Sex differences in metabolism and cardiometabolic disorders

Heart Rate Mystery Unveiled: Sex Differences in Human Sinoatrial Node Genes and Female Tachycardia

BACKGROUND

Despite over a century of clinical electrocardiographic studies showing that females exhibit a faster resting heart rate (HR), the mechanisms underlying sex differences in HR remain unresolved. Moreover, inappropriate sinus tachycardia primarily affects females, whereas males are at a higher risk for conduction block and atrial fibrillation. We hypothesized that the sexual dimorphism of genes responsible for sinoatrial node (SAN) pacemaking and signaling pathways may contribute to the sex differences in HR and susceptibility to arrhythmias.

METHODS

Human SAN central pacemaker and right atrial tissue were isolated from nondiseased ex vivo donor hearts. Gene expressions were quantified and validated using the transcriptomic panel and quantitative polymerase chain reaction. Gene set enrichment analysis, Ingenuity Pathway Analysis, and human-specific SAN models were utilized to define regulatory mechanisms and functional impacts of sex-biased gene transcription.

RESULTS

We identified differentially expressed region- and sex-specific genes, with gene sets enriched in HR regulation (eg, TBX3, HCN1) and metabolism (eg, ADIPOQ, LEP) pathways in female SAN. In contrast, differential genes and gene sets involved in collagen biosynthetic processes, fibrogenesis (eg, EGR1), and immune response (eg, IL6, CXCL8) pathways were enriched in males SAN and right atrial. Ingenuity Pathway Analysis predicted significant roles for TBX3 and estradiol in the sex-specific expression of genes involved in SAN function. Computational simulations showed that the sex-specific SAN differences in If (HCN1) and ICa,L (CACNA1D) can explain the faster HR in females, with females having a lower threshold for inappropriate sinus tachycardia, whereas males are more vulnerable to sinus arrest.

CONCLUSIONS

The human SAN exhibits region-specific sexual dimorphism in pacemaking gene sets. Higher expression of TBX3 and HCN1 in females may underlie their faster HR and increased susceptibility to inappropriate sinus tachycardia, whereas enriched gene sets related to inflammation and collagen biosynthesis in males may predispose them to conduction impairments and atrial fibrillation risk.

Application of ultrasound for quantitative assessment of body fat mass

BACKGROUND & AIMS

Obesity is a significant health concern associated with various diseases. Accurate measurement of body fat mass (BFM) and local fat thickness (FT) is crucial for health assessment. Ultrasound offers a non-invasive, portable, and cost-effective alternative for measuring FT, but its application for quantitative BFM estimation has not been fully explored. This study aimed to develop and validate a quantitative estimation algorithm for BFM based on local FT measured by ultrasound.

METHODS

A total of 179 volunteers were randomly divided into modeling and verification groups. BFM was measured using bioelectrical impedance analysis (BIA), and FT was measured at 10 sites throughout the body using ultrasound. In the modeling group, the correlation between FT and BFM at different sites was analyzed, and a BFM estimation algorithm based on FT was developed using multiple linear regression. The accuracy of the estimation equation was validated in the verification group.

RESULTS

Men had lower BFM than women (P < 0.05). At most sites, the FT of males was less than that of females (P < 0.001). Significant positive correlations were observed between FT at various sites (site 1 to 10) and BFM across all groups (P < 0.01). The estimation algorithm revealed that FT at 4 sites (intra-abdominal, posterior right perinephric, abdominal subcutaneous, and anterior upper arm) contributed to BFM estimation for men, while two additional sites (pre-peritoneal and posterior lower leg) were valuable for women. The R2 for the algorithms was 0.882 for men and 0.907 for women, with the standard error of estimate of 2.04 kg for both. The intraclass correlation coefficient between ultrasound-derived estimated BFM and the BFM measured by BIA in the verification group was 0.848 (P < 0.001).

CONCLUSIONS

BFM can be quantitatively estimated using a fitting algorithm based on ultrasound-derived local FT.

The Influence of Metabolic and Bariatric Surgery on Cardiovascular Health in Women: A Comprehensive Study

BACKGROUND

Cardiovascular disease (CVD) is the main cause of death in patients with obesity. Bariatric surgery has been shown to promote substantial reduction in carotid intima-media thickness (C-IMT).

AIM

To comprehensively determine the influence of metabolic and bariatric surgery (MBS) on cardiovascular health in women.

METHODS

A total of 24 female patients with a body mass index (BMI) > 35 kg/m2 underwent sleeve gastrectomy (SG), Roux-en-Y gastric bypass (RYGB), or one anastomosis gastric bypass (OAGB), a prospective cohort study in women. C-IMT were evaluated at baseline and 24 months post-MBS.

