The role of estrogens in control of energy balance and glucose homeostasis

Obesity and menopause

Obesity is not a choice or a result of lack of willpower, but a multifactorial, chronic, progressive, and relapsing disease. During menopause, hormonal and body composition changes lead to greater visceral adiposity, that aggravates women's health at a cardiometabolic, mechanic and mental level. Adiposity has been identified as an important modifier of reproductive hormones. During female midlife, obesity has been associated with menstrual cycle alterations (anovulatory cycles ending with abnormal bleedings), menopausal symptoms including hot flashes, poor quality of sleep, aches and joint pain, genitourinary symptoms, and reduced quality of life. However, the relationships between weight, the menopausal process, aging, and hormone levels remain poorly understood. Women with obesity have an increased risk of thromboembolic disease when using menopause hormone therapy (MHT), and it is probably the main medical condition to prescribe or not MHT. However, this risk depends on the route and type of MHT. The use of estrogen-only or combined transdermal MHT does not increase the risk of a thrombotic event in women with obesity.

Beyond Menstrual Dysfunction: Does Altered Endocrine Function Caused by Problematic Low Energy Availability Impair Health and Sports Performance in Female Athletes?

Low energy availability, particularly when problematic (i.e., prolonged and/or severe), has numerous negative consequences for health and sports performance as characterized in relative energy deficiency in sport. These consequences may be driven by disturbances in endocrine function, although scientific evidence clearly linking endocrine dysfunction to decreased sports performance and blunted or diminished training adaptations is limited. We describe how low energy availability-induced changes in sex hormones manifest as menstrual dysfunction and accompanying hormonal dysfunction in other endocrine axes that lead to adverse health outcomes, including negative bone health, impaired metabolic activity, undesired outcomes for body composition, altered immune response, problematic cardiovascular outcomes, iron deficiency, as well as impaired endurance performance and force production, all of which ultimately may influence athlete health and performance. Where identifiable menstrual dysfunction indicates hypothalamic-pituitary-ovarian axis dysfunction, concomitant disturbances in other hormonal axes and their impact on the athlete's health and sports performance must be recognized as well. Given that the margin between podium positions and "losing" in competitive sports can be very small, several important questions regarding low energy availability, endocrinology, and the mechanisms behind impaired training adaptations and sports performance have yet to be explored.

Is it time to revise the fighting strategy toward type 2 diabetes? Sex and pollution as new risk factors

Diabetes mellitus, a metabolic condition affecting around 537 million individuals worldwide, poses significant challenges, particularly among the elderly population. The etiopathogenesis of type 2 diabetes (T2D) depends on a combination of the effects driven by advancing age, genetic background, and lifestyle habits, e.g. overnutrition. These factors influence the development of T2D differently in men and women, with an obvious sexual dimorphism possibly underlying the diverse clinical features of the disease in different sexes. More recently, environmental pollution, estimated to cause 9 million deaths every year, is emerging as a novel risk factor for the development of T2D. Indeed, exposure to atmospheric pollutants such as PM2.5, O3, NO2, and Persistent Organic Pollutants (POP)s, along with their combination and bioaccumulation, is associated with the development of T2D and obesity, with a 15 % excess risk in case of exposure to very high levels of PM2.5. Similar data are available for plasticizer molecules, e.g. bisphenol A and phthalates, emerging endocrine-disrupting chemicals. Even though causality is still debated at this stage, preclinical evidence sustains the ability of multiple pollutants to affect pancreatic function, promote insulin resistance, and alter lipid metabolism, possibly contributing to T2D onset and progression. In addition, preclinical findings suggest a possible role also for plastic itself in the development of T2D. Indeed, pioneeristic studies evidenced that micro- or nanoplastics (MNP)s, particles in the micro- or nano- range, promote cellular damage, senescence, inflammation, and metabolic disturbances, leading to insulin resistance and impaired glucose metabolism in animal and/or in vitro models. Here we synthesize recent knowledge relative to the association between air-related or plastic-derived pollutants and the incidence of T2D, discussing also the possible mechanistic links suggested by the available literature. We then anticipate the need for future studies in the field of candidate therapeutic strategies limiting pollution-induced damage in preclinical models, such as SGLT-2 inhibitors. We finally postulate that future guidelines for T2D prevention should consider pollution and sex an additional risk factors to limit the diabetes pandemic.

Estrogen stimulates fetal vascular endothelial growth factor expression and microvascularization

We recently showed that the ratio of capillaries to myofibers in skeletal muscle, which accounts for 80% of insulin-directed glucose uptake and metabolism, was reduced in baboon fetuses in which estrogen was suppressed by maternal letrozole administration. Since vascular endothelial growth factor (VEGF) promotes angiogenesis, the present study determined the impact of estrogen deprivation on fetal skeletal muscle VEGF expression, capillary development, and long-term vascular and metabolic function in 4- to 8-year-old adult offspring. Maternal baboons were untreated or treated with letrozole or letrozole plus estradiol on days 100-164 of gestation (term = 184 days). Skeletal muscle VEGF protein expression was suppressed by 45% (P < 0.05) and correlated (P = 0.01) with a 47% reduction (P < 0.05) in the number of capillaries per myofiber area in fetuses of baboons in which serum estradiol levels were suppressed 95% (P < 0.01) by letrozole administration. The reduction in fetal skeletal muscle microvascularization was associated with a 52% decline (P = 0.02) in acetylcholine-induced brachial artery dilation and a 23% increase (P = 0.01) in mean arterial blood pressure in adult progeny of letrozole-treated baboons, which was restored to normal by letrozole plus estradiol. The present study indicates that estrogen upregulates skeletal muscle VEGF expression and systemic microvessel development within the fetus as an essential programming event critical for ontogenesis of systemic vascular function and insulin sensitivity/glucose homeostasis after birth in primate offspring.

Epigenetic developmental mechanisms underlying sex differences in cancer

Cancer risk is modulated by hereditary and somatic mutations, exposures, age, sex, and gender. The mechanisms by which sex and gender work alone and in combination with other cancer risk factors remain underexplored. In general, cancers that occur in both the male and female sexes occur more commonly in XY compared with XX individuals, regardless of genetic ancestry, geographic location, and age. Moreover, XY individuals are less frequently cured of their cancers, highlighting the need for a greater understanding of sex and gender effects in oncology. This will be necessary for optimal laboratory and clinical cancer investigations. To that end, we review the epigenetics of sexual differentiation and its effect on cancer hallmark pathways throughout life. Specifically, we will touch on how sex differences in metabolism, immunity, pluripotency, and tumor suppressor functions are patterned through the epigenetic effects of imprinting, sex chromosome complement, X inactivation, genes escaping X inactivation, sex hormones, and life history.

Association Between Lifestyle Behaviors and Obesity Among Stroke Survivors

AIM

The aim was to investigate factors influencing obesity among stroke survivors based on demographics and lifestyle behaviors.

BACKGROUND

Stroke survivors are more likely to experience stroke recurrence within a few years. As obesity is a traditional risk factor for stroke, obesity should be managed in stroke survivors to prevent stroke recurrence.

METHODS

A cross-sectional secondary data analysis analyzed data from the 2017 United States Behavioral Risk Factor Surveillance System (BRFSS) survey. Demographics, frequency of vegetable and fruit intake, smoking, alcohol use, physical activity, and sleep were examined.

RESULTS

Among 1032 stroke survivors, 57.8% were obese. Advanced age, female sex, veteran status, at least once-daily fruit intake, current smoking, and lack of physical activity were associated with obesity.

CONCLUSION

Stroke survivors should be encouraged to pursue healthy behaviors to manage obesity. Appropriate transitional care, including diet education and tailored exercise, can be an effective strategy.

Reproductive factors, genetic susceptibility and risk of type 2 diabetes: A prospective cohort study

AIM

To explore the relationships of multiple reproductive factors with type 2 diabetes mellitus (T2DM) risk and the joint effects of reproductive factors and genetic susceptibility.

METHODS

We included 262,368 women without prevalent T2DM from the UK biobank. Cox proportional hazards regression models were employed to estimate the relationships of reproductive factors with T2DM risk and the joint effects of reproductive factors and genetic susceptibility.

