Testosterone a key factor in gender related metabolic syndrome

Age-related impairment in testosterone elevation after anterior fibromuscular stroma preserved enucleation

OBJECTIVES

This study aims to evaluate the impact of anterior fibromuscular stroma preserved enucleation (AFSPE) of the prostate on serum testosterone levels in patients with benign prostatic obstruction (BPO) and to explore age-related differences in postoperative testosterone elevation.

METHODS

In a retrospective analysis, 304 patients from a pool of 560 who underwent AFSPE at Linkou Chang Gung Memorial Hospital between January 2018 and December 2021 were evaluated. Patients were stratified based on preoperative testosterone levels into low (<3.5 ng/mL) and normal (≥3.5 ng/mL) groups. Serum testosterone levels were measured preoperatively, at 1.5 and 3-6 months postoperatively. Age and other demographic data were analyzed as potential factors influencing testosterone changes.

RESULTS

The low-testosterone group (n = 90) showed significant testosterone increases, from an average of 2.61 ng/mL preoperatively to 3.3 ng/mL at 1.5 months and 3.59 ng/mL at 3-6 months postoperatively (p < 0.0001). The normal-testosterone group (n = 214) maintained stable testosterone levels at 1.5 months but exhibited a significant rise to 6.06 ng/mL by 3-6 months (p = 0.0079). Older age was inversely associated with postoperative testosterone elevation in both groups. Improvements in nocturia were notable in both groups.

CONCLUSIONS

AFSPE of the prostate significantly elevates serum testosterone levels in men with BPO, particularly benefiting those initially with low levels. Age is a crucial factor influencing postoperative testosterone changes, indicating that younger patients may benefit more from this intervention. AFSPE offers a promising approach for improving hormonal health in BPO patients, alongside alleviating urinary symptoms.

Gender Differences in the Prevalence and Clinical Correlates of Metabolic Syndrome in First-Episode and Drug-Naïve Patients With Major Depressive Disorder

OBJECTIVE

Major depressive disorder (MDD) is a severe psychiatric symptom worldwide, and the coexistence of MDD with metabolic syndrome (MetS) is common in clinical practice. However, gender differences in comorbid MetS in first-episode and drug-naïve (FEDN) MDD patients have not been reported. Here, we explored potential gender differences in the prevalence and clinical correlates of comorbid MetS in FEDN MDD patients.

METHODS

A cross-sectional study of 1718 FEDN MDD patients was conducted. Demographic and clinical data were collected. The Hamilton Depression Scale (HAMD), Hamilton Anxiety Scale, and Positive and Negative Syndrome Scale positive subscale were used to evaluate depression, anxiety, and psychotic symptoms, respectively.

RESULTS

The prevalence of MetS was 1.645-fold higher in female MDD patients (38.50%) than in male patients (26.53%). Patients with MetS had higher HAMD score, Hamilton Anxiety Scale score, and Positive and Negative Syndrome Scale positive subscale score than patients without MetS (p values < .001). Furthermore, suicide attempts (male: odds ratio [OR] = 1.706, p = .034; female: OR = 1.639, p = .004) and HAMD score (male: OR = 1.251, p < .001; female: OR = 1.148, p < .001) were independently associated with MetS in male and female patients, whereas age of onset was independently associated with MetS only in female patients (OR = 1.744, p = .047).

CONCLUSIONS

Our findings suggest significant gender differences in the prevalence and clinical correlates of comorbid MetS in FEDN MDD patients. Clinical variables (suicide attempts and HAMD scores) may be independently associated with MetS in MDD patients.

Advances in mitochondria-centered mechanism behind the roles of androgens and androgen receptor in the regulation of glucose and lipid metabolism

An increasing number of studies have reported that androgens and androgen receptors (AR) play important roles in the regulation of glucose and lipid metabolism. Impaired glucose and lipid metabolism and the development of obesity-related diseases have been found in either hypogonadal men or male rodents with androgen deficiency. Exogenous androgens supplementation can effectively improve these disorders, but the mechanism by which androgens regulate glucose and lipid metabolism has not been fully elucidated. Mitochondria, as powerhouses within cells, are key organelles influencing glucose and lipid metabolism. Evidence from both pre-clinical and clinical studies has reported that the regulation of glucose and lipid metabolism by androgens/AR is strongly associated with the impact on the content and function of mitochondria, but few studies have systematically reported the regulatory effect and the molecular mechanism. In this paper, we review the effect of androgens/AR on mitochondrial content, morphology, quality control system, and function, with emphases on molecular mechanisms. Additionally, we discuss the sex-dimorphic effect of androgens on mitochondria. This paper provides a theoretical basis for shedding light on the influence and mechanism of androgens on glucose and lipid metabolism and highlights the mitochondria-based explanation for the sex-dimorphic effect of androgens on glucose and lipid metabolism.

The impact of dietary fructose on gut permeability, microbiota, abdominal adiposity, insulin signaling and reproductive function

The excessive intake of fructose in the regular human diet could be related to global increases in metabolic disorders. Sugar-sweetened soft drinks, mostly consumed by children, adolescents, and young adults, are the main source of added fructose. Dietary high-fructose can increase intestinal permeability and circulatory endotoxin by changing the gut barrier function and microbial composition. Excess fructose transports to the liver and then triggers inflammation as well as de novo lipogenesis leading to hepatic steatosis. Fructose also induces fat deposition in adipose tissue by stimulating the expression of lipogenic genes, thus causing abdominal adiposity. Activation of the inflammatory pathway by fructose in target tissues is thought to contribute to the suppression of the insulin signaling pathway producing systemic insulin resistance. Moreover, there is some evidence that high intake of fructose negatively affects both male and female reproductive systems and may lead to infertility. This review addresses dietary high-fructose-induced deteriorations that are obvious, especially in gut permeability, microbiota, abdominal fat accumulation, insulin signaling, and reproductive function. The recognition of the detrimental effects of fructose and the development of relevant new public health policies are necessary in order to prevent diet-related metabolic disorders.

The male patient with obesity undergoing metabolic and bariatric surgery: changes in testosterone levels correlate with weight loss after one-anastomosis gastric bypass and Roux-en-Y gastric bypass

BACKGROUND

Male obesity secondary hypogonadism (MOSH) is a common disease among men with obesity and can be associated with metabolic syndrome and a variety of metabolic problems ultimately leading to androgen deficiency. Metabolic and bariatric surgery is a well-established treatment option associated with significant weight loss and reduction in metabolic co-morbidities.

OBJECTIVES

To evaluate the impact of surgery on plasma levels of sexual hormones and their effect on weight loss comparing 2 surgical methods (one-anastomosis gastric bypass [OAGB] and Roux-en-Y gastric bypass [RYGB]) in male patients with obesity.

SETTING

University hospital, Austria.

METHODS

Patients undergoing OAGB and RYGB between 2012 and 2017 were analyzed retrospectively. Follow-up in this study was up to 24 months. Systemic levels of sexual hormones (luteinizing hormone [LH]), follicle stimulating hormone [FSH], total testosterone [TT], sexual hormone binding globin [SHBG], 17 beta-estradiol [17bE], androstenedione [AS]) were retrieved at each visit. A linear mixed model was used to assess the correlation between changes in testosterone levels and percent excess weight loss (%EWL).

RESULTS

In 30.8% of all patients, MOSH was present preoperatively. A significant increase of TT was observed postoperatively that led to a complete resolution of hypogonadism within the period observed. Bioavailable testosterone (bTT) and FSH levels significantly increased each month of follow-up after surgery (all P < .01). Levels of 17bE did not change significantly after surgery. The overall change of TT, comparing preoperative and 1-year postoperative TT levels (ΔTT), significantly correlated with %EWL. Changes in TT levels were not affected by the choice of surgical method.