RESULTS

The results showed a significant reduction in BMI, weight, and C-IMT on the right side 24 months post-MBS (p < 0.001 for BMI and weight and p = 0.004 for C-IMT). There were also significant differences in fasting blood sugar (FBS), triglycerides (TG), total cholesterol, and low-density lipoprotein (LDL) levels. However, high-density lipoprotein (HDL) levels did not show a significant change.

CONCLUSION

The study underscores the potential of MBS in mitigating cardiovascular risk among women with obesity. However, further research is needed to fully understand the impact of MBS on various parameters. The findings highlight the importance of personalized and gender-specific approaches in the management of obesity and related disease.

Tryptophan and Its Metabolite Serotonin Impact Metabolic and Mental Disorders via the Brain-Gut-Microbiome Axis: A Focus on Sex Differences

The crisis of metabolic and mental disorders continues to escalate worldwide. A growing body of research highlights the influence of tryptophan and its metabolites, such as serotonin, beyond their traditional roles in neural signaling. Serotonin acts as a key neurotransmitter within the brain-gut-microbiome axis, a critical bidirectional communication network affecting both metabolism and behavior. Emerging evidence suggests that the gut microbiome regulates brain function and behavior, particularly through microbial influences on tryptophan metabolism and the serotonergic system, both of which are essential for normal functioning. Additionally, sex differences exist in multiple aspects of serotonin-mediated modulation within the brain-gut-microbiome axis, affecting feeding and affective behaviors. This review summarizes the current knowledge from human and animal studies on the influence of tryptophan and its metabolite serotonin on metabolic and behavioral regulation involving the brain and gut microbiome, with a focus on sex differences and the role of sex hormones. We speculate that gut-derived tryptophan and serotonin play essential roles in the pathophysiology that modifies neural circuits, potentially contributing to eating and affective disorders. We propose the gut microbiome as an appealing therapeutic target for metabolic and affective disorders, emphasizing the importance of understanding sex differences in metabolic and behavioral regulation influenced by the brain-gut-microbiome axis. The therapeutic targeting of the gut microbiota and its metabolites may offer a viable strategy for treating serotonin-related disorders, such as eating and affective disorders, with potential differences in treatment efficacy between men and women. This review would promote research on sex differences in metabolic and behavioral regulation impacted by the brain-gut-microbiome axis.

Acute Coronary Syndromes in Women: A Narrative Review of Sex-Specific Characteristics

Acute coronary syndromes (ACSs) encompass a spectrum of life-threatening cardiovascular conditions, including unstable angina (UA) and myocardial infarction. While significant progress has been made in the understanding and management of ACS over the years, it has become increasingly evident that sex-based differences play a pivotal role in the pathophysiology, presentation, and outcomes of these conditions. Despite this recognition, the majority of clinical research in the field has historically focused on male populations, leading to a significant knowledge gap in understanding the unique aspects of ACS in women. This review article aims to comprehensively explore and synthesize the current body of literature concerning the sex-specific characteristics of ACS, shedding light on the epidemiology, risk factors, clinical presentation, diagnostic challenges, treatment strategies, and prognosis in women. By elucidating the distinct aspects of ACS in women, this review intends to foster greater awareness and improved clinical management, ultimately contributing to enhanced cardiovascular care for female patients.

Sex-specific effects of aged polystyrene microplastics on hepatic AMPK pathway activation and lipid droplet accumulation in MAFLD mice

Microplastics (MPs) are environmental pollutants attracting widespread attention due to their environmental omnipresence and potential health effects. MPs undergo ageing in the environment and our previous research found that aged Polystyrene microplastics (PS-MPs) affected lipid metabolism in healthy female mice, but not males. In this study, we examined the effects of aged PS-MP exposure on lipid metabolism in mice with Metabolic Associated Fatty Liver Disease (MAFLD). 14 female and 14 male mice were furnished with a high-fat diet (HFD) for eight weeks to create MAFLD model mice. They were then orally administered aged PS-MPs for four weeks, and changes in the AMP-activated protein kinase signalling pathway were examined in order to determine PS-MP's effect on hepatic metabolism. The outcomes showed that though serum estradiol, inflammatory gene expression and ROS levels increased significantly in both male and female HFD-aged PS-MP groups, hepatic steatosis was attenuated only in the female group. Furthermore, serum ERα, ERβ, AMPKα, acetyl-CoA carboxylase, sterol regulatory element binding protein-1c, and Fas expressions were significantly increased in the MAFLD mice groups compared to the control group. Combining serum E2 levels, AMPK pathway changes, oxidative stress markers, and inflammatory gene levels, aged PS-MPs may stimulate E2 production and mobilize the liver AMPK signalling pathway of both male and female MAFLD mice. However, lipid metabolism is only affected in female MAFLD mice, suggesting other possible mechanisms besides the AMPK pathway may be at play. These results provide a new perspective on the potential health effects of MP exposure in individuals with metabolic disorders such as MAFLD.

