Obesity, insulin resistance and diabetes: sex differences and role of oestrogen receptors

Sex and sex steroids as determinants of cardiovascular risk

There are considerable sex differences regarding the risk of cardiovascular disease (CVD), including arterial hypertension, coronary artery disease (CAD) and stroke, as well as chronic renal disease. Women are largely protected from these conditions prior to menopause, and the risk increases following cessation of endogenous estrogen production or after surgical menopause. Cardiovascular diseases in women generally begin to occur at a later age than in men (on average with a delay of 10 years). Cessation of estrogen production also impacts metabolism, increasing the risk of developing obesity and diabetes. In middle-aged individuals, hypertension develops earlier and faster in women than in men, and smoking increases cardiovascular risk to a greater degree in women than it does in men. It is not only estrogen that affects female cardiovascular health and plays a protective role until menopause: other sex hormones such as progesterone and androgen hormones generate a complex balance that differentiates heart and blood vessel function in women compared to men. Estrogens improve vasodilation of epicardial coronary arteries and the coronary microvasculature by augmenting the release of vasodilating factors such as nitric oxide and prostacyclin, which are mechanisms of coronary vasodilatation that are more pronounced in women compared to men. Estrogens are also powerful inhibitors of inflammation, which in part explains their protective effects on CVD and chronic renal disease. Emerging evidence suggests that sex chromosomes also play a significant role in shaping cardiovascular risk. The cardiovascular protection conferred by endogenous estrogens may be extended by hormone therapy, especially using bioidentical hormones and starting treatment early after menopause.

Association between visceral adiposity index and risk of diabetes and prediabetes: Results from the NHANES (1999-2018)

OBJECTIVE

To investigate the association between the visceral adiposity index and the prevalence of diabetes and prediabetes in the US adult population.

METHOD

We conducted a cross-sectional study using data from the National Health and Nutrition Examination Survey (NHANES) from 1999 to 2018 for ten consecutive years, including 18745 eligible participants. The weighted multivariate logistic model and fitting curve were used to explore the correlation and dose-response relationship between visceral adiposity index (VAI) and diabetes (DM) and prediabetes in the general population and the prevalence of different subgroups.

RESULTS

In the fully adjusted continuous model, the risk of diabetes and prediabetes in the general population increased 0.15 times [1.15 (1.10,1.20), p<0.0001] with every increase of 1 unit of VAI. In the fully adjusted classification model, with the lowest quartile array Q1 of VAI as the reference group, Q2 of the second Quantile group, Q3 of the third Quantile group, and Q4 of the Quartile group increased 0.26 times [1.26 (1.10,1.44), p<0.001], 0.65 times [1.65 (1.43,1.89), p<0.0001], 1.60 times [2.60 (2.28,2.97), p<0.0001] respectively with the risk of diabetes and prediabetes. The above results showed that VAI was positively associated with the prevalence of diabetes and prediabetes, and the fitted curves showed a non-linear trend. (P for non-linear = 0<0.05). The results of the subgroup population were consistent with the total population and a significant interaction was found in gender (P for interaction<0.0001).

CONCLUSION

In conclusion, we found a non-linear positive association between VAI and the risk of diabetes and prediabetes in the US adult population and found that women have a higher risk of diabetes and prediabetes than men; therefore, we should focus on the female population, and we call for the use of VAI to manage the development of diabetes and prediabetes in the clinical setting.

Correlation between fat-to-muscle mass ratio and cognitive impairment in elderly patients with type 2 diabetes mellitus: a cross-sectional study

BACKGROUND

Fat to muscle mass ratio (FMR), a novel index integrating fat and muscle composition, has garnered attention in age-related conditions such as type 2 diabetes mellitus (T2DM) and neurodegenerative diseases. Despite this research on the relationship between FMR and cognitive impairment (CI) in T2DM remains scarce. This study aimed to investigate the sex-specific association between FMR and CI in elderly T2DM patients.

METHODS

A total of 768 elderly (> 60 years) T2DM in-patients (356 men and 412 women) were recruited from the Department of Endocrinology at Tianjin Nankai University affiliated hospital. Bioelectrical Impedance Analysis (BIA) was used to assess body composition, and Montreal Cognitive Assessment (MoCA) was used to evaluate cognitive performance. T2DM patients were categorized into normal cognitive function (NC) and cognitive impairment (CI) groups based on MoCA scores and stratified by sex. Binary logistic regression was employed to examine the association between FMR and CI.

RESULTS

Among the participants, 42.7% of men and 56.3% of women experienced cognitive deterioration. Women with CI exhibited lower body mass index (BMI) and skeletal muscle mass index (SMI), while men with cognitive disorders showed lower SMI, FMR, and higher fat mass index (FMI). FMR was consistently unrelated to cognition in females, irrespective of adjustment made. However, in males, FMR was significantly associated with an increasing risk of cognitive dysfunction after adjusting for demographic and clinical variables (OR: 1.175, 95% CI: 1.045-1.320, p = 0.007). Furthermore, for each 0.1 increase in FMR, the incidence of CI rose by 31.1% after additional adjustment for BMI. In males, the prevalence of CI increased sequentially across FMR quartiles (p < 0.05).

CONCLUSION

Elderly T2DM men with high FMR had unfavorable cognitive function. FMR is independently associated with an increased risk of CI in male T2DM patients regardless of BMI.

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.

Association between triglyceride glucose index and total bone mineral density: a cross-sectional study from NHANES 2011-2018

The Homeostatic Model Assessment for Triglyceride Glucose Index (TyG) and its related indices, including triglyceride glucose-waist circumference (TyG-WC), triglyceride glucose-waist-to-height ratio (TyG-WHtR) and triglyceride glucose-body mass index (TyG-BMI), has emerged as a practical tool for assessing insulin resistance in metabolic disorders. However, limited studies have explored the connection between TyG, TyG-related indices and osteoporosis. This population-based study, utilizing data from the National Health and Nutrition Examination Survey 2011-2018, involved 5456 participants. Through weighted multivariate linear regression and smoothed curve fitting, a significant positive correlation was found between TyG, TyG-related indices and total bone mineral density (BMD) after adjusting for covariates [β = 0.0124, 95% CI (0.0006, 0.0242), P = 0.0390; β = 0.0004, 95% CI (0.0003, 0.0004), P < 0.0001; β = 0.0116, 95% CI (0.0076, 0.0156), P < 0.0001; β = 0.0001, 95% CI (0.0001, 0.0001), P < 0.0001]. In subgroup analysis, race stratification significantly affected the relationship between TyG and total BMD. Additionally, gender and race were both significant for TyG-related indices. Non-linear relationships and threshold effects with inflection points at 9.106, 193.9265, 4.065, and 667.5304 (TyG, TyG-BMI, TyG-WHtR, TyG-WC) were identified. Saturation phenomena were observed between TyG-BMI, TyG-WC and total BMD with saturation thresholds at 314.177 and 1022.0428. These findings contributed to understanding the association between TyG, TyG-related indices and total BMD, offering insights for osteoporosis prevention and treatment.

Development and validation of machine learning-augmented algorithm for insulin sensitivity assessment in the community and primary care settings: a population-based study in China

Objective

Insulin plays a central role in the regulation of energy and glucose homeostasis, and insulin resistance (IR) is widely considered as the "common soil" of a cluster of cardiometabolic disorders. Assessment of insulin sensitivity is very important in preventing and treating IR-related disease. This study aims to develop and validate machine learning (ML)-augmented algorithms for insulin sensitivity assessment in the community and primary care settings.

Methods

We analyzed the data of 9358 participants over 40 years old who participated in the population-based cohort of the Hubei center of the REACTION study (Risk Evaluation of Cancers in Chinese Diabetic Individuals). Three non-ensemble algorithms and four ensemble algorithms were used to develop the models with 70 non-laboratory variables for the community and 87 (70 non-laboratory and 17 laboratory) variables for the primary care settings to screen the classifier of the state-of-the-art. The models with the best performance were further streamlined using top-ranked 5, 8, 10, 13, 15, and 20 features. Performances of these ML models were evaluated using the area under the receiver operating characteristic curve (AUROC), the area under the precision-recall curve (AUPR), and the Brier score. The Shapley additive explanation (SHAP) analysis was employed to evaluate the importance of features and interpret the models.

Results

The LightGBM models developed for the community (AUROC 0.794, AUPR 0.575, Brier score 0.145) and primary care settings (AUROC 0.867, AUPR 0.705, Brier score 0.119) achieved higher performance than the models constructed by the other six algorithms. The streamlined LightGBM models for the community (AUROC 0.791, AUPR 0.563, Brier score 0.146) and primary care settings (AUROC 0.863, AUPR 0.692, Brier score 0.124) using the 20 top-ranked variables also showed excellent performance. SHAP analysis indicated that the top-ranked features included fasting plasma glucose (FPG), waist circumference (WC), body mass index (BMI), triglycerides (TG), gender, waist-to-height ratio (WHtR), the number of daughters born, resting pulse rate (RPR), etc.

