Testosterone and obesity

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.

Comprehensive Analysis of the Association Between Sex Hormones and Body Mass Components Among Men Adults: Results From a Large Population-Based Study

BACKGROUND

As the human body ages, adverse body composition status such as sarcopenia and obesity become obvious phenotypes which can cause numerous health problems. We aimed to comprehensively investigate the association of sex hormones and body mass components in adult men of various age groups.

METHODS

We analysed national representative population data from the US National Health and Nutrition Examination Survey. Generalized linear model regression analyses were used to evaluate the association between sex hormones (total testosterone [TT], bio-available testosterone [BT], sex hormone-binding globulin [SHBG], estradiol [E2] and testosterone to estradiol ratio [T/E ratio]) and body mass components (weight, body mass index (BMI), total lean mass, appendicular lean mass, bone mineral content, total fat and trunk fat). The collection and testing time of blood samples were not fixed and there was no strict fasting, but in subsequent analysis we used statistical methods to minimize the impact of random testing.

RESULTS

After screening for inclusion and exclusion, 3759 male participants aged 20-85 years old were included in this study. Higher levels of TT, SHBG, BT and T/E ratios were significantly associated with higher total lean mass, appendicular lean mass and bone mineral content, while lower weight, BMI, total fat and trunk fat. For E2 levels in men, we found an opposite trend, with higher E2 levels significantly associated with lower total lean mass and appendicular lean mass, and higher weight, BMI, total fat and trunk fat. Notably, in subgroup analysis, the results showed that there were significant interaction effects of age and smoking history in the association between sex hormones and body mass components.

CONCLUSION

Higher TT levels, BT levels, SHBG levels and T/E ratios are associated with lower body weight and improved body composition in young adult men (characterized by higher lean body mass, higher bone density and lower fat mass). The relationship is especially pronounced among relatively young, nonsmoking men.

Effect of Endogenous Hormone Levels on Basal Metabolic Rate in Men With Obesity

OBJECTIVE

Basal metabolic rate (BMR) is an important factor in weight management and is influenced by fat-free mass (FFM), fat mass (FM) and age. Current knowledge of the influence of hormonal levels on BMR is based on studies with small populations, studies that investigate exogenous administration and studies frequently lacking correction for body composition.

DESIGN

Cross-sectional study.

PATIENTS

All men (n = 457) who were referred to our centre for a metabolic work-up were eligible for inclusion. Median age was 47 (18-78) years and the vast majority had obesity (BMI ≥ 30 kg/m², 90.9%).

MEASUREMENTS

All men had a measurement of BMR, body composition and measurement of testosterone, sex hormone binding globulin (SHBG), dehydroepiandrosterone sulphate (DHEAS), insulin-like growth factor 1 (IGF-1), thyroid-stimulating hormone (TSH) and free thyroxine (fT4). Men with low, normal and/or high levels of each of these hormones were compared. The association between hormone levels and BMR was assessed through linear regression models. All analyses were controlled for FFM, FM and age.

RESULTS

In men with obesity, testosterone (total or free) was not associated with BMR. Linear regression analysis showed that DHEAS was positively associated with BMR in a sample of men with obesity and normal endogenous DHEAS levels, with the following equation: BMR (adjusted R² = 0.72): (BMR [kcal/d] = 513.402 + 18.940 × FFM [kg] + 9.507 × FM [kg] - 3.362 × age [years] + 0.307 × DHEAS [µg/dL]) (p < 0.01). TSH, fT4 and IGF-1 were not associated with BMR.

CONCLUSION

In men with obesity, endogenous DHEAS is positively associated with BMR. Testosterone, TSH, fT4 and IGF-1 were not associated with BMR in men with obesity. Since we examined the specific population of men with obesity and only examined endogenous hormone levels, no extrapolation of results to other populations or the overall population can be made.

Association between the weight-adjusted-waist index and testosterone deficiency in adult males: a cross-sectional study

Testosterone deficiency has been recognized as a significant health concern and is closely related to obesity. The weight-adjusted-waist index (WWI) is an innovative adiposity parameter that is superior to BMI in certain aspects, but its relationship with testosterone levels has not been elucidated. The aim of this study was to investigate the relationships of the WWI with total testosterone levels and testosterone deficiency. Data from the National Health and Nutrition Examination Survey (NHANES, 2011-2016) were utilized. The WWI was calculated as waist circumference (cm) over the square root of weight (kg), and a total testosterone level of less than 300 ng/dL was defined as testosterone deficiency. Weighted multivariable regression models were used to assess the associations. A total of 6859 participants were included, 26.28% of whom were testosterone deficient. The WWI was inversely related to total testosterone levels (β = -49.93, 95% CI: -60.07, -39.78, P < 0.001) and positively associated with testosterone deficiency (OR = 1.46, 95% CI: 1.23, 1.72, P < 0.001) in the fully adjusted model. A significant nonlinear relationship was also detected between WWI and testosterone deficiency (P for nonlinearity = 0.004) with an inflection point of 9.486 cm/√kg. The associations were consistent in the subgroup analysis (all P > 0.05), except for the participants with eGFR < 60 mL/(min*1.73m2) and hypertension. A higher WWI was linked to lower total testosterone levels and a greater risk of developing testosterone deficiency, especially among those who had an eGFR ≥ 60 mL/(min*1.73m2) and were nonhypertensive.

A Mendelian Randomization Study of the Connection Between Exogenous Hormones and Perianal Abscess in Pediatric Patients

Background: Recent years have witnessed the hypothesis that bioavailable testosterone (BT) might be closely related to the development of inflammatory diseases, especially anal abscess (AA), a common inflammatory ailment with unclear pathogenesis. Given that AA is more prevalent among males, this study investigates the causal relationship between BT and AA. Objective: To explore the causal link between BT and AA, a Mendelian randomization (MR) study was conducted using large-scale genomic data. Materials and Methods: Utilizing genomic data from the UK Biobank and IEU OpenGWAS databases, a two-sample MR analysis was executed. Twenty-six genetic variants strongly associated with BT were selected as instrumental variables (IVs) to assess their link with AA risk. Various MR methods were employed for consistency checks, including sensitivity analyses for heterogeneity and horizontal pleiotropy. Results: Using a combination of MR methods, we identified a significant causal relationship between BT and the risk of AA. Specifically, the MR analysis revealed that higher levels of BT were associated with an increased risk of AA. Sensitivity analyses, including heterogeneity tests and assessments for horizontal pleiotropy, confirmed the robustness of these findings. The IVs used in the analysis demonstrated a strong association with BT and showed no evidence of significant heterogeneity or horizontal pleiotropy, indicating the validity of the causal inference. Conclusion: This study, employing two-sample MR for the first time, confirms a causal relationship between BT levels and the risk of AA. These findings provide preliminary evidence of the causal relationship between BT and AA and may offer new insights into the pathophysiological mechanism of AA and future therapeutic strategies.

Genetic determinants of plasma testosterone in male blood donors are associated with altered red blood cell characteristics and survival in cold storage and after transfusion

Genetic mutations in genes regulating plasma testosterone in men may interfere with effective erythropoiesis, and may result in red blood cell (RBC) dysfunction and hemolysis. The aim of this study was to identify genetic polymorphisms in male donors that regulate plasma testosterone and impact RBC survival in cold storage and after transfusion. We evaluated nine single nucleotide polymorphisms (SNPs) previously reported to be associated with circulating testosterone in male plasma. These SNPs were linked with donor-component-recipient databases (NIH REDS program) to determine SNP associations with donor RBC hematological indices, osmotic and oxidative hemolysis, and RBC transfusion effectiveness defined as adjusted hemoglobin increments (delta hemoglobin, ΔHb) following a single RBC unit transfusion. Four of the nine testosterone SNPs were located on the X chromosome, of which two (rs7057002, rs73629199) were significantly associated with reduced hemoglobin increments (0.2 and 0.3 g/dL, respectively) compared with reference alleles in transfused recipients. Seven of the nine testosterone SNPs were associated with significant changes in RBC susceptibility to osmotic hemolysis including a missense mutation in the major plasma carrier of testosterone (SHBG, rs6259), and four SNPs with changes in oxidative hemolysis. Four SNPs were associated with decreased RBC count, hemoglobin, and hematocrit. Ancestry/ethnicity-specific (African and Hispanic) associations were observed between two SNPs (rs7057002, rs7879462) and oxidative hemolysis. Genetic determinants of plasma testosterone in male donors significantly impact the quality and transfusion effectiveness of cold stored RBCs. Testosterone SNPs associated with decreased RBC transfusion effectiveness may have clinical implications and warrant further revaluation.