Association between appendicular skeletal muscle mass and myocardial glucose uptake measured by 18F-FDG PET

BACKGROUND

Low muscle mass is associated with high insulin resistance and an increased risk of cardiovascular disease. This study aims to determine whether low muscle mass affects the alterations in myocardial substrate metabolism that are associated with the development of cardiovascular disease.

METHOD

The study included 299 individuals (182 men and 117 women) who underwent examination at the Severance Health Check-up Center between January 2018 and February 2019. Myocardial glucose uptake was assessed using [18F]-fluorodeoxyglucose-positron emission tomography (18F-FDG PET/CT) scanning. Direct segmental bioimpedance analysis was used to measure appendicular skeletal muscle mass (ASM).

RESULTS

We analysed men and women separately owing to sex-related body composition differences. ASM/Ht2 was significantly positively correlated with myocardial glucose uptake measured by 18F-FDG PET/CT [ln (SUVheart/liver)] only in men (r = 0.154, P = 0.038 in men; r = -0.042, P = 0.652 in women, respectively). In men, myocardial glucose uptake was significantly associated with ASM/Ht2 even after adjusting for multiple confounders in a multivariable linear regression model (standardized β = 0.397, P = 0.004, in men; β = - 0.051, P = 0.698, in women). In women, age (β = -0.424 P = 0.029) was independent determinants of myocardial glucose uptake.

CONCLUSIONS

In men, ASM was strongly associated with myocardial glucose uptake as measured by 18F-FDG PET/CT. In women, age was significantly correlated with myocardial substrate utilization, but not with ASM.

Integrated serum pharmacochemistry, pharmacokinetics, and network analysis to explore active components of BuShao Tiaozhi Capsule on hyperlipidemia

BuShao Tiaozhi Capsule (BSTZC), a novel drug in China, has been used to treat hyperlipidemia (HLP) in clinical practice for many years. Despite our previous studies suggesting that BSTZC can treat HLP, there is a lack of a rapid and systematic method to explore its active components. Therefore, in this study, we aimed to investigate the active components and mechanisms of BSTZC in treating HLP by integrating serum pharmacology, pharmacokinetics, network analysis, and experimental validation. We first established UPLC fingerprints, calibrated 23 common peaks, and identified 13 common peaks, and the similarity was greater than 0.99 for 10 batches. A total of nine metabolites from BSTZC were identified in serum and considered as PK markers. The pharmacokinetic parameters of the PK markers were compared between the control group and the model group through the pharmacokinetics study to determine the dynamic changes of representative components in rats. Compared with the control group, the Cmax and AUC0→t of OXY, IVT, IVL, and KPF-3-G were significantly higher (P< 0.05); the AUC0→∞ of OXY, PN, and IVT was significantly higher (P< 0.05); and the t1/2 of IVT, SA, and KPF-3-G was significantly different (P< 0.05). In vivo experiments showed that BSTZC and its active components could effectively alleviate lipid metabolism disorders and liver injury, with obvious lipid-lowering effects. Further studies showed that BSTZC alleviated HLP by inhibiting the PI3K/Akt signaling pathway, which was consistent with the results of the network analysis study. Our results revealed the active components and mechanisms of BSTZC in the treatment of HLP, which could provide useful information to guide the clinical application of BSTZC.

Environmental sex reversal in parrotfish does not cause differences in the structure of their gut microbial communities

Parrotfish are a common fish in coral reef areas, but little is known about their gut microbial communities. In addition, parrotfish are capable of sex reversal, usually some males are sexually reversed from females, and it is still not known whether this sex reversal leads to significant changes in gut microbial communities. In this study, we investigated the gut microbial communities of three species of parrotfish including Scarus forsteni (4 females and 4 sex-reversed males), Scarus ghobban (5 females and 5 sex-reversed males), and Hipposcarus longiceps (5 females and 5 sex-reversed males) by using high-throughput sequencing technology. The gut microbial communities of these three species were mainly composed of Pseudomonadota (class Gammaproteobacteria) and Bacillota, while at the family level, they mainly included Vibrionaceae, Burkholderiaceae, Enterobacteriaceae, Streptococcacea, and Erwiniaceae. Although at the genus level, there were a large number of unclassified lineages, the remaining gut microorganisms were mainly composed of Vibrio, Photobacterium, Enterococcus and Lactococcus. Furthermore, we did not find significant differences in gut microbial community structure between the female parrotfish and corresponding female reversed males within each species, even in terms of the structure of gut microbial functional information obtained from 16 S rRNA gene sequence predictions. However, the gut microbial communities of these three species of parrotfish differed significantly not only in their community structure but also in their microbial functional information structure, mainly in terms of aspartate and asparagine biosynthesis, histidine degradation, inositol degradation, heptose biosynthesis, chitin derivatives degradation, enterobactin biosynthesis, and thiazole biosynthesis. Our study provides essential gut microbial community data for understanding the physiology and sex reversal phenomenon in parrotfish.