RESULTS

During a mean follow-up of 12.2 years, 8,996 T2DM cases were identified. Early menarche (<12 years, hazard ratio (HR) 1.08 [95 % confidence interval (CI) 1.02;1.13]), late menarche (≥15 years, HR 1.11 [1.04;1.17]), early menopause (<45 years, HR 1.20 [1.12;1.29]), short reproductive lifespan (<30 years, HR 1.25 [1.16;1.35]), hysterectomy (1.31, HR [1.23;1.40]), oophorectomy (HR 1.28 [1.20;1.36]), high parity (≥4, HR 1.25 [1.17;1.34]), early age at first live birth (<20 years, HR 1.23 [1.16;1.31]), miscarriage (HR 1.13 [1.07;1.19]), stillbirth (HR 1.14 [1.03;1.27]), and ever used hormonal replacement therapy (HR 1.19 [1.14;1.24]) were related to a higher T2DM risk, while ever used oral contraceptives (HR 0.93 [0.89;0.98]) was related to a lower T2DM risk. Furthermore, women with reproductive risk factors and high genetic risk had the highest T2DM risk compared to those with low genetic risk and without reproductive risk factors.

CONCLUSION

Our findings show that multiple reproductive factors are related to T2DM risk, particularly in women with high genetic risk.

Meta-stable state photoacid containing β-estradiol fragment with photomodulated biological activity and anti-cancer stem cells properties

Photopharmacology is a young and rapidly developing field of research that offers significant potential for new insights into targeted therapy. While it primarily focuses on cancer treatment, it also holds promise for other diseases. The key feature of photopharmacological agents is the presence of a photosensitive and biologically active component in the same molecule. In our current study, we synthesized a spiropyran-based meta-stable state photoacid containing a fragment of β-estradiol. This compound exhibits negative photochromism and photocontrolled fluorescence under visible-light irradiation due to the initial stabilization of its self-protonated form in solution. We conducted comprehensive biological studies on the HeLa cells model to assess the short- and long-term cytotoxicity of the photoacid, its metabolic effects, its influence on signaling and epithelial-mesenchymal transition super-system pathways, and the proportion of the population enriched with cancer stem cells. Our findings reveal that this derivative demonstrates low cytotoxicity to HeLa cells, yet it is capable of dramatically reducing malignant cells side population enriched in cancer stem cells. Additionally, appropriate structural modification lead to an increase in some other biological effects compared to β-estradiol. In particular, our substance possesses rare properties of AP-1 suppression and demonstrates some pro-oxidant and metabolic effects, which can be regulated by visible light irradiation. As a result, the new estradiol-based photoacid may be considered a promising multi-acting photopharmacological agent for the next-generation anti-cancer research & development.

Reproductive factors and their association with physical and comprehensive frailty in middle-aged and older women: a large-scale population-based study

STUDY QUESTION

Are women's reproductive factors associated with physical frailty and comprehensive frailty in middle-age and later life?

SUMMARY ANSWER

Early menarche at <13 years, age at menopause <45 years, surgical menopause, experiencing miscarriage and a shorter reproductive period of <35 years were associated with increased odds of frailty, while having two or three children was related to decreased likelihood of frailty.

WHAT IS KNOWN ALREADY

Evidence has shown that women are frailer than men in all age groups and across different populations, although women have longer lifespans. Female-specific reproductive factors may be related to risk of frailty in women.

STUDY DESIGN SIZE DURATION

A population-based cross-sectional study involved 189 898 women from the UK Biobank.

PARTICIPANTS/MATERIALS SETTING METHODS

Frailty phenotype and frailty index were used to assess physical frailty and comprehensive frailty (assessed using 38 health indicators for physical and mental wellbeing), respectively. Multivariable logistic regression models were used to estimate odds ratios (ORs) and 95% CI between reproductive factors and likelihood of physical frailty and comprehensive frailty. Restricted cubic spline models were used to test the non-linear associations between them. In addition, we examined the combined effect of categorized age at menopause and menopause hormone therapy (MHT) on frailty.

MAIN RESULTS AND THE ROLE OF CHANCE

There was a J-shape relationship between age at menarche, reproductive period, and frailty; age at menarche <13 years and >16 years, and reproductive period <35 years or >40 years were all associated with increased odds of frailty. There was a negative linear relationship between menopausal age (either natural or surgical) and odds of frailty. Surgical menopause was associated with 30% higher odds of physical frailty (1.34, 1.27-1.43) and 30% higher odds of comprehensive frailty (1.30, 1.25-1.35). Having two or three children was linked to the lowest likelihood of physical frailty (0.48, 0.38-0.59) and comprehensive frailty (0.72, 0.64-0.81). Experiencing a miscarriage increased the odds of frailty. MHT use was linked to increased odds of physical frailty in women with normal age at natural menopause (after 45 years), while no elevated likelihood was observed in women with early natural menopause taking MHT.

LIMITATIONS REASONS FOR CAUTION

The reproductive factors were self-reported and the data might be subject to recall bias. We lacked information on the types and initiation time of MHT, could not identify infertile women who later became pregnant, and the number of infertile women may be underestimated. Individuals participating in the UK Biobank are not representative of the general UK population, limiting the generalization of our findings.

WIDER IMPLICATION OF THE FINDINGS

The reproductive factors experienced by women throughout their life course can potentially predict frailty in middle and old age. Identifying these reproductive factors as potential predictors of frailty can inform healthcare providers and policymakers about the importance of considering a woman's reproductive history when assessing their risk for frailty.

STUDY FUNDING/COMPETING INTERESTS

This work was supported by the National Key Research and Development Program of China (2022YFC2703800), National Natural Science Foundation of China (82273702), Science Fund Program for Excellent Young Scholars of Shandong Province (Overseas) (2022HWYQ-030), Taishan Scholars Project Special Fund (No. tsqnz20221103), and the Qilu Young Scholar (Tier-1) Program (202099000066). All authors have no conflicts of interest to declare.

TRIAL REGISTRATION NUMBER

N/A.

Hyperglycemia and cognitive impairments anticipate the onset of an overt type 2 diabetes-like phenotype in TALLYHO/JngJ mice

Type 2 Diabetes mellitus (T2DM) is a metabolic disorder characterized by chronic hyperglycemia, resulting from deficits in insulin secretion, insulin action, or both. Whilst the role of insulin in the peripheral nervous system has been ascertained in countless studies, its role in the central nervous system (CNS) is emerging only recently. Brain insulin has been lately associated with brain disorders like Alzheimer's disease, obsessive compulsive disorder, and attention deficit hyperactivity disorder. Thus, understanding the role of insulin as a common risk factor for mental and somatic comorbidities may disclose novel preventative and therapeutic approaches. We evaluated general metabolism (glucose tolerance, insulin sensitivity, energy expenditure, lipid metabolism, and polydipsia) and cognitive capabilities (attention, cognitive flexibility, and memory), in adolescent, young adult, and adult male and female TALLYHO/JngJ mice (TH, previously reported to constitute a valid experimental model of T2DM due to impaired insulin signaling). Adult TH mice have also been studied for alterations in gut microbiota diversity and composition. While TH mice exhibited profound deficits in cognitive flexibility and altered glucose metabolism, we observed that these alterations emerged either much earlier (males) or independent of (females) a comprehensive constellation of symptoms, isomorphic to an overt T2DM-like phenotype (insulin resistance, polydipsia, higher energy expenditure, and altered lipid metabolism). We also observed significant sex-dependent alterations in gut microbiota alpha diversity and taxonomy in adult TH mice. Deficits in insulin signaling may represent a common risk factor for both T2DM and CNS-related deficits, which may stem from (partly) independent mechanisms.

Age and sex mediated effects of estrogen and Β3-adrenergic receptor on cardiovascular pathophysiology

Sex differences are consistently identified in determining the prevalence, manifestation, and response to therapies in several systemic disorders, including those affecting the cardiovascular (CV), skeletal muscle, and nervous system. Interestingly, such differences are often more noticeable as we age. For example, premenopausal women experience a lower risk of CV disease than men of the same age. While at an advanced age, with menopause, the risk of cardiovascular diseases and adverse outcomes increases exponentially in women, exceeding that of men. However, this effect appears to be reversed in diseases such as pulmonary hypertension, where women are up to seven times more likely than men to develop an idiopathic form of the disease with symptoms developing ten years earlier than their male counterparts. Explaining this is a complex question. However, several factors and mechanisms have been identified in recent decades, including a role for sex hormones, particularly estrogens and their related receptors. Furthermore, an emerging role in these sex differences has also been suggested for β-adrenergic receptors (βARs), which are essential regulators of mammalian physiology. It has in fact been shown that βARs interact with estrogen receptors (ER), providing further demonstration of their involvement in determining sexual differences. Based on these premises, this review article focused on the β3AR subtype, which shows important activities in adipose tissue but with new and interesting roles in regulating the function of cardiomyocytes and vascular cells. In detail, we examined how β3AR and ER signaling are intertwined and whether there would be sex- and age-dependent specific effects of these receptor systems.

Metabolic flexibility in postmenopausal women: Hormone replacement therapy is associated with higher mitochondrial content, respiratory capacity, and lower total fat mass

AIM

To investigate effects of hormone replacement therapy in postmenopausal women on factors associated with metabolic flexibility related to whole-body parameters including fat oxidation, resting energy expenditure, body composition and plasma concentrations of fatty acids, glucose, insulin, cortisol, and lipids, and for the mitochondrial level, including mitochondrial content, respiratory capacity, efficiency, and hydrogen peroxide emission.