Conclusion

The ML models using the LightGBM algorithm are efficient to predict insulin sensitivity in the community and primary care settings accurately and might potentially become an efficient and practical tool for insulin sensitivity assessment in these settings.

Non-linear association of triglyceride-glucose index with prevalence of prediabetes and diabetes: a cross-sectional study

Background

The Triglyceride-glucose (TyG) index has been acknowledged as a convenient, cost-effective, and relatively simple marker for insulin resistance (IR). Meanwhile, prediabetes, described as an asymptomatic, moderately hyperglycemic state, tends to be more prevalent than diabetes. Thus, the objective of this study was to explore the relationship between the TyG index and the prevalence of both prediabetes and diabetes within the U.S. population.

Methods

This study utilized a cross-sectional dataset derived from the National Health and Nutrition Survey (NHANES) spanning 1999 to 2018. The subjects were individuals aged 18 years and above, who had available fasting glucose and fasting triglyceride information, permitting a diagnosis of prediabetes or diabetes. The TyG index was computed using laboratory data, and participants were subsequently categorized into quartiles based on this information. The relationship between the TyG index and the prevalence of prediabetes and diabetes was investigated using logistic regression analysis.

Results

Out of the 25,159 participants, 23.88% were found to have prediabetes, while 16.22% were diagnosed with diabetes. After adjusting for confounding factors, a linear increase in relative odds was observed in Q2 (OR: 1.69; 95% CI: 1.52, 1.89), Q3 (OR: 2.57; 95% CI: 2.30, 2.88), and Q4 (OR: 4.88; 95% CI: 4.33, 5.49) groups in comparison to the reference group, Q1. In addition, a non-linear relationship was observed between the TyG index and the prevalence of prediabetes and diabetes. Specifically, patients with a TyG index greater than 8.00 overall exhibited a significantly higher risk of prediabetes and diabetes, confirming that an increase in the TyG index is associated with a corresponding increase in risk. However, this shift showed gender-specific variations; the threshold was observed at 8.00 in males but shifted to 9.00 in females.

Conclusion

The TyG index demonstrated a non-linear positive correlation with both prediabetes and diabetes. This suggests that maintaining the TyG index at a certain, reduced level could potentially aid in preventing the onset of prediabetes and diabetes.

Maternal dexamethasone exposure does not affect glucose tolerance but alters renal haemodynamics in F1 rats in a sex-dependent manner

INTRODUCTION

Prenatal programming with dexamethasone increases the risk of the development of hyperglycaemia and insulin resistance, leading to diabetes in adulthood. Dexamethasone also causes a decline in renal glomerular filtration in the adult offspring. Sodium-glucose cotransporter-2 (SGLT2) plays a significant role in regulating blood glucose and renal haemodynamics in diabetic patients. However, the role of SGLT2 in dexamethasone-induced programming and the putative sex-dependent effects on the changes named earlier is unknown. Therefore, this study aimed to investigate the impact of maternal dexamethasone treatment on glucose tolerance, insulin sensitivity, renal perfusion and renal function in adult male and female offspring and the possible contribution of SGLT2 to these changes.

METHODS AND RESULTS

Pregnant Sprague Dawley rats (F0 ) were treated with either vehicle or dexamethasone (0.2 mg/kg ip) from gestation Day 15 to 20. F1 males and F1 females were randomly selected from each mother at 4 months of age. There was no change in serum Na+ , Na+ excretion rate, glucose tolerance or insulin sensitivity in F1 male or female rats. However, dexamethasone caused significant glomerular hypertrophy and decreases in CSinistrin and CPAH indicating decreased glomerular filtration rate and renal plasma flow, respectively, in dexamethasone-treated F1 male but not female rats. Dexamethasone did not affect SGLT2 mRNA or protein expression in F1 males or females.

CONCLUSION

We conclude that dexamethasone-mediated prenatal programming of glomerular volume, renal function and haemodynamics is sex-dependent, occurring only in adult male offspring.

Phytoestrogen-Based Hormonal Replacement Therapy Could Benefit Women Suffering Late-Onset Asthma

It has been observed that plasmatic concentrations of estrogens, progesterone, or both correlate with symptoms in asthmatic women. Fluctuations in female sex steroid concentrations during menstrual periods are closely related to asthma symptoms, while menopause induces severe physiological changes that might require hormonal replacement therapy (HRT), that could influence asthma symptoms in these women. Late-onset asthma (LOA) has been categorized as a specific asthmatic phenotype that includes menopausal women and novel research regarding therapeutic alternatives that might provide relief to asthmatic women suffering LOA warrants more thorough and comprehensive analysis. Therefore, the present review proposes phytoestrogens as a promising HRT that might provide these females with relief for both their menopause and asthma symptoms. Besides their well-recognized anti-inflammatory and antioxidant capacities, phytoestrogens activate estrogen receptors and promote mild hormone-like responses that benefit postmenopausal women, particularly asthmatics, constituting therefore a very attractive potential therapy largely due to their low toxicity and scarce side effects.

A follow-up cohort study on the risk of prediabetes, comparing women with previous preeclamptic or normotensive pregnancies

Studies have shown that preeclampsia is associated insulin resistance and cardiovascular events later in life. However, knowledge is lacking regarding a possible association between PE and abnormal glucose tolerance/prediabetes. Thus, the current study aimed to compare the prevalence of prediabetes in women with previous severe preeclampsia to women with previous normotensive pregnancies. Women with severe preeclampsia (index women, n = 45) admitted to Danderyds University Hospital in 1999-2004 were compared to women with normotensive pregnancies, matched for age, parity, and year of delivery (control women, n = 53). In 2013-2016 BMI, blood pressure, waist circumference, insulin, C-peptide, hsCRP, Cystatin C, HDL, triglycerides, and HbA1c were measured and an OGTT was performed. Index women had a higher BMI (p < 0.001) and blood pressure (p < 0.001) in early pregnancy. At follow-up, prediabetes was more common among index women (p = 0.001), as were hypertension (p = 0.003), heredity for diabetes/cardiovascular disease (p = 0.020), and a larger waist circumference (p = 0.024). Preeclampsia increased the risk of having a fasting plasma glucose ≥ 5.6 mmol/l (aOR 7.28, 95% CI 2.44-21.76) and of prediabetes 11-16 years after index pregnancy (aOR 4.83, 95% CI 1.80-12.97). In conclusion, preeclampsia increases the risk of prediabetes independent of heredity, hypertension, and waist circumference. These findings may have implications for screening and prevention.

Estrogen regulates duodenal glucose absorption by affecting estrogen receptor-α on glucose transporters

The mechanisms of estrogen in glucose metabolism are well established; however, its role in glucose absorption remains unclear. In this study, we investigated the effects of estrogen on glucose absorption in humans, mice, and SCBN intestinal epithelial cells. We first observed a correlation between estrogen and blood glucose in young women and found that glucose tolerance was significantly less in the premenstrual phase than in the preovulatory phase. Similarly, with decreased serum estradiol levels in ovariectomized mice, estrogen receptors alpha (ERα) and beta (ERβ) in the duodenum were reduced, and weight and abdominal fat increased significantly. The expression of sodium/glucose cotransporter 1 (SGLT1) and glucose transporter 2 (GLUT2) and glucose absorption in the duodenum decreased significantly. Estrogen significantly upregulated SGLT1 and GLUT2 expression in SCBN cells. Silencing of ERα, but not ERβ, reversed this trend, suggesting that ERα may be key to estrogen-regulating glucose transporters. A mechanistic study revealed that downstream, estrogen regulates the protein kinase C (PKC) pathway. Overall, our findings indicate that estrogen promotes glucose absorption, and estrogen and ERα deficiency can inhibit SGLT1 and GLUT2 expression through the PKC signaling pathway, thereby reducing glucose absorption.

Unlocking the Potential: Amino Acids' Role in Predicting and Exploring Therapeutic Avenues for Type 2 Diabetes Mellitus

Diabetes mellitus, particularly type 2 diabetes mellitus (T2DM), imposes a significant global burden with adverse clinical outcomes and escalating healthcare expenditures. Early identification of biomarkers can facilitate better screening, earlier diagnosis, and the prevention of diabetes. However, current clinical predictors often fail to detect abnormalities during the prediabetic state. Emerging studies have identified specific amino acids as potential biomarkers for predicting the onset and progression of diabetes. Understanding the underlying pathophysiological mechanisms can offer valuable insights into disease prevention and therapeutic interventions. This review provides a comprehensive summary of evidence supporting the use of amino acids and metabolites as clinical biomarkers for insulin resistance and diabetes. We discuss promising combinations of amino acids, including branched-chain amino acids, aromatic amino acids, glycine, asparagine and aspartate, in the prediction of T2DM. Furthermore, we delve into the mechanisms involving various signaling pathways and the metabolism underlying the role of amino acids in disease development. Finally, we highlight the potential of targeting predictive amino acids for preventive and therapeutic interventions, aiming to inspire further clinical investigations and mitigate the progression of T2DM, particularly in the prediabetic stage.

