving symptoms and prognosis in various clinical contexts, including sarcopenia, frailty, dyslipidemia, arterial hypertension, diabetes mellitus, fracture risk, heart failure, stable angina, chronic kidney disease, mood disorders, and cognitive dysfunction.

The Effects of Aerobic Exercise Training on Testosterone Concentration in Individuals Who are Obese or Have Type 2 Diabetes: A Systematic Review and Meta-Analysis

BACKGROUND

Obesity and type 2 diabetes (T2D) are associated with alterations in testosterone concentrations. While evidence indicates that aerobic training can influence testosterone in healthy populations or females with hyperandrogenism, its impact in individuals with obesity or T2D remains unclear. Thus, the aim of this study was to investigate whether aerobic training can influence circulating testosterone concentrations in individuals with obesity or T2D.

METHODS

EBSCOhost (CINAHL, MEDLINE, SPORTDiscus), PubMed and Embase were searched for articles published until August 2023. Eligible articles included individuals with obesity or T2D that underwent an aerobic exercise intervention with testosterone concentrations measured at baseline and post intervention. Two reviewers independently screened the seven articles included in this meta-analysis and conducted data extraction and risk of bias assessments.

RESULTS

A total of 103 participants (62 men / 41 women) from three randomised controlled trials and four non-randomised controlled trials were included. Effect sizes were computed with random effects models. Aerobic exercise moderately increased testosterone concentrations in men (g = 0.565, 95% CI = 0.307 to 0.822, p < 0.001), but had no significant effect in women (g = -0.523, 95% CI = -1.541, 0.496, p = 0.314). Aerobic exercise had no significant effect on sex hormone-binding globulin or markers of insulin sensitivity (p > 0.05).

CONCLUSIONS

Aerobic training may be used to increase testosterone concentrations in men with obesity or T2D, but potentially has no influence in women. Given the low number of studies, further studies investigating the effect of exercise on circulating sex hormones in men and women with obesity or T2D are needed.

Testosterone and estradiol reduce inflammation of human macrophages induced by anti-SARS-CoV-2 IgG

COVID-19, the disease caused by SARS-CoV-2, particularly causes severe inflammatory disease in elderly, obese, and male patients. Since both aging and obesity are associated with decreased testosterone and estradiol expression, we hypothesized that decreased hormone levels contribute to excessive inflammation in the context of COVID-19. Previously, we and others have shown that hyperinflammation in severe COVID-19 patients is induced by the production of pathogenic anti-spike IgG antibodies that activate alveolar macrophages. Therefore, we developed an in vitro assay in which we stimulated human macrophages with viral stimuli, anti-spike IgG immune complexes, and different sex hormones. Treatment with levels of testosterone reflecting young adults led to a significant reduction in TNF and IFN-γ production by human macrophages. In addition, estradiol significantly attenuated the production of a very broad panel of cytokines, including TNF, IL-1β, IL-6, IL-10, and IFN-γ. Both testosterone and estradiol reduced the expression of Fc gamma receptors IIa and III, the two main receptors responsible for anti-spike IgG-induced inflammation. Combined, these findings indicate that sex hormones reduce the inflammatory response of human alveolar macrophages to specific COVID-19-associated stimuli, thereby providing a potential immunological mechanism for the development of severe COVID-19 in both older male and female patients.

Advancements in Understanding and Preventing Obesity-Related Colon Cancer

ABSTRACT

Obesity and colorectal cancer are global public health issues, with the prevalence of both conditions increasing over the last 4 decades. In the United States alone, the prevalence of obesity is greater than 40%, and this percentage is projected to increase past 50% by 2030. This review focuses on understanding the association between obesity and the risk of colorectal cancer while also highlighting hypotheses about molecular mechanisms underlying the link between these disease processes. We also consider whether those linkages can be disrupted via weight loss therapies, including lifestyle modifications, pharmacotherapy, bariatric surgery, and endobariatrics.

A Review on Testosterone: Estradiol Ratio-Does It Matter, How Do You Measure It, and Can You Optimize It?

There is a natural balance between the major sex steroids, testosterone and estradiol, controlled by gonadal secretion and peripheral conversion by aromatase. This balance is impacted by a variety of inborn and acquired conditions, and, more recently, by a growing use of exogenous testosterone therapy and off-label aromatase use under the guise of "men's health." We summarize reported testosterone:estradiol ratios, both naturally occurring and with pharmacologic manipulation and consider the ramifications of significant changes in these ratios. However, significant limitations exist in terms of steroid separation and measurement techniques, timing of samples, and lack of consistency from one assay to another, as well as definition of normative data. Limited data on the testosterone:estradiol ratio in men exists, particularly due to the scan data on concurrent estradiol values in men receiving testosterone therapy or aromatase inhibitors. Nonetheless, there seems to be a range of apparently beneficial values of the testosterone: estradiol radio at between 10 and 30, calculated as: testosterone in ng/dL/estradiol in pg/mL. Higher values appear to be associated with improved spermatogenesis and reduced bone density while lower values are associated with thyroid dysfunction. While there is growing awareness of the significance of the testosterone:estradiol ratio, and a sense of a desired range, the optimal value has not yet been determined. Further work is needed to clarify the measurement strategies and clearly-defined outcome measures related to the testosterone:estradiol ratio.

Hypogonadism and associated factors among male Leprosy patients

BACKGROUND

Leprosy affects various organs in addition to skin, eyes, and peripheral nerves. Testicular involvement in leprosy patients is common and causes disturbance in endocrine function of the testis and results in hypogonadism. Hypogonadism is frequently undiagnosed and underreported.

OBJECTIVE

This study aimed to assess hypogonadism and associated factors among leprosy patients at Alert Comprehensive Specialized Hospital, Ethiopia.

METHODS

A cross-sectional study design was used in which consecutive 146 male leprosy patients aged between 18 to 65 years attending outpatient follow-up at leprosy outpatient clinic were included. Data was gathered both from patient charts and through patients' interviews. Androgen deficiency symptoms were assessed by androgen deficiency in the aging male questionnaire, and 5ml of blood samples were taken from study participants and serum total testosterone, LH, and FSH were analyzed by Electrochemiluminescence method. Statistical correlation was assessed by Spearman correlation. A multivariable binary logistic regression model was used to identify the independent factors associated with hypogonadism and P-value <0.05 was used to declare statistical significance.

RESULTS

The prevalence of hypogonadism was 39 (26.7%). Out of this, 34 (87.2%) had primary hypogonadism, whereas 5 (12.8%) had secondary hypogonadism. Total testosterone was inversely correlated with Body mass index (r = -0.37, p = 0.002), Luteinizing hormone (r = -0.43, p <0.001), and Follicular stimulating hormone (r = -0.42, p< 0.001). However, Total testosterone was not significantly correlated with age (r = -0.019, p = 0.81). BMI [AOR = 1.32, 95%CI (1.16-1.51)] and grade-II disability [AOR = 3.80, 95%CI (1.23-11.64)] were identified as independent risk factors for hypogonadism.

CONCLUSION

Nearly one-fourth of male leprosy patients had hypogonadism. Overweight and grade-II disability were independent risk factors for hypogonadism.

The Impact of Diabetes on Male Silkworm Reproductive Health

The increasing prevalence of diabetic reproductive complications has prompted the development of innovative animal models. The use of the silkworm Bombyx mori as a model for diabetic reproductive damage shows potential as a valuable research tool. This study employed silkworms as a novel model to investigate diabetic reproductive damage. The silkworms were fed a high-glucose diet containing 10% glucose to induce a diabetic model. Subsequently, the study concentrated on assessing the influence of diabetes on the reproductive system of male silkworms. The results indicate that diabetes resulted in reduced luteinizing hormone (LH) and testosterone (T) levels, as well as elevated triglyceride (TG) levels in male silkworms. Moreover, diabetes mellitus was associated with pathological testicular damage in male silkworms, accompanied by decreased glutathione peroxidase (GSH-Px) and superoxide dismutase (SOD) levels, along with increased malondialdehyde (MDA) levels in the testis. Additionally, diabetes mellitus reduced the expression of siwi1 and siwi2 genes in the testis of male silkworms. Overall, these results support using silkworms as a valuable model for studying diabetic reproductive damage.