Higher Steroid Production in the Right Adrenal Gland Compared to the Left One in db/db Mice, a Model of Type 2 Diabetic Obesity

Vertebrates exhibit a left-right asymmetry from the central structures to the peripheral paired endocrine organs. However, the asymmetries in paired endocrine glands and the pathological consequences of such asymmetries remain largely unknown. The adrenal gland constitutes a pair of peripheral end organs in the neuroendocrine system, responsible for producing steroid hormones under stimuli. In the present study, the lateralized asymmetry of left and right adrenal glands in leptin receptor-deficit db/db mice was investigated. First, a morphological and histological examination showed that adrenal mass and adrenal cortex volume in db/db mice were significantly higher than in non-diabetic control mice. Then, adrenal transcriptomic and serum metabolomic analyses were performed. Adrenal steroid profiling showed that the levels of corticosterone and aldosterone in the right adrenal gland of db/db mice were two times higher than in the left one. The expression of multiple genes related to adrenal regeneration and innervation in db/db mice was reduced in contrast to the increased steroid hormone secretion. Furthermore, an examination of morphogens in asymmetric adrenal development revealed a significant differential expression of Shh and its receptor gene Ptch1. In conclusion, the present study has provided evidence that a superior steroidogenesis exists in the right adrenal gland of db/db mice and suggested that Shh signaling may play an important role in asymmetric adrenal responses in type 2 diabetes and its complications.

Can serum 17-hydroxy progesterone predict an improvement in semen parameters following micro-varicocelectomy? A prospective study

BACKGROUND & OBJECTIVES

Notably, 17-hydroxy progesterone (17-OHP) (17-OHP) is a precursor for testosterone (T) synthesis, and intratesticular testosterone (ITT) is essential for spermatogenesis. Varicocele (Vx) has an estimated prevalence of 15% in the general population and 35% in those with primary infertility. We aimed to evaluate the correlation between changes of serum 17-OHP after sub-inguinal micro-varicocelectomy and improvement of semen parameters.

PATIENTS AND METHODS

The current prospective study included 45 infertile men attending the andrology clinic form February 2021 to August 2021. Two semen analyses and hormonal profile were evaluated. Colored duplex ultasonography (CDUS) was done in standing and supine position for accurate measurements of testicular volumes and confirmation of Vx. Patients underwent sub-inguinal micro-varicocelectomy using a surgical microscope HB surgitech. We followed them prospectively up for three months following micro-varicocelectomy with serum TT and 17-OHP.

RESULTS

Sperm concentration improved significantly from 8.36 ± 5.04 million/ml to 12.52 ± 8.42 million/ml after 3 months following sub-inguinal micro-varicocelectomy (p= 0.001), with normalization of concentration in 15/45 (33%) patients. Total motility did not improve significantly but progressive motility improved significantly from 8.62 ± 8.74% to 16.24 ± 14.45% (p=0.001). Abnormal forms significantly declined from 96.67 ± 2.03% to 95.75 ± 2.47% (p=0.009).  Serum 17 OHP and 17 OHP/total testosterone (TT) improved significantly from 1.21 ± 0.45 ng/ml and 0.26 ± 0.09 to 1.42 ± 0.76 ng/ml and 0.3 ± 0.16 (p= 0.013, p= 0.004), respectively, while serum TT did not improve significantly. A significant correlation was found between improvement in sperm concentration and both serum 17 OHP and 17 OHP/TT ratio (p=0.001, p=004). Furthermore, change in abnormal sperm forms showed significant correlations with changes in both 17-OHP and 17-OHP/TT.

CONCLUSION

17 OHP and 17OHP/ TT ratio can be used as biomarkers to detect improvement in semen parameters following sub-inguinal micro-varicocelectomy.

The effects of opioid tapering on select endocrine measures in men and women with head and neck cancer-a longitudinal 12-month study

Introduction

Opioid treatment may affect endocrine measures in humans either through centrally or peripherally mediated mechanisms. There is a general lack of longitudinal studies examining endocrine measures in opioid-treated patients.

Objectives

To longitudinally follow the levels of select endocrine measures in men and women with head and neck cancer for 1 year, who after having completed radiotherapy began tapering opioids.

Methods

This was a prospective, longitudinal, observational study. Testosterone and estradiol were measured in men and women, respectively. Follicle-stimulating hormone (FSH), luteinizing hormone (LH), dehydroepiandrosterone sulfate (DHEAS), and prolactin were measured in both sexes. Women were grouped based on if premenopausal or postmenopausal. Samples were collected when opioid tapering started and at 1, 3, 6, and 12 months after tapering start. Daily opioid doses at the same time points were registered.

Results

Twenty-five men and 12 women were followed for 12 months. In men, testosterone levels increased significantly during the first month after opioid tapering started (P < 0.001). Levels of testosterone, FSH, DHEAS, and prolactin changed significantly in men during the study period. A moderate correlation between opioid dose reduction and testosterone level increase in men aged ≤60 years was found (r s = -0.577, 95% CI -0.854 to -0.044, P = 0.039). In postmenopausal women (n = 10), levels of FSH and LH changed significantly during the study period.

Conclusion

Previously known effects of opioids on endocrine measures in humans seem to be reversible as select endocrine measures changed significantly in men and postmenopausal women after opioid tapering was initiated.

Preparing the soil: Adjusting the metabolic health of patients with chronic wounds and musculoskeletal diseases

In recent years, systemic inflammation has emerged as a pivotal player in the development and progression of various degenerative diseases. This complex, chronic inflammatory state, often undetected, can have far-reaching consequences for the body's physiology. At the molecular level, markers such as C-reactive protein, cytokines and other inflammatory mediators serve as indicators of systemic inflammation and often act as predictors of numerous musculoskeletal diseases and even certain forms of cancer. The concept of 'meta-inflammation', specifically referring to metabolically triggered inflammation, allows healthcare professionals to understand inflammatory responses in patients with metabolic syndrome. Driven by nutrient excess and the expansion of adipose tissue, meta-inflammation is closely associated with insulin resistance, further propagating the metabolic dysfunction observed in many Western societies. Wound persistence, on the other hand, exacerbates the detrimental effects of prolonged inflammation at the local level. Acute inflammation is a beneficial and essential process for wound healing and infection control. However, when inflammation fails to resolve, it can impede the healing process, leading to chronic wounds, excessive scarring and even the activation of fibrotic pathways. This approach significantly reduces the efficacy of regenerative biological therapies. Our review focuses on the vital role of proteins, vitamins and minerals in collagen synthesis and cell proliferation for tissue healing. We also examine hormonal influences on regeneration, noting the negative effects of imbalances, and emphasize glucose regulation's importance in creating a stable environment for chronic wound healing.

Bodyweight influences the relationship between serum testosterone and bone mineral density in men with spinal cord injury

STUDY DESIGN

Cross-sectional study.

OBJECTIVE

To examine the association between serum testosterone levels (T levels) and bone mineral density after spinal cord injury (SCI).

SETTING

Medical research center.

METHODS

Body composition assessments were measured in 53 men with chronic SCI. Serum T levels were measured after an overnight fast. Total and regional bone mineral density (BMD) and bone mineral content (BMC) were measured using dual-energy X-ray absorptiometry. Participants were classified into three groups based on their body weight [<65 kg, 65-80 kg, >80 kg] or serum T levels into low (400 ng/dl), mid-normal (401-544 ng/dl) and normal (>545 ng/dl) ranges.

RESULTS

Serum T level was negatively related to body weight (r = -0.33, P = 0.016), fat mass (r = -0.46, P < 0.001) and percentage fat mass (r = -0.48, P < 0.001). There were no significant relationships between serum T levels and any of the bone health measurements. Body weight was related to total, regional (P < 0.01 for both) and knee BMD (P < 0.05). T level was only related to total and regional BMD in the group with body weight of 65-80 kg.

CONCLUSION

Testosterone has no direct relationship with BMD except within a specific weight group. However, body weight or fat mass negatively influences circulating T levels in men with SCI. The relationship between serum T levels and BMD is mediated by body weight in men with SCI.