Post-Transcriptional and Epigenetic Regulation of Estrogen Signaling

Post-translational and epigenetic regulation are important mechanisms controlling functions of genes and proteins. Although the "classic" estrogen receptors (ERs) have been acknowledged to function in mediating estrogen effects via transcriptional mechanisms, estrogenic agents modulate the turnover of several proteins via post-transcriptional and post-translational pathways including epigenetics. For instance, the metabolic and angiogenic action of G-protein coupled estrogen receptor (GPER) in vascular endothelial cells has been recently elucidated. By interacting with GPER, 17β-estradiol and the GPER agonist G1 enhance endothelial stability of 6-phosphofructo-2-kinase/fructose-2,6-biphosphatase 3 (PFKFB3) and capillary tube formation by increasing ubiquitin-specific peptidase 19 levels, thereby reducing PFKFB3 ubiquitination and proteasomal degradation. In addition to ligands, the functional expression and trafficking of ERs can be modulated by post-translational modification, including palmitoylation. MicroRNAs (miRNAs), the most abundant form of endogenous small RNAs in humans, regulate multiple target genes and are at the center of the multi-target regulatory network. This review also discusses the emerging evidence of how miRNAs affect glycolytic metabolism in cancer, as well as their regulation by estrogens. Restoring dysregulated miRNA expression represents a promising strategy to counteract the progression of cancer and other disease conditions. Accordingly, estrogen post-transcriptional regulatory and epigenetic mechanisms represent novel targets for pharmacological and nonpharmacological intervention for the treatment and prevention of hormone-sensitive noncommunicable diseases, including estrogen-sensitive cancers of the reproductive system in women. SIGNIFICANCE STATEMENT: The effects of estrogen are mediated by several mechanisms that are not limited to the transcriptional regulation of target genes. Slowing down the turnover of master regulators of metabolism by estrogens allows cells to rapidly adapt to environmental cues. Identification of estrogen-targeted microRNAs may lead to the development of novel RNA therapeutics that disrupt pathological angiogenesis in estrogen-dependent cancers.

Nutritional Approaches in Children with Overweight or Obesity and Hepatic Steatosis

Childhood obesity is a global public health problem. Worldwide, 41 million children under 5 years and 340 million children and adolescents between 5 and 19 years are overweight. In addition, the recent COVID-19 epidemic has further amplified this social phenomenon. Obesity is a condition associated with various comorbidities, such as nonalcoholic fatty liver disease (NAFLD). The pathophysiology of NAFLD in obesity is intricate and involves the interaction and dysregulation of several mechanisms, such as insulin resistance, cytokine signaling, and alteration of the gut microbiota. NAFLD is defined as the presence of hepatic steatosis in more than 5% of hepatocytes, evaluated by histological analysis. It can evolve from hepatic steatosis to steatohepatitis, fibrosis, cirrhosis, hepatocellular carcinoma, and end-stage liver failure. Body weight reduction through lifestyle modification remains the first-line intervention for the management of pediatric NAFLD. Indeed, studies suggest that diets low in fat and sugar and conversely rich in dietary fibers promote the improvement of metabolic parameters. This review aims to evaluate the existing relationship between obesity and NAFLD in the pediatric population and to assess the dietary patterns and nutritional supplementations that can be recommended to prevent and manage obesity and its comorbidities.

The G protein-coupled oestrogen receptor GPER in health and disease: an update

Oestrogens and their receptors contribute broadly to physiology and diseases. In premenopausal women, endogenous oestrogens protect against cardiovascular, metabolic and neurological diseases and are involved in hormone-sensitive cancers such as breast cancer. Oestrogens and oestrogen mimetics mediate their effects via the cytosolic and nuclear receptors oestrogen receptor-α (ERα) and oestrogen receptor-β (ERβ) and membrane subpopulations as well as the 7-transmembrane G protein-coupled oestrogen receptor (GPER). GPER, which dates back more than 450 million years in evolution, mediates both rapid signalling and transcriptional regulation. Oestrogen mimetics (such as phytooestrogens and xenooestrogens including endocrine disruptors) and licensed drugs such as selective oestrogen receptor modulators (SERMs) and downregulators (SERDs) also modulate oestrogen receptor activity in both health and disease. Following up on our previous Review of 2011, we herein summarize the progress made in the field of GPER research over the past decade. We will review molecular, cellular and pharmacological aspects of GPER signalling and function, its contribution to physiology, health and disease, and the potential of GPER to serve as a therapeutic target and prognostic indicator of numerous diseases. We also discuss the first clinical trial evaluating a GPER-selective drug and the opportunity of repurposing licensed drugs for the targeting of GPER in clinical medicine.

Association between MetS-IR and prediabetes risk and sex differences: a cohort study based on the Chinese population

Objective

The metabolic score for insulin resistance (MetS-IR) is an emerging surrogate marker for insulin resistance (IR). This study aimed to investigate the association and sex differences between MetS-IR and prediabetes risk in a Chinese population.

Methods

This cohort study included 100,309 adults with normoglycemia at baseline and had followed longitudinally for 5 years, and with prediabetes, defined according to the 2018 American Diabetes Association (ADA) recommended diagnostic criteria, as the outcome of interest. Multivariate Cox proportional hazards regression and restricted cubic spline (RCS) regression models were used to assess the association between MetS-IR and prediabetes risk.

Results

During an observation period of 312,843 person-years, 7,735 (14.84%) men and 4,617 (9.57%) women with pre-diabetes onset were recorded. After fully adjusting for confounders, we found an independent and positive correlation between MetS-IR and the risk of prediabetes in the Chinese population, and the degree of correlation was stronger in women than in men (HR: 1.24 vs 1.16, P-interaction<0.05). Furthermore, using RCS nested in the Cox regression model, we found that there was a nonlinear correlation between MetS-IR and prediabetes risk in both sexes with an obvious saturation effect point, and when the MetS-IR was greater than the value of the saturation effect point, the risk of prediabetes was gradually leveling off. We further calculated the saturation effect points of MetS-IR used to evaluate the risk of prediabetes which in men was 42.82, and in women was 41.78.

Conclusion

In this large cohort study, our results supported that MetS-IR was independently and positively associated with the risk of prediabetes in the Chinese population, with the association being stronger in women than in men.

Role of Sex Hormones in Prevalent Kidney Diseases

Chronic kidney disease (CKD) is a constantly growing global health burden, with more than 840 million people affected worldwide. CKD presents sex disparities in the pathophysiology of the disease, as well as in the epidemiology, clinical manifestations, and disease progression. Overall, while CKD is more frequent in females, males have a higher risk to progress to end-stage kidney disease. In recent years, numerous studies have highlighted the role of sex hormones in the health and diseases of several organs, including the kidney. In this review, we present a clinical overview of the sex-differences in CKD and a selection of prominent kidney diseases causing CKD: lupus nephritis, diabetic kidney disease, IgA nephropathy, and autosomal dominant polycystic kidney disease. We report clinical and experimental findings on the role of sex hormones in the development of the disease and its progression to end-stage kidney disease.

Fructose-induced salt-sensitive blood pressure differentially affects sympathetically mediated aortic stiffness in male and female Sprague-Dawley rats

Hypertension is the leading risk factor for major adverse cardiovascular events (MACE). Aortic stiffness and sympathoexcitation are robust predictors of MACE. Combined high fructose and sodium intake increases arterial pressure, aortic stiffness, renin, and sympathetic nerve activity in male rats. We hypothesized that activation of the renin angiotensin system (RAS) and/or the sympathetic system mediates aortic stiffness in rats with fructose-induced salt-sensitive blood pressure. Male and female Sprague-Dawley rats ingested 20% fructose or 20% glucose in drinking water with 0.4% NaCl chow for 1 week. Then, fructose-fed rats were switched to 4% NaCl chow (Fru + HS); glucose-fed rats remained on 0.4% NaCl chow (Glu + NS, controls for caloric intake). After 2 weeks, mean arterial pressure (MAP) and aortic pulsed wave velocity (PWV) were evaluated at baseline or after acute intravenous vehicle, clonidine, enalapril, losartan, or hydrochlorothiazide. Baseline global longitudinal strain (GLS) was also assessed. MAP and PWV were greater in male Fru + HS versus Glu + NS male rats (p < 0.05 and p < 0.001, respectively). PWV was similar between the female groups. Despite similarly reduced MAP after clonidine, PWV decreased in Fru + HS versus Glu + NS male rats (p < 0.01). Clonidine induced similar decreases in MAP and PWV in females on either diet. GLS was lower in Fru + HS versus Glu + NS male rats and either of the female groups. Thus, acute sympathoinhibition improved aortic compliance in male rats with fructose salt-sensitive blood pressure. Female rats retained aortic compliance regardless of diet. Acute RAS inhibition exerted no significant effects. Male rats on fructose high salt diet displayed an early deficit in myocardial function. Taken together, these findings suggest that adult female rats are protected from the impact of fructose and high salt diet on blood pressure, aortic stiffness, and early left ventricular dysfunction compared with male rats.