Management of male obesity-related secondary hypogonadism: A clinical update

The global obesity pandemic has resulted in a rise in the prevalence of male obesity-related secondary hypogonadism (MOSH) with emerging evidence on the role of testosterone therapy. We aim to provide an updated and practical approach towards its management. We did a comprehensive literature search across MEDLINE (via PubMed), Scopus, and Google Scholar databases using the keywords "MOSH" OR "Obesity-related hypogonadism" OR "Testosterone replacement therapy" OR "Selective estrogen receptor modulator" OR "SERM" OR "Guidelines on male hypogonadism" as well as a manual search of references within the articles. A narrative review based on available evidence, recommendations and their practical implications was done. Although weight loss is the ideal therapeutic strategy for patients with MOSH, achievement of significant weight reduction is usually difficult with lifestyle changes alone in real-world practice. Therefore, androgen administration is often necessary in the management of hypogonadism in patients with MOSH which also improves many other comorbidities related to obesity. However, there is conflicting evidence for the appropriate use of testosterone replacement therapy (TRT), and it can also be associated with complications. This evidence-based review updates the available evidence including the very recently published results of the TRAVERSE trial and provides comprehensive clinical practice pearls for the management of patients with MOSH. Before starting testosterone replacement in functional hypogonadism of obesity, it would be desirable to initiate lifestyle modification to ensure weight reduction. TRT should be coupled with the management of other comorbidities related to obesity in MOSH patients. Balancing the risks and benefits of TRT should be considered in every patient before and during long-term management.

The impact of obesity and sexual behavior on prostate cancer risk is mediated by testosterone levels: a mendelian randomization study and mediation analysis

Background

The relationship between obesity, sexual behavior, and prostate cancer (PCa) has been widely debated, contributing to a lack of understanding of its potential mechanisms and hindering the development of effective prevention measures.

Purpose

The aim of this study was to examine the causal effect of body mass index (BMI), age at first sexual intercourse (AFS), and bioavailable testosterone levels on PCa while also quantifying the potential roles of mediators.

Method

We conducted a Mendelian randomization (MR) study using summary statistics from genome-wide associations of BMI (152,893 European males), AFS (182,791 European males), bioavailable testosterone (184,205 European males), and PCa (79,148 cases, 61,106 controls, European ancestry). Inverse-variance weighted method, weighted median method, MR-Egger regression, Least Absolute Shrinkage and Selection Operator (LASSO), and outlier test were used for MR analyses. Reverse MR and mediation analysis were performed. Data analyses were conducted from December 2022 to July 2023.

Results

The results showed that genetic liability to BMI was protective of PCa (OR, 0.82; 95% CI: 0.74-0.91; P = 3.29 × 10-4). Genetic liability to later AFS (OR, 1.28; 95% CI: 1.08-1.53; P = 5.64 × 10-3) and higher bioavailable testosterone levels (OR = 1.11, 95% CI: 1.01-1.24, P = 0.04) were associated with an increased risk of PCa. All of these potential causal effects could only be forwarded and were not affected by prostate specific antigen (PSA) screening. After controlling for bioavailable testosterone levels, the causal impact of BMI and AFS on PCa was no longer significant. The mediation analysis suggested that the causal influence of AFS/BMI on PCa relied on bioavailable testosterone levels.

Conclusion

In conclusion, the difference between the univariable and multivariable MR results suggested that the causal influence of BMI and AFS on PCa relied on bioavailable testosterone levels. Further work is needed to identify other risk factors and to elucidate the specific mechanisms that underlie this causal pathway.

Potential roles of sex-linked differences in obesity and cancer immunotherapy: revisiting the obesity paradox

Obesity, a condition of excess adiposity usually defined by a BMI > 30, can have profound effects on both metabolism and immunity, connecting the condition with a broad range of diseases, including cancer and negative outcomes. Obesity and cancer have been associated with increased incidence, progression, and poorer outcomes of multiple cancer types in part due to the pro-inflammatory state that arises. Surprisingly, obesity has also recently been demonstrated in both preclinical models and clinical outcomes to be associated with improved response to immune checkpoint inhibition (ICI). These observations have laid the foundation for what has been termed the "obesity paradox". The mechanisms underlying these augmented immunotherapy responses are still unclear given the pleiotropic effects obesity exerts on cells and tissues. Other important variables such as age and sex are being examined as further affecting the obesity effect. Sex-linked factors exert significant influences on obesity biology, metabolism as well as differential effects of different immune cell-types. Age can be another confounding factor contributing to the effects on both sex-linked changes, immune status, and obesity. This review aims to revisit the current body of literature describing the immune and metabolic changes mediated by obesity, the role of obesity on cancer immunotherapy, and to highlight questions on how sex-linked differences may influence obesity and immunotherapy outcome.

Type 1 and type 2 diabetes mortality burden: Predictions for 2030 based on Bayesian age-period-cohort analysis of China and global mortality burden from 1990 to 2019

AIMS

This study assessed diabetes (type 1 and type 2) mortality in China and globally from 1990 to 2019, predicting the next decade's trends.

MATERIALS AND METHODS

Data came from the Global Burden of Disease (GBD) database. The annual percentage change (AAPC) in age-standardized mortality rates (ASMR) for diabetes (type 1 and type 2) during 1990-2019 was calculated. A Bayesian age-period-cohort (BAPC) model predicted diabetes (type 1 and type 2) mortality from 2020 to 2030.

RESULTS

In China, type 1 diabetes deaths declined from 6,005 to 4,504 cases (AAPC -2.827), while type 2 diabetes deaths rose from 64,084 to 168,388 cases (AAPC -0.763) from 1990 to 2019. Globally, type 1 diabetes deaths increased from 55,417 to 78,236 cases (AAPC 0.223), and type 2 diabetes deaths increased from 606,407 to 1,472,934 cases (AAPC 0.365). Both China and global trends showed declining type 1 diabetes ASMR. However, female type 2 diabetes ASMR in China initially increased and then decreased, while males had a rebound trend. Peak type 1 diabetes deaths were in the 40-44 age group, and type 2 diabetes peaked in those over 70. BAPC predicted declining diabetes (type 1 and type 2) mortality burden in China and globally over the next 10 years.

CONCLUSIONS

Type 2 diabetes mortality remained high in China and globally despite decreasing type 1 diabetes mortality over 30 years. Predictions suggest a gradual decrease in diabetes mortality over the next decade, highlighting the need for continued focus on type 2 diabetes prevention and treatment.

The Association of Free Testosterone with Sarcopenic Obesity in Community-Dwelling Older Men: A Cross-Sectional Study

Background and Objectives: Sarcopenic obesity, a clinical condition coexisting with obesity and sarcopenia, is associated with a high risk of functional impairment, reduced quality of life, and increased mortality. A decline in age-related free testosterone (FT) levels has been reported to be associated with decreased muscle mass and muscle strength and increased fat mass. However, the association between low FT levels and risk of sarcopenic obesity has not been well studied. This study aimed to investigate the direct association between low FT levels and sarcopenic obesity. Materials and Methods: This cross-sectional study used data of 982 community-dwelling men aged 70-84 years from the Korean Frailty and Aging Cohort Study. Sarcopenia was defined according to the criteria of the Asian Group for Sarcopenia (AWGS) 2019. Obesity was defined as a body fat mass ≥28.3%. Participants who met both sarcopenia and obesity criteria were defined as having sarcopenic obesity. Low FT levels were defined as FT levels <17.35 pmol/L according to the Endocrine Society Clinical Practice Guidelines. Results: The prevalence of sarcopenia, obesity, and sarcopenic obesity was significantly higher in the low-FT group than in the normal-FT group. Low FT levels were significantly associated with a higher risk of obesity (odds ratio [OR], 2.09, 95% confidence interval [CI], 1.11-3.92), sarcopenia (2.57, 95% CI 1.08-6.10), and sarcopenic obesity (3.66, 95% CI 1.58-8.47) compared with the healthy control group. The risk of low appendicular skeletal muscle mass index (ASMI) (1.78, 95% CI 1.04-3.02) and high fat mass (1.92, 95% CI 1.12-3.31) was significantly higher in the low-FT group than in the normal-FT group. Conclusions: This study showed that low FT levels were associated with a higher risk of sarcopenic obesity. Low FT levels were mainly related to body composition parameters such as low ASMI and high fat mass.

Association between weight-adjusted waist index and serum total testosterone in males aged 6-19 years in the United States: Data from NHANES 2013-2016

Objective

This study aimed to estimate the association between weight-adjusted waist index and serum total testosterone (sTT) in males aged 6-19 years in the United States.

Methods

A cross-sectional study was conducted using data from the National Health and Nutrition Examination Survey (NHANES) 2013-2016. sTT was considered as the response variable, and weight-adjusted waist circumference index (WWI) as the independent variable. Multiple linear regression was performed to estimate the association between the two variables, and subgroup analysis was performed to identify sensitive cohorts. Smoothing curve fitting and threshold effects analysis was carried out to assess possible nonlinear relationships between WWI and sTT.