Clomiphene Citrate Treatment as an Alternative Therapeutic Approach for Male Hypogonadism: Mechanisms and Clinical Implications

Male hypogonadism, which is characterized by low testosterone levels, has a significant impact on male sexual function, overall health, and fertility. Testosterone replacement therapy (TRT) is the conventional treatment for this condition, but it has potential adverse effects and is not suitable for men seeking to conceive. Testosterone plays an essential role in male sexual function, metabolism, mood, and overall well-being. Clomiphene citrate, a drug originally developed for female infertility, has recently gained attention as an off-label treatment for male hypogonadism. By blocking the negative feedback of estrogen on the hypothalamus and pituitary glands, clomiphene stimulates gonadotropin secretion, leading to increased endogenous testosterone production, which, in turn, improves sperm parameters and fertility and alleviates the symptoms of hypogonadism. Regarding the safety profile of clomiphene compared with TRT, clomiphene appears to confer a lower risk than TRT, which is associated with adverse effects such as polycythemia. Furthermore, combination therapy with clomiphene and anastrozole or human chorionic gonadotropin has been investigated as a potential approach to enhancing the effectiveness of treatments for improving hypogonadism symptoms. In conclusion, clomiphene citrate may offer a promising alternative to TRT for men with hypogonadism, particularly those desiring fertility preservations. However, its long-term efficacy and safety remain inadequately understood. Future research should focus on exploring the benefits of combination therapies and personalized treatment strategies based on individual patient characteristics.

Association between endogenous sex hormones and adiposity in youth across a weight status spectrum

BACKGROUND

While endogenous sex hormones (e.g., testosterone, estradiol) are important factors regulating adipose tissue distribution, studies evaluating such relationships in youth across a wide weight status spectrum are limited.

METHODS

We performed a cross-sectional analysis of 8-21-year-old youth. Multiple linear regression models were used to evaluate associations between sex hormones and adiposity measures (android/gynoid ratio (A/G), total fat mass (FM), visceral adipose tissue (VAT), waist circumference (WC)) and total lean mass (LM), adjusting for pubertal stage and race/ethnicity, and stratified by sex and weight status.

RESULTS

Among 342 youth, the mean age was 13.0 ± 2.8 years old (52.6% female; 38.9% normal weight [NW]; 27.8% overweight/obesity [OW/OB]; 33.3% severe obesity [SO]). Testosterone was positively associated with LM among males with NW (1462 g, 95% CI: 255-2668 g) and OW/OB (3792 g, 95% CI: 1244-6340 g), with A/G and WC among males with NW (0.01, 95% CI: 0-0.2 and 10 mm, 95% CI: 4-16 mm, respectively), and negatively associated with WC among males with SO (-43 mm, -81 to -5 mm). Estradiol was positively associated with A/G, FM, and WC among males with SO, and VAT in females with NW.

CONCLUSION

Our findings showed that sex hormones were associated with adipose tissue deposition in youth across the weight spectrum.

IMPACT STATEMENT

Sex hormones (e.g., testosterone, estradiol) are associated with various adiposity measures among male and female children and adolescents across a weight status spectrum. We evaluated associations between sex hormones and various adiposity measures among 8-21-year-olds across a weight status spectrum (normal weight, overweight/class 1 obesity, class 2-3 obesity). We found that estradiol was positively associated with total fat mass, android/gynoid ratio, and waist circumference in males with class 2-3 obesity, and testosterone was positively associated with lean mass in males with normal weight and overweight/class 1 obesity. Sex hormones may influence, or may be influenced by, adiposity in youth.

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.

Dysregulation of mitochondrial dynamics and mitophagy are involved in high-fat diet-induced steroidogenesis inhibition

Male obesity is a pandemic health issue and can disrupt testicular steroidogenesis. Here, we explored the mechanism by which a high-fat diet (HFD) induced steroidogenic inhibition. As expected, HFD induced lipid droplet accumulation and reduced the expression of StAR, P450scc, and 3β-HSD, three steroidogenic enzymes, in mouse testes. Palmitic acid (PA), a saturated fatty acid usually used to trigger lipotoxicity in vitro, induced greater accumulation of lipid droplets and the downregulation of steroidogenic enzymes in TM3 cells. Mechanistically, both HFD and PA disturbed mitochondrial fusion/fission dynamics and then induced mitochondrial dysfunction and mitophagy inhibition in mouse Leydig cells. Additionally, mitochondrial fusion promoter M1 attenuated PA-induced imbalance of mitochondrial dynamics, mitophagy inhibition, mitochondrial reactive oxygen species (ROS) production, and mitochondrial dysfunction in TM3 cells. Mitofusin 2 (Mfn2) knock-down further aggravated the PA-induced imbalance of mitochondrial dynamics, mitochondrial ROS production, and mitochondrial dysfunction in TM3 cells. Importantly, M1 rescued PA-induced downregulation of steroidogenic enzymes, whereas Mfn2 knock-down further aggravated PA-induced downregulation of steroidogenic enzymes in TM3 cells. Overall, our results provide laboratory evidence that mitochondrial dysfunction and mitophagy inhibition caused by dysregulation of mitochondrial fusion may be involved in HFD-induced steroidogenesis inhibition in mouse Leydig cells.

Evaluation of visceral adipose tissue thresholds for elevated metabolic syndrome risk across diverse populations: A systematic review

Beyond obesity, excess levels of visceral adipose tissue (VAT) significantly contribute to the risk of developing metabolic syndrome (MetS), although thresholds for increased risk vary based on population, regions of interest, and units of measure employed. We sought to determine whether a common threshold exists that is indicative of heightened MetS risk across all populations, accounting for sex, age, BMI, and race/ethnicity. A systematic literature review was conducted in September 2023, presenting threshold values for elevated MetS risk. Standardization equations harmonized the results from DXA, CT, and MRI systems to facilitate a comparison of threshold variations across studies. A total of 52 papers were identified. No single threshold could accurately indicate elevated risk for both males and females across varying BMI, race/ethnicity, and age groups. Thresholds fluctuated from 70 to 165.9 cm2, with reported values consistently lower in females. Generally, premenopausal females and younger adults manifested elevated risks at lower VAT compared to their older counterparts. Notably, Asian populations exhibited elevated risks at lower VAT areas (70-136 cm2) compared to Caucasian populations (85.6-165.9 cm2). All considered studies reported associations of VAT without accommodating covariates. No single VAT area threshold for elevated MetS risk was discernible post-harmonization by technology, units of measure, and region of interest. This review summarizes available evidence for MetS risk assessment in clinical practice. Further exploration of demographic-specific interactions between VAT area and other risk factors is imperative to comprehensively delineate overarching MetS risk.

Effect of time restricted eating versus daily calorie restriction on sex hormones in males and females with obesity

This study examined the effects of time restricted eating (TRE) on sex hormones in males and females, versus daily calorie restriction (CR). Adults with obesity (n = 90) were randomized to 1 of 3 groups for 12-months: 8-h TRE (eating only between 12:00 to 8:00 pm, with no calorie counting); CR (25% energy restriction daily); or control. Body weight decreased (P < 0.01) in the TRE and CR groups, relative to controls, in males, premenopausal females, and postmenopausal females, by month 12. Total testosterone, dehydroepiandrosterone (DHEA), and sex hormone binding globulin (SHBG) levels did not change over time, or between groups, in males, premenopausal females, and postmenopausal females. Estradiol, estrone, and progesterone were only measured in postmenopausal females, and remained unchanged. These findings suggest that TRE produces significant weight loss but does not impact circulating sex hormone levels in males and females with obesity over 12 months, relative to CR and controls.

AAV-mediated gene therapy restores natural fertility and improves physical function in the Lhcgr-deficient mouse model of Leydig cell failure

Leydig cell failure (LCF) caused by gene mutations leads to testosterone deficiency, infertility and reduced physical function. Adeno-associated virus serotype 8 (AAV8)-mediated gene therapy shows potential in treating LCF in the Lhcgr-deficient (Lhcgr-/-) mouse model. However, the gene-treated mice still cannot naturally sire offspring, indicating the modestly restored testosterone and spermatogenesis in AAV8-treated mice remain insufficient to support natural fertility. Recognizing this, we propose that enhancing gene delivery could yield superior results. Here, we screened a panel of AAV serotypes through in vivo transduction of mouse testes and identified AAVDJ as an impressively potent vector for testicular cells. Intratesticular injection of AAVDJ achieved markedly efficient transduction of Leydig cell progenitors, marking a considerable advance over conventional AAV8 vectors. AAVDJ-Lhcgr gene therapy was well tolerated and resulted in significant recovery of testosterone production, substantial improvement in sexual development, and remarkable restoration of spermatogenesis in Lhcgr-/- mice. Notably, this therapy restored fertility in Lhcgr-/- mice through natural mating, enabling the birth of second-generation. Additionally, this treatment led to remarkable improvements in adipose, muscle, and bone function in Lhcgr-/- mice. Collectively, our findings underscore AAVDJ-mediated gene therapy as a promising strategy for LCF and suggest its broader potential in addressing various reproductive disorders.