Interaction between sex and one-hour post-load glucose on metabolic syndrome and its components among Chinese people at high risk of diabetes

BACKGROUND

Recently, International Diabetes Federation position statement has adopted one-hour post-load glucose (1hPG) ≥ 8.6 mmol/L for diagnosing intermediate hyperglycemia. We aimed to assess the association of 1hPG ≥ 8.6 mmol/L with metabolic syndrome (MetS) and its components, as well as interaction between sex and 1hPG ≥ 8.6 mmol/L on MetS and its components in Chinese people at high risk of diabetes.

METHODS

The cross-sectional study was conducted in DaQing city of HeiLongJiang Province, China between August, 2023 and January, 2024. Eligible individuals with fasting glucose of 5.6-6.9 mmol/L and age of 25-55 years in health checkup data in the year of 2023 or with at least one risk factor of diabetes were invited to receive the oral glucose tolerance test and biochemical examinations. Individuals with self-reported presence of diabetes or usage of glucose-lowering medication were excluded. MetS was defined as presence of at least three of the five components according to the Chinese Diabetes Society criteria. Logistic regression was performed to evaluate the association of 1hPG ≥ 8.6 mmol/L with MetS and its components. Additive interaction was estimated using the relative excess risk due to interaction, attributable proportion due to interaction (AP), and synergy index.

RESULTS

A total of 2419 subjects comprising 1465 men (60.6%) with a mean age of 45.77 ± 6.20 years were included, and the prevalence of MetS was 46.8%, with 59.7% in men and 27.1% in women. 1hPG ≥ 8.6 mmol/L was associated with MetS (aOR = 4.40, 95% CI 3.26-6.01), elevated blood pressure (aOR = 1.46, 95% CI 1.13-1.89), hyperglycemia (aOR = 15.46, 95% CI 11.56-20.98), and reduced HDL-C (aOR = 1.51, 95% CI 1.07-2.15) in the overall population, whereas no significant association between 1hPG ≥ 8.6 mmol/L and elevated blood pressure in men (aOR = 1.36, 95% CI 0.97-1.91) or dyslipidemia in women (elevated TG: aOR = 0.81, 95% CI 0.47-1.39; reduced HDL-C: aOR = 1.08, 95% CI 0.49-2.37). Additive interaction effect between sex and 1hPG ≥ 8.6 mmol/L on MetS was observed, with 31% attributed to the interaction effect between men and 1hPG ≥ 8.6 mmol/L (AP = 0.31, 95% CI 0.06-0.49).

CONCLUSIONS

There was an additive interaction effect between sex and 1hPG on MetS among Chinese people at high risk of diabetes. 1hPG test and sex-specific strategies should be taken into consideration in cardiometabolic disorder identification and management.

Biological Sex Is an Effect Modifier of Allergen-Mediated Alteration of the Lung Proteome

Asthma exhibits a distinct sex bias in the disease prevalence, severity, and response to therapy. However, sex-related differences in alterations of the lung proteome mediated by aeroallergens critical in asthma, such as house dust mites (HDM), remain unknown. In this study, we define sex-related differences in the lung proteome using an HDM-challenged mouse model by 1D LC-MS/MS. Sex-disaggregated data analysis showed that 406 proteins were uniquely altered in females, 273 proteins were uniquely altered in males, and 414 proteins were altered in both females and males in response to HDM. In a linear mixed model analysis, sex modified the HDM exposure effect for 163 proteins, i.e., a significant sex:exposure interaction was identified in 84 proteins in females and 35 proteins in males. Of these, 12 proteins showed a significant sex effect in both female and male lungs. We further selected 3 proteins Tjp1, Lamtor1, and G3BP2 for independent confirmation studies. Our findings detail the sex-specific lung proteome in response to an aeroallergen critical in asthma and demonstrate that sex is a significant effect modifier of HDM response. These results will serve as a valuable resource for delineating sex-specific mechanisms in aeroallergen-driven responses in asthma research.

Sex differences in shared genetic determinants between severe mental disorders and metabolic traits

High rates of metabolic risk factors contribute to premature mortality in patients with severe mental disorders, but the molecular underpinnings of this association are largely unknown. We performed the first analysis on shared genetic factors between severe mental disorders and metabolic traits considering the effect of sex. We applied an integrated analytical pipeline on the largest sex-stratified genome-wide association datasets available for bipolar disorder (BD), major depressive disorder (MDD), schizophrenia (SZ), and for body mass index (BMI) and waist-to-hip ratio (WHR) (all including participants of European origin). We observed extensive genetic overlap between all severe mental disorders and variants associated with BMI in women or men and identified several genetic loci shared between BD, or SZ and BMI in women (24 and 91, respectively) or men (13 and 208, respectively), with mixed directions of effect. A large part of the identified genetic variants showed sex differences in terms of location, genes modulated in adipose tissue and/or brain regions, and druggable targets. By providing a complete picture of disorder specific and cross-disorder shared genetic determinants, our results highlight potential sex differences in the genetic liability to metabolic comorbidities in patients with severe mental disorders.