METHODS

22 postmenopausal women were included. 11 were undergoing estradiol and progestin treatment (HT), and 11 were matched non-treated controls (CONT). Peak oxygen consumption, maximal fat oxidation, glycated hemoglobin, body composition, and resting energy expenditure were measured. Blood samples were collected at rest and during 45 min of ergometer exercise (65% VO2peak). Muscle biopsies were obtained at rest and immediately post-exercise. Mitochondrial respiratory capacity, efficiency, and hydrogen peroxide emission in permeabilized fibers and isolated mitochondria were measured, and citrate synthase (CS) and 3-hydroxyacyl-CoA dehydrogenase (HAD) activity were assessed.

RESULTS

HT showed higher absolute mitochondrial respiratory capacity and post-exercise hydrogen peroxide emission in permeabilized fibers and higher CS and HAD activities. All respiration normalized to CS activity showed no significant group differences in permeabilized fibers or isolated mitochondria. There were no differences in resting energy expenditure, maximal, and resting fat oxidation or plasma markers. HT had significantly lower visceral and total fat mass compared to CONT.

CONCLUSION

Use of hormone therapy is associated with higher mitochondrial content and respiratory capacity and a lower visceral and total fat mass. Resting energy expenditure and fat oxidation did not differ between HT and CONT.

Are there sex differences in the variability of fasting metabolism?

There is evidence across species and across many traits that males display greater between-individual variance. In contrast, (premenopausal) females display large within-individual variance in sex hormone concentrations, which can increase within-individual variance in many other parameters. The latter may contribute to the lower representation of females in metabolic research. This study is a pooled secondary analysis of data from seven crossover studies to investigate the between-individual and the within-individual variance in fasting plasma metabolites, resting metabolic rate (RMR), and body mass. Females demonstrated higher within-individual variability of plasma 17β-estradiol [coefficient of variation (CV): 15 ± 15% for males vs. 38 ± 34% for females, P < 0.001] and progesterone concentrations (CV: 13 ± 11% for males vs. 52 ± 51% for females, P < 0.001) but there were no meaningful differences in the variability of plasma glucose (CV: 4 ± 3% for males vs. 5 ± 5% for females), insulin, lactate, triglycerides (CV: 15 ± 9% for males vs. 15 ± 10% for females), and esterified fatty acid concentrations or in RMR and body mass (CV: 0.43 ± 0.34% for males vs. for 0.42 ± 0.33% females; P > 0.05 for all outcomes). Males displayed higher between-individual variance in RMR compared with females (SD: 224 kcal·day-1 for males vs. 151 kcal·day-1 for females). In conclusion, these data do not provide evidence that females show greater within-individual variability in many fasting metabolic variables, RMR, or body mass compared with males. We conclude that including females in metabolic research is unlikely to introduce greater within-individual variance when using the recruitment and control procedures described in these studies.NEW & NOTEWORTHY To investigate the within-individual variability in metabolic parameters in males and females, we performed a pooled secondary analysis of fasting blood samples, resting metabolic rate, and body mass from seven crossover studies. We found a greater day-to-day variation in 17β-estradiol and progesterone in females compared with males but no meaningful difference in within-individual variability of fasting plasma glucose, insulin, lactate, triglycerides, NEFA, resting metabolic rate, or body mass between females and males.

Estrogen counteracts age-related decline in beige adipogenesis through the NAMPT-regulated ER stress response

Thermogenic beige adipocytes are recognized as potential therapeutic targets for combating metabolic diseases. However, the metabolic advantages that they offer are compromised with aging. Here we show that treating mice with estrogen (E2), a hormone that decreases with age, can counteract the age-related decline in beige adipogenesis when exposed to cold temperature while concurrently enhancing energy expenditure and improving glucose tolerance in mice. Mechanistically, we found that nicotinamide phosphoribosyl transferase (NAMPT) plays a pivotal role in facilitating the formation of E2-induced beige adipocytes, which subsequently suppresses the onset of age-related endoplasmic reticulum (ER) stress. Furthermore, we found that targeting NAMPT signaling, either genetically or pharmacologically, can restore the formation of beige adipocytes by increasing the number of perivascular adipocyte progenitor cells. Conversely, the absence of NAMPT signaling prevents this process. Together, our findings shed light on the mechanisms regulating the age-dependent impairment of beige adipocyte formation and underscore the E2-NAMPT-controlled ER stress pathway as a key regulator of this process.

Intermittent fasting as a dietary intervention with potential sexually dimorphic health benefits

Intermittent fasting (IF) has proven to be a feasible dietary intervention for the wider population. The recent increase in IF clinical trials highlights its potential effects on health, including changes in body composition, cardiometabolic status, and aging. Although IF may have clinical applications in different populations, studies suggest there may be sex-specific responses in parameters such as body composition or glucose and lipid metabolism. Here, the existing literature on IF clinical trials is summarized, the application of IF in both disease prevention and management is discussed, and potential disparities in response to this type of diet between men and women are assessed. Moreover, the potential mechanisms that may be contributing to the sexually dimorphic response, such as age, body composition, tissue distribution, or sex hormones are investigated. This review underscores the need to further study these sex-specific responses to IF to define the most effective time frames and length of fasting periods for men and women. Tailoring IF to specific populations with a personalized approach may help achieve its full potential as a lifestyle intervention with clinical benefits.

The Expression of Adipogenic Marker Is Significantly Increased in Estrogen-Treated Lipedema Adipocytes Differentiated from Adipose Stem Cells In Vitro

Lipedema is a chronic, idiopathic, and painful disease characterized by an excess of adipose tissue in the extremities. The goal of this study is to characterize the gene expression of estrogen receptors (ERα and ERβ), G protein-coupled estrogen receptor (GPER), and ER-metabolizing enzymes: hydroxysteroid 17-beta dehydrogenase (HSD17B1, 7, B12), cytochrome P450 (CYP19A1), hormone-sensitive lipase (LIPE), enzyme steroid sulfatase (STS), and estrogen sulfotransferase (SULT1E1), which are markers in Body Mass Index (BMI) and age-matched non-lipedema (healthy) and lipedema ASCs and spheroids. Flow cytometry and cellular proliferation assays, RT-PCR, and Western Blot techniques were used to determine the expression of ERs and estrogen-metabolizing enzymes. In 2D monolayer culture, estrogen increased the proliferation and the expression of the mesenchymal marker, CD73, in hormone-depleted (HD) healthy ASCs compared to lipedema ASCs. The expression of ERβ was significantly increased in HD lipedema ASCs and spheroids compared to corresponding healthy cells. In contrast, ERα and GPER gene expression was significantly decreased in estrogen-treated lipedema spheroids. CYP19A1 and LIPE gene expressions were significantly increased in estrogen-treated healthy ASCs and spheroids, respectively, while estrogen upregulated the expression of PPAR-ϒ2 and ERα in estrogen-treated lipedema-differentiated adipocytes and spheroids. These results indicate that estrogen may play a role in adipose tissue dysregulation in lipedema.

Combined supplementation with hesperidin, phytosterols and curcumin decreases adiposity and improves metabolic health in ovariectomized rats

In recent years many women have looked for alternative therapies to address menopause. Hesperidin, phytosterols and curcumin are bioactive compounds that can ameliorate some cardiovascular risk factors associated with menopause, although there are no data concerning the effects of their combined supplementation. We used ovariectomized (OVX) rats, a postmenopausal model with oestrogen deficiency, to evaluate whether supplementation with a multi-ingredient (MI) including hesperidin, phytosterols and curcumin for 57 days would display beneficial effects against fat mass accretion and metabolic disturbances associated with menopause. Twenty OVX rats were orally supplemented with either MI (OVX-MI) or vehicle (OVX). Furthermore, 10 OVX rats orally received the vehicle along with subcutaneous injections of 17β-oestradiol biweekly (OVX-E2), whereas 10 rats were sham operated and received oral and injected vehicles (control group; SH). MI supplementation partly counteracted the fat mass accretion observed in OVX animals, which was evidenced by decreased total fat mass, adiposity index, the weight of retroperitoneal, inguinal and mesenteric white adipose tissue (MWAT) depots and MWAT adipocyte hypertrophy. These effects were accompanied by a significant decrease in the circulating levels of leptin and the mRNA levels of the fatty acid uptake-related genes Lpl and Cd36 in MWAT. These results were very similar to those observed in OVX-E2 animals. OVX-MI rats also displayed a higher lean body mass, lean/fat mass ratio, adiponectin-to-leptin ratio and insulin sensitivity than their OVX counterparts. Our findings can pave the way for using this MI formulation as an alternative therapy to manage obesity and to improve the cardiometabolic health of menopausal women.