CONCLUSIONS

Serum plasma testosterone levels rise significantly after metabolic and bariatric surgery in male patients. The change of testosterone levels seems to play a role in continued weight loss after surgery. This is true irrespective of the surgical method used.

Circadian disruption impairs glucose homeostasis in male but not in female mice and is dependent on gonadal sex hormones

Circadian disruption (CD) is the consequence of a mismatch between endogenous circadian rhythms and behavior, and frequently occurs in shift workers. CD has often been linked to impairment of glucose and lipid homeostasis. It is, however, unknown if these effects are sex dependent. Here, we subjected male and female C57BL/6J mice to 6-h light phase advancements every 3 days to induce CD and assessed glucose and lipid homeostasis. Within this model, we studied the involvement of gonadal sex hormones by injecting mice with gonadotropin-releasing hormone-antagonist degarelix. We demonstrate that CD has sex-specific effects on glucose homeostasis, as CD elevated fasting insulin levels in male mice while increasing fasting glucose levels in female mice, which appeared to be independent of behavior, food intake, and energy expenditure. Absence of gonadal sex hormones lowered plasma insulin levels in male mice subjected to CD while it delayed glucose clearance in female mice subjected to CD. CD elevated plasma triglyceride (TG) levels and delayed plasma clearance of TG-rich lipoproteins in both sexes, coinciding with reduced TG-derived FA uptake by adipose tissues. Absence of gonadal sex hormones did not notably alter the effects of CD on lipid metabolism. We conclude that CD causes sex-dependent effects on glucose metabolism, as aggravated by male gonadal sex hormones and partly rescued by female gonadal sex hormones. Future studies on CD should consider the inclusion of both sexes, which may eventually contribute to personalized advice for shift workers.

An insight into gut microbiota and metabolites in the mice with adenomyosis

Background

Adenomyosis (AM) is a benign uterine disease characterized pathologically by the invasion of endometrial tissue into the myometrium. The pathogenesis of AM is still far from clear. Although the gut microbiome and metabolomics are thought to contribute to a variety of diseases, the role of them in AM has not been revealed.

Objective

To investigate changes in the gut microbiota and derived metabolites in AM mice.

Method

Female ICR mice were randomly assigned to AM and control groups, and pituitary transplantation was employed to perform AM modeling. Then, the fecal samples were obtained for microbial (16S rRNA gene sequencing) and metabolomic (liquid chromatography mass spectrometry, LC-MS) analysis.

Result

The results of gut microbiota analysis showed that the intestinal microbiota composition of AM mice was altered. The ratio of Firmicutes/Bacteroidetes and the relative abundance of Lactobacillus in AM group increased compared with the control group. Sixty differential expressed metabolites were identified in intestinal metabolites, mainly involved in steroid hormone biosynthesis, cysteine and methionine metabolism, and alanine, aspartate, and glutamate metabolism. Further, correlation analysis verified that L-methionine and L-cystine were negatively correlated with Bacteroides and positively correlated with Desulfovibrio. The Pregnenolone, Androsterone glucuronide, and Testosterone glucuronide were negatively correlated with Unidentified_Ruminococcaceae and Alistipes, whereas they positively correlated with Bacteroides.

Conclusion

AM mice have a unique gut microbiome and intestinal metabolites.

Age-Related Sex Differences in Glucose Tolerance by 75 g Oral Glucose Tolerance Test in Japanese

To elucidate the age-related sex difference in glucose tolerance, we conducted 75 g oral glucose tolerance tests in 1156 participants. Participants were divided into four groups, namely, young (22−29) males, young females, middle-aged (>50) males, and middle-aged females. According to the Japanese Clinical Practice Guideline for Diabetes 2019, the prevalence of normal glucose tolerance (NGT) was significantly lower in middle-aged than in young participants. The prevalence of high-normal fasting plasma glucose (FPG) was higher, and NGT was lower in young males (high-normal FPG 15.2%, NGT 82.0%) than young females (high-FPG 3.9%, NGT 94.3%). Combined glucose intolerance (CGI) was higher and NGT was lower in middle-aged males (CGI 10.2%, NGT 25.2%) than in middle-aged females (CGI 3.3%, NGT 39.8%). FPG and body mass index (BMI) were the lowest and Homeostatic model assessment beta cell function (HOMA-β) was the highest in young females, followed by young males, middle-aged females, and middle-aged males. Multiple linear regression analysis revealed that BMI weakly correlated with HOMA-β and Matsuda index in all subjects except young females. The superior glucose tolerance in females was apparent in young, but attenuated in middle-aged females. The differences are due to the higher insulin secretion potential and lower BMI in young females.

The Beneficial Effect of a Healthy Dietary Pattern on Androgen Deprivation Therapy-Related Metabolic Abnormalities in Patients with Prostate Cancer: A Meta-Analysis Based on Randomized Controlled Trials and Systematic Review

Metabolic abnormalities as side effects of androgen-deprivation therapy (ADT) can accelerate progression of prostate cancer (PCa) and increase risks of cardiovascular diseases. A healthy dietary pattern (DP) plays an important role in regulating glycolipid metabolism, while evidence about DP on ADT-related metabolic abnormalities is still controversial. To explore the effect of DP on metabolic outcomes in PCa patients with ADT, PubMed, Embase, Cochrane, and CINAHL were searched from inception to 10 September 2022. Risk of biases was evaluated through Cochrane Collaboration’s Tool. If heterogeneity was low, the fixed-effects model was carried out; otherwise, the random-effects model was used. Data were determined by calculating mean difference (MD) or standardized MD (SMD) with 95% confidence intervals (CIs). Nine studies involving 421 patients were included. The results showed that healthy DP significantly improved glycated hemoglobin (MD: −0.13; 95% CI: −0.24, −0.02; p = 0.020), body mass index (MD: −1.02; 95% CI: −1.29, −0.75; p < 0.001), body fat mass (MD: −1.78; 95% CI: −2.58, −0.97; p < 0.001), triglyceride (MD: −0.28; 95% CI: −0.51, −0.04; p = 0.020), systolic blood pressure (MD: −6.30; 95% CI: −11.15, −1.44; p = 0.010), and diastolic blood pressure (MD: −2.94; 95% CI: −5.63, −0.25; p = 0.030), although its beneficial effects on other glycolipid metabolic indicators were not found. Additionally, a healthy DP also lowered the level of PSA (MD: −1.79; 95% CI: −2.25, −1.33; p < 0.001). The meta-analysis demonstrated that a healthy DP could improve ADT-related metabolic abnormalities and be worthy of being recommended for PCa patients with ADT.

Sex hormones, intestinal inflammation, and the gut microbiome: Major influencers of the sexual dimorphisms in obesity

Obesity is defined as the excessive accumulation of body fat and is associated with an increased risk of developing major health problems such as cardiovascular disease, diabetes and stroke. There are clear sexual dimorphisms in the epidemiology, pathophysiology and sequelae of obesity and its accompanying metabolic disorders, with females often better protected compared to males. This protection has predominantly been attributed to the female sex hormone estrogen and differences in fat distribution. More recently, the sexual dimorphisms of obesity have also been attributed to the differences in the composition and function of the gut microbiota, and the intestinal immune system. This review will comprehensively summarize the pre-clinical and clinical evidence for these sexual dimorphisms and discuss the interplay between sex hormones, intestinal inflammation and the gut microbiome in obesity. Major gaps and limitations of this rapidly growing area of research will also be highlighted in this review.