Subregion-specific transcriptomic profiling of rat brain reveals sex-distinct gene expression impacted by adolescent stress

Stress during adolescence clearly impacts brain development and function. Sex differences in adolescent stress-induced or exacerbated emotional and metabolic vulnerabilities could be due to sex-distinct gene expression in hypothalamic, limbic, and prefrontal brain regions. However, adolescent stress-induced whole-genome expression changes in key subregions of these brain regions were unclear. In this study, female and male adolescent Sprague Dawley rats received one-hour restraint stress daily from postnatal day (PD) 32 to PD44. Corticosterone levels, body weights, food intake, body composition, and circulating adiposity and sex hormones were measured. On PD44, brain and blood samples were collected. Using RNA-sequencing, sex-specific differences in stress-induced differentially expressed (DE) genes were identified in subregions of the hypothalamus, limbic system, and prefrontal cortex. Canonical pathways reflected well-known sex-distinct maladies and diseases, substantiating the therapeutic potential of the DE genes found in the current study. Thus, we proposed specific sex distinct, adolescent stress-induced transcriptional changes found in the current study as examples of the molecular bases for sex differences witnessed in stress induced or exacerbated emotional and metabolic disorders. Future behavioral studies and single-cell studies are warranted to test the implications of the DE genes identified in this study in sex-distinct stress-induced susceptibilities.

Peripheral Blood Cells From Older Adults Exhibit Sex-Associated Differences in Mitochondrial Function

Blood-based mitochondrial bioenergetic profiling is a feasible, economical, and minimally invasive approach that can be used to examine mitochondrial function and energy metabolism in human subjects. In this study, we use 2 complementary respirometric techniques to evaluate mitochondrial bioenergetics in both intact and permeabilized peripheral blood mononuclear cells (PBMCs) and platelets to examine sex dimorphism in mitochondrial function among older adults. Employing equal numbers of PBMCs and platelets to assess mitochondrial bioenergetics, we observe significantly higher respiration rates in female compared to male participants. Mitochondrial bioenergetic differences remain significant after controlling for independent parameters including demographic parameters (age, years of education), and cognitive parameters (mPACC5, COGDX). Our study illustrates that circulating blood cells, immune cells in particular, have distinctly different mitochondrial bioenergetic profiles between females and males. These differences should be taken into account as blood-based bioenergetic profiling is now commonly used to understand the role of mitochondrial bioenergetics in human health and aging.

Sexual dimorphism in the gut microbiota and sexual dimorphism in chronic diseases: Association or causation?

Understanding the sexual dimorphism in diseases is essential to investigate the pathogenesis of some chronic diseases (e.g., autoimmune diseases, etc). The gut microbiota has been found to show a notable impact on the pathology of several chronic diseases in recent years. Intriguingly, the composition of the gut microbiota varies between sexes. Here, we reviewed 'facts and fiction' regarding sexual dimorphism in chronic diseases and sexual dimorphism in the gut microbiota respectively. The association and causative relationship between them aiming to elucidate the pathological mechanisms of sexual dimorphism in chronic diseases were further explored. The development of gender-special food products based on the sexual dimorphism in the gut microbiota were recommended, which would be beneficial to facilitating the personalized treatment.

Body mass index and waist circumference trajectories across the life course and birth cohorts, 1996-2015 Malaysia: sex and ethnicity matter

OBJECTIVE

The global obesity epidemic remains a significant threat to public health and the economy. Age-period-cohort (APC) analysis is one method to model the trajectory of obesity. However, there is scarce published evidence of such analyses among the South East Asian population. This study aims to explore the sex and ethnic variations of BMI and waist circumference trajectories over time among non-institutionalized Malaysian adults aged 18 to 80 years.

METHODS

Data from four population-based National Health and Morbidity Surveys conducted in 1996, 2006, 2010, and 2015 were pooled. Hierarchical Age-Period-Cohort (HAPC) analysis explored the trajectories of BMI and waist circumference across the life course and birth cohorts by sex and ethnicity. These models assumed no period effect.

RESULTS

Generally, BMI and waist circumference trajectories increased across age and birth cohorts. These trajectories varied by sex and ethnicity. Females have more profound increasing BMI and waist circumference trajectories than their male counterparts as they age and as cohort recency increases. Chinese have less profound BMI and waist circumference increases across the life course and birth cohorts than other ethnic groups.