Results

The study included 4207 participants. The mean value of sTT (117.93 ng/dl) was used as the grouping basis, with 1066 participants having serum total testosterone levels above the mean. A negative association was observed between WWI and sTT [beta coefficient (β) = -72.50, 95% confidence interval (CI): -79.45, -65.55], which decreased as WWI increased (P for trend<0.05). Subgroup analysis indicated a stronger negative correlation in late adolescent (16-19 years) males (β = -128.94, 95% CI: -146.75, -111.13). The smoothing curve fit analysis revealed a U-shaped curve relationship for the negative correlation between WWI and sTT. Threshold effect analysis suggested a significant change when WWI exceeded 10.09 (β = -15.82, 95% CI: -24.11, -7.54), and stepwise threshold effect analysis indicated that this negative correlation became less stable when WWI exceeded 11.45 (β = -0.80, 95% CI: -9.15, 7.56).

Conclusions

Participants with higher WWI exhibited lower total testosterone levels, and a negative association was found between WWI and total testosterone, particularly in late adolescent males aged 16-19 years. Among males aged 6-19 years, caution should be exercised regarding the risk of lower testosterone levels associated with elevated WWI, particularly when WWI is below 10.09.

Androgen signaling inhibits de novo lipogenesis to alleviate lipid deposition in zebrafish

Testosterone is closely associated with lipid metabolism and known to affect body fat composition and muscle mass in males. However, the mechanisms by which testosterone acts on lipid metabolism are not yet fully understood, especially in teleosts. In this study, cyp17a1-/- zebrafish ( Danio rerio) exhibited excessive visceral adipose tissue (VAT), lipid content, and up-regulated expression and activity of hepatic de novo lipogenesis (DNL) enzymes. The assay for transposase accessible chromatin with sequencing (ATAC-seq) results demonstrated that chromatin accessibility of DNL genes was increased in cyp17a1-/- fish compared to cyp17a1+/+ male fish, including stearoyl-CoA desaturase ( scd) and fatty acid synthase ( fasn). Androgen response element (ARE) motifs in the androgen signaling pathway were significantly enriched in cyp17a1+/+ male fish but not in cyp17a1-/- fish. Both androgen receptor ( ar)-/- and wild-type (WT) zebrafish administered with Ar antagonist flutamide displayed excessive visceral adipose tissue, lipid content, and up-regulated expression and activity of hepatic de novo lipogenesis enzymes. The Ar agonist BMS-564929 reduced the content of VAT and lipid content, and down-regulated acetyl-CoA carboxylase a ( acaca), fasn, and scd expression. Mechanistically, the rescue effect of testosterone on cyp17a1-/- fish in terms of phenotypes was abolished when ar was additionally depleted. Collectively, these findings reveal that testosterone inhibits lipid deposition by down-regulating DNL genes via Ar in zebrafish, thus expanding our understanding of the relationship between testosterone and lipid metabolism in teleosts.

Changes in Plasma, Urine, and Fecal Metabolome after 16 Weeks of Consuming Dairy With Different Food Matrixes - A Randomized Controlled Trial

SCOPE

Understanding the mode-of-action by which fermented dairy consumption influences health is of interest. The aim of this study is to elucidate the impact of the chemical-physical properties of the dairy matrix and postbiotic effects on the metabolomics response to fermented dairy consumption.

METHODS AND RESULTS

Hundred males (Body Mass Index (BMI) 28.0-45.0 kg m-2, waist circumference ≥ 102 cm) are included in the study. During a 16-week intervention, the study subjects are instructed to consume 400 g per day of either 1) milk, 2) yogurt, 3) heat-treated yogurt, or 4) chemically acidified milk as part of their habitual diet. Nuclear Magnetic Resonance (NMR)-based metabolomics is conducted on plasma, urine, and fecal samples collected before and after the intervention. Both consumption of acidified milk and heat-treated yogurt resulted in changes in the fecal metabolome including decreases in the level of amino acids (leucine, valine, and threonine), and the branched-chain fatty acid (BCFA) isobutyrate that indicated an altered protein putrefaction, and proteolytic metabolism in the gut. In the plasma metabolome, an increased citrate is found for yogurt consumption. No difference in the urine metabolome is found.

CONCLUSIONS

Our metabolomics analyses indicate that consumption of heat-treated yogurt and acidified milk exerted similar effects on the metabolic activity in the gut as yogurt consumption.

The Impact of Obesity on the Host-Pathogen Interaction with Influenza Viruses - Novel Insights: Narrative Review

After exposure to a viral pathogen, the host-pathogen interaction is essential to determine whether or not infection will ensue, and what the clinical outline of the infection will be. Recent research has shown that the patient with obesity presents a set of particular pathophysiological changes that lead to higher severity of viral infections, and this is particularly true for infection with influenza viruses. Herein, we describe the main metabolic, endocrine, and immune dysregulations that occur in the presence of obesity and their impact on driving intra-host viral diversity, leading to heightened severity and virulence of influenza. We show that obesity is linked to modified responses of both the innate and adaptive immune systems during viral infections, including influenza. Due to chronic inflammation and metabolic, endocrine, and signaling pathway disruptions, individuals with obesity have a suboptimal immune response. This results in longer illness duration, increased virus shedding, higher risk of hospitalization and complications, and greater mortality rates. Additionally, they may have a blunted response to vaccination and a higher likelihood of genetic mutation selection. Understanding the intricate interplay between obesity and viral pathogenesis is crucial for developing efficacious therapeutic approaches and public health policies, particularly in light of the escalating worldwide incidence of obesity.

The Association between Obesity and Reduced Weight-Adjusted Bone Mineral Content in Older Adults: A New Paradigm That Contrasts with the Obesity Paradox

The relationship between body weight and bone mass in the elderly remains unclear, and whether obesity is a protective factor is still a matter of debate. For this reason, the aim of this study is to assess the association between body mass index (BMI) and bone mineral content adjusted by body weight, expressed as a percentage (w-BMC%), and to test the validity of the obesity paradox in this context. A cohort of 1404 older adults was categorized according to the World Health Organization's BMI cut-off points and completed a total and segmental body composition measurement by means of a dual X-ray absorptiometry scan. Individuals with obesity displayed a lower mean w-BMC% (3.06 ± 0.44%; 2.60 ± 0.37%) compared to those who were normal-weight (3.95 ± 0.54%; 3.38 ± 0.48%) and overweight (3.06 ± 0.44%; 3.04 ± 0.37%) in both genders. Linear regression analysis also showed a negative association between BMI and w-BMC% in males (β = -0.09; p < 0.001) and females (β = -0.06; p < 0.001). Finally, among individuals with obesity, and after adjusting for age, the linear regression models revealed a significant decrease of 0.75% and 0.28% in w-BMC% for every one-unit increase in the trunk fat/appendicular lean mass ratio in both males (β = -0.749; p < 0.0001) and females (β = -0.281; p < 0.001). In conclusion, we suggest a new paradigm regarding the impact of obesity on bone mass, in which the former does not appear to be a protective factor of the latter, especially in individuals with central obesity and low muscle mass.

Effect of surgical, medical, and behavioral weight loss on hormonal and sexual function in men: a contemporary narrative review

This review explores the mechanisms and ramifications of weight loss achieved through lifestyle modifications, medical treatments, and bariatric surgery on testosterone levels and sexual health. Obesity significantly affects the hypothalamic-pituitary-gonadal axis in men, leading to diminished libido and erectile dysfunction. Here, we delve into the physiological disruptions caused by this imbalance and the intricate interplay of hormonal factors contributing to the dysregulation associated with obesity to comprehensively grasp the consequences of weight loss via diverse mechanisms. Lifestyle modifications involving dietary adjustments and regular exercise represent a widely employed and efficacious means of weight loss. While adherence demands discipline, our review scrutinizes various studies specifically investigating the impact of weight loss, attained through lifestyle modifications, on serum hormone levels and sexual function. Notably, several randomized controlled trials within the existing body of literature corroborate the enhancement of testosterone levels and sexual function consequent to weight loss through lifestyle modifications. The realm of medical management in addressing obesity is growing, notably propelled by the popularity of pharmacotherapy. Despite its prevalence, the current literature exploring the effects of weight loss medications on men remains insufficient. Nonetheless, we examine available studies on the medical management of obesity and its implications for sexual health, emphasizing pivotal avenues requiring further investigation. Bariatric surgery stands as an effective approach for individuals seeking substantial weight loss. Our review assesses existing literature that evaluates the impact of various surgical techniques on serum hormone levels, sexual function, and semen parameters. Despite certain limitations, the available body of evidence suggests enhancements in hormone levels and sexual function post-surgery, with semen parameters generally exhibiting minimal changes. This review critically evaluates the landscape of weight loss and its correlation with sexual function, while highlighting crucial areas necessitating future research endeavors.