Associations between sex hormones and metabolic-associated fatty liver disease in a middle-aged and elderly community

Metabolic-associated fatty liver disease (MAFLD) was proposed by an international expert consensus to replace non-alcoholic fatty liver disease (NAFLD) in 2020. Previous studies have shown that sex hormones are strongly linked to NAFLD development. This study aims to explore whether sex hormones are associated with MAFLD and liver fat content (LFC) in a middle-aged and elderly community. The study included 732 subjects aged 50-80 years enrolled from communities. MAFLD was diagnosed using the 2020 International Expert Consensus. LFC was calculated using parameters from abdominal ultrasound images. Serum estradiol (E2), total testosterone (TT), sex hormone-binding globulin (SHBG), FSH, and LH were measured by chemiluminescent microparticle immunoassay. MAFLD was diagnosed in 107/304 (35.2%) men and 154/428 (35.2%) women. After adjustments for confounding factors, logistic regression analysis showed that SHBG was negatively correlated with MAFLD in men (OR, 0.95 [0.93-0.97], p < 0.001). In women, SHBG and FSH were negatively correlated with MAFLD (OR, 0.95 [0.94-0.97], p < 0.001; OR, 0.97 [0.96-0.98], p < 0.001). Multivariate linear regression analysis showed that SHBG was a negative factor for LFC in both men (standardized β = -0.188, p < 0.001) and women (standardized β = -0.184, p < 0.001). FSH was a negative factor for LFC in women (standardized β = -0.082, p = 0.046). SHBG was negatively correlated with MAFLD in middle-aged and elderly men and women. Moreover, FSH was negatively correlated, and bioactive testosterone was positively correlated with MAFLD in women. These findings suggest a relationship between sex hormones and MAFLD.

Low Serum Total Testosterone Is Associated with Non-Alcoholic Fatty Liver Disease in Men but Not in Women with Type 2 Diabetes Mellitus

Materials and Methods

There were 1155 patients with T2DM included in the analysis. Serum levels of total testosterone and the precursors of androgens, including androstenedione, DHEA, and DHEAS, were quantified using liquid chromatography-tandem mass spectrometry assays.

Results

The risk of NAFLD decreased as total testosterone concentration increased in men with T2DM. After adjusting for age, current smoking, current drinking, body mass index, duration of T2DM, diastolic blood pressure, total cholesterol, triglycerides, low-density lipoprotein/high-density lipoprotein cholesterol ratio, uric acid, C-reactive protein, and sex hormones in model 4, the adjusted odds ratio (OR) and 95% confidence interval (CI) of NAFLD for tertile3 vs tertile1 was 0.37 (0.17-0.77; P = 0.024 for trend). When taken as a continuous variable, this association was still robust in model 4 (OR, 0.58; 95% CI, 0.42-0.80; P < 0.05). No significant associations were found between increasing levels of the precursors of androgens and the odds of NAFLD in men with T2DM (all P > 0.05). Moreover, women showed no significant associations of total testosterone, androstenedione, DHEA, and DHEAS, with the odds of NAFLD (all P > 0.05).

Conclusions

Serum total testosterone was independently associated with the risk of NAFLD among men with T2DM. This study highlights the potential role of testosterone as a risk factor for NAFLD in patients with T2DM.

Rapeseed (canola) oil aggravates metabolic syndrome-like conditions in male but not in female stroke-prone spontaneously hypertensive rats (SHRSP)

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Canola oil shortens life of male SHRSP.

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Testis is the target of canola oil toxicity.

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Inhibition of negative regulation by testosterone of aldosterone production may be a trigger of canola oil toxicity.

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Facilitation of hypertension by aldosterone may lead to life-shortening.

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Increased plasma lipids by canola oil have no relevance to life-shortening.

This study was conducted to investigate whether or not there are sex differences in canola oil (CAN)-induced adverse events in the rat and to understand the involvement and the role of testosterone in those events, including life-shortening. Stroke-prone spontaneously hypertensive rats (SHRSP) of both sexes were fed a diet containing 10 wt/wt% soybean oil (SOY, control) or CAN as the sole dietary fat. The survival of the males fed the CAN diet was significantly shorter than that of those fed the SOY diet. In contrast, the survival of the females was not affected by CAN. The males fed the CAN diet showed elevated blood pressure, thrombopenia and insulin-tolerance, which are major symptoms of metabolic syndrome, whereas such changes by the CAN diet were not found in the females. Plasma testosterone was significantly lower in animals of both sexes fed the CAN diet than in those fed the SOY diet, but interestingly, the lowered testosterone was accompanied by a marked increase in plasma aldosterone only in the males. These results demonstrate significant sex differences in CAN-toxicity and suggest that those sex differences may be attributable to the increased aldosterone level, which triggers aggravation of the genetic diseases specific to SHRSP, that is, metabolic syndrome-like conditions, but only in the males. The present results also suggest that testosterone may negatively regulate aldosterone production in the physiology of the males, and the inhibition of that negative regulation caused by the CAN diet is one of the possible causes of the adverse events.

Association of Sex Hormones and Fat Distribution in Men with Different Obese and Metabolic Statuses

Purpose

Although several studies have explored the association of sex hormones with glucose metabolism, the association between sex hormones and body fat distribution, which is closely related to insulin resistance, has not been fully elucidated. We have tried to explore the relationship of testosterone (T) and estradiol (E2) with visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT) mass in Chinese men with different obese and metabolic statuses.

Patients and Methods

A total of 128 men from the Health Management Center of the Second Xiangya Hospital, Central South University were collected and grouped in accordance with their obese and metabolic syndrome (MS) statuses: metabolically healthy non-overweight/obese men (MHNO), metabolically healthy overweight/obese men (MHO) and metabolically unhealthy overweight/obese men (MUO). Multiple regression analyses were performed to estimate contributions of sex hormones levels to the variations of body fat distribution and the contributions of body fat distribution to the variations of sex hormone levels.

Results

With fat mass parameters as independent variables, SAT had a strong negative association with T in MHNO (β = −2.772, P = 0.034), VAT was positively correlated with E2 in MHO (β = 22.269, P = 0.009), and SAT was negatively associated with T in MUO (β = −3.315, P = 0.010). With sex hormones as independent variables, E2 positively correlated with VAT (β = −176.259, P = 0.048), while T negatively correlated with VAT in MHO (β = 183.150, P = 0.029). In MUO, an inverse association of T with SAT was observed (β = −213.689, P = 0.021).

Conclusion

E2 and VAT had a mutual influence, thus resulting in a vicious circle, and the negative correlation between T and VAT may be related to the decrease of the MS occurrence in the MHO group. There were bi-directional relationships between sex hormones and fat distribution in men with different obese and metabolic statuses.

Trial Registration

Chinese Clinical Trial Registry, ChiCTR-EOC-16010194. Retrospectively registered.

Androgen dysfunction in non-alcoholic fatty liver disease: Role of sex hormone binding globulin

Non-alcoholic fatty liver disease (NAFLD) is the most common form of chronic liver disease in the world. It is linked mainly to insulin resistance and metabolic syndrome including obesity and dyslipidemia. In addition, various endocrine dysfunctions including polycystic ovary syndrome (PCOS) and hypogonadism are involved in the development and progression of NAFLD. We need to know the disease pathophysiology more accurately due to the heterogeneity of clinical presentation of fatty liver disease. The liver is the major metabolic organ with sexual dimorphism. Sexual dimorphism is associated not only with behavioral differences between men and women, but also with physiological differences reflected in liver metabolism. In men, normal androgen levels prevent hepatic fat accumulation, whereas androgen deficiency induce hepatic steatosis. In women, higher androgens can increase the risk of NAFLD in PCOS. Sex hormone binding globulin (SHBG) is involved in androgen regulation. Recently, SHBG may be reported as a surrogate marker for NAFLD. Therefore, this review will focus on the mechanism of androgen dysfunction in the regulation of hepatic metabolism, the risk of developing NAFLD, and the potential role of SHBG in the course of NAFLD.; Keywords: Non-alcoholic fatty liver disease, insulin resistance, sexual dimorphism, androgen, sex hormone binding globulin.

Metabolic flexibility differs by body composition in adults

BACKGROUND & AIMS

With the rise of global cardiometabolic diseases, it is important to investigate risk factors such as obesity. Metabolic flexibility, the ability to maintain metabolic homeostasis following an acute challenge, can reflect cardiometabolic health. We investigated the association between body composition and the metabolic flexibility following meal consumption in an adult population.