Biomechanical and biological factors of sexual dimorphism in anterior knee pain: Current concepts

Female gender is one of the commonly mentioned risk factors for anterior knee pain (AKP), among a spectrum of other factors including anatomical, biomechanical, hormonal, behavioral and psychological elements contributing to its development. Despite the focus on individual risk factors, there's a notable gap in comprehending how gender influences and interacts with other risk factors. The objective of this review was to identify and emphasize the connections between these interactions, gender-related risk factors for AKP, and the potential mechanisms that explain their associations with other risk factors, aiming to aid in the creation of precise prevention and treatment approaches. Gender influences the majority of risk factors for AKP, including anatomical, biomechanical, hormonal, behavioral and psychological factors. Women have on average smaller patellae, higher patellofemoral cartilage stress and for AKP, disadvantageous trochlear morphology, ligament and muscle composition and unfavorable neuromuscular control pattern. In contrast, men show on average an increased ability to strengthen their hip external rotators, which are both protective against AKP. Particularly in kinetic and kinematic analysis, men have been shown to have a distinctly different risk factor profile than women. Sex hormones may also play a role in the risk of AKP, with estrogen potentially influencing ligamentous laxity, increasing midfoot loading and affecting neuromuscular control of the lower extremities and testosterone positively affecting muscle mass and strength. The higher incidence of AKP in women is likely due to a combination of slightly increased risk factors. Although all risk factors can be present in both men and women and the holistic evaluation of each individual's risk factor composition is imperative regardless of gender, knowing distinctive risk factors may help with focused evaluation, treatment and implementing preventive measures of AKP.

Apigenin improves testosterone synthesis by regulating endoplasmic reticulum stress

Obesity is a growing epidemic among reproductive-age men, which can cause and exacerbate male infertility by means of associated comorbidities, endocrine abnormalities, and direct effects on the fidelity and throughput of spermatogenesis. A prominent consequence of male obesity is a reduction in testosterone levels. Natural products have shown tremendous potential anti-obesity effects in metabolic diseases. This study aimed to investigate the potential of apigenin (AP) to alleviate testicular dysfunction induced by a high-fat diet (HFD) and to investigate the underlying mechanisms, focusing on endoplasmic reticulum stress (ERS) and testosterone synthesis. A murine model of obesity was established using HFD-fed mice. The effects of AP on obesity, lipid metabolism, testicular dysfunction, and ERS were assessed through various physiological, histological, and molecular techniques. Administration of AP (10 mg/kg) ameliorated HFD-induced obesity and testicular dysfunction in a mouse model, as evidenced by decreased body weight, improved lipid profiles and testicular pathology, and restored protein levels related to testosterone. Furthermore, in vitro studies demonstrated that AP relieved ERS and recovered testosterone synthesis in murine Leydig cells (TM3) treated with free fatty acids (FFAs). It was also observed that AP rescued testosterone synthesis enzymes in TM3 cells, similar to that observed with the inhibitor of the PERK pathway (GSK2606414). In addition, ChIP, qPCR, and gene silencing showed that the C/EBP homologous protein (CHOP) bound directly to the promoter region of steroidogenic STAR and negatively modulated its expression. Collectively, AP has remarkable potential to alleviate HFD-induced obesity and testicular dysfunction. Its protective effects are attributable partly to mitigating ERS and restoring testosterone synthesis in Leydig cells.

Difference in Body Composition Patterns between Age Groups in Italian Individuals with Overweight and Obesity: When BMI Becomes a Misleading Tool in Nutritional Settings

Little is known about the changes in body composition (BC) in people with overweight or obesity. The aim of this study was to assess the differences in BC patterns in this population based on gender and age. A total of 2844 Italian adults of mixed gender and a body mass index (BMI) of ≥25 kg/m2 underwent a BC assessment by means of dual-energy X-ray absorptiometry (DXA). The sample was categorized into three age groups: 'young' (20-39 years), 'middle' (40-59 years), and 'older' (60-80 years) adults, after being matched by body weight and BMI. Males showed higher total body fat percentage (BF%) and a lower total lean mass (LM), progressively from the young to the middle to the older age groups, while females showed similar values for these total compartments between the three age groups. However, in both genders, participants in the middle and older groups were more likely to have a higher trunk fat percentage by +1.23% to +4.21%, and lower appendicular lean mass (ALM) by -0.81 kg to -2.63 kg with respect to the young group, indicating expression of major central adiposity and sarcopenia. While our findings underscore the limitations of BMI to detect these differences between age groups, the identification of new tools suitable for this aim is greatly needed in this population. Moreover, further investigation that clarifies the impact of these differences in BC patterns between gender and age groups on health outcomes is also required.

Sex- and Gender-Related Differences in Obesity: From Pathophysiological Mechanisms to Clinical Implications

Obesity, primarily characterized by excessive fat accumulation, is a multifactorial chronic disease with an increasing global prevalence. Despite the well-documented epidemiology and significant advances in understanding its pathophysiology and clinical implications, the impact of sex is typically overlooked in obesity research. Worldwide, women have a higher likelihood to become obese compared to men. Although women are offered weight loss interventions more often and at earlier stages than men, they are more vulnerable to psychopathology. Men, on the other hand, are less likely to pursue weight loss intervention and are more susceptible to the metabolic implications of obesity. In this narrative review, we comprehensively explored sex- and gender-specific differences in the development of obesity, focusing on a variety of biological variables, such as body composition, fat distribution and energy partitioning, the impact of sex steroid hormones and gut microbiota diversity, chromosomal and genetic variables, and behavioural and sociocultural variables influencing obesity development in men and women. Sex differences in obesity-related comorbidities and varying effectiveness of different weight loss interventions are also extensively discussed.

Sex-Based Differences in Muscle Stem Cell Regulation Following Exercise

Sexual dimorphism, driven by the sex hormones testosterone and estrogen, influences body composition, muscle fiber type, and inflammation. Research related to muscle stem cell (MuSC) responses to exercise has mainly focused on males. We propose a novel hypothesis that there are sex-based differences in MuSC regulation following exercise, such that males have more MuSCs, whereas females demonstrate a greater capacity for regeneration.

Relationship between Serum Total Testosterone Concentration and Metabolic Syndrome in Premenopausal Obese Women

BACKGROUND

Men with low testosterone levels are at an increased risk of developing metabolic syndrome, irrespective of age or obesity. However, the relationship between metabolic syndrome and testosterone levels in women remains unclear. We compared the total testosterone concentrations between premenopausal obese women with and without metabolic syndrome and identified the factors affecting these concentrations.

METHODS

A single-center retrospective analysis was conducted using the medical records of 580 premenopausal women with obesity. The diagnostic criteria for metabolic syndrome were established using the National Cholesterol Education Program Adult Treatment Panel III guidelines.

RESULTS

The mean±standard deviation age, weight, and body mass index were 38.8±8.4 years, 78.0±11.8 kg, and 30.0±4.1 kg/m2, respectively. The mean total testosterone concentration was lower in the metabolic syndrome group than in the non-metabolic syndrome group (n=385 vs. n=195; 0.22±0.10 ng/mL vs. 0.24±0.11 ng/mL; P<0.001). In a model adjusted for age, body mass index, skeletal muscle mass, body fat mass, and body fat percentage, the odds ratio for metabolic syndrome with respect to the total testosterone level was 0.128 (P=0.028). Testosterone concentration was negatively correlated with age (r=-0.334), systolic blood pressure (r=-0.084), and triglyceride concentration (r=-0.093) but positively correlated with weight (r=0.144), body mass index (r=0.140), waist circumference (r=0.133), body fat mass (r=0.167), and body fat percentage (r=0.167). Stepwise regression analysis revealed that age (β=-0.004, P<0.001), body mass index (β=0.003, P=0.004), and high-density lipoprotein cholesterol concentration (β=0.001, P=0.019) were independently associated with total testosterone concentration (adjusted R2=12.6%).

CONCLUSION

Metabolic syndrome and obesity may be independently associated with testosterone levels in premenopausal women with obesity.