Polymorphisms −374 T/A and −429 T/C of the Receptor for Advanced Glycation End-Products (RAGE) and Serum Levels of RAGE (sRAGE) Are Not Associated with Metabolic Syndrome

RAGE is a multi-ligand transmembrane glycoprotein that promotes biological signals associated with inflammatory responses and degenerative diseases. sRAGE is a soluble variant, proposed as an inhibitor of RAGE activity. −374 T/A and −429 T/C polymorphisms of the advanced glycation end products receptor AGER gene are associated with the development of some diseases, such as type of cancer, cardiovascular disease, and micro and macrovascular disease in diabetes among others but their role in metabolic syndrome (MS) is still unknown. We studied 80 healthy men without MS, and 80 men with MS according to the harmonized criteria. −374 T/A and −429 T/C polymorphisms were genotyped by RT-PCR, and sRAGE was measured by ELISA. Allelic and genotypic frequencies did not differ between Non-MS and MS groups (−374 T/A p = 0.48, p = 0.57 and −429 T/C p = 0.36, p = 0.59). Significant differences were found in fasting glucose levels and diastolic blood pressure among the genotypes of the −374 T/A polymorphism in the Non-MS group (p < 0.01 and p = 0.008). Glucose levels were different between −429 T/C genotypes in the MS group (p = 0.02). sRAGE levels were similar in both groups, but in the Non-MS group showed a significant difference between individuals with only 1 or 2 components of the metabolic syndrome (p = 0.047). However, no associations of any SNP with MS were found (recessive model p = 0.48, dominant model p = 0.82 for −374 T/A; recessive model p = 0.48, dominant model p = 0.42 for −429 T/C). −374 T/A and −429 T/C polymorphisms are not associated with MS in Mexican population and have no influence on serum sRAGE levels.

Relationship between triglyceride-glucose index and aminotransferase among Royal Thai Army personnel 2017-2021: a serial cross-sectional study

BACKGROUND

Insulin resistance (IR) is a major pathogenesis of nonalcoholic fatty liver disease (NAFLD). The triglyceride-glucose (TyG) index has recently gained popularity to assess IR and NAFLD due to its simplicity and low cost. The aim of the current study was to evaluate the relationship between the TyG index and aminotransferase.

METHODS

A serial cross-sectional study was conducted among 232,235 Royal Thai Army (RTA) personnel aged 35-60 years from 2017-2021. Elevated aminotransferase was defined as ≥ 40 U/L and ≥ 35 U/L among males and females, respectively. A linear regression analysis between the TyG index and log-transformed aminotransferase was performed. High- and low-TyG index groups were divided according to Youden's index cut point for predicting elevated aminotransferase. Multivariable logistic analysis was also utilized to investigate the association between the TyG index and elevated aminotransferase.

RESULTS

The TyG index revealed a dose‒response relationship with log-transformed aminotransferase in both sexes and all age groups. The TyG index was positively associated with the prevalence of elevated aminotransferases. In comparison with the first TyG quartile (< 8.37), participants in the fourth quartile (> 9.23) had a higher chance for elevated ALT (AOR: 2.81, 95% CI: 2.71-2.90 for males and AOR: 4.01, 95% CI: 3.50-4.60 for females, P < 0.001 for both). In the fourth TyG quartile, the prevalence of elevated ALT was 47.8% and 40.2% in the participants aged 35-44 and male participants, respectively.

CONCLUSION

A high TyG index is a novel risk factor for elevated aminotransferase among RTA personnel. Those with a high TyG index should be screened for elevated aminotransferase, particularly males aged 35-44 years.

Interactions between sex and the age at disease onset on cardiometabolic risk factors in a Ghanaian population with type 2 diabetes mellitus: A cross-sectional study

Background and Aim

The are sex differences in cardiometabolic risk factors in type 2 diabetes mellitus (T2DM) as well as the age at disease onset. However, the impact of these risk factors on the age at onset of T2DM is less known in the Ghanaian population. An understanding of the differential impact of cardiometabolic risk factors on the age at onset on T2DM may lead to sex-specific interventions in preventive and management strategies for T2DM.

Methods

The study was cross-sectional from January to June 2019 at the Bolgatanga regional hospital. The study involved 163 T2DM patients (Female = 103, Male = 60), aged from 25 to 70 years. The body mass index (BMI) and the waist-to-hip ratio (WHR) were measured following standardized anthropometric techniques. Fasting venous blood samples were collected and analyzed for cardiometabolic risk factors including total cholesterol (TCHOL) and low-density lipoprotein (LDL) cholesterol.

Results

While TCHOL was higher in males than females (mean [SD]: F = .78 [1.37], M = 4.27 [1.39]) and LDL higher in females than males (mean [SD]: [F = 4.33 [1.22], M = 3.87 [1.26]), these did not, however, attain conventional statistical significance for TCHOL (t = 1.985, p = 0.05) and LDL (t = 2.001, p = 0.05). There were however, significant interactions between sex and the age at disease onset on TCHOL (t = -2.816, p = 0.006) and LDL (t = -2.874, p = 0.005), which were independent of the BMI, WHR and disease duration. The relationship between the age at disease onset and that of TCHOL and LDL were positive in females but negative in males.

Conclusion

Fasting plasma TCHOL and LDL increases with increasing age at onset of T2DM in females but decreases in males. Strategies for the prevention and management of T2DM should be sex-specific. Females with T2DM should be given more attention regarding their fasting plasma cholesterol (total) and LDL cholesterol as they are more likely than men to have increased levels of these lipids with increasing age at disease onset.

Combined Effects of ESRα DNA Methylation and Progesterone on Glucose Metabolic Disorders: The Henan Rural Cohort Study

To explore the independent and combined effects of ESRα methylation and progesterone on impaired fasting glucose (IFG) and type 2 diabetes mellitus (T2DM), a case-control study including 901 subjects was conducted. Generalized linear models were performed to assess the independent and combined effects of ESRα methylation and progesterone on IFG or T2DM. Methylation level of cytosine-phosphoguanine (CpG) 1 in the estrogen receptor α (ESRα) gene was positively related to IFG in both men (odds ratio (OR) (95% confidence interval (CI)): 1.77 (1.05, 3.00)) and postmenopausal women (OR (95% CI): 1.82 (1.09, 3.04)), whereas the association between CpG 1 and T2DM was not significant. Positive associations of progesterone with IFG and T2DM were observed in both men (OR (95% CI): 2.03 (1.18, 3.49) and 3.00 (1.63, 5.52)) and postmenopausal women (OR (95% CI): 2.13 (1.27, 3.56) and 3.30 (1.85, 5.90)). Participants with high CpG 1 methylation plus high progesterone had an increased risk of IFG and T2DM, both in men and postmenopausal women. ESRα methylation and progesterone were positively associated with IFG, and the positive association between progesterone and T2DM was also found. Importantly, we firstly found the combined effects of ESRα methylation and progesterone on IFG and T2DM.

Mammalian models of diabetes mellitus, with a focus on type 2 diabetes mellitus

Although no single animal model replicates all aspects of diabetes mellitus in humans, animal models are essential for the study of energy balance and metabolism control as well as to investigate the reasons for their imbalance that could eventually lead to overt metabolic diseases such as type 2 diabetes mellitus. The most frequently used animal models in diabetes mellitus research are small rodents that harbour spontaneous genetic mutations or that can be manipulated genetically or by other means to influence their nutrient metabolism and nutrient handling. Non-rodent species, including pigs, cats and dogs, are also useful models in diabetes mellitus research. This Review will outline the advantages and disadvantages of selected animal models of diabetes mellitus to build a basis for their most appropriate use in biomedical research.

Estrogen receptors as potential therapeutic target in endometrial cancer

Endometrial cancer (EC) is one of the most common gynecological carcinomas in both developed and developing countries. Majority of the gynecological malignancies are hormonally driven where estrogen signaling acts as an oncogenic signal. Estrogen's effects are mediated via classical nuclear estrogen receptors; estrogen receptor alpha and beta (ERα and ERβ) and a trans-membrane G protein-coupled estrogen receptor (GPR30 and GPER). ERs and GPER through ligand binding triggers multiple downstream signaling pathways causing cell cycle regulation, cell differentiation, migration, and apoptosis in various tissues including endometrium. Although the molecular aspect of estrogen function in ER-mediated signaling is now partly understood, the same is not true for GPER-mediated signaling in endometrial malignancies. Understanding the physiological roles of ERα and GPER in EC biology therefore leads to the identification of some novel therapeutic targets. Here we review the effect of estrogen signaling through ERα-and GPER in EC, major types, and some affordable treatment approaches for endometrial tumor patients which has interesting implications in understanding uterine cancer progression.

Clinical determinants of insulin requirements during treatment of prednisolone-induced hyperglycaemia

AIMS

The optimal treatment of prednisolone-associated hyperglycaemia is unclear, but guidelines recommend using a body weight-based daily insulin dose. This study evaluated how clinical variables were associated with insulin requirements in hospitalised patients with prednisolone-associated hyperglycaemia.