METHODS

In this study of 1027 participants (mean age 44.0 y ± SD 4.2 y), we administered a mixed-macronutrient meal challenge. Fasting and 2-h postprandial plasma were assayed for lipids, glycemic, and inflammation biomarkers. We characterized metabolic flexibility through meal-induced biomarker responses (%Δ, the difference between postprandial and fasting concentrations, divided by fasting concentration). We then compared the responses by sex-specific tertiles of body mass index (BMI) and percent body fat.

RESULTS

With every unit (kg/m²) increase in BMI, %Δ (95% confidence interval) increased by 0.17% (0.09, 0.26%) for total cholesterol, 0.31% (0.07, 0.54%) for triglycerides, and 0.11% (0.01, 0.20%) for apoA-I, whereas insulin elevation was reduced (-6.30%; -8.41, -4.20%), and the reduction in leptin was attenuated (0.64%; 0.25, 1.05%). With each unit (percent) increase in body fat, we observed similar changes in the %Δ of total cholesterol and leptin but not in triglycerides, apoA-I, or insulin. Glucose response increased by 0.29% (0.06, 0.51%) as body fat increases by one unit.

CONCLUSION

Metabolic flexibility, as assessed by biomarker responses to an acute physiological meal challenge, differed by body composition. These findings may help elucidate the pathways through which obesity contributes to cardiometabolic diseases.

Estrogens and the regulation of glucose metabolism

The main estrogens: estradiol, estrone, and their acyl-esters have been studied essentially related to their classical estrogenic and pharmacologic functions. However, their main effect in the body is probably the sustained control of core energy metabolism. Estrogen nuclear and membrane receptors show an extraordinary flexibility in the modulation of metabolic responses, and largely explain gender and age differences in energy metabolism: part of these mechanisms is already sufficiently known to justify both. With regard to energy, the estrogen molecular species act essentially through four key functions: (1) Facilitation of insulin secretion and control of glucose availability; (2) Modulation of energy partition, favoring the use of lipid as the main energy substrate when more available than carbohydrates; (3) Functional protection through antioxidant mechanisms; and (4) Central effects (largely through neural modulation) on whole body energy management. Analyzing the different actions of estrone, estradiol and their acyl esters, a tentative classification based on structure/effects has been postulated. Either separately or as a group, estrogens provide a comprehensive explanation that not all their quite diverse actions are related solely to specific molecules. As a group, they constitute a powerful synergic action complex. In consequence, estrogens may be considered wardens of energy homeostasis.

Association between the metabolic syndrome and muscle weakness among Chinese older adults: results from the China Health and Retirement Longitudinal Study

BACKGROUND

Metabolic syndrome (MetS) may adversely influence muscle strength. However, the relationship remains poorly understood in China, despite its large older population and the high prevalence of MetS.

OBJECTIVES

We aimed to investigate the association between MetS and muscle weakness among older Chinese.

METHODS

We included 2,418 older adults who completed the 2011 and 2015 waves of the China Health and Retirement Longitudinal Study (CHARLS) and had normal handgrip strength at baseline. Data were analyzed using descriptive statistics and logistic regressions.

RESULTS

Baseline MetS was associated with increased risks for incident muscle weakness (OR = 1.35, 95% CI: 1.08-1.67). Among all the MetS components, baseline central obesity component was predictive of muscle weakness. The association between MetS and declined muscle strength existed in men but not women.

CONCLUSION

There was an increased risk of muscle strength decline associated with MetS, which was more prominent in men.

The Role of Physical Activity-Related Health Competence and Leisure-Time Physical Activity for Physical Health and Metabolic Syndrome: A Structural Equation Modeling Approach for German Office Workers

Office workers (OWs) are prone to insufficient physical activity (PA), which increases their risk of metabolic syndrome (MetS) and impaired physical health. The Physical Activity-related Health Competence (PAHCO) model holds the potential to facilitate a healthy physically active lifestyle. Therefore, in this study, we investigate the interplay between PAHCO, leisure-time PA, physical health, and MetS in OWs in Germany. In a cross-sectional study, OWs (N = 316, 25% female) completed self-report questionnaires along with an occupational health checkup to examine their Metabolic Syndrome Severity Score (MetSSS) values. Structural equation modeling indicated a strong positive association between PAHCO and leisure-time PA and a small positive association with physical health. PAHCO showed a considerable negative association with the MetSSS. Leisure-time PA was a positive mediator for the PAHCO-physical health association but was not a significant mediator for the association between PAHCO and the MetSSS. These findings underscore the importance of PAHCO in the context of leisure-time PA, physical health, and MetS in OWs. Furthermore, our findings highlight the health-enhancing value of the qualitative aspects of PA, such as motivational and volitional components in PA participation, with respect to physical health and MetS.

Fatty liver index is associated with the risk of testosterone deficiency in aging men without metabolic syndrome

OBJECTIVES

Non-alcoholic fatty liver disease (NAFLD) is suggested to be a precursor of metabolic syndrome (MetS) and could influence the risk of testosterone deficiency (TD). Fatty liver index (FLI) is a simple and useful screening tool for NAFLD. We determined the association between the risk of NAFLD assessed by FLI and TD in aging Taiwanese men, especially those without MetS.

MATERIALS AND METHODS

A free health screening program was conducted for men (age: >40 years) in a medical center in Kaohsiung, Taiwan. All participants underwent a physical examination; answered a questionnaire assessing demographics, medical history, and clinical symptoms of TD; and provided 20-mL whole blood samples for biochemical, adipocytokine, and hormonal evaluations. The risk of NAFLD was evaluated using FLI. The presence of NAFLD was ruled out if FLI value was <25 and ruled in if FLI value was ≥35.

RESULTS

A total of 552 men (mean age: 54.7 ± 7.7 years) were enrolled. The prevalence rates of TD and MetS were significantly higher among men with NAFLD than those without NAFLD (both p < 0.001). FLI was significantly correlated with total testosterone (TT) and adipocytokines associated with insulin resistance, such as adiponectin, leptin, and retinol-binding protein-4 (RBP-4) levels, respectively (all p < 0.001). Among men without MetS, those at risk of and with NAFLD had a 3.82 and 8.50 times higher risk of TD, respectively, than those without NAFLD after adjusting for potential covariates.

CONCLUSION

The FLI is associated with the risk of TD in aging Taiwanese men, especially in those without MetS. Our findings also suggest that insulin resistance may be an important link among the inter-relationships of NAFLD, MetS, and TD. Further population-based studies with larger sample sizes of different ethnicities are warranted to confirm these preliminary results.