Association between weight-adjusted waist index and testosterone deficiency in adult American men: findings from the national health and nutrition examination survey 2013-2016

BACKGROUND

Testosterone deficiency (TD) and obesity are globally recognized health concerns, with a bidirectional causal relationship between them. And a newly discovered obesity indicator, the Weight-Adjusted-Waist Index (WWI), has been proposed, demonstrating superior adiposity identification capability compared to traditional body mass index (BMI) and waist circumference (WC) indicators. Therefore, we present the inaugural investigation into the associations of WWI with total testosterone levels and the risk of TD.

METHODS

Data restricted to the National Health and Nutrition Examination Survey (NHANES) between 2013 and 2016 were analyzed. Only males aged > 20 years who completed body measures and underwent serum sex hormone testing were potentially eligible for analysis. Weighted multivariable linear regression and logistic regression analyses were employed to investigate the relationships between WWI and total testosterone levels, and the risk of TD, respectively. Smooth curve fittings and weighted generalized additive model (GAM) regression were conducted to examine the linear relationship among them. Additionally, subgroup analyses with interaction tests were performed to assess the stability of the results.

RESULTS

Finally, a total of 4099 participants with complete data on testosterone and WWI were included in the formal analysis. The mean age of study participants was 46.74 ± 0.35 years with a TD prevalence of 25.54%. After adjusting all potential confounders, the continuous WWI displayed a negative linear relationship with total testosterone levels (β=-61.41, 95%CI: -72.53, -50.29, P < 0.0001) and a positive linear relationship with risk of TD (OR = 1.88, 95%CI: 1.47, 2.39, P < 0.0001). When WWI was transformed into quartiles as a categorical variable, participants in Q4 exhibited lower total testosterone levels (β=-115.4, 95%CI: -142.34, -88.45, P < 0.0001) and a higher risk of TD (OR = 3.38, 95% CI: 2.10, 5.44, P < 0.001). These associations remained stable in subgroup analyses without significant interaction (all P for interaction > 0.05).

CONCLUSIONS

This investigation firstly unveiled a negative linear association between WWI and total testosterone levels, coupled with a positive linear relationship with the prevalence of TD in U.S. male adults aged 20 years and older. Further studies are needed to validate the potential utility of WWI for the early identification and timely intervention of TD.

Multivariate genetic architecture reveals testosterone-driven sexual antagonism in contemporary humans

Sex difference (SD) is ubiquitous in humans despite shared genetic architecture (SGA) between the sexes. A univariate approach, i.e., studying SD in single traits by estimating genetic correlation, does not provide a complete biological overview, because traits are not independent and are genetically correlated. The multivariate genetic architecture between the sexes can be summarized by estimating the additive genetic (co)variance across shared traits, which, apart from the cross-trait and cross-sex covariances, also includes the cross-sex-cross-trait covariances, e.g., between height in males and weight in females. Using such a multivariate approach, we investigated SD in the genetic architecture of 12 anthropometric, fat depositional, and sex-hormonal phenotypes. We uncovered sexual antagonism (SA) in the cross-sex-cross-trait covariances in humans, most prominently between testosterone and the anthropometric traits - a trend similar to phenotypic correlations. 27% of such cross-sex-cross-trait covariances were of opposite sign, contributing to asymmetry in the SGA. Intriguingly, using multivariate evolutionary simulations, we observed that the SGA acts as a genetic constraint to the evolution of SD in humans only when selection is sexually antagonistic and not concordant. Remarkably, we found that the lifetime reproductive success in both the sexes shows a positive genetic correlation with anthropometric traits, but not with testosterone. Moreover, we demonstrated that genetic variance is depleted along multivariate trait combinations in both the sexes but in different directions, suggesting absolute genetic constraint to evolution. Our results indicate that testosterone drives SA in contemporary humans and emphasize the necessity and significance of using a multivariate framework in studying SD.

Obesity and cardiovascular health

Obesity has risen to epidemic levels worldwide over the past few decades and has become a huge global health burden owing to its direct contribution to the development of some of the most prevalent chronic diseases including diabetes, hypertension, hyperlipidaemia, and other cardiovascular diseases. Obesity is a disease of positive energy balance resulting from complex interactions between abnormal neurohumoral responses and an individual's socioeconomic, environmental, behavioural, and genetic factors leading to a state of chronic inflammation. Understanding the complex nature of the disease is crucial in determining the best approach to combat its rising numbers. Despite recent advancements in pharmacological therapy for the treatment of obesity, reversing weight gain and maintaining weight loss is challenging due to the relapsing nature of the disease. Prevention, therefore, remains the key which needs to start in utero and continued throughout life. This review summarizes the role obesity plays in the pathophysiology of various cardiovascular diseases both by directly affecting endothelial and myocyte function and indirectly by enhancing major cardiovascular risk factors like diabetes, hypertension, and hyperlipidaemia. We highlight the importance of a holistic approach needed to prevent and treat this debilitating disease. Particularly, we analyse the effects of plant-based diet, regular exercise, and non-exercise activity thermogenesis on obesity and overall cardiorespiratory fitness. Moreover, we discuss the significance of individualizing obesity management with a multimodal approach including lifestyle modifications, pharmacotherapy, and bariatric surgery to tackle this chronic disease.

Predictive power of lipid-related indicators for testosterone deficiency: a comparative analysis, NHANES 2011-2016

BACKGROUND

Studies have shown that lipid-related indicators are associated with testosterone deficiency. However, it is difficult to determine which indicator is the most accurate predictor of testosterone deficiency. We aimed to identify the lipid-related indicators most predictive of testosterone deficiency in adults in the United States.

METHODS

This observational research was conducted on a population aged ≥ 20 years. By plotting the receiver operating characteristic curve (ROC) and obtaining the corresponding area under the curve (AUC) value, we assessed the predictive capacity of TyG, WTI, LAP, and VAI for testosterone deficiency. We compared the area under the curve (AUC) values of these measures to determine if there were any statistically significant differences. The relationship between lipid-related indices and testosterone hormones was investigated using regression modeling, eXtreme Gradient Boosting (XGBoost) modeling, and sensitivity analysis.

RESULTS

A total of 3,272 eligible participants were included in the study. Testosterone deficiency was found to exist in 20.63% of the participants. Subjects with higher lipid-related markers were more likely to have lower testosterone levels. LAP was the best predictor of testosterone deficiency in ROC analysis over other indicators (AUC = 0.7176, (95% CI: 0.6964-0.7389)).

CONCLUSION

LAP is the most straightforward and convenient indicator for identifying testosterone deficiency in clinical practice.

Systemic Sirtuin 1 as a Potential Target to Mediate Interactions Between Body Fat and Testosterone Concentration in Master Athletes

Evidence indicates that master athletes have higher concentration of Sirtuin 1 (Sirt1), lower body fat (BF), and greater activity of the hypothalamic-pituitary-gonadal axis in comparison to untrained peers. However, no published data have demonstrated possible mediation effect of Sirt1 in the interaction of BF and testosterone in this population. Therefore, this study compared and verified possible associations between Sirt1, BF, fat mass index (FMI), testosterone, luteinizing hormone (LH), and testosterone/luteinizing hormone (T/LH) ratio in middle-aged master athletes (n = 54; 51.22 ± 7.76 years) and control middle-aged peers (n = 21; 47.76 ± 8.47 years). Venous blood was collected for testosterone, LH, and Sirt1. BF was assessed through skinfold protocol. Although LH concentration did not differ between groups, master athletes presented higher concentration of Sirt1, testosterone, and T/LH ratio, and lower BF and FMI in relation to age-matched nonathletes. Moreover, Sirt1 correlated positively with testosterone and T/LH ratio, negatively with BF, and was not significantly correlated with LH (mediation analysis revealed the effect of BF on testosterone is mediated by Sirt1 and vice versa; R2 = .1776; p = .032). In conclusion, master athletes have higher testosterone, T/LH ratio, and Sirt1, and lower BF and FMI in relation to untrained peers. Furthermore, Sirt1 was negatively associated with BF and positively associated with testosterone and T/LH ratio. These findings suggest that increased circulating Sirt1, possibly due to the master athlete's training regimens and lifestyle, exhibits a potential mediation effect on the interaction between endocrine function and body composition.