Female obesity: clinical and psychological assessment toward the best treatment

Obesity is a heterogeneous condition which results from complex interactions among sex/gender, sociocultural, environmental, and biological factors. Obesity is more prevalent in women in most developed countries, and several clinical and psychological obesity complications show sex-specific patterns. Females differ regarding fat distribution, with males tending to store more visceral fat, which is highly correlated to increased cardiovascular risk. Although women are more likely to be diagnosed with obesity and appear more motivated to lose weight, as confirmed by their greater representation in clinical trials, males show better outcomes in terms of body weight and intra-abdominal fat loss and improvements in the metabolic risk profile. However, only a few relatively recent studies have investigated gender differences in obesity, and sex/gender is rarely considered in the assessment and management of the disease. This review summarizes the evidence of gender differences in obesity prevalence, contributing factors, clinical complications, and psychological challenges. In addition, we explored gender differences in response to obesity treatments in the specific context of new anti-obesity drugs.

Effects of follicle-stimulating hormone on energy balance and tissue metabolic health after loss of ovarian function

Loss of ovarian function imparts increased susceptibility to obesity and metabolic disease. These effects are largely attributed to decreased estradiol (E2), but the role of increased follicle-stimulating hormone (FSH) in modulating energy balance has not been fully investigated. Previous work that blocked FSH binding to its receptor in mice suggested this hormone may play a part in modulating body weight and energy expenditure after ovariectomy (OVX). We used an alternate approach to isolate the individual and combined contributions of FSH and E2 in mediating energy imbalance and changes in tissue-level metabolic health. Female Wistar rats were ovariectomized and given the gonadotropin releasing hormone (GnRH) antagonist degarelix to suppress FSH production. E2 and FSH were then added back individually and in combination for a period of 3 wk. Energy balance, body mass composition, and transcriptomic profiles of individual tissues were obtained. In contrast to previous studies, suppression and replacement of FSH in our paradigm had no effect on body weight, body composition, food intake, or energy expenditure. We did, however, observe organ-specific effects of FSH that produced unique transcriptomic signatures of FSH in retroperitoneal white adipose tissue. These included reductions in biological processes related to lipogenesis and carbohydrate transport. In addition, rats administered FSH had reduced liver triglyceride concentration (P < 0.001), which correlated with FSH-induced changes at the transcriptomic level. Although not appearing to modulate energy balance after loss of ovarian function in rats, FSH may still impart tissue-specific effects in the liver and white adipose tissue that might affect the metabolic health of those organs.NEW & NOTEWORTHY We find no effect of follicle-stimulating hormone (FSH) on energy balance using a novel model in which rats are ovariectomized, subjected to gonadotropin-releasing hormone antagonism, and systematically given back FSH by osmotic pump. However, tissue-specific effects of FSH on adipose tissue and liver were observed in this study. These include unique transcriptomic signatures induced by the hormone and a stark reduction in hepatic triglyceride accumulation.

Immunotherapy targeting the obese white adipose tissue microenvironment: Focus on non-communicable diseases

Obesity triggers inflammatory responses in the microenvironment of white adipose tissue, resulting in chronic systemic inflammation and the subsequent development of non-communicable diseases, including type 2 diabetes, coronary heart disease, and breast cancer. Current therapy approaches for obesity-induced non-communicable diseases persist in prioritizing symptom remission while frequently overlooking the criticality of targeting and alleviating inflammation at its source. Accordingly, this review highlights the importance of the microenvironment of obese white adipose tissue and the promising potential of employing immunotherapy to target it as an effective therapeutic approach for non-communicable diseases induced by obesity. Additionally, this review discusses the challenges and offers perspective about the immunotherapy targeting the microenvironment of obese white adipose tissue.

The complementary roles of iron and estrogen in menopausal differences in cardiometabolic outcomes

Biological hormonal changes are frequently cited as an explanatory factor of sex and menopause differences in cardiometabolic diseases (CMD) and its associated risk factors. However, iron metabolism which varies between sexes and among women of different reproductive stages could also play a role. Recent evidence suggest that iron may contribute to CMD risk by modulating oxidative stress pathways and inflammatory responses, offering insights into the mechanistic interplay between iron and CMD development. In the current review, we provide a critical appraisal of the existing evidence on sex and menopausal differences in CMD, discuss the pitfall of current estrogen hypothesis as sole explanation, and the emerging role of iron in CMD as complementary pathway. Prior to menopause, body iron stores are lower in females as compared to males, but the increase during and after menopause, is tandem with an increased CMD risk. Importantly, basic science experiments show that an increased iron status is related to the development of type 2 diabetes (T2D), and different cardiovascular diseases (CVD). While epidemiological studies have consistently reported associations between heme iron intake and some iron biomarkers such as ferritin and transferrin saturation with the risk of T2D, the evidence regarding their connection to CVD remains controversial. We delve into the factors contributing to this inconsistency, and the limitation of relying on observational evidence, as it does not necessarily imply causation. In conclusion, we provide recommendations for future studies on evaluating the potential role of iron in elucidating the sex and menopausal differences observed in CMD.

Small molecule conjugates with selective estrogen receptor β agonism promote anti-aging benefits in metabolism and skin recovery

Estrogen is imperative to mammalian reproductivity, metabolism, and aging. However, the hormone activating estrogen receptor (ERs) α can cause major safety concerns due to the enrichment of ERα in female tissues and certain malignancies. In contrast, ERβ is more broadly expressed in metabolic tissues and the skin. Thus, it is desirable to generate selective ERβ agonist conjugates for maximizing the therapeutic effects of ERs while minimizing the risks of ERα activation. Here, we report the design and production of small molecule conjugates containing selective non-steroid ERβ agonists Gtx878 or genistein. Treatment of aged mice with our synthesized conjugates improved aging-associated declines in insulin sensitivity, visceral adipose integrity, skeletal muscle function, and skin health, with validation in vitro. We further uncovered the benefits of ERβ conjugates in the skin using two inducible skin injury mouse models, showing increased skin basal cell proliferation, epidermal thickness, and wound healing. Therefore, our ERβ-selective agonist conjugates offer novel therapeutic potential to improve aging-associated conditions and aid in rejuvenating skin health.

Effects of the Pituitary-targeted Gland Axes on Hepatic Lipid Homeostasis in Endocrine-associated Fatty Liver Disease-A Concept Worth Revisiting

Hepatic lipid homeostasis is not only essential for maintaining normal cellular and systemic metabolic function but is also closely related to the steatosis of the liver. The controversy over the nomenclature of non-alcoholic fatty liver disease (NAFLD) in the past three years has once again sparked in-depth discussions on the pathogenesis of this disease and its impact on systemic metabolism. Pituitary-targeted gland axes (PTGA), an important hormone-regulating system, are indispensable in lipid homeostasis. This review focuses on the roles of thyroid hormones, adrenal hormones, sex hormones, and their receptors in hepatic lipid homeostasis, and summarizes recent research on pituitary target gland axes-related drugs regulating hepatic lipid metabolism. It also calls on researchers and clinicians to recognize the concept of endocrine-associated fatty liver disease (EAFLD) and to re-examine human lipid metabolism from the macroscopic perspective of homeostatic balance.

Metabolic Profiling in Plasma and Brain Induced by 17β-Estradiol Supplementation in Ovariectomized Mice

17β-Estradiol is an ovarian hormone that regulates energy circulation and storage by acting on the central nervous system. However, the metabolic differences between the blood and brain when stimulated by 17β-estradiol are poorly understood. Moreover, research using menopause-induced models to investigate primary metabolites in the blood and brain is limited. Thus, this study aimed to identify metabolic changes in the plasma and brain resulting from 17β-estradiol supplementation in an estrogen-deficient mouse model. Three groups of mice were utilized: sham-operated mice (Sham), ovariectomized mice (OVX), and ovariectomized mice that received a weekly supplementation of 17β-estradiol (E2). Plasma and brain samples from these mice were subjected to metabolic analysis using gas chromatography-time-of-flight-mass spectrometry. Compared with the plasma samples from the Sham and OVX groups, the plasma samples from the E2 group contained higher contents of branched-chain amino acids (BCAAs), such as valine, isoleucine, and leucine. Meanwhile, the brain samples from the E2 group contained higher contents of most metabolites, including BCAAs, neurotransmitters, tricarboxylic acid cycle intermediates, and fatty acids, than those from the two other groups. This study is the first to reveal differences in energy metabolism induced by 17β-estradiol supplementation through brain metabolic profiling of ovariectomized mice, emphasizing the importance of brain metabolic profiling in menopausal hormone research.