The Postnatal Offspring of Finasteride-Treated Male Rats Shows Hyperglycaemia, Elevated Hepatic Glycogen Storage and Altered GLUT2, IR, and AR Expression in the Liver

Background: A growing body of data indicates that the physiology of the liver is sex-hormone dependent, with some types of liver failure occurring more frequently in males, and some in females. In males, in physiological conditions, testosterone acts via androgen receptors (AR) to increase insulin receptor (IR) expression and glycogen synthesis, and to decrease glucose uptake controlled by liver-specific glucose transporter 2 (GLUT-2). Our previous study indicated that this mechanism may be impaired by finasteride, a popular drug used in urology and dermatology, inhibiting 5α-reductase 2, which converts testosterone (T) into dihydrotestosterone (DHT). Our research has also shown that the offspring of rats exposed to finasteride have an altered T–DHT ratio and show changes in their testes and epididymides. Therefore, the goal of this study was to assess whether the administration of finasteride had an trans-generational effect on (i) GLUT-2 dependent accumulation of glycogen in the liver, (ii) IR and AR expression in the hepatocytes of male rat offspring, (iii) a relation between serum T and DHT levels and the expression of GLUT2, IR, and AR mRNAs, (iv) a serum glucose level and it correlation with GLUT-2 mRNA. Methods: The study was conducted on the liver (an androgen-dependent organ) from 7, 14, 21, 28, and 90-day old Wistar male rats (F1:Fin) born by females fertilized by finasteride-treated rats. The control group was the offspring (F1:Control) of untreated Wistar parents. In the histological sections of liver the Periodic Acid Schiff (PAS) staining (to visualize glycogen) and IHC (to detect GLUT-2, IR, and AR) were performed. The liver homogenates were used in qRT-PCR to assess GLUT2, IR, and AR mRNA expression. The percentage of PAS-positive glycogen areas were correlated with the immunoexpression of GLUT-2, serum levels of T and DHT were correlated with GLUT-2, IR, and AR transcript levels, and serum glucose concentration was correlated with the age of animals and with the GLUT-2 mRNA by Spearman’s rank correlation coefficients. Results: In each age group of F1:Fin rats, the accumulation of glycogen was elevated but did not correlate with changes in GLUT-2 expression. The levels of GLUT-2, IR, and AR transcripts and their immunoreactivity statistically significantly decreased in F1:Fin animals. In F1:Fin rats the serum levels of T and DHT negatively correlated with androgen receptor mRNA. The animals from F1:Fin group have statistically elevated level of glucose. Additionally, in adult F1:Fin rats, steatosis was observed in the liver (see Appendix A). Conclusions: It seems that treating male adult rats with finasteride causes changes in the carbohydrate metabolism in the liver of their offspring. This can lead to improper hepatic energy homeostasis or even hyperglycaemia, insulin resistance, as well as some symptoms of metabolic syndrome and liver steatosis.

Sex-Specific Associations of Testosterone and Genetic Factors With Health Span

BACKGROUND

Previous studies have suggested associations between testosterone, genetic factors, and a series of complex diseases, but the associations with the lifespan phenotype, such as health span, remain unclear.

METHODS

In this prospective cohort study, we analyzed 145,481 men and 147,733 women aged 38-73 years old from UK Biobank (UKB) to investigate the sex-specific associations of total testosterone (TT), free testosterone (FT), or polygenic risk score (PRS) with health span termination (HST) risk. At baseline, serum testosterone levels were measured. HST was defined by eight events strongly associated with longevity. PRS, an efficient tool combining the effect of common genetic variants to discriminate genetic risk of complex phenotypes, was constructed by 12 single-nucleotide polymorphisms related to health span from UKB (P ≤ 5.0 × 10^-8). We used multivariable Cox regression models to estimate hazard ratios (HRs) and 95% confidence intervals (CIs).

RESULTS

With a median follow-up time of 7.70 years, 26,748 (18.39%) men and 18,963 (12.84%) women had HST. TT was negatively associated with HST in men [HR per standard deviation (SD) increment of log-TT: 0.92, 95% CI: 0.88-0.97]. Inversely, both TT (HR per SD increment of log-TT: 1.05, 95% CI: 1.02-1.08) and FT (HR per SD increment of log-FT: 1.08, 95% CI: 1.05-1.11) presented an increased risk of HST in women. PRS was positively associated with HST risk (quintile 5 versus quintile 1, men, HR: 1.19, 95% CI: 1.15-1.24; women, HR: 1.21, 95% CI: 1.16-1.27). Moreover, men with high TT and low genetic risk showed the lowest HST risk (HR: 0.80, 95% CI: 0.73-0.88), whereas HST risk for women with both high TT and genetic risk increased obviously (HR: 1.32, 95% CI: 1.19-1.46). Similar joint effects were observed for FT in both genders.

CONCLUSIONS

We observed sex-specific associations that testosterone was negatively associated with HST risk in men and positively associated with HST risk in women. Genetic factors increased the HST risk, suggesting that participants with both high genetic risk and abnormal testosterone levels (high level in women or low level in men) should be the target for early intervention. Although our findings highlight the associations between testosterone and health span, further mechanistic studies and prospective trials are warranted to explore the causation behind.

Mitochondria in Sex Hormone-Induced Disorder of Energy Metabolism in Males and Females

Androgens have a complex role in the regulation of insulin sensitivity in the pathogenesis of type 2 diabetes. In male subjects, a reduction in androgens increases the risk for insulin resistance, which is improved by androgen injections. However, in female subjects with polycystic ovary syndrome (PCOS), androgen excess becomes a risk factor for insulin resistance. The exact mechanism underlying the complex activities of androgens remains unknown. In this review, a hormone synergy-based view is proposed for understanding this complexity. Mitochondrial overactivation by substrate influx is a mechanism of insulin resistance in obesity. This concept may apply to the androgen-induced insulin resistance in PCOS. Androgens and estrogens both exhibit activities in the induction of mitochondrial oxidative phosphorylation. The two hormones may synergize in mitochondria to induce overproduction of ATP. ATP surplus in the pancreatic β-cells and α-cells causes excess secretion of insulin and glucagon, respectively, leading to peripheral insulin resistance in the early phase of type 2 diabetes. In the skeletal muscle and liver, the ATP surplus contributes to insulin resistance through suppression of AMPK and activation of mTOR. Consistent ATP surplus leads to mitochondrial dysfunction as a consequence of mitophagy inhibition, which provides a potential mechanism for mitochondrial dysfunction in β-cells and brown adipocytes in PCOS. The hormone synergy-based view provides a basis for the overactivation and dysfunction of mitochondria in PCOS-associated type 2 diabetes. The molecular mechanism for the synergy is discussed in this review with a focus on transcriptional regulation. This view suggests a unifying mechanism for the distinct metabolic roles of androgens in the control of insulin action in men with hypogonadism and women with PCOS.

Associations between serum total, free and bioavailable testosterone and non-alcoholic fatty liver disease in community-dwelling middle-aged and elderly women

BACKGROUND AND AIMS

Non-alcoholic fatty liver disease (NAFLD) is considered both a cause and consequence of the metabolic syndrome (MetS). While emerging evidence has indicated that testosterone is associated with MetS, the relationship between testosterone and NAFLD in women remains unclear. Therefore, this study investigated the associations between serum testosterone levels and NAFLD prevalence risk in a community-based cross-sectional study.

METHODS

A total of 2117 adult women were included in the analysis. Serum total testosterone (TT) was measured by chemiluminescence immunoassay, and other testosterone-related indices, such as concentrations and percentages of calculated free testosterone (cFT) and bioavailable testosterone (BioT), and free androgen index (FAI), were also calculated. NAFLD was diagnosed by clinical criteria. Logistic regression was used to explore these associations.

RESULTS

There were significant differences in TT, FAI, cFT and BioT between women with and without NAFLD (all P<0.001). Multivariate logistic-regression analyses demonstrated that both absolute concentrations and percentages of cFT and BioT were positively associated with NAFLD risk prevalence in all models. Adjusted ORs (95% CI) for quartile 4 vs quartile 1 of % cFT and % BioT were 5.94 (4.29-8.22) and 5.21 (3.79-7.17) in model 2, and 4.35 (3.07-6.18) and 3.58 (2.55-5.03) in model 3 (all P<0.001 for trend). In addition, quartiles of TT, FAI, cFT and BioT were significantly correlated with degree of hepatic steatosis. ROC analysis also showed that % cFT and % BioT were more accurate for predicting NAFLD prevalence than was TT.

CONCLUSION

Serum cFT and BioT were positively associated with NAFLD risk, and elevated levels of cFT and BioT could be independent risk factors of NAFLD prevalence in middle-aged and elderly women.