The effects of sex hormones on the size of intestinal lipoproteins

Larger intestinal lipoproteins are more likely to be retained longer in the intestinal wall, allowing more time for their fat to be hydrolyzed and subsequently taken up by the abdominal viscera. Since men generally accumulate more abdominal visceral fat than women, we sought to determine if males produce larger intestinal lipoproteins compared to females. Using the conscious lymph fistula mouse model, we discovered that the male mice indeed produced larger intestinal lipoproteins than the female mice when they were intraduodenally infused with lipid emulsion. We then employed our differentiated Caco-2 cell model with semipermeable membrane system to determine the effects of sex hormones on the size of intestinal lipoproteins. Lipoprotein size was quantitatively measured by calculating the ratio of triglycerides (TG)/Apolipoprotein B (ApoB) and by analyzing their transmission electron micrographs. Our studies showed that while there was no dose-dependent effect of estrogen and progesterone, testosterone significantly increased the size of lipoproteins. When these hormones were combined to resemble the physiological concentrations observed in males and the different ovarian cycle phases in premenopausal females, both the male and luteal groups had significantly larger lipoproteins than the ovulatory group; and the male group also had significantly larger lipoproteins than the follicular group. The ovulatory group secreted a significantly lower amount of TG than the male and luteal groups. ApoB was comparable among all these groups. These findings support our hypothesis that, through their testosterone effects, males are more likely to produce larger intestinal lipoproteins. Larger lipoproteins tend to remain longer in the intestinal wall and may facilitate fat uptake preferentially by the abdominal viscera. Our studies may partly explain why men are more prone to accumulating abdominal visceral fat, which is an independent predictor of mortality.

Brain-derived neurotrophic factor, sex hormones and cognitive decline in male patients with schizophrenia receiving continuous antipsychotic therapy

BACKGROUND

There are systematic differences in clinical features between women and men with schizophrenia (SCZ). The regulation of sex hormones may play a potential role in abnormal neurodevelopment in SCZ. Brain-derived neurotrophic factor (BDNF) and sex hormones have complex interacting actions that contribute to the etiology of SCZ.

AIM

To investigate the influence of BDNF and sex hormones on cognition and clinical symptomatology in chronic antipsychotic-treated male SCZ patients.

METHODS

The serum levels of follicle-stimulating hormone, luteinizing hormone (LH), estradiol (E2), progesterone, testosterone (T), prolactin (PRL) and BDNF were compared between chronic antipsychotic-treated male (CATM) patients with SCZ (n = 120) and healthy controls (n = 120). The Positive and Negative Syndrome Scale was used to quantify SCZ symptoms, while neuropsychological tests were used to assess cognition. Neuropsychological tests, such as the Digit Cancellation Test (DCT), Semantic Verbal Fluency (SVF), Spatial Span Test (SS), Paced Auditory Serial Addition Test (PASAT), Trail Making Task (TMT-A), and Block Design Test (BDT), were used to assess executive functions (BDT), attention (DCT, TMT-A), memory (SS, PASAT), and verbal proficiency (SVF).

RESULTS

Although E2 levels were significantly lower in the patient group compared to the healthy controls, T, PRL, and LH levels were all significantly higher. Additionally, the analysis revealed that across the entire sample, there were positive correlations between E2 Levels and BDNF levels as well as BDNF levels and the digital cancellation time. In CATM patients with SCZ, a significant correlation between the negative symptoms score and PRL levels was observed.

CONCLUSION

Sex hormones and BDNF levels may also be linked to cognitive function in patients with chronic SCZ.

Correlation between visceral adiposity index and erectile dysfunction in American adult males: a cross-sectional study based on NHANES

Background

The risk of visceral obesity on erectile function has recently attracted much attention. The visceral adiposity index (VAI) is a brief and reliable indicator of visceral obesity measurement. Nevertheless, the association between VAI and erectile dysfunction (ED) is not completely clarified.

Methods

Data from NHANES 2001-2004 were enrolled in this study. Erectile function was assessed by a database-self-administered questionnaire. VAI was calculated with body mass index (BMI), waist circumference (WC), triglyceride (TG), and high-density lipoprotein (HDL) cholesterol. The weighted logistic regression model was performed to evaluate the association between VAI and ED.

Results

Ultimately, 3380 participants were enrolled in the study, including 900 with ED and 2480 without ED. Compared to participants without ED, those with ED generally had higher levels of VAI (1.76 vs. 1.53). The weighted logistic regression analyses demonstrated increased odds of developing ED in participants within the 4th quartile (Q4) of VAI compared to the 1st quartile (Q1) of VAI (OR = 2.023; 95% CI, 1.534-2.669; P < 0.001). Similar results were still obtained after adjusting for the relevant covariates (OR = 1.404; 95% CI, 1.008-1.954; P = 0.044). In subgroup analyses grouped by smoking status, higher VAI was associated with increased odds of developing ED only in the current smoking group (OR = 1.092; 95% CI, 1.021-1.167; P = 0.010).

Conclusion

This study indicated that higher VAI is independently related to ED risk and that early intervention is necessary to reduce the progression of ED with high VAI levels.

Urinary cortisol and cardiovascular events in women vs. men: The multi-ethnic study of atherosclerosis

Research suggests that women experience greater cardiovascular ischemic effects from stress than men. Visceral adiposity is an endocrine tissue that differs by sex and interacts with stress hormones. We hypothesized that urinary cortisol would be associated with increased cardiovascular events and change in coronary artery calcium score (CAC) in women, and these relationships would vary by central obesity. In the Multi-Ethnic Study of Atherosclerosis Stress Ancillary study, cortisol was quantified by 12-h overnight urine collection. Central obesity was estimated by waist-hip ratio (WHR). Multivariable Cox models estimated the relationship between cortisol and cardiovascular events and assessed for moderation by WHR. The relationship between cortisol and change in CAC Agatston score was assessed by Tobit regression models. 918 patients were analyzed with median follow up of 11 years. There was no association between urinary cortisol and cardiovascular events in the cohort. However, in individuals with below median WHR, higher urinary cortisol levels (upper tertile) were associated with higher cardiovascular event rates in the full cohort, women, and men, but not in groups with above median WHR. There was significant moderation by WHR in women, but not men, whereby the association between elevated cortisol and increased cardiovascular events diminished as WHR increased. Urinary cortisol was associated with increased change in CAC in women (P = 0.003) but not men, without moderation by WHR. Our study highlights associations between cortisol and subclinical atherosclerosis in women, and moderation of the relationship between cortisol and cardiovascular events by central obesity in both genders.

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.

Analysis of semen parameters, and hormonal changes of FSH, LH, testosterone, and libido following bariatric surgery

Introduction

Although studies have shown that bariatric surgery can have a positive effect on the patient's sexual function, there are still disagreements and contradictions in this regard. The present study is aimed to evaluate semen parameters, hormonal changes of FSH, LH, testosterone, and libido following bariatric surgery.

Methods

The present research as a prospective study was performed on 20 male candidates for bariatric surgery referred to Golestan and Aria hospitals in Ahvaz in 2021. Semen parameters (volume, count, motility, and the percentage of sperm with normal morphology), hormonal profile (including FSH, LH test hormones), and sexual function were evaluated using the International Index of Erectile Function (IIEF-5) questionnaire before and 6 months after the surgery.

Results

The results of this study indicated that semen parameters did not change significantly 6 months after surgery in comparison with before the surgery (P < 0.05). After the operation, just the total level of testosterone increased significantly (2.23 nmol/L vs. 2.74, P = 0.009). However, LH and FSH levels did not change significantly six months after surgery (P = 0.858 and P = 0.287). The results indicated significant improvement in IIEF score after the operation (P = 0.011).

Conclusion

The findings of the present study indicated that the decrement of weight as a result of bariatric surgery had a favorable effect on the levels of serum testosterone and sexual performance, while semen parameters did not improve after surgery.

Do Obesity-Related Traits Affect Prostate Cancer Risk through Serum Testosterone? A Mendelian Randomization Study

OBJECTIVE

This study aimed to investigate whether testosterone mediates or confounds the effect of obesity-related traits on prostate cancer (PCa) using Mendelian randomization (MR) analysis.