METHODS

In this prospective study, fifty adult inpatients who were taking prednisolone ≥20 mg/day and experienced hyperglycaemia were prescribed a 24-h intravenous insulin infusion. The daily insulin dose required to attain a mean glucose of 8 mmol/L was calculated. The associations between daily insulin dose and clinical variables were assessed.

RESULTS

The participants age was 69 ± 10 years, daily prednisolone dose was 34 ± 10 mg, HbA1c was 7.7 ± 2.0 % (61 ± 10 mmol/mol), 77 % had known type 2 diabetes and 30 % were female. In univariate analysis, weight was associated with daily insulin dose (r² = 0.11, p = 0.024). A multivariate model comprising sex, HbA1c, a prior diagnosis of diabetes, diabetes treatment and weight explained nearly-two thirds of the variability in daily insulin dose (r² = 0.65, p < 0.001).

CONCLUSIONS

In patients with prednisolone-associated hyperglycaemia, calculating insulin doses based on sex, HbA1c, diabetes status and regular diabetes treatment and weight may improve glycaemic control compared to weight-based dosing.

The Association of Metabolic Syndrome and Obesity With Clinical Hip Osteoarthritis in the Study of Osteoporotic Fractures and the Osteoporotic Fractures in Men Study Cohorts

OBJECTIVE

Metabolic dysregulation frequently co-occurs with obesity, which has been shown to be a risk factor for lower extremity osteoarthritis (OA). We evaluated the association between metabolic syndrome (MetS), alone and in combination with obesity, and hip OA.

METHODS

In two parallel cross-sectional analyses, we studied 403 women from the Study of Osteoporotic Fractures (SOF) and 2354 men from the Osteoporotic Fractures in Men (MrOS) study. We used multivariable logistic regression to evaluate associations of obesity (body mass index ≥30 kg/m2 ) and/or MetS (three of five National Cholesterol Education Program Adult Treatment Panel III criteria) with clinical hip OA, defined as a modified Croft score of 2 or more or total hip replacement, and pain or limited range of motion. Our analysis adjusted for demographics.

RESULTS

Approximately 3.5% of SOF women and 5.4% of MrOS men had clinical hip OA. Among women, obesity was not associated with hip OA, yet those with MetS had a 365% higher odds of hip OA (95% CI: 1.37-15.83). Among men, those who had obesity had a 115% higher odds of hip OA (95% CI: 1.39-3.32), yet MetS was not associated with hip OA. There was no interaction between MetS, obesity, and hip OA in either women or men.

CONCLUSION

In women, but not in men, MetS was associated with hip OA. In men, but not in women, obesity was associated with hip OA. These findings suggest that mechanical effects of obesity may predominate in the pathogenesis of hip OA in men, whereas metabolic effects predominate in women.

Novel targets for potential therapeutic use in Diabetes mellitus

Future targets are a promising prospect to overcome the limitation of conventional and current approaches by providing secure and effective treatment without compromising patient compliance. Diabetes mellitus is a fast-growing problem that has been raised worldwide, from 4% to 6.4% (around 285 million people) in past 30 years. This number may increase to 430 million people in the coming years if there is no better treatment or cure is available. Ageing, obesity and sedentary lifestyle are the key reasons for the worsening of this disease. It always had been a vital challenge, to explore new treatment which could safely and effectively manage diabetes mellitus without compromising patient compliance. Researchers are regularly trying to find out the permanent treatment of this chronic and life threatening disease. In this journey, there are various treatments available in market to manage diabetes mellitus such as insulin, GLP-1 agonist, biguanides, sulphonyl ureas, glinides, thiazolidinediones targeting the receptors which are discovered decade before. PPAR, GIP, FFA1, melatonin are the recent targets that already in the focus for developing new therapies in the treatment of diabetes. Inspite of numerous preclinical studies very few clinical data available due to which this process is in its initial phase. The review also focuses on the receptors like GPCR 119, GPER, Vaspin, Metrnl, Fetuin-A that have role in insulin regulation and have potential to become future targets in treatment for diabetes that may be effective and safer as compared to the conventional and current treatment approaches.

Relationship between obstructive sleep apnea, insulin resistance, and metabolic syndrome: a nationwide population-based survey

We aimed to identify the association between obstructive sleep apnea (OSA), insulin resistance (IR), and metabolic syndrome (MetS) in a nationwide population-based sample. A total of 7,900 adults with information on the STOP-Bang score and MetS (3,341 men and 4,469 women) were identified from the dataset of the Korea National Health and Nutrition Examination Survey 2019-2020. The association between OSA, IR, MetS, and its components was estimated using complex sample logistic regression analysis with adjustments for age, body mass index, residence, smoking status, alcohol consumption, household income, education, and the presence of diabetes. Participants with a high OSA score were more likely to have IR (odds ratio [OR] 2.78, 95% confidence interval [CI] 1.96-3.95 in men and OR 2.64, 95% CI 0.55-12.80 in women), MetS (OR 6.05, 95% CI 4.23-8.69 in men and OR 4.20, 95% CI 1.23-15.70 in women), and components of MetS, compared to individuals with a low OSA score. Compared to premenopausal women, postmenopausal women had a more intense association between OSA and IR (OR 1.78, 95% CI 0.13-24.43 for premenopausal women and OR 3.64, 95% CI 0.60-22.28 for postmenopausal women) and MetS (OR 2.58, 95% CI 0.23-29.55 for premenopausal women and OR 5.36, 95% CI 1.42-20.21 for postmenopausal women). OSA was associated with abdominal obesity and hypertension in premenopausal women, while all components of MetS were associated with OSA in postmenopausal women. Further studies are necessary to elucidate the underlying mechanisms of these findings.

Sex-specific differences in the effect of the atherogenic index of plasma on prediabetes and diabetes in the NHANES 2011-2018 population

BACKGROUND

Although a great deal of scientific evidence on the epidemiological risk factors for diabetes and prediabetes has been accumulated, there is still insufficient evidence to explore sex-related differences. The aim of this study was to examine sex-specific differences in the effect of the atherogenic index of plasma (AIP) on prediabetes and diabetes.

METHODS

This cross-sectional study included data from 10099 American adults. The exposure variable was the AIP, which was defined as log10 (triglycerides/high-density lipoprotein cholesterol). The outcome variables included prediabetes and diabetes defined by the 2013 American Diabetes Association guidelines.

RESULTS

The median age (mean ± SD) was 48.51 ± 18.42 years, and the average value (SD) of the AIP was - 0.09 (0.34). The prevalence of prediabetes was 40.24%, and that of diabetes was 21.32%. Overall, there was a significant positive association between the AIP and prediabetes and diabetes (per 1-unit increment in the AIP: OR, 2.49; 95% CI 1.75, 3.54). The multivariate logistic regression model demonstrated that for each unit increment in the AIP, the prediabetes and diabetes prevalence increased 4.96-fold among female participants (OR 4.96, 95% CI 2.68, 9.18) but not among male participants. We found that the AIP was not related to the prevalence of prediabetes or diabetes (OR 1.41; 95% CI 0.87, 2.29) among males. There was an interaction between sex and the AIP (P for interaction < 0.0001).

CONCLUSIONS

This study showed that a higher AIP was significantly associated with an increased prevalence of prediabetes and diabetes, and the above relationships occurred only among women and not men.

G Protein-Coupled Estrogen Receptor GPER: Molecular Pharmacology and Therapeutic Applications

The actions of estrogens and related estrogenic molecules are complex and multifaceted in both sexes. A wide array of natural, synthetic, and therapeutic molecules target pathways that produce and respond to estrogens. Multiple receptors promulgate these responses, including the classical estrogen receptors of the nuclear hormone receptor family (estrogen receptors α and β), which function largely as ligand-activated transcription factors, and the 7-transmembrane G protein-coupled estrogen receptor, GPER, which activates a diverse array of signaling pathways. The pharmacology and functional roles of GPER in physiology and disease reveal important roles in responses to both natural and synthetic estrogenic compounds in numerous physiological systems. These functions have implications in the treatment of myriad disease states, including cancer, cardiovascular diseases, and metabolic disorders. This review focuses on the complex pharmacology of GPER and summarizes major physiological functions of GPER and the therapeutic implications and ongoing applications of GPER-targeted compounds.

Nutritional intake and metabolic parameters of Japanese university students with and without obesity: Sex-specific differences

OBJECTIVE

To establish effective methods of obesity prevention among young adults, we analyzed the relationship between obesity-related food intake and metabolic factors in Japanese university students.

METHODS

We performed a cross-sectional analysis of nutrient intake information and metabolic parameters among 1,206 Gifu University students categorized by body mass index.

RESULTS

The overweight/obesity rate was significantly higher in males. Additionally, among males, the intake of protein, potassium, magnesium, phosphorus, iron, zinc, all lipids/fats, and all metabolic parameters including blood sugar, hemoglobin A1c, uric acid, alanine aminotransferase, aspartate aminotransferase, low-density lipoprotein, high-density lipoprotein, triglycerides, and blood pressure significantly differed between the obese and non-obese groups. However, the same comparison among females revealed no significant differences in nutrient intake and significant differences in only half of the parameters. Among males, energy intake from protein and fat was significantly higher in the obese group, while the percentage of total energy intake from carbohydrates and fat was lower and higher, respectively, among females in the obese group.