Diabetogenic diet-induced insulin resistance associates with lipid droplet proteins and adipose tissue secretome, but not with sexual dimorphic adipose tissue fat accumulation in wistar rats

The role of sexual dimorphic adipose tissue fat accumulation in the development of insulin resistance is well known. However, whether vitamin A status and/or its metabolic pathway display any sex- or depot (visceral/subcutaneous)-specific pattern and have a role in sexual dimorphic adipose tissue development and insulin resistance are not completely understood. Therefore, to assess this, 5 weeks old Wistar male and female rats of eight from each sex were provided either control or diabetogenic (high fat, high sucrose) diet for 26 weeks. At the end, consumption of diabetogenic diet increased the visceral fat depots (p < 0.001) in the males and subcutaneous depot (p < 0.05) in the female rats, compared to their sex-matched controls. On the other hand, it caused adipocyte hypertrophy (p < 0.05) of visceral depot (retroperitoneal) in the females and subcutaneous depot of the male rats. Although vitamin A levels displayed sex- and depot-specific increase due to the consumption of diabetogenic diet, the expression of most of its metabolic pathway genes in adipose depots remained unaltered. However, the mRNA levels of some of lipid droplet proteins (perilipins) and adipose tissue secretory proteins (interleukins, lipocalin-2) did display sexual dimorphism. Nonetheless, the long-term feeding of diabetogenic diet impaired the insulin sensitivity, thus affected glucose clearance rate and muscle glucose-uptake in both the sexes of rats. In conclusion, the chronic consumption of diabetogenic diet caused insulin resistance in the male and female rats, but did not corroborate with sexual dimorphic adipose tissue fat accumulation or its vitamin A status.

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Role of vitamin A and its metabolic pathway on sexual dimorphic fat accumulation and insulin resistance was studied.

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Consumption of diabetogenic diet caused insulin resistance, but not associated with sexual-dimorphic fat deposition.

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Vitamin A accumulation displayed a sex- and fat depot-specific pattern without altering its metabolic pathway genes.

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However, the lipid droplet proteins and secretome of the adipose depots displayed sex- and/or depot-specific pattern.

Whole-genome and enzymatic analyses of an androstenedione-producing Mycobacterium strain with residual phytosterol-degrading pathways

Mycobacterium neoaurum strains can transform phytosterols to 4-androstene-3,17-dione (4-AD), a key intermediate for the synthesis of advanced steroidal medicines. In this work, we presented the complete genome sequence of the M. neoaurum strain HGMS2, which transforms β-sitosterol to 4-AD. Through genome annotation, a phytosterol-degrading pathway in HGMS2 was predicted and further shown to form a 9,10-secosteroid intermediate by five groups of enzymes. These five groups of enzymes included three cholesterol oxidases (ChoM; group 1: ChoM1, ChoM2 and Hsd), two monooxygenases (Mon; group 2: Mon164 and Mon197), a set of enzymes for side-chain degradation (group 3), one 3-ketosteroid-1,2-dehydrogenase (KstD; group 4: KstD211) and three 3-ketosteroid-9a-hydroxylases (Ksh; group 5: KshA226, KshA395 and KshB122). A gene cluster encoding Mon164, KstD211, KshA226, KshB122 and fatty acid β-oxidoreductases constituted one integrated metabolic pathway, while genes encoding other key enzymes were sporadically distributed. All key enzymes except those from group 3 were prepared as recombinant proteins and their activities were evaluated, and the proteins exhibited distinct activities compared with enzymes identified from other bacterial species. Importantly, we found that the KstD211 and KshA395 enzymes in the HGMS2 strain retained weak activities and caused the occurrence of two major impurities, i.e., 1,4-androstene-3,17-dione (ADD) and 9-hydroxyl-4-androstene-3,17-dione (9OH-AD) during β-sitosterol fermentation. The concurrence of these two 4-AD analogs not only lowered 4-AD production yield but also hampered 4-AD purification. HGMS2 has the least number of genes encoding KstD and Ksh enzymes compared with current industrial strains. Therefore, HGMS2 could be a potent strain by which the 4-AD production yield could be enhanced by disabling the KstD211 and KshA395 enzymes. Our work also provides new insight into the engineering of the HGMS2 strain to produce ADD and 9OH-AD for industrial application.

Individual and joint association of bioavailable testosterone and aging with neutrophil-to-lymphocyte ratio in Chinese middle-aged and elderly men

BACKGROUND AND OBJECTIVES

Accumulating evidences suggest that chronic systemic inflammation (CSI) is independently associated with large number of major non-communicable chronic diseases (NCDs) ranging from metabolic disorders to cancers, and neutrophil-to-lymphocyte ratio (NLR) has been accepted as a novel, convenient marker for CSI response. Testosterone deficiency in men is linked to high risk of NCDs. This cross-sectional study aimed to investigate the individual and joint association of bioavailable testosterone (BIOT) and aging with NLR.

METHODS

A total of 132 male adults were enrolled during Jan. 2011 and Oct. 2017 in the first affiliated hospital of University of Science and Technology of China. Local weighted regression (LOESS) and multivariable generalized linear regression models were utilized to comprehensively examine the individual and joint association between BIOT and age with NLR.

RESULTS

Obvious linear relationships between NLR and BIOT or age were observed with the LOESS models. NLR was negatively correlated to BIOT after adjusting for some potential confounding factors (P = 0.034). As compared to the lowest quartile of BIOT, the adjusted decrease of NLR for the 2nd, 3rd and 4th quartiles were 0.40, 0.64 and 0.72, respectively. Meanwhile, NLR was observed to be independently correlated to elevated age (P = 0.043). Furthermore, as compared to the counterparts, men over 70 years combined with plasma BIOT less than 4.7 nmol/L had the highest NLR level, which suggested that low BIOT and aging jointly correlated to the level of NLR (P = 0.005).

CONCLUSION

BIOT deficiency and aging were individually and jointly correlated to CSI. Men over 70 years combined with BIOT < 4.7 nmol/L were more like to have higher grade of CSI than others.

Pre-operative Obesity-Associated Hyperandrogenemia in Women and Hypogonadism in Men Have No Impact on Weight Loss Following Bariatric Surgery

Background

In severe obesity, hypogonadism in men and androgen excess in women are frequently observed. Sex hormones play an important role in body composition and glucose and lipid metabolism. However, whether pre-operative gonadal dysfunction impacts weight loss after bariatric surgery is not fully known.

Methods

A total of 49 men and 104 women were included in a retrospective analysis. Anthropometric characteristics, glucose and lipid metabolism, and androgen concentrations were assessed pre-operatively and 17.9 ± 11 or 19.3 ± 12 months post-operatively in men and women. Men with (HYPO_male) and without (controls: CON_male) pre-operative hypogonadism, as well as women with (HYPER_female) and without (controls: CON_female) pre-operative hyperandrogenemia, were compared.

Results

In men, pre-operative hypogonadism was present in 55% and linked to a higher body mass index (BMI): HYPO_male 50 ± 6 kg/m² vs. CON_male 44 ± 5 kg/m², p = 0.001. Bariatric surgery results in comparable changes in BMI in HYPO_male and CON_male − 16 ± 6 kg/m² vs. − 14 ± 5 kg/m², p = 0.30. Weight loss reversed hypogonadism in 93%. In women, androgen excess was present in 22%, independent of pre-operative BMI: CON_female 44 ± 7 kg/m² vs. HYPER_female 45 ± 7 kg/m², p = 0.57. Changes in BMI were comparable in HYPER_female and CON_female after bariatric surgery − 15 ± 6 kg/m² vs. − 15 ± 5 kg/m², p = 0.88. Hyperandrogenemia was reversed in 61%.

Conclusions

Besides being frequently observed, hypogonadism in men and androgen excess in women have no impact on post-surgical improvements in body weight and glucose and lipid metabolism. Weight loss resulted in reversal of hypogonadism in almost all men and of hyperandrogenemia in the majority of women.