An estrogen receptor α-derived peptide improves glucose homeostasis during obesity

Estrogen receptor α (ERα) plays a crucial role in regulating glucose and energy homeostasis during type 2 diabetes mellitus (T2DM). However, the underlying mechanisms remain incompletely understood. Here we find a ligand-independent effect of ERα on the regulation of glucose homeostasis. Deficiency of ERα in the liver impairs glucose homeostasis in male, female, and ovariectomized (OVX) female mice. Mechanistic studies reveal that ERα promotes hepatic insulin sensitivity by suppressing ubiquitination-induced IRS1 degradation. The ERα 1-280 domain mediates the ligand-independent effect of ERα on insulin sensitivity. Furthermore, we identify a peptide based on ERα 1-280 domain and find that ERα-derived peptide increases IRS1 stability and enhances insulin sensitivity. Importantly, administration of ERα-derived peptide into obese mice significantly improves glucose homeostasis and serum lipid profiles. These findings pave the way for the therapeutic intervention of T2DM by targeting the ligand-independent effect of ERα and indicate that ERα-derived peptide is a potential insulin sensitizer for the treatment of T2DM.

Association of maternal exposure to endocrine disruptor chemicals with cardio-metabolic risk factors in children during childhood: a systematic review and meta-analysis of cohort studies

BACKGROUND

In the present systematic review and meta-analysis, the association of maternal exposure to the endocrine disrupting chemicals (EDCs) with cardio-metabolic risk factors in children during childhood for the first time.

METHOD

The PubMed, Scopus, EMBASE, and Web of Science databases were systematically searched, up to Feb 2023. In total 30 cohort studies had our inclusion criteria. A random-effects model was used for the variables that had considerable heterogeneity between studies. The Newcastle-Ottawa Scale (NOS) tool was used to classify the quality score of studies. All statistical analyses were conducted using Stata 14 and P-value < 0.05 considered as a significant level.

RESULTS

In the meta-analysis, maternal exposure to the EDCs was weakly associated with higher SBP (Fisher_Z: 0.06, CI: 0.04, 0.08), BMI (Fisher_Z: 0.07, CI: 0.06, 0.08), and WC (Fisher_Z: 0.06, CI: 0.03, 0.08) z-scores in children. A significant linear association was found between maternal exposure to the bisphenol-A and pesticides with BMI and WC z-score in children (p < 0.001). Subgroup analysis showed significant linear association of BPA and pesticides, in the urine samples of mothers at the first trimester of pregnancy, with BMI and WC z-score in children from 2-8 years (p < 0.05).

CONCLUSION

Prenatal exposure to the EDCs in the uterine period could increase the risk of obesity in children. Maternal exposure to bisphenol-A and pesticides showed the strongest association with the obesity, especially visceral form, in the next generation.

Incidence of Type 2 Diabetes Mellitus in Transgender Individuals Undergoing Gender Affirming Hormonal Therapy: A Systematic Review

Gender-affirming hormonal therapy (GAHT), which includes estrogen, testosterone, androgen agonists, is commonly used in transgender individuals to change their secondary sexual characteristics to align with their gender identity. However, this treatment could result in metabolic side effects that could increase the chances of acquiring type 2 diabetes mellitus. Thus, this study aims to compare differences in body mass index (BMI), insulin resistance, and the incidence of type 2 diabetes mellitus between cisgender and transgender individuals undergoing GAHT. Following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) standards, we conducted a systematic review searching through PubMed, Google Scholar, Medline (Medical Literature Analysis and Retrieval System Online), and ResearchGate for articles published between 2014 and 2024. The final search was conducted in February 2024. Out of the 3,934 articles reviewed, 11 were selected, focusing on insulin sensitivity/resistance, diabetes incidence, and BMI changes with GAHT. Although our result findings did not show clear evidence of increased diabetes incidence among GAHT patients, it was observed that GAHT does increase BMI and insulin resistance in transgender individuals. Notably, compared to transgender men, transgender women on GAHT were found to be more prone to insulin resistance. We recommend regularly monitoring insulin sensitivity parameters and HbA1c during GAHT to monitor metabolic side effects. Further research and more clinical trials are needed to confirm the GAHT's impact on insulin resistance and to evaluate its role in the onset of type 2 diabetes mellitus.

Dynamics of serum exosome microRNA profile altered by chemically induced estropause and rescued by estrogen therapy in female mice

The decline in the ovarian reserve leads to menopause and reduced serum estrogens. MicroRNAs are small non-coding RNAs, which can regulate gene expression and be secreted by cells and trafficked in serum via exosomes. Serum miRNAs regulate tissue function and disease development. Therefore, the aim of this study was to identify miRNA profiles in serum exosomes of mice induced to estropause and treated with 17β-estradiol (E2). Female mice were divided into three groups including control (CTL), injected with 4-Vinylcyclohexene diepoxide (VCD), and injected with VCD plus E2 (VCD + E2). Estropause was confirmed by acyclicity and a significant reduction in the number of ovarian follicles (p < 0.05). Body mass gain during estropause was higher in VCD and VCD + E2 compared to CTL females (p = 0.02). Sequencing of miRNAs was performed from exosomes extracted from serum, and 402 miRNAs were detected. Eight miRNAs were differentially regulated between CTL and VCD groups, seven miRNAs regulated between CTL and VCD + E2 groups, and ten miRNAs regulated between VCD and VCD + E2 groups. Only miR-200a-3p and miR-200b-3p were up-regulated in both serum exosomes and ovarian tissue in both VCD groups, suggesting that these exosomal miRNAs could be associated with ovarian activity. In the hepatic tissue, only miR-370-3p (p = 0.02) was up-regulated in the VCD + E2 group, as observed in serum. Our results suggest that VCD-induced estropause and E2 replacement have an impact on the profile of serum exosomal miRNAs. The miR-200 family was increased in serum exosomes and ovarian tissue and may be a candidate biomarker of ovarian function.

Aging and Adiposity-Focus on Biological Females at Midlife and Beyond

Menopause is a physiological phase of life of aging women, and more than 1 billion women worldwide will be in menopause by 2025. The processes of global senescence parallel stages of reproductive aging and occur alongside aging-related changes in the body. Alterations in the endocrine pathways accompany and often predate the physiologic changes of aging, and interactions of these processes are increasingly being recognized as contributory to the progression of senescence. Our goal for this review is to examine, in aging women, the complex interplay between the endocrinology of menopause transition and post-menopause, and the metabolic transition, the hallmark being an increasing tendency towards central adiposity that begins in tandem with reproductive aging and is often exacerbated post menopause. For the purpose of this review, our choice of the terms 'female' and 'woman' refer to genetic females.

Neonatal inhibition of androgen activity alters the programming of body weight and orexinergic peptides differentially in male and female rats

The involvement of androgens in the regulation of energy metabolism has been demonstrated. The main objective of the present research was to study the involvement of androgens in both the programming of energy metabolism and the regulatory peptides associated with feeding. For this purpose, androgen receptors and the main metabolic pathways of testosterone were inhibited during the first five days of postnatal life in male and female Wistar rats. Pups received a daily s.c. injection from the day of birth, postnatal day (P) 1, to P5 of Flutamide (a competitive inhibitor of androgen receptors), Letrozole (an aromatase inhibitor), Finasteride (a 5-alpha-reductase inhibitor) or vehicle. Body weight, food intake and fat pads were measured. Moreover, hypothalamic Agouti-related peptide (AgRP), neuropeptide Y (NPY), orexin, and proopiomelanocortin (POMC) were analyzed by quantitative real-time polymerase chain reaction assay. The inhibition of androgenic activity during the first five days of life produced a significant decrease in body weight in females at P90 but did not affect this parameter in males. Moreover, the inhibition of aromatase decreased hypothalamic AgRP mRNA levels in males while the inhibition of 5α-reductase decreased hypothalamic AgRP and orexin mRNA levels in female rats. Finally, food intake and visceral fat, but not subcutaneous fat, were affected in both males and females depending on which testosterone metabolic pathway was inhibited. Our results highlight the differential involvement of androgens in the programming of energy metabolism as well as the AgRP and orexin systems during development in male and female rats.