CONCLUSIONS

Overeating of protein and fat in males and unbalanced nutrition in females are sex-specific characteristics of Japanese university students with obesity, and metabolic abnormalities in students with obesity are more remarkable in males than in females.

Associations of the Triglyceride and Glucose Index With Hypertension Stages, Phenotypes, and Their Progressions Among Middle-Aged and Older Chinese

Objectives: To assess the associations of the triglyceride and glucose (TyG) index with hypertension stages, phenotypes, and their progressions. Methods: The data originated from the China Health and Retirement Longitudinal Study. Multinomial logistic regression investigated the associations of the TyG index with hypertension stages (stage 1, stage 2), phenotypes (isolated systolic hypertension [ISH], isolated diastolic hypertension [IDH], systolic diastolic hypertension [SDH]), their progressions. Results: Compared with the lowest quartile of TyG index, the highest quartile was associated with increased risks of stage 1 hypertension (OR 1.71, 95% CI 1.38-2.13), stage 2 (1.74, 1.27-2.38), ISH (1.66, 1.31-2.11), IDH (2.52, 1.26-5.05), and SDH (1.65, 1.23-2.23). Similar results were found when TyG index was a continuous variable. From 2011 to 2015, a higher baseline TyG index was associated with normotension to stage 1 (per-unit: 1.39, 1.16-1.65), normotension to ISH (per-unit: 1.28, 1.04-1.56), and normotension to IDH (per-unit: 1.94, 1.27-2.97). Conclusion: The TyG index was associated with different hypertension stages, phenotypes, their progressions, and could be served as a surrogate indicator for early hypertension management.

Damp-heat constitution influences gut microbiota and urine metabolism of Chinese infants

Background

As an increasingly popular complementary and alternative approach for early detection and treatment of disease, traditional Chinese medicine constitution (TCMC) divides human beings into those with balanced constitution (BC) and unbalanced constitution, where damp-heat constitution (DHC) is one of the most unbalanced constitutions. Many studies have been carried out on the microscopic mechanism of constitution classification; however, most of these studies were conducted in adults and rarely in infants. Many diseases are closely related to intestinal microbiota, and metabolites produced by the interaction between microbiota and the body may impact constitution classification. Herein, we investigated the overall constitution distribution in Chinese infants, and analyzed the profiles of gut microbiota and urine metabolites of DHC to further promote the understanding of infants constitution classification.

Methods

General information was collected and TCMC was evaluated by Constitutional Medicine Questionnaires. 1315 questionnaires were received in a cross-sectional study to investigate the constitution composition in Chinese infants. A total of 56 infants, including 30 DHC and 26 BC, were randomly selected to analyze gut microbiota by 16S rRNA sequencing and urine metabolites by UPLC-Q-TOF/MS method.

Results

BC was the most common constitution in Chinese infants, DHC was the second common constitution. The gut microbiota and urine metabolites in the DHC group showed different composition compared to the BC group. Four differential genera and twenty differential metabolites were identified. In addition, the combined marker composed of four metabolites may have the high potential to discriminate DHC from BC with an AUC of 0.765.

Conclusions

The study revealed the systematic differences in the gut microbiota and urine metabolites between infants with DHC and BC. Moreover, the differential microbiota and metabolites may offer objective evidences for constitution classification.

Selective estrogen receptor α and β antagonist aggravate cardiovascular dysfunction in type 2 diabetic ovariectomized female rats

OBJECTIVES

Type 2 diabetes (T2D) is a major risk factor for cardiovascular disorders (CVD), characterized by pathological diastolic as well as systolic dysfunction, ventricular dilation, and cardiomyocyte hypertrophy. CVD is the main cause of death in postmenopausal women. Estradiol (E2) has protective effects on cardiovascular function. The biological effects of E2 are mainly mediated by classical estrogen receptors (ERs). The present study aimed to investigate the cardioprotective effects of classical ERs in ovariectomized (OVX) diabetic female rats.

METHODS

T2D was induced in female rats by high-fat diet feeding along with a low dose of streptozotocin. Then diabetic animals were divided into eight groups: Sham-control, OVX, OVX + Vehicle (Veh), OVX + E2, OVX + E2 + MPP (ERα antagonist), OVX + E2 + PHTPP (ERβ antagonist), OVX + E2 + Veh, OVX + E2 + MPP + PHTPP. Animals received E2, MPP, and PHTPP every four days for 28 days. At the end blood was collected, serum separated, and used for biochemical parameters. Heart tissue was used for cardiac angiotensin II and cytokines measurement.

RESULTS

E2 treatment improved the metabolic disorders caused by T2D, and its receptor antagonists intensified the effects of T2D on the metabolic status. Also, E2 therapy decreased cardiac inflammatory cytokines, and MPP and PHTPP increased cardiac inflammation by increasing TNF-α and IL-6 and decreasing IL-10.

CONCLUSIONS

Classical ERs have protective effects on diabetic hearts by improving the metabolic status and inflammatory balance.

Sex differences in the association between the change in triglyceride‑glucose index and cognitive decline: A population-based cohort study

BACKGROUND

Previous studies indicated that insulin resistance (IR) was related to cognitive decline. This study aimed to investigate whether triglyceride-glucose (TyG) as a surrogate marker of IR can detect the association between IR and cognitive decline, and explore sex-specific association between the longitudinal change in TyG index and cognitive decline in the middle-aged and elderly population in China.

METHODS

Data from the China Health and Retirement Longitudinal Study, which include 2358 females and 2062 males, were used. The TyG index was calculated as ln (fasting triglyceride [mg/dL] × fasting blood glucose [mg/dL] / 2). Cognitive score was measured by word recall test and mental status test. Logistic regression was used to assess the association between change in TyG index and cognitive decline in men and women from 2011 to 2015, respectively. Subgroup analysis by age was also performed.

RESULTS

The fourth quartile of change in TyG index was significantly associated with the increased risk of decline in global cognition compared with the first quartile in men [odds ratio (OR) 1.32, 95 % CI 1.03 to 1.71]. Stratified by age groups, the significant association between TyG index and cognitive decline was only found in men aged under 60 years old (OR 1.51, 95 % CI 1.07 to 2.13).

LIMITATIONS

We only observed the association between TyG index and cognitive decline, but not the severity of the decline.

CONCLUSIONS

The increased TyG index is related to the risk of cognitive decline in men. This study provided new evidence for formulating sex-specific prevention and treatment strategies for cognitive decline.

Establishment and validation of a sensitive LC-MS/MS method for quantification of urinary estrogens in women with gestational diabetes mellitus

Gestational diabetes mellitus (GDM) is not only a threat to the health of pregnant women, but also has profound effects on the health of offspring. Studies have shown that the imbalance of estrogen metabolism is associated with an increased risk of GDM. In this study, an ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method was established and validated for simultaneous quantification of thirteen estrogens in the urine of GDM women, including estrone (E1), estradiol (E2), estriol (E3), and their hydroxylated and methylated metabolites. The method was achieved on a Waters CORTECS C18 column (2.1 mm × 150 mm, 1.6 µm) within 8.5 min. The linear range of thirteen estrogens in urine was 2-1000 pg·mL^-1. Both intra- and inter-day precision for each analyte were less than 15%, with accuracies ranging from 8.3% to 7.3%. The extraction recoveries rate were between 86% and 111%, and stability verification results met the requirements for determination of biological samples. The results suggested that the concentrations of estrogens in all urine samples range from 0.08 to 134.06 (pg·mg^-1 creatinine). The mean levels of E1, E2 and most estrogen metabolites in the urine of GDM women were higher than those in healthy pregnant women. Notably, the mean level of 2-hydroxyestrone (2-OHE1) in GDM women was 13.2-fold lower than that in healthy pregnant women. The types of estrogens with the highest mean levels in the urine of GDM and healthy pregnant women were obviously different, which are 2-methoxyestrone (2MeOE1) and E3, respectively. Our results demonstrated that this specific and sensitive method is suitable for quantifying estrogens in human urine and could provide support for further research on estrogen-related pathological mechanisms in GDM and other diseases.

Sex- and age-specific associations between cardiometabolic risk and white matter brain age in the UK Biobank cohort

Cardiometabolic risk (CMR) factors are associated with accelerated brain aging and increased risk for sex-dimorphic illnesses such as Alzheimer's disease (AD). Yet, it is unknown how CMRs interact with sex and apolipoprotein E-ϵ4 (APOE4), a known genetic risk factor for AD, to influence brain age across different life stages. Using age prediction based on multi-shell diffusion-weighted imaging data in 21,308 UK Biobank participants, we investigated whether associations between white matter Brain Age Gap (BAG) and body mass index (BMI), waist-to-hip ratio (WHR), body fat percentage (BF%), and APOE4 status varied (i) between males and females, (ii) according to age at menopause in females, and (iii) across different age groups in males and females. We report sex differences in associations between BAG and all three CMRs, with stronger positive associations among males compared to females. Independent of APOE4 status, higher BAG (older brain age relative to chronological age) was associated with greater BMI, WHR, and BF% in males, whereas in females, higher BAG was associated with greater WHR, but not BMI and BF%. These divergent associations were most prominent within the oldest group of females (66-81 years), where greater BF% was linked to lower BAG. Earlier menopause transition was associated with higher BAG, but no interactions were found with CMRs. In conclusion, the findings point to sex- and age-specific associations between CMRs and brain age. Incorporating sex as a factor of interest in studies addressing CMR may promote sex-specific precision medicine, consequently improving health care for both males and females.