Thirty years of translational research in Mobility Medicine: Collection of abstracts of the 2020 Padua Muscle Days

More than half a century of skeletal muscle research is continuing at Padua University (Italy) under the auspices of the Interdepartmental Research Centre of Myology (CIR-Myo), the European Journal of Translational Myology (EJTM) and recently also with the support of the A&CM-C Foundation for Translational Myology, Padova, Italy. The Volume 30(1), 2020 of the EJTM opens with the collection of abstracts for the conference "2020 Padua Muscle Days: Mobility Medicine 30 years of Translational Research". This is an international conference that will be held between March 18-21, 2020 in Euganei Hills and Padova in Italy. The abstracts are excellent examples of translational research and of the multidimensional approaches that are needed to classify and manage (in both the acute and chronic phases) diseases of Mobility that span from neurologic, metabolic and traumatic syndromes to the biological process of aging. One of the typical aim of Physical Medicine and Rehabilitation is indeed to reduce pain and increase mobility enough to enable impaired persons to walk freely, garden, and drive again. The excellent contents of this Collection of Abstracts reflect the high scientific caliber of researchers and clinicians who are eager to present their results at the PaduaMuscleDays. A series of EJTM Communications will also add to this preliminary evidence.

Sex differences on adipose tissue remodeling: from molecular mechanisms to therapeutic interventions

Sexual dimorphism greatly influences adipose tissue remodeling, which is characterized by changes in the activity, number, and/or size of adipocytes in response to distinct stimuli, including lifestyle and anti-obesity drugs. This sex dependence seems to be due to the anatomical and endocrine disparities between men and women. At the molecular level, sex hormones are believed to mediate such differences and involve estrogen and androgen receptor-induced gene expression. The signaling pathways that regulate adipose tissue metabolism and function include peroxisome proliferator-activated receptor gamma, uncoupling protein 1 (UCP1), 5' adenosine monophosphate-activated protein kinase (AMPK), and mitochondrial oxidative phosphorylation (OXPHOS), among other molecular players. Sex hormone-related pathways also interplay with adrenergic signaling, probably the most well-characterized molecular mechanism implicated in the remodeling of white adipose tissue. This review overviews and integrates the signaling pathways behind sexual dimorphism in adipose tissue remodeling, hoping to increase the knowledge on the pathogenesis of diseases, such as obesity and related comorbidities, and consequently, to drive future studies to investigate the regulation of this tissue homeostasis, either in men or women.

Vascular mechanisms of testosterone: The non-genomic point of view

Testosterone (T) is the predominant endogenous androgen in the bloodstream. At the vascular level, T presents genomic and non-genomic effects, and both effects may overlap. The genomic actions assume that androgens can freely cross the plasma membrane of target cells and bind to nuclear androgen receptors, inducing gene transcription and protein synthesis. The non-genomic effects have a more rapid onset and may be related to the interaction with protein/receptor/ion channels of the plasma membrane. The key T effect at the vascular level is vasorelaxation, which is primarily due to its rapid effect. Thus, the main purpose of this review is to discuss the T non-genomic effects at the vascular level and the molecular pathways involved in its vasodilator effect observed in in vivo and in vitro studies. In this sense, the nuclear receptor activation, the influence of vascular endothelium and the activation or inhibition of ion channels (potassium and calcium channels, respectively) will be reviewed regarding all the data that corroborated or not. Moreover, this review also provides a brief update on the association of T with the risk factors for cardiovascular diseases, namely metabolic syndrome, type 2 diabetes mellitus, obesity, atherosclerosis, dyslipidaemia, and hypertension. In summary, in this paper we consider the non-genomic vascular mode of action of androgen in physiological conditions and the main risk factors for cardiovascular diseases.

Cyclophilin D participates in the inhibitory effect of high-fat diet on the expression of steroidogenic acute regulatory protein

OBJECTIVE

The high-fat diet (HFD)-induced obesity is responsible for the testosterone deficiency (TD). However, the mechanism remains unknown. Mitochondrial homeostasis is proved to be important for maintaining the function of steroidogenic acute regulatory protein (StAR), the first rate-limiting enzyme in testosterone synthesis. As the key regulator of mitochondrial membrane permeability, cyclophilin D (CypD) plays a crucial role in maintaining mitochondrial function. In this study, we sought to elucidate the role of CypD in the expression of StAR affected by HFD.

METHODS

To analyse the influence of CypD on StAR in vivo and in vitro, mouse models of HFD, CypD overexpression and CypD knockout (Ppif-/- ) as well as Leydig cells treated with palmitic acid (PA) and CypD overexpression plasmids were examined with an array of metabolic, mitochondrial function and molecular assays.

RESULTS

Compared with the normal diet mice, consistent with reduced testosterone in testes, the expressions of StAR in both mRNA and protein levels in HFD mice were down-regulated, while expressions of CypD were up-regulated. High-fat intake impaired mitochondrial function with the decrease in StAR in Leydig cells. Overexpression of CypD inhibited StAR expressions in vivo and in vitro. Compared with C57BL/6 mice with HFD, expressions of StAR were improved in Ppif-/- mice with HFD.

CONCLUSIONS

Mitochondrial CypD involved in the inhibitory effect of HFD on StAR expression in testes.

Structure-based reconstruction of a Mycobacterium hypothetical protein into an active Δ5-3-ketosteroid isomerase

Protein engineering based on structure homology holds the potential to engineer steroid-transforming enzymes on demand. Based on the genome sequencing analysis of industrial Mycobacterium strain HGMS2 to produce 4-androstene-3,17-dione (4-AD), three hypothetical proteins were predicted as putative Δ⁵-3-ketosteroid isomerases (KSIs) to catalyze an intramolecular proton transfer involving the transformation of 5-androstene-3,17-dione (5-AD) into 4-AD, which were defined as mKSI228, mKSI291 and mKSI753. Activity assays indicated that mKSI228 and mKSI291 exhibited weak activity, as low as 0.7% and 1.5%, respectively, of a well-studied and highly active KSI from Pseudomonas putida KSI (pKSI), while mKSI753 had no activity similar to Mycobacterium tuberculosis KSI (mtKSI). Although the 3D structures of the putative mKSIs were homologous to pKSI, their amino acid sequences were significantly different from those of pKSI and tKSI. Thus, by use of these two KSIs as homology models, we were able to convert the low-active mKSI291 into a high-active active KSI by site-directed mutagenesis. On the other hand, an X-ray crystallographic structure of mKSI291 identified a water molecule in its active site. This unique water molecule might function as a bridge to connect Ser-OH, Tyr57-OH and C3O of the intermediate form a hydrogen-bonding network that was responsible for its weak activity, compared with that of mtKSI. Our results not only demonstrated the use of a protein engineering approach to understanding KSI catalytic mechanism, but also provided an example for engineering the catalytic active sites and gaining a functional enzyme based on homologous structures.

Bone Marrow Adipocytes: The Enigmatic Components of the Hematopoietic Stem Cell Niche

Bone marrow adipocytes (BMA) exert pleiotropic roles beyond mere lipid storage and filling of bone marrow (BM) empty spaces, and we are only now beginning to understand their regulatory traits and versatility. BMA arise from the differentiation of BM mesenchymal stromal cells, but they seem to be a heterogeneous population with distinct metabolisms, lipid compositions, secretory properties and functional responses, depending on their location in the BM. BMA also show remarkable differences among species and between genders, they progressively replace the hematopoietic BM throughout aging, and play roles in a range of pathological conditions such as obesity, diabetes and anorexia. They are a crucial component of the BM microenvironment that regulates hematopoiesis, through mechanisms largely unknown. Previously considered as negative regulators of hematopoietic stem cell function, recent data demonstrate their positive support for hematopoietic stem cells depending on the experimental approach. Here, we further discuss current knowledge on the role of BMA in hematological malignancies. Early hints suggest that BMA may provide a suitable metabolic niche for the malignant growth of leukemic stem cells, and protect them from chemotherapy. Future in vivo functional work and improved isolation methods will enable determining the true essence of this elusive BM hematopoietic stem cell niche component, and confirm their roles in a range of diseases. This promising field may open new pathways for efficient therapeutic strategies to restore hematopoiesis, targeting BMA.