Characterization of metabolic alterations in the lean metabolically unhealthy alpha defensin transgenic mice

Inflammation is consistently linked to dysmetabolism. In transgenic mice (Def+/+) model the neutrophilic peptide, alpha defensin, proved atherogenic. This phenotype occurred despite favorable cholesterol and glucose levels, and lower body weight and blood pressure. In this study, integration of metabolic&behavioral phenotyping system, endocrine, biochemical and mitochondrial assessment, pathological and immunohistochemical tests, and multiple challenge tests was established to explore the metabolic impact of alpha defensin. Compared to the control group, Def+/+ mice exhibited lower total energy expenditure and carbohydrate utilization, and higher fat oxidation. Their ACTH-cortisol and thyroid profiles were intact. Intriguingly, they had low levels of glucagon, with high ammonia, uric acid, triglyceride, and lactate. Mitochondrial evaluations were normal. Overall, defensin-induced hypoglucagonemia is associated with lipolysis, restricted glucose oxidation, and enhanced wasting. Def+/+ mice may be a useful model for studying the category of lean, apparently metabolically healthy, and atherosclerotic phenotype, with insight into a potential inflammatory-metabolic link.

Addressing the global obesity burden: a gender-responsive approach to changing food environments is needed

Obesity is a leading cause of death and disability globally. There is a higher proportion of women living with obesity than men, with differences in prevalence rates between women and men particularly staggering in low- and middle-income countries. The food environments that most people live in have been defined as 'obesogenic', characterised by easy access to energy dense, highly palatable foods with poor nutritional value. There is an established need to intervene to change food environments to prevent obesity. However, minimal successes are evident with no country set to meet the WHO goal of reducing obesity prevalence to 2010 numbers by 2025. In this review, we provide a narrative around the sex (biological)- and gender (sociocultural)-related considerations for the relationship between nutrition, interactions with the food environment and obesity risk. We provide an argument that there are gendered responses to food environments that place women at a higher risk of obesity particularly in relation to food industry influences, due to gendered roles and responsibilities in relation to paid and unpaid labour, and due to specific food security threats. This review concludes with hypotheses for addressing the obesity burden in a gender-responsive manner, with a call for gender equity to be a key component of the development, implementation and monitoring of obesity prevention focused policies going forward.

The Metabolic Syndrome, a Human Disease

This review focuses on the question of metabolic syndrome (MS) being a complex, but essentially monophyletic, galaxy of associated diseases/disorders, or just a syndrome of related but rather independent pathologies. The human nature of MS (its exceptionality in Nature and its close interdependence with human action and evolution) is presented and discussed. The text also describes the close interdependence of its components, with special emphasis on the description of their interrelations (including their syndromic development and recruitment), as well as their consequences upon energy handling and partition. The main theories on MS's origin and development are presented in relation to hepatic steatosis, type 2 diabetes, and obesity, but encompass most of the MS components described so far. The differential effects of sex and its biological consequences are considered under the light of human social needs and evolution, which are also directly related to MS epidemiology, severity, and relations with senescence. The triggering and maintenance factors of MS are discussed, with especial emphasis on inflammation, a complex process affecting different levels of organization and which is a critical element for MS development. Inflammation is also related to the operation of connective tissue (including the adipose organ) and the widely studied and acknowledged influence of diet. The role of diet composition, including the transcendence of the anaplerotic maintenance of the Krebs cycle from dietary amino acid supply (and its timing), is developed in the context of testosterone and β-estradiol control of the insulin-glycaemia hepatic core system of carbohydrate-triacylglycerol energy handling. The high probability of MS acting as a unique complex biological control system (essentially monophyletic) is presented, together with additional perspectives/considerations on the treatment of this 'very' human disease.

Oestrogens, adipose tissues and environmental exposures influence obesity and diabetes across the lifecycle

Endogenous oestrogens regulate essential functions to include menstrual cycles, energy balance, adipose tissue distribution, pancreatic β-cell function, insulin sensitivity and lipid homeostasis. Oestrogens are a family of hormones which include oestradiol (E2), oestrone (E1) and oestriol (E3). Oestrogens function by binding and activating oestrogen receptors (ERs). Phytoestrogens are plant-derived compounds which exhibit oestrogenic-like activity and can bind to ERs. Phytoestrogens exert potential oestrogenic-like benefits; however, their effects are context-dependent and require cautious consideration regarding generalised health benefits. Xenoestrogens are synthetic compounds which have been determined to disrupt endocrine function through binding to ERs. Xenoestrogens enter the body through various routes and given their chemical structure they can accumulate, posing long-term health risks. Xenoestrogens interfere with endogenous oestrogens and their functions contributing to conditions like cancer, infertility, and metabolic disorders. Understanding the interplay between endogenous and exogenous oestrogens is critical in order to determine their potential health consequences and requires further investigation. This manuscript provides a summary of the role endogenous oestrogens have in regulating metabolic functions. Additionally, we discuss the impact phytoestrogens and synthetic xenoestrogens have on biological systems across various life stages. We highlight their mechanisms of action, potential benefits, risks and discuss the need for further research to bridge gaps in understanding and mitigate exposure-related health risks.

Associations of legacy perfluoroalkyl and polyfluoroalkyl substances, alternatives, and isomers with gestational diabetes mellitus and glucose homeostasis among women conceiving through assisted reproduction in Shanghai, China

Prior research has reported that perfluoroalkyl and polyfluoroalkyl substances (PFAS) may be linked to impaired glucose homeostasis in pregnant women. However, few studies have investigated PFAS alternatives and isomers, and even less is known about the association among women conceiving through assisted reproductive technology (ART). The prospective cohort study aimed to explore associations of legacy PFAS, alternatives and isomers with gestational diabetes mellitus (GDM) and glucose homeostasis during pregnancy among 336 women conceiving through ART. Nineteen PFAS, including nine linear legacy PFAS, four short-chain alternatives, four branched isomers, and two emerging PFAS alternatives, were determined in first-trimester maternal serum. Fasting plasma glucose (FPG), 1-h and 2-h glucose concentrations following the oral glucose tolerance test (OGTT), and glycated hemoglobin (HbA1c) were measured during the second trimester. After adjusting for confounding variables, nearly half of individual PFAS (10/19) and PFAS mixtures were correlated with increased GDM risk or elevated 2-h glucose levels. Among PFAS congeners, emerging PFAS alternatives, chlorinated perfluoroalkyl ether sulfonic acids (Cl-PFESAs), showed a notable association with impaired glucose homeostasis. For example, 6:2 Cl-PFESA exhibited a correlation with GDM (OR = 1.31, 95% CI = 1.02, 1.68) and 2-h glucose concentrations (β = 0.22, 95% CI = 0.08, 0.36), and contributed most to the overall association with 2-h glucose concentrations. Compared to those diagnosed with male factor infertility, the associations were more pronounced in infertile women with reproductive endocrine diseases. We provide evidence that exposure to PFAS, especially emerging PFAS alternatives, may impair glucose homeostasis and increase the risk of GDM among women conceiving through ART.

Size matters: the biochemical logic of ligand type in endocrine crosstalk

The endocrine system is a fundamental type of long-range cell-cell communication that is important for maintaining metabolism, physiology, and other aspects of organismal homeostasis. Endocrine signaling is mediated by diverse blood-borne ligands, also called hormones, including metabolites, lipids, steroids, peptides, and proteins. The size and structure of these hormones are fine-tuned to make them bioactive, responsive, and adaptable to meet the demands of changing environments. Why has nature selected such diverse ligand types to mediate communication in the endocrine system? What is the chemical, signaling, or physiologic logic of these ligands? What fundamental principles from our knowledge of endocrine communication can be applied as we continue as a field to uncover additional new circulating molecules that are claimed to mediate long-range cell and tissue crosstalk? This review provides a framework based on the biochemical logic behind this crosstalk with respect to their chemistry, temporal regulation in physiology, specificity, signaling actions, and evolutionary development.

Metabolic hormones are integral regulators of female reproductive health and function

The female reproductive system is strongly influenced by nutrition and energy balance. It is well known that food restriction or energy depletion can induce suppression of reproductive processes, while overnutrition is associated with reproductive dysfunction. However, the intricate mechanisms through which nutritional inputs and metabolic health are integrated into the coordination of reproduction are still being defined. In this review, we describe evidence for essential contributions by hormones that are responsive to food intake or fuel stores. Key metabolic hormones-including insulin, the incretins (glucose-dependent insulinotropic polypeptide and glucagon-like peptide-1), growth hormone, ghrelin, leptin, and adiponectin-signal throughout the hypothalamic-pituitary-gonadal axis to support or suppress reproduction. We synthesize current knowledge on how these multifaceted hormones interact with the brain, pituitary, and ovaries to regulate functioning of the female reproductive system, incorporating in vitro and in vivo data from animal models and humans. Metabolic hormones are involved in orchestrating reproductive processes in healthy states, but some also play a significant role in the pathophysiology or treatment strategies of female reproductive disorders. Further understanding of the complex interrelationships between metabolic health and female reproductive function has important implications for improving women's health overall.