Environmental cadmium inhibits testicular testosterone synthesis via Parkin-dependent MFN1 degradation

Low testosterone (T) levels are associated with many common diseases, such as obesity, male infertility, depression, and cardiovascular disease. It is well known that environmental cadmium (Cd) exposure can induce T decline, but the exact mechanism remains unclear. We established a murine model in which Cd exposure induced testicular T decline. Based on the model, we found Cd caused mitochondrial fusion disorder and Parkin mitochondrial translocation in mouse testes. MFN1 overexpression confirmed that MFN1-dependent mitochondrial fusion disorder mediated the Cd-induced T synthesis suppression in Leydig cells. Further data confirmed Cd induced the decrease of MFN1 protein by increasing ubiquitin degradation. Testicular specific Parkin knockdown confirmed Cd induced the ubiquitin-dependent degradation of MFN1 protein through promoting Parkin mitochondrial translocation in mouse testes. Expectedly, testicular specific Parkin knockdown also mitigated testicular T decline. Mito-TEMPO, a targeted inhibitor for mitochondrial reactive oxygen species (mtROS), alleviated Cd-caused Parkin mitochondrial translocation and mitochondrial fusion disorder. As above, Parkin mitochondrial translocation induced mitochondrial fusion disorder and the following T synthesis repression in Cd-exposed Leydig cells. Collectively, our study elucidates a novel mechanism through which Cd induces T decline and provides a new treatment strategy for patients with androgen disorders.

Effect of time restricted eating versus daily calorie restriction on sex hormones in males and females with obesity

This study examined the effects of time restricted eating (TRE) on sex hormones in males and females, versus daily calorie restriction (CR). Adults with obesity (n = 90) were randomized to 1 of 3 groups for 12-months: 8-h TRE (eating only between 12:00 to 8:00 pm, with no calorie counting); CR (25% energy restriction daily); or control. Body weight decreased (P < 0.01) in the TRE and CR groups, relative to controls, in males, premenopausal females, and postmenopausal females, by month 12. Total testosterone, dehydroepiandrosterone (DHEA), and sex hormone binding globulin (SHBG) levels did not change over time, or between groups, in males, premenopausal females, and postmenopausal females. Estradiol, estrone, and progesterone were only measured in postmenopausal females, and remained unchanged. These findings suggest that TRE produces significant weight loss but does not impact circulating sex hormone levels in males and females with obesity over 12 months, relative to CR and controls.

Trial registration

Clinicaltrials.gov , NCT04692532 .

The retrotransposon - derived capsid genes PNMA1 and PNMA4 maintain reproductive capacity

The human genome contains 24 gag -like capsid genes derived from deactivated retrotransposons conserved among eutherians. Although some of their encoded proteins retain the ability to form capsids and even transfer cargo, their fitness benefit has remained elusive. Here we show that the gag -like genes PNMA1 and PNMA4 support reproductive capacity. Six-week-old mice lacking either Pnma1 or Pnma4 are indistinguishable from wild-type littermates, but by six months the mutant mice become prematurely subfertile, with precipitous drops in sex hormone levels, gonadal atrophy, and abdominal obesity; overall they produce markedly fewer offspring than controls. Analysis of donated human ovaries shows that expression of both genes declines normally with aging, while several PNMA1 and PNMA4 variants identified in genome-wide association studies are causally associated with low testosterone, altered puberty onset, or obesity. These findings expand our understanding of factors that maintain human reproductive health and lend insight into the domestication of retrotransposon-derived genes.

Erectile Dysfunction as an Obesity-Related Condition in Elderly Men with Coronary Artery Disease

Background: This cross-sectional study aimed to investigate the prevalence of erectile dysfunction (ED) in elderly men with overweight or obesity and coronary artery disease. Methods: Patients recruited in cardiac rehabilitation centers post-myocardial infarction provided demographic and anthropomorphic data. ED was assessed using the abbreviated International Index of Erectile Function 5 (IIEF-5) Questionnaire. Results: The study included 661 men with a mean age of 67.3 ± 5.57 years, a mean BMI of 27.9 ± 3.6 m/kg2, and a mean waist circumference of 98.9 ± 10.23 cm. Over 90% of men experienced ED, with similar proportions across BMI categories. The development of ED in men with a waist circumference of ≥100 cm had 3.74 times higher odds (OR 3.74; 95% CI: 1.0-13.7; p = 0.04) than in men with a waist circumference of <100 cm. Men with obesity and moderate-to-severe and severe ED were older compared to those without these disorders (67.1 ± 5.29 vs. 65.3 ± 4.35; p = 0.23). Conclusions: The prevalence of ED in men with coronary artery disease surpasses 90%. An increased body weight raises the risk of ED, with waist circumference proving to be a more reliable predictor of this risk compared to BMI. Physicians are encouraged to screen elderly patients with cardiovascular disease for ED and address obesity to enhance overall health.

Effect of testosterone replacement therapy on scar quality in gender-affirming mastectomies

BACKGROUND

The term transgenders refer to people who sense discordance between their gender identity and the sex assigned to them at birth. Some transgenders receive hormonal therapy, which may lead to specific skin conditions. The purpose of the present study was to determine whether a causal relationship exists between hormonal therapy (specifically testosterone therapy) and unsatisfying surgical scarring, including hypertrophic and keloid scars. In addition, this study may serve as a basis for future studies, which may test means that aim to reduce such undesired effects.

METHODS

In this retrospective, observational cohort study, data were collected regarding 170 patients who underwent mastectomy as a gender-affirming surgery by the senior author between 2003 and 2021. The medical records were analysed to obtain personal, medical (including the duration of testosterone treatment) and surgical information from the patients' medical files. A blinded evaluator assessed the surgical scars by reviewing the postoperative clinical pictures of the patients. The scars were rated using the validated Stony Brook Scar Evaluation Scale (SBSES). The use of pictures to assess surgical scars is described in the validation study of the SBSES and is, therefore, accepted.

RESULTS

In total, 63 patients were included in the testosterone group and 63 were included in the non-testosterone treated group. The averages of the SBSES score were 2.74 and 2.66, respectively. The difference between the two averages was not statistically significant.

CONCLUSION

In our retrospective cohort study, we did not find the effect of testosterone therapy on post-operative surgical scars to be significant.

EVIDENCE BASED MEDICINE (EBM) LEVEL

3.

Anabolic steroids induced changes at the level of protein expression: Effects of prolonged administration of testosterone and nandrolone to pigs

Synthetic derivatives of steroid hormones, specifically anabolic-androgenic steroids (AAS), have gained prominence due to their observed benefits in enhancing meat quality. The study replicated the administration of banned AAS and investigated their impacts on pigs to contribute to the understanding of animal biochemistry and to explore the feasibility of detecting AAS administration by employing a non-targeted analysis. The effects were corroborated by evaluating changes in the expression of selected proteins, as well as examining haematological and biochemical profiles and histological alterations. Exposure to AAS influenced the expression of proteins related to drug-metabolizing enzymes, muscle and lipid metabolism, kidney function, reproductive processes, immune system functions, and carcinogenic changes. The effects of AAS appear intricate and contingent on factors such as the specific drug used, dosage, and duration of administration. The results underscore that protein expression analysis holds promise as a valuable tool for detecting illicit AAS use in the fattening process.

Sarcopenic obesity is part of obesity paradox in dementia development: evidence from a population-based cohort study

BACKGROUND

Sarcopenic obesity, a clinical and functional condition characterized by the coexistence of obesity and sarcopenia, has not been investigated in relation to dementia risk and its onset.

METHODS

We included 208,867 participants from UK biobank, who aged 60 to 69 years at baseline. Dementia diagnoses were identified using hospital records and death register data. Hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated using Cox proportional hazards models to evaluate the associations of obesity, sarcopenia, and sarcopenic obesity with dementia risk, stratified by sex. Stratified analyses were performed across dementia-related polygenic risk score (PRS). Restricted mean survival time models were established to estimate the difference and 95%CIs of dementia onset across different status. Additionally, linear regression models were employed to estimate associations of different status with brain imaging parameters. The mediation effects of chronic diseases were also examined.

RESULTS

Obese women with high PRS had a decreased risk (HR = 0.855 [0.761-0.961]), but obese men with low PRS had an increased risk (HR = 1.223 [1.045-1.431]). Additionally, sarcopenia was associated with elevated dementia risk (HRwomen = 1.323 [1.064-1.644]; HRmen = 2.144 [1.753-2.621]) in those with low PRS. Among those with high PRS, however, the association was only significant in early-life (HRwomen = 1.679 [1.355-2.081]; HRmen = 2.069 [1.656-2.585]). Of note, sarcopenic obesity was associated with higher dementia risk (HRwomen = 1.424 [1.227-1.653]; HRmen = 1.989 [1.702-2.323]), and results remained similar stratified by PRS. Considering dementia onset, obesity was associated with dementia by 1.114 years delayed in women, however, 0.170 years advanced in men. Sarcopenia (women: 0.080 years; men: 0.192 years) and sarcopenic obesity (women: 0.109 years; men: 0.511 years) respectively advanced dementia onset. Obesity, sarcopenia, and sarcopenic obesity were respectively related to alterations in different brain regions. Association between sarcopenic obesity and dementia was mediated by chronic diseases.