CONCLUSIONS

The profound increasing cohort trajectories of obesity, regardless of sex and ethnicity, are alarming. Future studies should focus on identifying factors associated with the less profound cohort effect among the Chinese to reduce the magnitude of trajectories in obesity, particularly among future generations.

Clustering of lifestyle behaviours and analysis of their associations with MAFLD: a cross-sectional study of 196,515 individuals in China

BACKGROUND

The aggregation of lifestyle behaviours and their association with metabolic-associated fatty liver disease (MAFLD) remain unclear. We identified lifestyle patterns and investigated their association with the risk of developing MAFLD in a sample of Chinese adults who underwent annual physical examinations.

METHODS

Annual physical examination data of Chinese adults from January 2016 to December 2020 were used in this study. We created a scoring system for lifestyle items combining a statistical method (multivariate analysis of variance) and clinical expertise (Delphi method). Subsequently, principal component analysis and two-step cluster analysis were implemented to derive the lifestyle patterns of men and women. Binary logistic regression analysis was used to explore the prevalence risk of MAFLD among lifestyle patterns stratified by sex.

RESULTS

A total of 196,515 subjects were included in the analysis. Based on the defined lifestyle scoring system, nine and four lifestyle patterns were identified for men and women, respectively, which included "healthy or unhealthy" patterns and mixed patterns containing a combination of healthy and risky lifestyle behaviours. This study showed that subjects with an unhealthy or mixed pattern had a significantly higher risk of developing MAFLD than subjects with a relatively healthy pattern, especially among men.

CONCLUSIONS

Clusters of unfavourable behaviours are more prominent in men than in women. Lifestyle patterns, as important factors influencing the development of MAFLD, show significant sex differences in the risk of MAFLD. There is a strong need for future research to develop targeted MAFLD interventions based on the identified behavioural clusters by sex stratification.

High-frequency variants in PKA signaling-related genes within a large pediatric cohort with obesity or metabolic abnormalities

Introduction

Pediatric obesity has steadily increased in recent decades. Large-scale genome-wide association studies (GWAS) conducted primarily in Eurocentric adult populations have identified approximately 100 loci that predispose to obesity and type II diabetes. GWAS in children and individuals of non-European descent, both disproportionately affected by obesity, are fewer. Rare syndromic and monogenic obesities account for only a small portion of childhood obesity, so understanding the role of other genetic variants and their combinations in heritable obesities is key to developing targeted and personalized therapies. Tight and responsive regulation of the cAMP-dependent protein kinase (PKA) signaling pathway is crucial to maintaining healthy energy metabolism, and mutations in PKA-linked genes represent the most common cause of monogenic obesity.

Methods

For this study, we performed targeted exome sequencing of 53 PKA signaling-related genes to identify variants in genomic DNA from a large, ethnically diverse cohort of obese or metabolically challenged youth.

Results

We confirmed 49 high-frequency variants, including a novel variant in the PDE11A gene (c.152C>T). Several other variants were associated with metabolic characteristics within ethnic groups.

Discussion

We conclude that a PKA pathway-specific variant search led to the identification of several new genetic associations with obesity in an ethnically diverse population.

The Power of the Heterogeneous Stock Rat Founder Strains in Modeling Metabolic Disease

Metabolic diseases are a host of complex conditions, including obesity, diabetes mellitus, and metabolic syndrome. Endocrine control systems (eg, adrenals, thyroid, gonads) are causally linked to metabolic health outcomes. N/NIH Heterogeneous Stock (HS) rats are a genetically heterogeneous outbred population developed for genetic studies of complex traits. Genetic mapping studies in adult HS rats identified loci associated with cardiometabolic risks, such as glucose intolerance, insulin resistance, and increased body mass index. This study determined underappreciated metabolic health traits and the associated endocrine glands within available substrains of the HS rat founders. We hypothesize that the genetic diversity of the HS rat founder strains causes a range of endocrine health conditions contributing to the diversity of cardiometabolic disease risks. ACI/EurMcwi, BN/NHsdMcwi, BUF/MnaMcwi, F344/StmMcwi, M520/NRrrcMcwi, and WKY/NCrl rats of both sexes were studied from birth until 13 weeks of age. Birth weight was recorded, body weight was measured weekly, metabolic characteristics were assessed, and blood and tissues were collected. Our data show wide variation in endocrine traits and metabolic health states in ACI, BN, BUF, F344, M520, and WKY rat strains. This is the first report to compare birth weight, resting metabolic rate, endocrine gland weight, hypothalamic-pituitary-thyroid axis hormones, and brown adipose tissue weight in these rat strains. Importantly, this work unveils new potential for the HS rat population to model early life adversity and adrenal and thyroid pathophysiology. The HS population likely inherited risk alleles for these strain-specific traits, making the HS rat a powerful model to investigate interventions on endocrine and metabolic health.