MATERIALS AND METHODS

Data of obesity-related traits (body mass index [BMI], waist-to-hip ratio [WHR], and waist-to-hip ratio adjusted for body mass index [WHRadjBMI]) were obtained from up to 806,834 people of European ancestry; data of testosterone (bioavailable testosterone [BT], total testosterone [TT], and sex hormone-binding globulin [SHBG]) were extracted from up to 194,453 participants in the UK Biobank; and the summary-level data of PCa (79,194 cases and 61,112 controls) were obtained from the PRACTICAL consortium.

RESULT

The results supported the causal relationship between higher BMI and a reduced risk of PCa (OR = 0.91, 95% confidence interval [CI]: 0.86-0.96). Furthermore, increased BT levels were associated with an elevated risk of PCa (OR = 1.15, 95% CI: 1.06-1.24). Importantly, our analysis revealed a unidirectional causal effect-higher BMI was linked to lower BT levels (beta = -0.27, 95% CI: -0.3--0.24), but not the other way around. This suggests that BT may mediate the effect of BMI on PCa rather than confound it. Our multivariable MR results further demonstrated that considering BT as a mediator led to the weakening of BMI's effect on PCa risk (OR = 0.97, 95% CI: 0.90-1.05), while the impact of BT on PCa remained unchanged when accounting for BMI. Moreover, we identified a significant indirect effect of BMI on PCa risk (OR = 0.96, 95% CI: 0.94-0.98).

CONCLUSION

Our study provided genetic evidence that serum BT can mediate the effect of BMI on the risk of PCa, indicating the possible mechanism by which obesity reduces PCa risk.

Genetic regulation of testosterone level in overweight males from the Kazakh population and its association with hypogonadism

Male hypogonadism and erectile dysfunction in different populations are associated with excess body weight. A key aspect in most studies is the metabolism of sexual hormones, primarily testosterone. At the same time, the binding protein sex hormone binding globulin (SHBG) can play a large role, as it determines the ratio of total and bioavailable testosterone in blood, i.e. both the hormone content and level of its production. Recent research has identified common mutations that affect SHBG levels, such as the rs727428 polymorphic locus, which is associated with alterations in histone protein function, affecting the regulation of ribonucleic acid (RNA) protein SHBG synthesis. Similar relationships have been observed for prevalent mutations, including rs5934505 and rs10822184, in diverse populations. This study involved 300 individuals of Kazakh nationality from the Eastern Kazakhstan region, examining three polymorphic variants of the SHBG gene (rs727428, rs5934505, and rs10822184). The participants were categorized into three groups: individuals with hypogonadism and obesity (group 1, n=85), those with excess body weight but no hypogonadism (group 2, n=70), and individuals with neither excess body weight nor hypogonadism (group 3, n=145). The frequency of mutant gene alleles impacting GPS (SHBG) synthesis in the Kazakh population was notably high, comparable to European and South-East Asian populations. However, the association between excess body weight and these mutations exhibited varying patterns. Hypogonadism was linked to decreased GPS levels, strongly correlating with total testosterone but not bioavailable testosterone. The retention of sexual functions in overweight men was not always directly related to BMI levels and GPS concentrations.

Body mass index and sex differences for mortality in hospitalized COVID-19 patients: a path analysis using a brazilian national database

Previous studies have shown that associations between obesity and other comorbidities favor worse outcomes in COVID-19. However, it is not clear how these factors interrelate and whether effects on men and women differ. We conducted an observational, cross-sectional study using a national COVID-19 inpatient database. We studied differences in direct and indirect effects of obesity and comorbidities according to sex and body mass index (BMI) categories in hospitalized COVID-19 patients in Brazil using path analysis models and logistic regression. For men, path analysis showed a direct association between BMI and death and a negative correlation of death and chronic cardiovascular disease (CCD). For women, the association of BMI and death was indirect, mediated by admission to the ICU and comorbidities and association with CCD was non-significant. In the logistic regression analyses, there was a positive association between death and BMI, age, diabetes mellitus, kidney and lung diseases and ICU admission. We highlight the need to consider the distinct impact of obesity and sex on COVID-19, of monitoring of BMI and of the design for specific male-targeted approaches to manage obesity.

Differential Association of Sex Hormones with Metabolic Parameters and Body Composition in Men and Women from the United States

Sex hormones impact body composition. Data on the specific impact of each hormone on different body depots in men and women are scarce. The aim of this study is to evaluate the association between testosterone, estradiol and body fat distribution in the general population. This is a population-based cross-sectional study based on data from the 2013-2016 cycles of the National Health and Nutrition Examination Survey. Dual energy X-ray absorptiometry (DXA) and liquid chromatography tandem mass spectrometry were performed on participants aged 18-59 years to evaluate body composition and sex hormone levels, respectively. Weighted multivariable linear regression analyses were performed to evaluate the association between these parameters after adjustment for potential confounders. A total of 6655 participants (3309 males and 3346 females) was included in the analysis. Men with lower testosterone levels were older, had a higher body mass index (BMI) and had a generally unfavorable metabolic profile, while no specific trends were found in women. Among men, testosterone was positively associated with lean body mass and was negatively associated with fat mass and the android/gynoid (A/G) ratio, while an opposite trend was found for estradiol. Among women, testosterone did not impact body composition, while estradiol levels were positively associated with lean mass and were negatively associated with fat mass. Our results support the notion that the impact of different sex hormones on specific fat depots varies substantially between men and women.

Sex differences in the influence of type 2 diabetes (T2D)-related genes, parental history of T2D, and obesity on T2D development: a case-control study

BACKGROUND

This study investigated the effect of sex and age at type 2 diabetes (T2D) diagnosis on the influence of T2D-related genes, parental history of T2D, and obesity on T2D development.

METHODS

In this case-control study, 1012 T2D cases and 1008 healthy subjects were selected from the Diabetes in Mexico Study database. Participants were stratified by sex and age at T2D diagnosis (early, ≤ 45 years; late, ≥ 46 years). Sixty-nine T2D-associated single nucleotide polymorphisms were explored and the percentage contribution (R²) of T2D-related genes, parental history of T2D, and obesity (body mass index [BMI] and waist-hip ratio [WHR]) on T2D development was calculated using univariate and multivariate logistic regression models.

RESULTS

T2D-related genes influenced T2D development most in males who were diagnosed early (R² = 23.5%; females, R² = 13.5%; males and females diagnosed late, R² = 11.9% and R² = 7.3%, respectively). With an early diagnosis, insulin production-related genes were more influential in males (76.0% of R²) while peripheral insulin resistance-associated genes were more influential in females (52.3% of R²). With a late diagnosis, insulin production-related genes from chromosome region 11p15.5 notably influenced males while peripheral insulin resistance and genes associated with inflammation and other processes notably influenced females. Influence of parental history was higher among those diagnosed early (males, 19.9%; females, 17.5%) versus late (males, 6.4%; females, 5,3%). Unilateral maternal T2D history was more influential than paternal T2D history. BMI influenced T2D development for all, while WHR exclusively influenced males.

CONCLUSIONS

The influence of T2D-related genes, maternal T2D history, and fat distribution on T2D development was greater in males than females.

A cross-sectional analysis of the association between testosterone and biopsy-proven non-alcoholic fatty liver disease in men with obesity

PURPOSE

To study the association between testosterone and non-alcoholic fatty liver disease (NAFLD) since prior studies have reported inconsistent results.

METHODS

A retrospective analysis was performed including obese men who underwent a liver biopsy and a metabolic and hepatological work-up. Free testosterone (CFT) was calculated by the Vermeulen equation. The association between total testosterone (total T) and CFT on the one hand and NAFLD and fibrosis on the other hand was investigated and corrected for biasing factors such as metabolic parameters.

RESULTS

In total, 134 men (mean age 45 ± 12 years, median BMI 39.6 (25.0-64.9) kg/m²) were included. The level of total T and CFT did not significantly differ between NAFL and NASH and the stages of steatosis and ballooning. CFT was significantly lower in a higher stage of fibrosis (p = 0.013), not seen for total T and not persisting after controlling for the influence of BMI, HDL cholesterol and HOMA-IR. A higher stage of lobular inflammation was associated with a lower level of total T (p = 0.033), not seen for CFT and not persisting after controlling for the influence of visceral adipose tissue surface and HOMA-IR.

CONCLUSIONS

This is the second largest study investigating the association between testosterone and biopsy-proven NAFLD. No significant association between testosterone levels and NAFLD, and the different histological subgroups or fibrosis was seen. The lower level of CFT in a higher stage of fibrosis and the association between total T and lobular inflammation was driven by poor metabolic parameters.