Estrogen Mediates an Atherosclerotic-Protective Action via Estrogen Receptor Alpha/SREBP-1 Signaling

Menopause is associated with dyslipidemia and an increased risk of cardiovascular disease, the underlying mechanism of dyslipidemia is attributed to an insufficiency of estrogen. In this study, we find that estrogen mediates an atherosclerotic-protective action via estrogen receptor alpha/SREBP-1 signaling. Increased lipid accumulation and low-density lipoprotein (LDL)-uptake in HepG2 cells and THP-1 macrophages were induced by treatment of mixed hyperlipidemic serum from postmenopausal women; 17β-estradiol [estrogen (E2)] (10 nM) administration significantly improved hyperlipidemic profiles, relieved fatty-liver damage and attenuated the plaque area in the heart chamber of high-fat diet (HFD)-fed ovariectomized (OVX) ApoE–/– mice. Expression of sterol regulatory element-binding protein (SREBP)-1 mRNA of circulating leukocytes in postmenopausal women was strongly correlated to the serum E2 level. Exploration of data from the Gene Expression Profiling Interactive Analysis (GEPIA) database revealed that expression of SREBP-1 protein correlated to expression of estrogen receptor (ESR)α protein in the liver, blood and in normal tissue. Genetic overexpression/inhibition of ESRα resulted in increased/decreased SREBP-1 expression as well as attenuated/deteriorated lipid deposition in vitro. An inhibitor of the protein kinase B/mammalian target of rapamycin (AKT/mTOR) pathway, AZD8055, abolished ESRα-induced SREBP-1 expression in HepG2 cells. Moreover, E2 and statin co-treatment significantly reduced lipid accumulation in vitro and hindered the progression of atherosclerosis and fatty-liver damage in OVX ApoE–/– mice. Collectively, our results suggest that estrogen could exerted its atherosclerotic-protective action via ESRα/SREBP-1 signaling. E2 might enhance the cellular sensitivity of statins and could be used as a novel therapeutic strategy against atherosclerotic disorders in postmenopausal women.

Sexual Dimorphism and Sex-2D : 4D Interactions on Fasting Lipid Variables in an Adult Ghanaian Population

Prenatal hormone exposure has been suggested as a correlate of adult circulating estrogen and testosterone. If this observation is true, then prenatal hormone exposure may have an association with lipid homeostasis in adulthood. The study sought to investigate sexual dimorphism and the interactions between the putative marker of prenatal hormone exposure (2D : 4D) and sex on adult fasting plasma lipid variables. The study was cross-sectional from June to December 2021 at the University for Development Studies. The participants were between 18 and 30 years of age and consisted of 206 healthy persons (female = 93, male = 113). The right hand (2D : 4DR), the left hand (2D : 4DL), and the right-left 2D : 4D difference (Dr-l) were measured using computer-assisted analysis. Fasting venous blood samples were collected and analyzed for lipid variables including total cholesterol (TCHOL) and high-density lipoprotein cholesterol (HDL-C). There were no significant differences in the 2D : 4D ratio and lipid variables between males and females. However, after adjusting for age and BMI, the 2D : 4DR (P = 0.014) and the 2D : 4DL (P = 0.007) increased with increasing fasting plasma HDL-C on average. Moreover, there were significant interactions between sex and the 2D : 4DR (P = 0.002) and also, the 2D : 4DL (P = 0.005) on fasting plasma HDL-C. The relationship between HDL-C and the 2D : 4D ratio was positive in females but negative in males. The 2D : 4DR accounted for about 54.9% and 46.0% while the 2D : 4DL accounted for about 48.2% and 14.0% of the variabilities in fasting plasma HDL-C in females and males, respectively. Prenatal hormone exposure may partly account for the sexual dimorphism in adult lipid homeostasis.

Potential Influence of Age and Diabetes Mellitus Type 1 on MSH2 (MutS homolog 2) Expression in a Rat Kidney Tissue

Background: Homeostasis of proliferating tissues is strongly dependent on intact DNA. Both neoplastic and non-neoplastic diseases have been associated with MSH2 (MutS homolog 2, a mismatch repair protein) deficiency. In this study, we examined how age and diabetes mellitus influence the expression of MSH2 in the kidney. Methods: To study the effect of age, three groups of healthy rats were formed: 2 months, 8 months, and 14 months old. Two groups of diabetic rats were formed: 8 months old and 14 months old. Expression of MSH2 in the kidney was studied by quantifying immunofluorescent staining. Results: Age was identified as the main factor that influences MSH2 expression in kidneys. The effect of age followed parabolic dynamics, with peak expression at 8 months of age and similar levels at 2 and 14 months. Diabetes had an age-dependent effect, which manifested as the increase of MSH2 expression in 14-month-old diabetic rats in comparison to healthy animals. Conclusions: Age influences MSH2 expression in the kidney more than diabetes mellitus. Since ageing is a risk factor for kidney neoplasia, downregulation of MSH2 in older rats might represent one of the pro-oncogenic mechanisms of ageing at a molecular level.

The older, the less potential benefit for type 2 diabetes from weight control

BACKGROUND

Although moderate weight loss improves outcomes of type 2 diabetes mellitus (T2DM) in young and middle-aged adults, there is a lack of high-quality evidence to support the strong relationship between obesity and T2DM in older people. This study aims to investigate whether the association of obesity with T2DM changes with aging.

METHODS

In this cross-sectional study, we recruited 63,180 Chinses and US subjects from 3 datasets. Subjects were divided into young & middle-aged (≤59 years), young-old (60-75 years), and old-old (≥75 years). Logistic regression was used to determine the odds ratio (OR) and 95% confidence intervals (95% CI) for the association between obesity and T2DM, stratified by common confounders. A sliding-window based algorithm and restricted cubic splines were used to smoothly estimate the changes with aging.

RESULTS

The OR (95% CI) for the associations between general obesity and T2DM were decreased from the young & middle-aged group (OR, 5.91; 95% CI, 5.33-6.56) to the young-old group (OR, 3.98; 95% CI, 3.56-4.45) and then to the old-old group (OR, 3.06; 95% CI, 2.57-3.66). The trend for this reduced association with aging persisted after stratification by obesity type, region, gender, recruiting time, hypertension, and hyperlipidemia in both Chinese and Americans. We also identified a weakened gender disparity for this association between the young & middle-aged subjects (P for disparity < 0.001) and the old-old group (P for disparity = ~ 0.36).

CONCLUSIONS

The obesity-T2DM association is clearly reduced with aging, which indicates that the elderly may gain fewer potential benefits in weight lose than the younger patients. Considering this attenuated association, as well as the increased incidence of geriatric syndrome in the elderly, clinicians should comprehensively balance the benefits and side effects of weight loss in geriatric T2DM interventions.

Role of Estrogen and Its Receptors in Adipose Tissue Glucose Metabolism in Pre- and Postmenopausal Women

CONTEXT

Reduced estrogen levels in postmenopausal women predispose them to metabolic side effects, including insulin resistance and type 2 diabetes; however, the cellular mechanisms are not well understood.

OBJECTIVE

This work aimed to study the expression of estrogen receptors in adipose tissue from pre- and postmenopausal women and the effects of estradiol (E2) on glucose uptake of adipocytes.

METHODS

Subcutaneous (SAT) and visceral adipose tissue (VAT) obtained from pre- and postmenopausal women (19-51 and 46-75 years old, respectively) were used to measure gene expression of ESR1 and ESR2. SAT tissue was incubated with E2, and glucose uptake and estrogen receptor levels were measured. Polymorphisms in ESR1 and ESR2 were addressed in public databases to identify single nucleotide polymorphisms associated with metabolic traits.

RESULTS

ESR2 expression was lower in pre- vs postmenopausal women, corresponding to lower ESR1:ESR2 gene expression ratio in postmenopausal women. In premenopausal women, the expression of ESR1 was higher in VAT than in SAT. In both pre- and postmenopausal women, ESR2 expression was lower in VAT than in SAT. In late, but not pre- or early postmenopausal women, E2 reduced glucose uptake and GLUT4 protein and increased expression of ESR2. ESR1 polymorphisms were associated with weight, body fat distribution, and total cholesterol, and ESR2 polymorphisms were associated with total cholesterol and triglyceride levels and with body fat percentage.