High progesterone levels are associated with family history of premature coronary artery disease in young healthy adult men

BACKGROUND & AIMS

The offspring of patients with premature coronary artery disease (P-CAD) are at higher risk for cardiovascular disease, compared with subjects without a family history (FH) of P-CAD. The increased risk for cardiovascular disease in subjects with FH of early-onset CAD results from unfavorable genetic variants as well as social, behavioral and environmental factors, which are more prevalent in this group. Previous studies have shown that specific sex hormone levels may be associated with the risk of cardiovascular disease. The aim of this study was to compare wide range of biochemical marker levels including i.e. the levels of luteinizing hormone (LH), follicle-stimulating hormone (FSH), progesterone, estradiol, testosterone and sex-hormone binding globulin (SHBG) between young healthy male adults with and without FH of P-CAD.

METHODS

The study group consisted of young healthy Polish male adults enrolled in a MAGNETIC case-control study, who were recruited between July 2015 and October 2017. The inclusion criteria were as follows: male sex, age ≥18 and ≤35 years old, FH of P-CAD (cases) or no P-CAD in first-degree relatives (controls). The comparison of continuous and categorical variables was performed using the Student's t-test or the U-Mann-Whitney test, and Fisher's exact test, respectively. The correlations between FSH, LH, testosterone, progesterone, SHBG and other laboratory parameters were assessed using the Spearman rank correlation test. Both univariable and multivariable logistic regression analyses were performed to assess the association between analyzed variables and FH of P-CAD.

RESULTS

A total of 411 subjects (223 cases and 188 controls) were included in the study. There was a higher prevalence of major cardiovascular risk factors in subjects with FH of P-CAD (smoking, higher total and LDL cholesterol levels, higher body mass index and lower HDL cholesterol level). Moreover, the offspring of patients with P-CAD had lower SHBG level, and higher LH and progesterone levels in the crude comparison, compared with individuals without FH of P-CAD. After adjustment for confounding variables, progesterone and LH were determined to be independently associated with FH of P-CAD.

CONCLUSION

Progesterone and LH levels are significantly associated with FH of P-CAD, independent of traditional risk factors for CAD.

Sex-Specific Associations of Testosterone With Metabolic Traits

Background: Testosterone levels are differentially linked with diabetes risk in men and women: lower testosterone levels in men and higher testosterone levels in women are associated with type 2 diabetes, though, the mechanisms are not fully clear. We addressed sex-specific links between testosterone and major pathogenetic mechanisms of diabetes. Methods: We analyzed data of 623 subjects (202 male, 345 female without, and 76 female with oral contraceptive therapy [OCT]) for whom insulin sensitivity and insulin secretion were assessed by oral glucose tolerance test. Body fat percentage was assessed by bioelectrical impedance. Testosterone was measured by enzyme-linked immunoassay; free testosterone and Framingham risk score were calculated. Results: There were significant interactions between testosterone and sex for all tested metabolic traits. Increasing testosterone was associated with less body fat, elevated insulin sensitivity, and reduced glycemia, independent of adiposity in men. In women without OCT, testosterone correlated with more body fat, insulin resistance, and higher glucose concentrations. Testosterone was not associated with insulin secretion in either sex, but with lower Framingham risk score in men and higher Framingham risk score in women. Conclusions: Similar to diabetes risk, insulin resistance has different association directions with testosterone levels in males and females. Insulin resistance could therefore constitute the best biological candidate linking testosterone levels and diabetes prevalence. The question of antiandrogen therapy being able to improve metabolism, glucose tolerance and cardiovascular risk in women was not clarified in our study but should be reviewed with higher numbers in a carefully matched study to reduce the influence of confounding variables.

Testosterone-Associated Dietary Pattern Predicts Low Testosterone Levels and Hypogonadism

Obesity and low serum testosterone (T) levels are interrelated and strongly influenced by dietary factors, and their alteration entails a great risk of hypogonadism. Substantial evidence suggests a bidirectional relationship between nutrient metabolism (e.g., glucose, lipids, and iron) and T levels in men; however, T-related dietary patterns remain unclear. This study investigated the dietary patterns associated with serum total T levels and its predictive effect on hypogonadism and the body composition. Anthropometry, blood biochemistry, and food frequency questionnaires were collected for 125 adult men. Dietary patterns were derived using a reduced rank regression from 32 food groups. Overall prevalence rates of central obesity and hypogonadism were 48.0% and 15.7%, respectively. An adjusted linear regression showed that age, insulin, red blood cell (RBC) aggregation, and transferrin saturation independently predicted serum total T levels (all p < 0.01). The total T-related dietary pattern (a high consumption of bread and pastries, dairy products, and desserts, eating out, and a low intake of homemade foods, noodles, and dark green vegetables) independently predicted hypogonadism (odds ratio: 5.72; 95% confidence interval: 1.11‒29.51, p < 0.05) for those with the highest dietary pattern scores (Q4) compared to those with the lowest (Q1). Scores were also negatively correlated with the skeletal muscle mass (p for trend = 0.002) but positively correlated with the total body fat mass (p for trend = 0.002), visceral fat mass (p for trend = 0.001), and to a lesser extent, subcutaneous fat mass (p for trend = 0.035) after adjusting for age. Randomized controlled trials are needed to confirm that improvement in dietary pattern can improve T levels and reduce hypogonadism.

40 YEARS of IGF1: Understanding the tissue-specific roles of IGF1/IGF1R in regulating metabolism using the Cre/loxP system

It is clear that insulin-like growth factor-1 (IGF1) is important in supporting growth and regulating metabolism. The IGF1 found in the circulation is primarily produced by the liver hepatocytes, but healthy mature hepatocytes do not express appreciable levels of the IGF1 receptor (IGF1R). Therefore, the metabolic actions of IGF1 are thought to be mediated via extra-hepatocyte actions. Given the structural and functional homology between IGF1/IGF1R and insulin receptor (INSR) signaling, and the fact that IGF1, IGF1R and INSR are expressed in most tissues of the body, it is difficult to separate out the tissue-specific contributions of IGF1/IGF1R in maintaining whole body metabolic function. To circumvent this problem, over the last 20 years, investigators have taken advantage of the Cre/loxP system to manipulate IGF1/IGF1R in a tissue-dependent, and more recently, an age-dependent fashion. These studies have revealed that IGF1/IGF1R can alter extra-hepatocyte function to regulate hormonal inputs to the liver and/or alter tissue-specific carbohydrate and lipid metabolism to alter nutrient flux to liver, where these actions are not mutually exclusive, but serve to integrate the function of all tissues to support the metabolic needs of the organism.

Gender in Endocrine Diseases: Role of Sex Gonadal Hormones

Gender- and sex- related differences represent a new frontier towards patient-tailored medicine, taking into account that theoretically every medical specialty can be influenced by both of them. Sex hormones define the differences between males and females, and the different endocrine environment promoted by estrogens, progesterone, testosterone, and their precursors might influence both human physiology and pathophysiology. With the term Gender we refer, instead, to behaviors, roles, expectations, and activities carried out by the individual in society. In other words, "gender" refers to a sociocultural sphere of the individual, whereas "sex" only defines the biological sex. In the last decade, increasing attention has been paid to understand the influence that gender can have on both the human physiology and pathogenesis of diseases. Even the clinical response to therapy may be influenced by sex hormones and gender, but further research is needed to investigate and clarify how they can affect the human pathophysiology. The path to a tailored medicine in which every patient is able to receive early diagnosis, risk assessments, and optimal treatments cannot exclude the importance of gender. In this review, we have focused our attention on the involvement of sex hormones and gender on different endocrine diseases.