The association of asthma duration with body mass index and Weight-Adjusted-Waist index in a nationwide study of the U.S. adults

BACKGROUNDS

The association between obesity and asthma has been of interest, but whether the duration of asthma has an effect on obesity is still limitedly studied.

AIM

The purpose of this study was to investigate the association between asthma duration and obesity-related indexes, where obesity-related indexes include Body mass index (BMI) and Weight-adjusted-waist index (WWI).

METHODS

Data from National Health and Nutrition Examination Survey (NHANES) 2009-2018 were obtained to conduct this cross-sectional study. Duration of asthma was used as the independent variable and obesity-related indexes as the response variables. Multiple linear regression was used to assess the association between the independent variable and the response variables, and subsequently smoothed curve fitting and threshold effect analysis were performed to clarify whether there was a nonlinear correlation between the independent variable and the response variables. Finally, subgroup analysis was conducted to find sensitive populations.

RESULTS

A total of 9170 participants were included in the analysis. Asthma duration was statistically different between the two groups when all participants were grouped by median WWI (Q1 < 11.65, Q2 ≥ 11.65) (P < 0.001), but not by median BMI (Q1 < 31.8, Q2 ≥ 31.8) (P = 0.130). There was a positive association between asthma duration and WWI [β = 0.016, 95% CI (0.016, 0.017)], but a negative one with BMI [β = - 0.098, 95% CI (- 0.112, - 0.085)], and the correlations between the independent and response variables became more pronounced with increasing asthma duration (P for trend < 0.01). In addition, there were nonlinear relationships between asthma duration with BMI and WWI (log likelihood ratio < 0.001), with the best valid inflection points for asthma duration being 2 years (with WWI as the response variable) and 3 years (with BMI as the response variable), respectively. In the subgroup analysis, the positive association between asthma duration and WWI was more pronounced in the participants who were male, aged less than 40 years, and had asthma onset before 12 years of age. In contrast, when BMI was used as the response variable, the negative association between it and asthma duration was more pronounced among participants of female, aged 60 years or older, and with asthma onset less than 12 years of age.

CONCLUSIONS

In US adults, asthma duration might cause changes in obesity-related indexes. Longer asthma duration might cause weight loss, but might increase the risk of abdominal obesity.

Metabolically Healthy Obesity: Are Interventions Useful?

PURPOSE OF REVIEW

This review aims to detail the current global research state of metabolically healthy obesogenesis with regard to metabolic factors, disease prevalence, comparisons to unhealthy obesity, and targeted interventions to reverse or delay progression from metabolically healthy to unhealthy obesity.

RECENT FINDINGS

As a long-term condition with increased risk of cardiovascular, metabolic, and all-cause mortality risks, obesity threatens public health on a national level. The recent discovery of metabolically healthy obesity (MHO), a transitional condition during which obese persons carry comparatively lower health risks, has added to confusion about the true effect of visceral fat and subsequent long-term health risks. In this context, the evaluation of fat loss interventions, such as bariatric surgery, lifestyle changes (diet/exercise), and hormonal therapies require re-evaluation in light of evidence that progression to high-risk stages of obesity relies on metabolic status and that strategies to protect the metabolism may be useful in the prevention of metabolically unhealthy obesity. Typical calorie-based exercise and diet interventions have failed to reduce the prevalence of unhealthy obesity. Holistic lifestyle, psychological, hormonal, and pharmacological interventions for MHO, on the other hand, may at least prevent progression to metabolically unhealthy obesity.

Association between testosterone levels and mood disorders: A minireview

BACKGROUND

Although many studies reported the neuropsychiatric involvement of testosterone (T) levels in the development of mood disorders, its role in this disabling disorder is still not well understood. Therefore, in this review, we aim to summarize the current literature exploring serum testosterone levels in both major depressive disorder (MDD) and bipolar disorder (BD), with particular attention given to the possible causal relationship between pathological mood alterations and T levels.

METHODS

We selected 9 original studies from a bibliographic search on PubMed, excluding studies on hormonal therapy and other psychiatric disorders other than mood disorders.

RESULTS

The results reported by the reviewed studies were conflicting especially with regards to the presence of dysfunctional levels of T in patients with BD. Specifically, while MDD was found to be associated with low levels of T compared to healthy controls (HC), in BD the results were highly heterogeneous, with a mixed picture of reduced, increased or no difference in T levels in BD patients compared to HC.

LIMITATIONS

Studies were highly heterogeneous in terms of samples employed, psychometric scales used for assessing depressive symptoms, T assay methods and therapeutic regimens.

CONCLUSIONS

Overall, T levels were shown to be reduced in both MDD and BD patients, ultimately suggesting that T could be useful as a biomarker in mood disorders and provide guidance for future research.

Male sex hormones, aging, and inflammation

Adequate levels of androgens (eugonadism), and specifically testosterone, are vital compounds for male quality of life, longevity, and positive health outcomes. Testosterone exerts its effects by binding to the androgen receptor, which is expressed in numerous tissues throughout the body. Significant research has been conducted on the impact of this steroid hormone on skeletal, muscle and adipose tissues and on the cardiovascular, immune, and nervous systems. Testosterone levels have also been studied in relation to the impact of diseases, aging, nutrition and the environment on its circulating levels. Conversely, the impact of testosterone on health has also been evaluated with respect to its cardiac and vascular protective effects, body composition, autoimmunity and all-cause mortality. The male aging process results in decreasing testosterone levels over time. The exact mechanisms and impact of these changes in testosterone levels with age on health- and life-span are still not completely clear. Further research is needed to determine the optimal testosterone and androgen levels to protect from chronic age-related conditions such as frailty and osteoporosis.

Increased fat mass negatively influences femoral neck bone mineral density in men but not women

BACKGROUND

Obesity is known to be a protective factor against osteoporosis. However, recent studies have shown that excessive adiposity may be detrimental for bone health.

OBJECTIVE

To determine the association of lean mass (LM) and fat mass (FM) with bone mineral density (BMD) in Thais.

METHODS

Bone density studies of consecutive patients of Srinagarind Hospital, Khon Kaen, Thailand between 2010 and 2015 were reviewed. LM, FM, lumbar spine (LS) and femoral neck (FN) BMD were measured. Lean mass index (LMI) and fat mass index (FMI) were calculated [LMI=LM (kg)/height (m)², FMI=FM (kg)/height (m)²] and analyzed to determine the association with LS and FN BMD using multiple regression analysis. This study was approved by the institutional ethical committee (HE42116).

RESULTS

A total of 831 participants were included. The mean ± SD age was 50.0 ± 16.3 years. In men, LMI (per 1 kg/m² increase) was positively correlated with FN BMD (g/cm², β 0.033) and LS BMD (g/cm², β 0.031), after adjusting for age, height and FMI. Whereas FMI (per 1 kg/m² increase) was negatively correlated with FN BMD (g/cm², β -0.015) but not with LS BMD (g/cm², β 0.005) after adjusting for age, height and LMI. In women, both LMI and FMI were positively correlated with LS BMD (g/cm², LMI: β 0.012; FMI: β 0.016) and FN BMD (g/cm², LMI: β 0.034; FMI: β 0.007) with age, height, LMI and FMI included in the model.

CONCLUSION

Our findings indicate that FM has a sex-specific influence on BMD in Thais.

Testosterone deficiency in non-obese type 2 diabetic male patients

BACKGROUND AND AIMS

it is unclear whether male hypogonadism is ascribable to the diabetic state per se, or because of other factors, such as obesity or age. We aimed to investigate the prevalence and identify the predictors for testosterone deficiency among non-obese type 2 diabetic males.

METHODS

This cross-sectional study was conducted on 95 nonobese type 2 diabetic males with BMI below 30. We evaluated the total testosterone (TT) levels to determine prevalence and risk factors of testosterone deficiency. Serum TT ≤ 300 ng/dl defined testosterone deficiency.

RESULTS

The prevalence of testosterone deficiency was 29.1%. Testosterone deficient patients had statistically significantly higher visceral adiposity index (VAI), waist, and triglyceride in comparison with normal testosterone patients. TT level correlated with VAI, waist, BMI, LH, and age. VAI was the only significant predictor of TT levels even after adjustment for age and BMI in regression analysis. Furthermore, VAI was a statistically significant risk factor for testosterone deficiency in binary logistic analysis.