CONCLUSIONS

Sarcopenic obesity and sarcopenia were respectively associated with increased dementia risk and advanced dementia onset to vary degree. The role of obesity in dementia may differ by sex and genetic background.

Pediatric obesity and development of the penis and testis

PURPOSE

Pediatric obesity is increasing in many countries as socioeconomic status improves and the consumption of high calorie food increases. Thus, effect of obesity on genital development is an important topic. This study aimed to determine relationships of body mass index (BMI) with penile parameters and testicular volume in pediatric patients without penile or testicular abnormalities.

MATERIALS AND METHODS

Data from 1,499 male pediatric patients from our center were analyzed. Patients with penile or testicular abnormalities were excluded. Their age ranged from 2 to 18 years. These patients were divided into two groups based on their BMI: normal BMI (5th-85th percentile) and high BMI (≥85th percentile). Factors used in analysis included age, anthropometric indicators, baseline penile length (BPL), stretched penile length (SPL), penile circumference (PC), and mean testicular volume. These same parameters were analyzed for different age groups.

RESULTS

Pediatric patients with normal BMI showed longer BPL and SPL than patients with high BMI (p<0.05). However, PC and mean testicular volumes showed no significant difference between the two groups. BPL was significantly longer in the normal BMI group starting at ten years of age. SPL was significantly longer in the normal BMI group starting at eleven years of age.

CONCLUSIONS

Our study confirms that having a higher BMI during childhood has a negative effect on penile length. However, there was no significant relationship between BMI and PC or testicular volume.

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

PURPOSE

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSION

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

Development of external genitalia during mini-puberty: is it related to somatic growth or reproductive hormones?

Although hypothalamo-pituitary-gonadal axis is active during mini-puberty, its relationship with somatic growth and the role on the development of external genitalia has not been fully elucidated. We aimed to evaluate the effects of somatic growth and reproductive hormones on the development of external genitalia during mini-puberty. Anthropometric data, pubertal assesment, serum follicle-stimulating hormone (FSH), luteinizing hormone (LH), dehydroepiandrosterone sulfate (DHEAS), androstenedione (A4), sex-hormone binding globulin (SHBG), estradiol (E2) and inhibin-B, testosterone (T), and anti-Mullerian Hormone (AMH) of healthy infants aged 1-4 months were evaluated. Free sex hormone index was calculated as T/SHBG for boys and E2/SHBG for girls. The mean age of 148 (74 female) infants included in the study was 2.31 ± 0.76 months. Tanner stage 2-3 sex steroid and gonadotropin levels were observed. A statistically significant difference was found between the weight, height, BMI, weight gain and serum FSH, LH, and A4 measurements of girls and boys (p < 0.05). Penile length was associated with weight (r = 0.24, p = 0.03), height (r = 0.25, p = 0.02), and AMH (r = 0.3, p = 0.01), but not with testosterone (p = 0.56 respectively). A negative correlation was found between weight and serum LH (r =  - 0.26, p = 0.2) and T/SHBG levels in males (r =  - 0.38, p = 0.015 respectively). Weight-SDS was negatively correlated with testosterone in males (r =  - 0.25, p = 0.02). Testicular size and breast stage did not correlate with any of the hormonal and anthropometric parameters.  Conclusions: External genitalia in males during mini-puberty is related more to somatic growth rather than reproductive hormones. Similar to pubertal developmental stages, both total and free testosterone are negatively associated with higher weight during mini-puberty. What is Known: • Mini-puberty allows early assessment of HPG axis function in infancy. • There is an inverse relationship between the amount of adipose tissue and circulating testosterone levels in males during puberty and adulthood. • The potential effect of somatic growth and reproductive hormones on external genital development during mini-puberty remains unclear. What is New: • During mini-puberty, males' external genitalia is more related to somatic growth than to reproductive hormones, but this relationship is not observed in girls. • Both total and free testosterone are negatively associated with higher weight during mini-puberty, similar to the pubertal developmental stages.

Men's physical health and life history transitions in the Philippines: Evidence for 'marital selection' but not protective effects of partnering and fatherhood

In Euro-American societies, married people typically have lower overall risks for total mortality and for certain chronic conditions compared to non-married people. However, people becoming partnered and parents also tend to gain weight in Euro-American settings. Few studies have tested whether links between physical health and life history status translate to other cultural contexts where the socio-ecological dynamics of family life may differ. This limits the application of these insights to men's well-being in global public health. To help address this gap, we drew on a large, long-running birth cohort study of Filipino men, using data collected at three waves between 2005 and 2014 when men were 21.5-30.5 years old (N = 607, obs. = 1760). We tested for the effects of the transition to partnering (marriage/cohabitation) and fatherhood on men's physical health (waist circumference, fat-free mass index, and grip strength). Men becoming partnered or partnered fathers (P/PF) had comparable longitudinal physical health trajectories to men remaining single non-fathers. However, men who became P/PF by their mid 20s had higher fat-free mass index values than single non-fathers at each wave, with the largest effect observed when all men were single non-fathers at baseline. Men who became P/PF by their early 30s were also stronger than the reference group at baseline. Thus, men who were more muscular and stronger at baseline were more likely to transition to P/PF status, consistent with a 'marital selection' model. In complementary analyses, men did not exhibit adverse health effects when they became partnered fathers as young adults or parents to infants, respectively. These findings suggest that links between health and life history transitions in this setting differ from those commonly observed in Euro-American societies. While transitions to marriage and fatherhood are promising windows for interventions to improve men's health, our results highlight the importance of tailoring such approaches to local dynamics.

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.

Body composition and cancer survival: a narrative review

Interest in understanding the relationship between body composition and cancer survival has remained strong for decades, with a number of recent systematic reviews on the topic. However, the current state of evidence is based on heterogeneous exposure definitions based on anthropometry, yielding inconsistent findings with regard to this association. Recently the field has taken an exciting direction with the application of radiological assessments to measure specific aspects of body composition, yet reconciliation of findings from these modern assessment tools with those from the historic use of anthropometric data proves challenging. In this paper, I briefly review the biological basis for a link between body composition and cancer survival and summarize the epidemiological evidence with consideration to specific exposure measures. As enthusiasm is building around novel assessments, I conclude with a discussion of issues that researchers should be aware of when interpreting results from these new modalities.

Low testosterone at age 31 associates with maternal obesity and higher body mass index from childhood until age 46: A birth cohort study

BACKGROUND

Low testosterone (T) levels in men associate with increased risks of obesity, type 2 diabetes, metabolic syndrome, and cardiovascular diseases. However, most studies are cross-sectional with follow-up-time < 10 years, and data on early growth are limited.

OBJECTIVE

To compare prenatal factors and body mass index (BMI) development from birth to age 46 in relation to low T at age 31.

MATERIALS AND METHODS

Men with low T (T < 12.1 nmol/L, n = 132) and men with normal T at age 31 (n = 2561) were derived from the Northern Finland Birth Cohort 1966. Prenatal factors, longitudinal weight and height data from birth to age 14, and cross-sectional weight and height data at ages 31 and 46, and waist-hip-ratio (WHR) and T levels at age 31 were analyzed. Longitudinal modeling and timing of adiposity rebound (AR, second BMI rise at age 5-7 years) were calculated from fitted BMI curves. Results were adjusted for mother's pre-pregnancy BMI and smoking status, birth weight for gestational age, alcohol consumption, education level, smoking status, and WHR at age 31.

RESULTS

Neither gestational age nor birth weight was associated with low T at age 31; however, maternal obesity during gestation was more prevalent among men with low T (9.8% vs. 3.5%, adjusted aOR: 2.43 [1.19-4.98]). Men with low T had earlier AR (5.28 vs. 5.82, aOR: 0.73 [0.56-0.94]) and higher BMI (p < 0.001) from AR onward until age 46. Men with both early AR and low T had the highest BMI from AR onward.

CONCLUSIONS

In men, maternal obesity and early weight gain associate with lower T levels at age 31, independently of adulthood abdominal obesity. Given the well-known health risks related to obesity, and the rising prevalence of maternal obesity, the results of the present study emphasize the importance of preventing obesity that may also affect the later reproductive health of the offspring.