Early modulation of the gut microbiome by female sex hormones alters amyloid pathology and microglial function

It is well-established that women are disproportionately affected by Alzheimer's disease. The mechanisms underlying this sex-specific disparity are not fully understood, but several factors that are often associated-including interactions of sex hormones, genetic factors, and the gut microbiome-likely contribute to the disease's etiology. Here, we have examined the role of sex hormones and the gut microbiome in mediating Aβ amyloidosis and neuroinflammation in APPPS1-21 mice. We report that postnatal gut microbiome perturbation in female APPPS1-21 mice leads to an elevation in levels of circulating estradiol. Early stage ovariectomy (OVX) leads to a reduction of plasma estradiol that is correlated with a significant alteration of gut microbiome composition and reduction in Aβ pathology. On the other hand, supplementation of OVX-treated animals with estradiol restores Aβ burden and influences gut microbiome composition. The reduction of Aβ pathology with OVX is paralleled by diminished levels of plaque-associated microglia that acquire a neurodegenerative phenotype (MGnD-type) while estradiol supplementation of OVX-treated animals leads to a restoration of activated microglia around plaques. In summary, our investigation elucidates the complex interplay between sex-specific hormonal modulations, gut microbiome dynamics, metabolic perturbations, and microglial functionality in the pathogenesis of Alzheimer's disease.

Sex-Related Differences in Self-Reported Symptoms at Diagnosis in Pheochromocytomas and Paragangliomas

Context

Biological sex can play a role in the severity of certain diseases.

Objective

Our objective was to evaluate whether sex-related differences affect the signs and symptoms of pheochromocytomas and paragangliomas (PPGLs) at presentation.

Methods

We reviewed the records of patients with PPGLs at our center from 1995 to 2022.

Results

Our study included 385 patients with PPGLs: 118 (30.6%) head and neck paragangliomas (HNPGLs), 58 (15.1%) thoracoabdominal paragangliomas (TAPGLs) and 209 (54.3%) pheochromocytomas (PHEOs). The cohort consisted of 234 (60.8%) women and 151 (39.2%) men. At diagnosis, more women than men presented with headaches (47.5% vs 32.4%; P = .007); however, more men presented with diabetes (21.1% vs 12.5%; P = .039). When subdivided by tumor location, headaches occurred more often in women with HNPGLs and TAPGLs (31.0% vs 11.4%; P = .0499 and 60.0% vs 21.7%; P = .0167). More men presented with diabetes among patients with PHEOs (28.2% vs 11.2%; P = .0038). In regard to nonsecretory PPGLs, women presented with a higher prevalence of headaches (46.9% vs 3.6%; P = .0002), diaphoresis (16.3% vs 0.0%; P = .0454), and palpitations (22.4% vs 0.0%; P = .0057). In patients with secretory tumors, women presented with more headaches (58.9% vs 42.7%; P = .0282) and men with more diabetes (29.3% vs 12.5%; P = .0035).

Conclusion

In our cohort, more women presented with headaches across all tumor types and secretory statuses. More men presented with diabetes among patients with PHEOs and secretory tumors. In nonsecretory PPGLs, women had more adrenergic symptoms. These findings can be explained by differences in adrenergic receptor sensitivity, self-reported symptoms, and possibly other vasoactive peptides and sex-hormone status.

Host-gut microbiota interactions during pregnancy

Mammalian pregnancy is characterized by a well-known suite of physiological changes that support fetal growth and development, thereby positively affecting both maternal and offspring fitness. However, mothers also experience trade-offs between current and future maternal reproductive success, and maternal responses to these trade-offs can result in mother-offspring fitness conflicts. Knowledge of the mechanisms through which these trade-offs operate, as well as the contexts in which they operate, is critical for understanding the evolution of reproduction. Historically, hormonal changes during pregnancy have been thought to play a pivotal role in these conflicts since they directly and indirectly influence maternal metabolism, immunity, fetal growth and other aspects of offspring development. However, recent research suggests that gut microbiota may also play an important role. Here, we create a foundation for exploring this role by constructing a mechanistic model linking changes in maternal hormones, immunity and metabolism during pregnancy to changes in the gut microbiota. We posit that marked changes in hormones alter maternal gut microbiome composition and function both directly and indirectly via impacts on the immune system. The gut microbiota then feeds back to influence maternal immunity and metabolism. We posit that these dynamics are likely to be involved in mediating maternal and offspring fitness as well as trade-offs in different aspects of maternal and offspring health and fitness during pregnancy. We also predict that the interactions we describe are likely to vary across populations in response to maternal environments. Moving forward, empirical studies that combine microbial functional data and maternal physiological data with health and fitness outcomes for both mothers and infants will allow us to test the evolutionary and fitness implications of the gestational microbiota, enriching our understanding of the ecology and evolution of reproductive physiology.

The association of menopause with cardiometabolic disease risk factors in low- and middle-income countries: a systematic review and meta-analyses

IMPORTANCE

Menopause is an integral part of women's health, and studies in high-income countries have shown an increase in cardiometabolic disease (CMD) risk factors in postmenopausal compared with premenopausal women. However, to date, no study has combined and assessed such studies across low- and middle-income countries. This would better inform early monitoring and intervention strategies for reducing CMD risk factor levels in midlife women in these regions.

OBJECTIVE

This study aimed to evaluate evidence from the literature on differences in CMD risk factors between premenopausal and postmenopausal midlife women living in low- and middle-income countries.

EVIDENCE REVIEW

A systematic review with meta-analysis of original articles of all study designs from the databases PubMed, PubMed Central, Scopus, and ISI Web of Science was conducted from conception until April 24, 2023. Studies that met the inclusion criteria were included in the analysis. Quality assessment of the articles was done using the Newcastle-Ottawa Scale, adapted for each study design. The study protocol was registered with the International Prospective Register of Systematic Reviews and adheres to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis. For the meta-analysis, fixed-effects models were used to pool the odds ratios (OR), as measures of association.

FINDINGS

Our search identified 4,849 relevant articles: 44 for the systematic review and 16 for the meta-analysis, in accordance with our inclusion criteria. Compared with premenopausal women, the postmenopausal stage was associated with metabolic syndrome (OR, 1.18 [95% CI, 1.11-1.27]), high waist-to-hip ratio (OR, 1.22 [95% CI, 1.12-1.32]), hypertension (OR, 1.10 [95% CI, 1.04-1.16]), elevated triglycerides (OR, 1.16 [95% CI, 1.11-1.21]), and elevated plasma glucose (OR, 1.21 [95% CI, 1.15-1.28]).

CONCLUSIONS AND RELEVANCE

This study confirmed that CMD risk factors are present at higher levels in postmenopausal than premenopausal women. This demonstrates an urgent need for public health policies that focus on early monitoring and interventions targeted at reducing CMD risk and related adverse outcomes in midlife women in these nations.

S-Dihydrodaidzein and 3-(1,3-benzoxazol-2-yl)-benzamide, Two New Potential β-estrogen Receptor Ligands with Anti-adipogenic Activity

BACKGROUND

The elucidation of molecular pathways associated with adipogenesis has evidenced the relevance of estrogen and estrogen receptor beta (ERβ). The positive effects of ERβ ligands on adipogenesis, energy expenditure, lipolysis, food intake, and weight loss, make ERβ an attractive target for obesity control. From ligand-based virtual screening, molecular docking, and molecular dynamic simulations, six new likely ERβ ligands (C1 to C6) have been reported with potential for pharmacological obesity treatment.

OBJECTIVE

In this study, the effect of molecules C1-C6 on adipogenesis using the murine 3T3-L1 cell line was evaluated.

METHODS

Cell viability was assessed by MTT assays. Lipid accumulation and gene expression were investigated by ORO staining and real-time quantitative RT-PCR experiments, respectively.

RESULTS

Cell viability was not significantly affected by C1-C6 at concentrations up to 10 μM. Interestingly, treatment with 10 μM of C1 (S-Dihydrodaidzein) and C2 (3-(1,3-benzoxazol-2-yl)- benzamide) for 72 h inhibited adipocyte differentiation; moreover, ORO staining evidenced a reduced intracellular lipid accumulation (40% at day 7). Consistently, mRNA expression of the adipogenic markers, PPARγ and C/EBPα, was reduced by 50% and 82%, respectively, in the case of C1, and by 83% and 59%, in the case of C2.

CONCLUSION

Altogether, these results show the two new potential β-estrogen receptor ligands, C1 and C2, to exhibit anti-adipogenic activity. They could further be used as lead structures for the development of more efficient drugs for obesity control.

Ketone production and excretion even during mild hyperglycemia and the impact of sodium-glucose co-transporter inhibition in type 1 diabetes

AIMS

We aimed to determine if ketone production and excretion are increased even at mild fasting hyperglycemia in type 1 diabetes (T1D) and if these are modified by ketoacidosis risk factors, including sodium-glucose co-transporter inhibition (SGLTi) and female sex.