CONCLUSIONS

testosterone deficient non-obese type 2 diabetic male patients had elevated VAI, waist, and triglyceride. Moreover, elevated VAI was a risk factor for testosterone deficiency. VAI could be an easily applicable and reliable index for the evaluation and prediction in type 2 non-obese diabetic males.

Combining effect of camellia oil and squalene on hyperlipidemia-induced reproductive damage in male rats

Introduction

Camellia oil (CO), a common edible oil in China, contains a variety of active ingredients. In this study, we explored the combining effect and optimal feeding time of CO and squalene on hyperlipemia-induced reproductive damage rats and probably provided supportive data for use of CO for health benefits.

Methods

We established the hyperlipidaemia-induced reproductive damage model, and then the successfully modeled rats were randomly classified into four groups including a model control (MC) group, a camellia oil (CO) group, a camellia oil + squalene (COS) group, and a sildenafil (SN) group, which were feeding with different subjects during days 30 and 60. The normal (NC) group was fed under the same conditions.

Results

Our results showed that compared with the MC group, the CO, COS, and SN groups could significantly decline the serum TG, TC and LDL-C levels, increase the serum testosterone levels, the sperm counts in epididymidis and organ coefficients of penises, and no pathological change in penis and testis at days 30 and 60. Compared with the pure CO, the mixture of CO and squalene could significantly enhance the effect of decreasing the concentrations of TG, TC, and LDL-C and increasing the serum testosterone level and sperm count of epididymal tail, and the results of day 30 were better than those of day 60.

Discussion

CO and squalene have a combining effect on lowering blood lipid, improving the level of testosterone and the number of epididymal tail sperm, and promoting the recovery of erectile and sexual function on hyperlipidemia-induced reproductive damage rats on day 30.

Predictors of testosterone in zoo-managed male African elephants (Loxodonta Africana)

Reproductive complications for both male and female zoo-managed African elephants (Loxodonta africana) contribute to the rapidly declining population. In zoo-managed bull elephants, few studies have explored the potential physiological, physical, social, and environmental factors that influence bull fertility, particularly, androgen production. Testosterone is the essential steroid hormone for male sexual maturation and inadequate concentrations can be detrimental for spermatogenesis. Testosterone, fecal glucocorticoid metabolites, leptin, glucose, insulin, and triglycerides were analyzed from weekly fecal and blood serum samples taken over 6 months from six zoo-managed African elephant bulls (10-19 years of age). Testosterone levels were compared to endocrine factors, weekly social and environmental variables, daily musth signs, and body condition scores (BCS). The glucose-to-insulin ratio (G:I) was the only physiological biomarker found to be positively associated with testosterone. Predictive physical variables included Musth Score (+) and Moderate Exercise (+). Bulls with BCS signifying overweight (BCS 4) had lower testosterone (36.6 ± 1.6 ng/g fecal extraction [FE]) than bulls with healthy BCS 3; 51.2 ± 4.9 ng/g FE). Numerous social variables influenced testosterone concentrations, including Total Contact Day (+), Female Interaction Day (+), Indirect Contact Day (+), Indirect Contact Night (+) and Total No Contact (-). Both percentage of Time Outdoor and Time Mixed positively influenced testosterone, whereas testosterone decreased for percentage of Time Indoors. Each additional daily browse opportunity increased testosterone by approximately 7 ng/g FE. In managed care, the emphasis should be placed on optimizing these predictors of testosterone production to promote bull reproductive health.

Factors of Obesity and Metabolically Healthy Obesity in Asia

The East Asian region (China, Japan, and South Korea) is comprised of almost 1.5 billion people and recent industrialization has brought with it a pandemic of rising obesity, even in children. As these countries are rapidly aging and functioning at sub-replacement birthrates, the burgeoning costs of obesity-related care may threaten socialized healthcare systems and quality of life. However, a condition called metabolically healthy obesity (MHO) has been found to be without immediate cardiopulmonary or diabetic risk. Thus, maintenance of the MHO condition for the obese in East Asia could buffer the burden of long-term obesity care on medical systems and knowledge of the biochemical, genetic, and physiological milieu associated with it could also provide new targets for intervention. Diverse physiological, psychological, environmental, and social factors play a role in obesogenesis and the transition of MHO to a metabolically unhealthy obesity. This review will give a broad survey of the various causes of obesity and MHO, with special emphasis on the East Asian population and studies from that region.

The impact of diabetes mellitus type 2 on the steroidogenesis of male Zucker Diabetic Fatty rats

The aim of this study was to evaluate the impact of diabetes mellitus type 2 (DM2) on the male endocrine system of Zucker Diabetic Fatty (ZDF) rats. Sexually mature ZDF rats were divided to a lean (control) and obese group, and had diabetes confirmed by blood tests. For the in vivo experiment, fasting blood was collected to obtain blood plasma. In case of the in vitro experiments, testicular fragments were cultured for 24 h, and the culture medium was collected. The concentrations of testosterone (T), androstenedione (A4), dehydroepiandrosterone (DHEA-S), estradiol (E2), follicle-stimulating hormone (FSH) and luteinizing hormone (LH) were quantified in the blood plasma and the medium by the ELISA method, while cholesterol (CHOL) was assessed spectrophotometrically. A significant decline of T (36.31 %), A4 (25.11 %) and FSH (26.99 %) as well as a significant increase of CHOL and E2 (36.17 %) was observed in the blood plasma of obese ZDF rats in comparison to the control. Under in vitro conditions, a significant decrease of FSH (23.35 %) accompanied by an increase of E2 was observed in the obese group compared to the control. In the case of CHOL, LH, T, DHEA and A4 no significant differences were observed. Our results suggest that except for FSH and E2 all steroid biomolecules were synthetized normally by the testicular tissue, however a dramatic endocrine disturbance was observed at the system level. We may conclude that DM2 has negative effects on systemic hormone secretion and these alterations are more pronounced in combination with obesity.

Effects of a 3-Month Physical Training on Cortisol and Testosterone Responses in Women After Bariatric Surgery

PURPOSE

Although it is well established that physical activity (PA) may partially correct the metabolic and hormonal alterations observed in patients with obesity, knowledge of its impact after bariatric surgery (BS) remains poor. The purpose of this study was to assess the repercussions of physical training on cortisol and testosterone responses in post-BS women.

MATERIALS AND METHODS

According to a randomized clinical trial, a PA group (11 women) started a 3-month physical training 6 weeks after BS, whereas no specific activity was proposed to a control group (9 women). Submaximal exercise (i.e., 30 min at 60% VO₂peak) was performed by all subjects just before and after the 3-month period. Blood samples were taken at rest, after 10, 20, and 30 min of exercise and 10 min of passive recovery for cortisol and testosterone analyses. Blood glucose, blood lactate, and heart rate were assessed at the same time.

RESULTS

Before the program, a significant increase in cortisol, blood lactate, and heart rate was observed in all subjects during the submaximal exercise vs. rest, with no change in blood glucose and testosterone. After vs. before the 3-month period, no modification in any parameter was noted at rest in either group. However, during exercise, lack of cortisol increase and lower heart rate were found in the PA group only, with disappearance of the increase in blood lactate in both groups.

CONCLUSION

Our results show some beneficial effects of physical training on hormonal and physical parameters. Further studies are needed to determine the biological and clinical significance of these adaptations induced by physical training in women after BS.

Adipose Tissue Dysfunction and Obesity-Related Male Hypogonadism

Obesity is a chronic illness associated with several metabolic derangements and comorbidities (i.e., insulin resistance, leptin resistance, diabetes, etc.) and often leads to impaired testicular function and male subfertility. Several mechanisms may indeed negatively affect the hypothalamic–pituitary–gonadal health, such as higher testosterone conversion to estradiol by aromatase activity in the adipose tissue, increased ROS production, and the release of several endocrine molecules affecting the hypothalamus–pituitary–testis axis by both direct and indirect mechanisms. In addition, androgen deficiency could further accelerate adipose tissue expansion and therefore exacerbate obesity, which in turn enhances hypogonadism, thus inducing a vicious cycle. Based on these considerations, we propose an overview on the relationship of adipose tissue dysfunction and male hypogonadism, highlighting the main biological pathways involved and the current therapeutic options to counteract this condition.

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

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

Nonpharmacological Interventions for the Management of Testosterone and Sperm Parameters: A Scoping Review

PURPOSE

Testosterone replacement and associated pharmacologic agents are effective strategies to treat male hypogonadism; however, nutraceutical agents and lifestyle modification approaches have gained medical interest. The purpose of this scoping review is to highlight the evidence (or lack thereof) of nutraceuticals and lifestyle modification approaches in the management of testosterone levels and sperm parameters.