Dietary fat quality and serum androgen concentrations in middle-aged men

BACKGROUND/OBJECTIVES

Average testosterone concentrations in men have declined over the last few decades. The reasons for this are not fully known, but changes in dietary fat quality have been suggested to have a role. This study aimed to investigate the associations of different dietary fatty acids with serum androgen concentrations.

SUBJECTS/METHODS

A total of 2546 men with a mean age of 53 from the Kuopio Ischaemic Heart Disease Risk Factor Study were included in this cross-sectional study. Associations between dietary saturated (SFA), monounsaturated (MUFA), polyunsaturated (PUFA) and trans (TFA) fatty acids and concentrations of serum total and free testosterone and steroid hormone binding globulin (SHBG) were analyzed with analysis of covariance and linear regression analysis. Associations of isocaloric replacement of nutrients and androgen concentrations were analyzed with multivariate nutrient-density models.

RESULTS

After adjustment for age, examination year and energy intake, higher SFA intake was associated with higher serum total and free testosterone and SHBG concentrations, and higher PUFA intake with lower concentrations. However, the associations were attenuated and not statistically significant after further adjustments for potential confounders. MUFA and TFA intakes were not associated with androgen concentrations. In isocaloric substitution models, replacing dietary protein with SFA was associated with higher serum total testosterone and SHBG concentrations. After excluding men with history of CVD or diabetes (n = 1021), no statistically significant associations were found.

CONCLUSIONS

Dietary fat quality was not independently associated with serum androgen concentrations in middle-aged men. However, replacing protein with SFA may be associated with higher serum androgen concentrations.

Associations of Serum Testosterone and Sex Hormone-binding Globulin With Incident Arrhythmias in Men From UK Biobank

CONTEXT

Sex hormones have been identified as cardiovascular risk factors, whereas the relationship between sex hormones and the risk of arrhythmias in men has not yet been well studied in the prospective cohort study.

OBJECTIVE

To analyze associations of serum testosterone and SHBG concentrations and calculate free testosterone (cFT) with arrhythmias in men.

METHODS

Sex hormones were measured at baseline from UK Biobank. Main outcomes were incidence of atrial fibrillation/flutter (AF), ventricular arrhythmia (VA), and bradyarrhythmia (BA).

RESULTS

Of 173 498 men (aged 37-73 years, followed for 11 years), 11 368 had incident AF, 1646 had incident VA, and 4788 had incident BA. Compared with the third quartiles, the lowest category of serum testosterone was associated with increased risks of AF (hazard ratio [HR], 1.06; 95% CI, 1.00-1.12) and BA (HR, 1.11; 95% CI, 1.02-1.20) after multivariable adjustment, but no VA. Likewise, similar associations were found between cFT values and AF and BA events. Furthermore, higher levels of cFT were associated with increased risks of AF (HR, 1.07; 95% CI, 1.02-1.13) and VA (HR, 1.18; 95% CI, 1.01-1.37). Higher SHBG concentrations were associated with increased risks of AF (HR, 1.44; 95% CI, 1.34-1.54), VA (HR, 1.27; 95% CI, 1.07-1.52), and BA (HR, 1.17; 95% CI ,1.05-1.29).

CONCLUSIONS

Lower levels of testosterone and cFT were associated with increased risk of AF and BA. Higher cFT levels were associated with increased risk of AF and VA. Higher SHBG levels were associated with increased risk of AF, VA, and BA.

Testosterone Therapy Is Associated With Increased Odds of Quadriceps Tendon Injury

BACKGROUND

Anabolic steroid use at supraphysiologic doses has been associated with an increased risk of tendon injury. However, the musculoskeletal effects of testosterone therapy in the clinical setting are not well understood.

QUESTIONS/PURPOSES

(1) Is prescription testosterone associated with a higher odds of subsequent quadriceps muscle or tendon injury? (2) Is prescription testosterone associated with a higher odds of surgical repair of the quadriceps tendon?

METHODS

The PearlDiver Database, which contains data on Medicaid, Medicare, and commercially insured patients, allows for a large representative sample of the US population including both publicly and privately insured patients. The database was queried for all patients between 2011 and 2018 who filled a testosterone prescription. Additionally, all quadriceps injuries using ICD-9 and ICD-10 codes between 2011 and 2018 were queried. Propensity score matching based on age, sex, Charlson comorbidity index, and specific comorbidities allowed us to create matched control groups. We used the t-test and chi-square analysis to compare the unmatched and matched cohorts. A total of 151,797 patients (123,627 male patients and 28,170 female patients) with a history of filled testosterone prescriptions were included in the study after matching with the control group, which was of equal size and representation of age, male-female proportions, and comorbidities. Chi-square and logistic regression analyses were performed to compare odds of quadriceps injury and quadriceps tendon repair among the testosterone groups to that of their respective control groups by age and sex.

RESULTS

Within 1 year of filling prescriptions for testosterone, 0.06% (97 of 151,797) of patients experienced a quadriceps injury compared with less than 0.01% (18 of 151,797) of patients in the control group (OR 5.4 [95% CI 3.4 to 9.2]; p < 0.001). Within the sex-specific matched groups, filling a testosterone prescription was associated with an increase in the odds of quadriceps injury in male patients within 1 year of the prescription (OR 5.8 [95% CI 3.5 to 10.3]; p < 0.001). Additionally, patients who filled a testosterone prescription were at increased risk of having quadriceps tendon repair within a year of the injury than were patients in the matched control group (OR 4.7 [95% CI 2.0 to 13.8]; p = 0.001).

CONCLUSION

Considering these findings, it is important for physicians to counsel patients receiving testosterone replacement therapy of the substantially increased odds of quadriceps tendon injury. Future investigations into the mechanisms of influence of exogenous anabolic steroids on tendon injury remains of interest.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Exercise and Caloric Restriction Exert Different Benefits on Skeletal Muscle Metabolism in Aging Condition

Exercise and caloric restriction improve skeletal muscle metabolism. However, the benefits of exercise and caloric restriction on skeletal muscle metabolism in aging have never been compared. Seven-week-old male Wistar rats (n = 24) were divided into 4 groups (n = 6 per group) to receive either normal saline solution for 28 weeks, 150 mg/kg/day of D-galactose for 28 weeks to induce premature aging, 150 mg/kg/day of D-galactose for 28 weeks plus exercise for 16 weeks (week 13-28), or 150 mg/kg/day of D-galactose for 28 weeks plus 30% caloric restriction for 16 weeks (week 13-28). The 17-month-old rats (n = 6) were also injected with normal saline solution for 28 weeks as the naturally aged controls. At the end of week 28, total walking distance and fatty acid and carbohydrate oxidation during physical activity were determined. Then, all rats were euthanized for the collection of blood and tibialis anterior muscle. The results showed that D-galactose successfully mimicked the natural aging of skeletal muscle. Exercise and caloric restriction equally improved carbohydrate oxidation during physical activity and myogenesis. However, exercise was superior to caloric restriction in terms of improving fatty acid oxidation and oxidative phosphorylation. Interestingly, caloric restriction decreased oxidative stress, whereas exercise increased oxidative stress of skeletal muscle. All of these findings indicated that the benefits of exercise and caloric restriction on skeletal muscle metabolism during aging were different, and therefore the combination of exercise and caloric restriction might provide greater efficacy in ameliorating skeletal muscle aging.

Androgen Excess and Deficiency: Analytical and Diagnostic Approaches

BACKGROUND

Androgens are synthesized from cholesterol through sequential conversions by enzymes in the adrenal glands and gonads. Serum levels of androgens change during the different phases of life and regulate important developmental and maturational processes. Androgen excess or deficiency can therefore present at various ages in various ways.

CONTENT

The diagnostic approach for atypical genitalia, premature pubarche, delayed pubertal onset or progression, and hirsutism or virilization, including measurement of androgens (testosterone, androstenedione, 17-OHprogesterone, dehydroepiandrosterone, and dihydrotestosterone) is discussed in the current review. Androgens can be measured in serum, saliva, urine, or dried blood spots. Techniques to measure androgens, including immunoassays and LC-MS, have their own advantages and pitfalls. In addition, pre- and postanalytical issues are important when measuring androgens.

SUMMARY

During clinical interpretation of androgen measurements, it is important to take preanalytical circumstances, such as time of blood withdrawal, into account. As immunoassays have major drawbacks, especially in samples from women and neonates, concentrations measured using these assays should be interpreted with care. Reference intervals can only be used in relation to the measurement technique and the standardization of the assay. In the near future, new androgens will probably be added to the current repertoire to further improve the diagnosis and follow-up of androgen excess or deficiency.