Sexual Dimorphism in Cardiometabolic Diseases: The Role of AMPK

Cardiovascular diseases (CVDs) are the leading cause of mortality and disability among both males and females. The risk of cardiovascular diseases is heightened by the presence of a risk factor cluster of metabolic syndrome, covering obesity and obesity-related cardiometabolic risk factors such as hypertension, glucose, and lipid metabolism dysregulation primarily. Sex hormones contribute to metabolic regulation and make women and men susceptible to obesity development in a different manner, which necessitates sex-specific management. Identifying crucial factors that protect the cardiovascular system is essential to enhance primary and secondary prevention of cardiovascular diseases and should be explicitly studied from the perspective of sex differences. It seems that AMP-dependent protein kinase (AMPK) may be such a factor since it has the protective role of AMPK in the cardiovascular system, has anti-diabetic properties, and is regulated by sex hormones. Those findings highlight the potential cardiometabolic benefits of AMPK, making it an essential factor to consider. Here, we review information about the cross-talk between AMPK and sex hormones as a critical point in cardiometabolic disease development and progression and a target for therapeutic intervention in human disease.

Sex-specific responses in glucose-insulin homeostasis and lipoprotein-lipid components after high-dose supplementation with marine n-3 PUFAs in abdominal obesity: a randomized double-blind crossover study

Background

Clinical studies on effects of marine-derived omega-3 (n-3) polyunsaturated fatty acids (PUFAs), mainly eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), and the plant-derived omega-6 (n-6) PUFA linoleic acid (LA) on lipoprotein-lipid components and glucose-insulin homeostasis have shown conflicting results, which may partly be explained by differential responses in females and males. However, we have lacked data on sexual dimorphism in the response of cardiometabolic risk markers following increased consumption of n-3 or n-6 PUFAs.

Objective

To explore sex-specific responses after n-3 (EPA + DHA) or n-6 (LA) PUFA supplementation on circulating lipoprotein subfractions, standard lipids, apolipoproteins, fatty acids in red blood cell membranes, and markers of glycemic control/insulin sensitivity among people with abdominal obesity.

Methods

This was a randomized double-blind crossover study with two 7-week intervention periods separated by a 9-week washout phase. Females (n = 16) were supplemented with 3 g/d of EPA + DHA (fish oil) or 15 g/d of LA (safflower oil), while males (n = 23) received a dose of 4 g/d of EPA + DHA or 20 g/d of LA. In fasting blood samples, we measured lipoprotein particle subclasses, standard lipids, apolipoproteins, fatty acid profiles, and markers of glycemic control/insulin sensitivity.

Results

The between-sex difference in relative change scores was significant after n-3 for total high-density lipoproteins (females/males: -11%*/-3.3%, p = 0.036; *: significant within-sex change), high-density lipoprotein particle size (+2.1%*/-0.1%, p = 0.045), and arachidonic acid (-8.3%*/-12%*, p = 0.012), and after n-6 for total (+37%*/+2.1%, p = 0.041) and small very-low-density lipoproteins (+97%*/+14%, p = 0.021), and lipoprotein (a) (-16%*/+0.1%, p = 0.028). Circulating markers of glucose-insulin homeostasis differed significantly after n-3 for glucose (females/males: -2.1%/+3.9%*, p = 0.029), insulin (-31%*/+16%, p < 0.001), insulin C-peptide (-12%*/+13%*, p = 0.001), homeostasis model assessment of insulin resistance index 2 (-12%*/+14%*, p = 0.001) and insulin sensitivity index 2 (+14%*/-12%*, p = 0.001), and quantitative insulin sensitivity check index (+4.9%*/-3.4%*, p < 0.001).

Conclusion

We found sex-specific responses after high-dose n-3 (but not n-6) supplementation in circulating markers of glycemic control/insulin sensitivity, which improved in females but worsened in males. This may partly be related to the sex differences we observed in several components of the lipoprotein-lipid profile following the n-3 intervention.

Clinical trial registration

https://clinicaltrials.gov/, identifier [NCT02647333].