CONCLUSION

E2 inhibits glucose utilization in human adipocytes in late postmenopausal women. Changes in glucose utilization over time since menopause may be explained by a lower ESR1:ESR2 ratio. This can have clinical implications on the timing of estrogen treatment in postmenopausal women.

Single-nucleotide polymorphisms as important risk factors of diabetes among Middle East population

Diabetes is a chronic metabolic disorder that leads to the dysfunction of various tissues and organs, including eyes, kidneys, and cardiovascular system. According to the World Health Organization, diabetes prevalence is 8.8% globally among whom about 90% of cases are type 2 diabetes. There are not any significant clinical manifestations in the primary stages of diabetes. Therefore, screening can be an efficient way to reduce the diabetic complications. Over the recent decades, the prevalence of diabetes has increased alarmingly among the Middle East population, which has imposed exorbitant costs on the health care system in this region. Given that the genetic changes are among the important risk factors associated with predisposing people to diabetes, we examined the role of single-nucleotide polymorphisms (SNPs) in the pathogenesis of diabetes among Middle East population. In the present review, we assessed the molecular pathology of diabetes in the Middle East population that paves the way for introducing an efficient SNP-based diagnostic panel for diabetes screening among the Middle East population. Since, the Middle East has a population of 370 million people; the current review can be a reliable model for the introduction of SNP-based diagnostic panels in other populations and countries around the world.

Association of fasting plasma glucose change trajectory and risk of hypertension: a cohort study in China

We aimed to assess the association between fasting plasma glucose (FPG) change trajectory and incident hypertension among Chinese population. This cohort study included 11,791 adults aged 18-80 years without hypertension at first entry and who completed at least four follow-ups between 2009 and 2016. Logistic regression was used to estimate odds ratios (ORs) and 95% CIs for the association between FPG change trajectory and probability of hypertension. During a median follow-up of 5.10 years (total person-years 61,887.76), hypertension developed in 2177 participants. After adjusting for baseline potential confounders, the probability of hypertension increased with the increasing FPG change trajectory (adjusted OR (aOR) 1.22, 95% CI 1.07-1.40), bell-shape trajectory (aOR 1.15, 95% CI 1.02-1.30) and other-shape trajectory (aOR 1.13, 95% CI 1.02-1.25) which showed a higher variability of FPG compared to the decreasing group. In addition, the increasing FPG change trajectory was associated with a higher probability of hypertension compared with the decreasing group regardless of age and BMI but was only significant in males and in those with normal FPG at baseline. Our study indicates that the increasing FPG change trajectory determines the highest risk of hypertension, demonstrating the importance of maintaining low and stable levels of FPG, especially in males and in those with normal FPG.

Assessment of Metabolic Regulation by Estrogen Receptors

Estrogens, predominantly 17β-estradiol (E2), are a class of steroid hormones critical for diverse functions in the body both during normal physiology and disease. Primary actions of E2 include reproduction and development of secondary sexual characteristics. In addition, E2 action is involved in the nervous, immune, vascular, muscular, skeletal, and endocrine systems, all of which contribute to multiple aspects of metabolism. The actions of E2 have traditionally been attributed to the classical nuclear estrogen receptors (ERα and ERβ) that largely mediate transcriptional/genomic activities. However, over the last decade, the G protein-coupled estrogen receptor (GPER/GPR30) has become recognized as a mediator of rapid as well as transcriptional actions of E2, employing both in vitro and in vivo approaches. Recent evidence strongly supports the role of GPER in metabolic regulation. Murine genetic knockout (KO) models and pharmacological tools (agonists and antagonists) represent important approaches to understand the mechanisms of E2 action in physiology and disease via GPER. Studies in cells and GPER KO mice have revealed functions for GPER in the regulation of body weight and metabolism. This chapter focuses on methods relevant for the evaluation of metabolic parameters in vivo, ex vivo, and in vitro. We have emphasized glucose homeostasis through the determination of glucose and insulin tolerance, pancreatic islet function, and glucose uptake. In addition, we describe methods of adipocyte isolation, differentiation of preadipocytes, and evaluation of mitochondrial function.

The importance of estradiol for body weight regulation in women

Obesity in women of reproductive age has a number of adverse metabolic effects, including Type II Diabetes (T2D), dyslipidemia, and cardiovascular disease. It is associated with increased menstrual irregularity, ovulatory dysfunction, development of insulin resistance and infertility. In women, estradiol is not only critical for reproductive function, but they also control food intake and energy expenditure. Food intake is known to change during the menstrual cycle in humans. This change in food intake is largely mediated by estradiol, which acts directly upon anorexigenic and orexigenic neurons, largely in the hypothalamus. Estradiol also acts indirectly with peripheral mediators such as glucagon like peptide-1 (GLP-1). Like estradiol, GLP-1 acts on receptors at the hypothalamus. This review describes the physiological and pathophysiological mechanisms governing the actions of estradiol during the menstrual cycle on food intake and energy expenditure and how estradiol acts with other weight-controlling molecules such as GLP-1. GLP-1 analogs have proven to be effective both to manage obesity and T2D in women. This review also highlights the relationship between steroid hormones and women's mental health. It explains how a decline or imbalance in estradiol levels affects insulin sensitivity in the brain. This can cause cerebral insulin resistance, which contributes to the development of conditions such as Parkinson's or Alzheimer's disease. The proper use of both estradiol and GLP-1 analogs can help to manage obesity and preserve an optimal mental health in women by reducing the mechanisms that trigger neurodegenerative disorders.

Monocyte Trafficking and Polarization Contribute to Sex Differences in Meta-Inflammation

Obesity is associated with systemic inflammation and immune cell recruitment to metabolic tissues. Sex differences have been observed where male mice challenged with high fat diet (HFD) exhibit greater adipose tissue inflammation than females demonstrating a role for sex hormones in differential inflammatory responses. Circulating monocytes that respond to dietary lipids and chemokines and produce cytokines are the primary source of recruited adipose tissue macrophages (ATMs). In this study, we investigated sexual dimorphism in biological pathways in HFD-fed ATMs from male and female mice by RNA-seq. We also conducted chemotaxis assays to investigate sex differences in the migration of monocytes isolated from bone marrow from male and female mice toward a dietary saturated lipid - palmitate (PA), and a chemokine - monocyte chemoattractant protein 1 (MCP1), factors known to stimulate myeloid cells in obesity. ATM RNA-Seq demonstrated sex differences of both metabolic and inflammatory activation, including pathways for chemokine signaling and leukocyte trans-endothelial migration. In vivo monocyte transfer studies demonstrated that male monocytes traffic to female adipose tissue to generate ATMs more readily. In chemotaxis assays, lean male monocytes migrated in greater numbers than females toward PA and MCP1. With short-term HFD, male and female monocytes migrated similarly, but in chronic HFD, male monocytes showed greater migration than females upon PA and MCP1 stimulation. Studies with monocytes from toll-like receptor 4 knockout mice (Tlr4^-/- ) demonstrated that both males and females showed decreased migration than WT in response to PA and MCP1 implying a role for TLR4 in monocyte influx in response to meta-inflammation. Overall, these data demonstrate the role of sexual dimorphism in monocyte recruitment and response to metabolic stimuli that may influence meta-inflammation in obesity.

Insulin receptor cleavage induced by estrogen impairs insulin signaling

INTRODUCTION

Soluble insulin receptor (sIR), which is the ectodomain of insulin receptor (IR), is present in human plasma. Plasma sIR levels are positively correlated with blood glucose levels and negatively correlated with insulin sensitivity. An in vitro model of IR cleavage shows that extracellular calpain 2 directly cleaves IR, which generates sIR, and sequential cleavage of the IRβ subunit by γ-secretase impairs insulin signaling in a glucose concentration-dependent manner. Nevertheless, sIR levels vary among subjects with normal glucose levels.

RESEARCH DESIGN AND METHODS

We examined sIR levels of pregnant women throughout gestation. Using an in vitro model, we also investigated the molecular mechanisms of IR cleavage induced by estradiol.

RESULTS

In pregnant women, sIR levels were positively correlated with estrogen levels and significantly increased at late pregnancy independent of glucose levels. Using an in vitro model, estrogen elicited IR cleavage and impaired cellular insulin signaling. Estradiol-induced IR cleavage was inhibited by targeting of calpain 2 and γ-secretase. Estrogen exerted these biological effects via G protein-coupled estrogen receptor, and its selective ligand upregulated calpain 2 expression and promoted exosome secretion, which significantly increased extracellular calpain 2. Simultaneous stimulation of estrogen and high glucose levels had a synergic effect on IR cleavage. Metformin prevented calpain 2 release in exosomes and restored insulin signaling impaired by estrogen.

CONCLUSIONS

Estradiol-induced IR cleavage causes cellular insulin resistance, and its molecular mechanisms are shared with those by high glucose levels. sIR levels at late pregnancy are significantly elevated along with estrogen levels. Therefore, estradiol-induced IR cleavage is preserved in pregnant women and could be part of the etiology of insulin resistance in gestational diabetes mellitus and overt diabetes during pregnancy.