METHODS

In secondary analysis of an 8-week single-arm open-label trial of empagliflozin (NCT01392560) we evaluated ketone concentrations during extended fasting and clamped euglycemia (4-6 mmol/L) and mild hyperglycemia (9-11 mmol/L) prior to and after treatment. Plasma and urine beta-hydroxybutyrate (BHB) concentrations and fractional excretion were analyzed by metabolomic analysis.

RESULTS

Forty participants (50 % female), aged 24 ± 5 years, HbA1c 8.0 ± 0.9 % (64 ± 0.08 mmol/mol) with T1D duration of 17.5 ± 7 years, were studied. Increased BHB production even during mild hyperglycemia (median urine 6.3[3.5-13.6] vs. 3.5[2.2-7.0] µmol/mmol creatinine during euglycemia, p < 0.001) was compensated by increased fractional excretion (0.9 % [0.3-1.6] vs. 0.4 % [0.2-0.9], p < 0.001). SGLTi increased production and attenuated the increased BHB fractional excretion (decreased to 0.3 % during mild hyperglycemia, p < 0.001), resulting in higher plasma concentrations (increased to 0.21 [0.05-0.40] mmol/L, p < 0.001), particularly in females (interaction p < 0.001).

CONCLUSIONS

Even mild hyperglycemia is associated with greater ketone production, compensated by urinary excretion, in T1D. However, SGLTi exaggerates production and partially reduces compensatory excretion, particularly in women.

Sex differences in energy metabolism: natural selection, mechanisms and consequences

Metabolic homeostasis operates differently in men and women. This sex asymmetry is the result of evolutionary adaptations that enable women to resist loss of energy stores and protein mass while remaining fertile in times of energy deficit. During starvation or prolonged exercise, women rely on oxidation of lipids, which are a more efficient energy source than carbohydrates, to preserve glucose for neuronal and placental function and spare proteins necessary for organ function. Carbohydrate reliance in men could be an evolutionary adaptation related to defence and hunting, as glucose, unlike lipids, can be used as a fuel for anaerobic high-exertion muscle activity. The larger subcutaneous adipose tissue depots in healthy women than in healthy men provide a mechanism for lipid storage. As female mitochondria have higher functional capacity and greater resistance to oxidative damage than male mitochondria, uniparental inheritance of female mitochondria may reduce the transmission of metabolic disorders. However, in women, starvation resistance and propensity to obesity have evolved in tandem, and the current prevalence of obesity is greater in women than in men. The combination of genetic sex, programming by developmental testosterone in males, and pubertal sex hormones defines sex-specific biological systems in adults that produce phenotypic sex differences in energy homeostasis, metabolic disease and drug responses.

Social Stress during the Estrus or Luteal Phase in Sheep

In mammals, progesterone and estrogens affect the stress response. The study aimed to compare the physiological and behavioral responses to the social isolation of ewes during the estrus or luteal phase. Estrous and diestrous ewes (n = 10 and 8 respectively) were individually isolated in a novel place for 10 min. Ewes' behavior was recorded during the test. Cortisol, blood proteins and glucose concentrations, and the skin surface temperature were determined before and after the test. Cortisol increased immediately after the test ended (P = 0.02). Serum total protein (P = 0.02), globulin (P < 0.0001), and plasma glucose (P = 0.006) concentrations were greater in estrus than in the luteal phase. The abdominal skin surface temperature was greater during estrus than during the luteal phase (P = 0.02). Ewes in estrus spent more time standing up immobile than ewes in the luteal phase (P = 0.05). In conclusion, the physiological and behavioral responses changed according to the phase of the estrous cycle. These results highlight the need for future studies focusing on how reproductive status influences the stress response to different management practices in sheep.

GPER/PKA-Dependent Enhancement of Hormone-Sensitive Lipase Phosphorylation in 3T3-L1 Adipocytes by Piceatannol

We previously reported that piceatannol (PIC) had an anti-obesity effect only in ovariectomized (OVX) postmenopausal obesity mice. PIC was found to induce the phosphorylation of hormone-sensitive lipase (pHSL) in OVX mice. To elucidate the mechanism by which PIC activates HSL, we investigated the effect of PIC using 3T3-L1 adipocytes. PIC induced HSL phosphorylation at Ser563 in 3T3-L1 cells, as in vivo experiments showed. pHSL (Ser563) is believed to be activated through the β-adrenergic receptor (β-AR) and protein kinase A (PKA) pathways; however, the addition of a selective inhibitor of β-AR did not inhibit the effect of PIC. The addition of a PKA inhibitor with PIC blocked pHSL (Ser563), suggesting that the effects are mediated by PKA in a different pathway than β-AR. The addition of G15, a selective inhibitor of the G protein-coupled estrogen receptor (GPER), reduced the activation of HSL by PIC. Furthermore, PIC inhibited insulin signaling and did not induce pHSL (Ser565), which represents its inactive form. These results suggest that PIC acts as a phytoestrogen and phosphorylates HSL through a novel pathway that activates GPER and its downstream PKA, which may be one of the inhibitory actions of PIC on fat accumulation in estrogen deficiency.

The Importance of Nutrition in Menopause and Perimenopause-A Review

Menopause is associated with an increased prevalence of obesity, metabolic syndrome, cardiovascular diseases, and osteoporosis. These diseases and unfavorable laboratory values, which are characteristic of this period in women, can be significantly improved by eliminating and reducing dietary risk factors. Changing dietary habits during perimenopause is most effectively achieved through nutrition counseling and intervention. To reduce the risk factors of all these diseases, and in the case of an already existing disease, dietary therapy led by a dietitian should be an integral part of the treatment. The following review summarizes the recommendations for a balanced diet and fluid intake, the dietary prevention of cardiovascular diseases, the role of sleep, and the key preventive nutrients in menopause, such as vitamin D, calcium, vitamin C, B vitamins, and protein intake. In summary, during the period of perimenopause and menopause, many lifestyle factors can reduce the risk of developing all the diseases (cardiovascular disease, insulin resistance, type 2 diabetes mellitus, osteoporosis, and tumors) and symptoms characteristic of this period.

Naringenin protects pancreatic β cells in diabetic rat through activation of estrogen receptor β

Naringenin is a citrus flavonoid that potently improves metabolic parameters in animal models of metabolic disorders, such as type 2 diabetes. Estrogen receptor (ER) activation promotes β cell function and survival, thereby improving systemic glucose metabolism. In this study, we used a luciferase reporter assay, isolated rat islets and a diabetic rat model to investigate the effects of naringenin on ER signaling and the underlying mechanism of naringenin-mediated improvement of islet function in diabetes. Naringenin specifically activated ERβ without affecting the activity of ERα, G protein-coupled estrogen receptor (GPER) or estrogen-related receptor (ERR) α/β/γ. Additionally, treatment with naringenin enhanced glucose-stimulated insulin secretion in isolated rat islets. This effect was abrogated by PHTPP, an ERβ antagonist. Transcriptomic analysis revealed that naringenin upregulated the expression of genes, such as Pdx1 and Mafa, which are closely linked to improved β-cell function. In consistence, single administration of naringenin to normal rats elevated plasma insulin levels and improved glucose responses. These beneficial effects were blocked by PHTPP. In streptozocin-nicotinamide induced diabetic rats, treatment for 2 weeks with naringenin alone, but not in combination with PHTPP, significantly restored pancreatic β cell mass and improved glucose metabolism. Collectively, these data support that naringenin specifically activate ERβ to improve insulin secretion in the primary rat islets. Furthermore, naringenin administration also protected β cell function and reversed glucose dysregulation in diabetic rats. These beneficial effects are at least partially dependent on the ERβ pathway.

Gut feelings in the islets: The role of the gut microbiome and the FFA2 and FFA3 receptors for short chain fatty acids on β-cell function and metabolic regulation

Short-chain fatty acids (SCFAs) are biosynthesized via fermentation of polysaccharides by gastrointestinal microbiota and have been shown to have wide-reaching effects on almost all tissues, including the pancreatic islets. Historically, the effects of SCFAs have been attributed to their intracellular metabolism and function as energy sources, but the discovery of free fatty acid G protein-coupled receptors (GPCRs) in the 2000s suggested that many functional outcomes of SCFAs are receptor-mediated. The SCFA receptors FFA2/GPR43 and FFA3/GPR41 are expressed on β-cells, where they regulate glucose-dependent insulin secretion, making them attractive targets for treatment of diabetes and other metabolic disorders. Here, we provide an update on the current evidence regarding regulation of FFA2/FFA3 receptors by specific probiotic bacterial species within the gut microbiome that synthesize SCFAs. We also review the body of research regarding the FFA2- and FFA3 receptor-specific function of SCFAs on β-cells and discuss the somewhat controversial and opposing findings within these studies.