METHODS

A scoping review of nonpharmacologic interventions (supplements, herbal medicines, diets, sleep, and exercise) with the potential to improve male health was undertaken to elucidate changes in testosterone levels and sperm parameters in men with hypogonadism or infertility compared with healthy patients.

FINDINGS

A multitude of nutraceuticals and functional nutrients are purported to stimulate testosterone production; however, only a select few have had promising results, such as zinc, vitamin D (in case of hypovitaminosis D), l-arginine, mucuna, and ashwagandha, based on well-controlled randomized clinical trials of men with low testosterone levels and related problems. Except for l-arginine, these natural agents, as well as tribulus and ω3 fatty acids, can improve some degree of sperm parameters in infertile men. Before implementing these nutraceutical agents, adequate sleep, exercise, and weight loss in patients with obesity are imperative. The effects of nonpharmacologic interventions on testosterone levels are modest and hence do not directly translate into clinical benefits. Correspondingly, androgen receptor content, but not endogenous androgens, has been regarded as the principal factor in muscle hypertrophy.

IMPLICATIONS

A limited number of supplements and herbal medicines can be considered as adjunctive approaches in the management of testosterone levels and sperm parameters, primarily in men with low testosterone levels and infertility, whereas most nonpharmacologic supplements appear to lack evidence. Although proper physical exercise, sleep, and diet are indisputable approaches because of the general benefits to health, the use of nutraceuticals, if considered, must be personalized by physicians and/or registered dietitians.

Associations of plasma betaine, plasma choline, choline intake and MTHFR polymorphism (rs1801133) with anthropometric parameters of healthy adults are sex-dependent

OBJECTIVE

Choline and its metabolites seem to have relationships with body mass index (BMI), body fat, and body weight, but research results have proved inconsistent. We thus investigated the associations of plasma levels of TMAO, choline, and betaine, with anthropometric measurements, including modulatory effects of genetics and diet.

METHODS

The study was performed on a group of 421 adults aged 20 to 40, who had been recruited in Poland. Plasma concentrations of choline, betaine, and TMAO were determined using RP-UHPLC-ESI-MS. The following polymorphisms were genotyped using TaqMan probes: rs180113 (MTHFR), the rs70991108 (DHFR), rs2236225 (MTHFD1), and rs7946 and rs12325817 (PEMT). We employed multivariate linear regression to examine the associations between anthropometric measurements, one carbon metabolism metabolites, and genotypes.

RESULTS

Higher plasma choline was associated with higher BMI (β=0.17; p< 0.01), body weight (β=0.11; p< 0.05), body fat mass (β=0.10; p<0.05), and waist circumference (WC) (β=0.14; p<0.01), whereas higher choline intake was associated with lower body fat mass (β=-0.14; p< 0.01), and lower WC (β=-0.12; p<0.01). After stratification by sex, plasma betaine was found to be associated with BMI (β=-0.20; p<0.05) and body weight (β=-0.16; p<0.05) in men only, while choline intake was associated with body fat mass (β=-0.19; p<0.05), and WHR (β=-0.19; p<0.05), and MTHFR CC genotype was associated with WHR (β=0.15; p<0.05) in women only.

CONCLUSIONS

Higher plasma betaine and higher dietary choline are associated with lower fat mass and body weight, whereas higher plasma choline is positively associated with body weight status and adiposity. Moreover, these associations seem to be sex-specific. This article is protected by copyright. All rights reserved.

Effect of Intermittent Fasting on Reproductive Hormone Levels in Females and Males: A Review of Human Trials

Intermittent fasting is a popular diet for weight loss, but concerns have been raised regarding the effects of fasting on the reproductive health of women and men. Accordingly, we conducted this literature review to clarify the effects of fasting on reproductive hormone levels in humans. Our results suggest that intermittent fasting decreases androgen markers (i.e., testosterone and the free androgen index (FAI)) while increasing sex hormone-binding globulin (SHBG) levels in premenopausal females with obesity. This effect was more likely to occur when food consumption was confined to earlier in the day (eating all food before 4 pm). In contrast, fasting did not have any effect on estrogen, gonadotropins, or prolactin levels in women. As for men, intermittent fasting reduced testosterone levels in lean, physically active, young males, but it did not affect SHBG concentrations. Interestingly, muscle mass and muscular strength were not negatively affected by these reductions in testosterone. In interpreting these findings, it is important to note that very few studies have been conducted on this topic. Thus, it is difficult to draw solid conclusions at present. From the limited data presented here, it is possible that intermittent fasting may decrease androgen markers in both genders. If this is the case, these results would have varied health implications. On the one hand, fasting may prove to be a valuable tool for treating hyperandrogenism in females with polycystic ovarian syndrome (PCOS) by improving menstruation and fertility. On the other hand, fasting may be shown to decrease androgens among males, which could negatively affect metabolic health and libido. More research is warranted to confirm these preliminary findings.

Anti-Obesity Medications and Investigational Agents: An Obesity Medicine Association (OMA) Clinical Practice Statement (CPS) 2022

Background

This "Anti-Obesity Medications and Investigational Agents: An Obesity Medicine Association Clinical Practice Statement 2022" is intended to provide clinicians an overview of Food and Drug Administration (FDA) approved anti-obesity medications and investigational anti-obesity agents in development.

Methods

The scientific information for this Clinical Practice Statement (CPS) is based upon published scientific citations, clinical perspectives of OMA authors, and peer review by the Obesity Medicine Association leadership.

Results

This CPS describes pharmacokinetic principles applicable to those with obesity, and discusses the efficacy and safety of anti-obesity medications [e.g., phentermine, semaglutide, liraglutide, phentermine/topiramate, naltrexone/bupropion, and orlistat, as well as non-systemic superabsorbent oral hydrogel particles (which is technically classified as a medical device)]. Other medications discussed include setmelanotide, metreleptin, and lisdexamfetamine dimesylate. Data regarding the use of combination anti-obesity pharmacotherapy, as well as use of anti-obesity pharmacotherapy after bariatric surgery are limited; however, published data support such approaches. Finally, this CPS discusses investigational anti-obesity medications, with an emphasis on the mechanisms of action and summary of available clinical trial data regarding tirzepatide.

Conclusion

This "Anti-Obesity Medications and Investigational Agents: An Obesity Medicine Association Clinical Practice Statement 2022" is one of a series of OMA CPSs designed to assist clinicians in the care of patients with pre-obesity/obesity.

The 2D:4D index is associated with the development of excess body weight in adults, but not with the rate of weight loss following bariatric surgery

2D:4D finger length ratio is a proxy of prenatal sex hormone exposure. Prenatal testosterone decreases and prenatal estrogens increase this index. In the current study we investigated whether the 2D:4D index, as a marker of the prenatal hormonal environment, is associated with the development of overweight and obesity in adults, and whether is it correlated with the rate of weight loss in patients after bariatric surgery. We tested 125 adults with obesity (BMI ≥ 30.0 kg/m²), 125 adults with overweight (BMI 25.0–29.9 kg/m²) and 153 persons with normal body weight (BMI < 25 kg/m²) of both sexes. We have found that the development of excessive body weight in men and women, and fat accumulation in the upper arms, thighs and lower legs in women with obesity (but not men) are associated with increased prenatal estrogen exposure. This relationship indicates a new area of activity in the field of obesity prevention. Moreover, it seems that the 2D:4D index (especially of the right hand) may be a useful factor in early prediction of the risk of developing excessive body weight in humans. The rate of weight loss after bariatric surgery is independent of prenatal exposure to sex hormones.

Testosterone deficiency and the aging male

Testosterone deficiency (TD), also known as male hypogonadism, is a complex syndrome encompassing physical, biochemical, and social aspects that increasingly affects the aging population. TD has been analyzed over recent decades, with an enhanced focus on etiologies relating to aging males. There is debate whether testosterone decline leading to hypogonadism is directly and primarily related to age-specific processes or if it is the subsequent result of accumulating comorbidities throughout a lifetime. Several studies have been done to further characterize this distinction. Chronic comorbidities that have commonly been associated with TD include hypertension (HTN), cardiovascular disease (CVD), diabetes mellitus (DM), obesity, metabolic syndrome (MetS), chronic kidney disease (CKD), and tobacco use. Although clear associations between hypogonadism and aging have been biochemically demonstrated, many large studies have illustrated the concomitant effects of highly prevalent chronic diseases and social behaviors in aging men. Given the significant impact of hypogonadism on the physical and mental health of men, this paper aims to delve into these studies and further define the complex relationship of testosterone deficiency in the aging male.