Sex-Related Differences in the Pharmacological Response in SARS-CoV-2 Infection, Dyslipidemia, and Diabetes Mellitus: A Narrative Review

Pharmacological responses vary by sex in several illnesses. This narrative review summarizes sex variations in pharmaceutical response in SARS-CoV-2 infection, dyslipidemia, and diabetes mellitus. Infection with SARS-CoV-2 is more severe and deadly in men than women. This may be attributed to immunological responses, genetics, and hormones. Some research shows that men may respond better to genomic vaccinations and females to antiviral medications such as remdesivir (Moderna and Pfizer-BioNTech). In dyslipidemia, women tend to have greater HDL-C and lower LDL-C than men. Some studies show that females may need lower statin dosages than men to obtain equal LDL-C reductions. Ezetimibe co-administered with a statin significantly improved lipid profile indicators in men compared to women. Statins reduce dementia risk. Atorvastatin decreased dementia risk in males (adjusted HR 0.92, 95% CI 0.88-0.97), whereas lovastatin lowered dementia risk in women (HR 0.74, 95% CI 0.58-0.95). In diabetes mellitus, evidence suggests that females may have a higher risk of developing certain complications such as diabetic retinopathy and neuropathy, despite having lower rates of cardiovascular disease than males. This could be the result of differences in hormonal influences and genetic factors. Some research shows females may respond better to oral hypoglycemic medications such as metformin. In conclusion, sex-related differences in pharmacological response have been observed in SARS-CoV-2 infection, dyslipidemia, and diabetes mellitus. Further research is needed to better understand these differences and to develop personalized treatment strategies for males and females with these conditions.

Sex-based differences in risk of cardiovascular disease development and cardiovascular risk factors among individuals with hypertension: A cross-sectional study from primary care facilities

BACKGROUND

Over the last two decades, the understanding of cardiovascular disease (CVD) has expanded in Asian countries. Despite this progress, there have been limited investigations into sex-based differences in the development of CVD and cardiovascular risk factors (CVRFs).

AIM

We investigated whether males and females with hypertension had different risks of developing CVD and CVRFs.

METHODS

We used a stratified multi-stage sampling design involving 15 primary care centers in Thailand. We recruited 1,448 individuals aged 35-74 years old. The Framingham cardiovascular risk algorithm was used to determine the risk of CVD development.

RESULTS

Female patients were overall more likely to have lower CVD risk scores. However, they demonstrated higher scores in the moderate-risk (p < 0.001) and high-risk (p < 0.001) groups as compared with males. One in four females was at a high risk of developing CVD. Females had higher rates of all CVRFs against males across sub-risk groups, with the highest odds ratio observed in the high-risk group, which persisted after adjusting for covariations. Overall, female patients had higher rates of diabetes, hyperlipidemia, obesity, and abdominal obesity as compared with males. Females in the overall group had a lower prevalence of uncontrolled hypertension than males, in contrast to the high-risk group. Female patients also had a lower prevalence of cigarette smoking and alcohol consumption than males.

CONCLUSION

There is evidence of sex-based differences in the risk of CVD development in hypertensive individuals. The interaction of CVRFs with a high risk of developing CVD was noted in females.

Evaluating adverse effects of environmental agents in food: a brief critique of the US FDA's criteria

BACKGROUND

In the US, the Food and Drug Administration (US FDA) is charged with protecting the safety of food from both pathogens and chemicals used in food production and food packaging. To protect the public in a transparent manner, the FDA needs to have an operational definition of what it considers to be an "adverse effect" so that it can take action against harmful agents. The FDA has recently published two statements where, for the first time, it defines the characteristics of an adverse effect that it uses to interpret toxicity studies.

OBJECTIVE

In this brief review, we examine two recent actions by the FDA, a proposed rule regarding a color additive used in vegetarian burgers and a decision not to recall fish with high levels of scombrotoxin. We evaluated the FDA's description of the criteria used to determine which outcomes should be considered adverse.

OVERVIEW

We describe three reasons why the FDA's criteria for "adverse effects" is not public health protective. These include an unscientific requirement for a monotonic dose response, which conflates hazard assessment and dose response assessment while also ignoring evidence for non-linear and non-monotonic effects for many environmental agents; a requirement that the effect be observed in both sexes, which fails to acknowledge the many sex- and gender-specific effects on physiology, disease incidence and severity, and anatomy; and a requirement that the effects are irreversible, which does not acknowledge the role of exposure timing or appreciate transgenerational effects that have been demonstrated for environmental chemicals.

CONCLUSIONS

The FDA's criteria for identifying adverse effects are inadequate because they are not science-based. Addressing this is important, because the acknowledgement of adverse effects is central to regulatory decisions and the protection of public health.

Glucose metabolism after bariatric surgery: implications for T2DM remission and hypoglycaemia

Although promising therapeutics are in the pipeline, bariatric surgery (also known as metabolic surgery) remains our most effective strategy for the treatment of obesity and type 2 diabetes mellitus (T2DM). Of the many available options, Roux-en-Y gastric bypass (RYGB) and vertical sleeve gastrectomy (VSG) are currently the most widely used procedures. RYGB and VSG have very different anatomical restructuring but both surgeries are effective, to varying degrees, at inducing weight loss and T2DM remission. Both weight loss-dependent and weight loss-independent alterations in multiple tissues (such as the intestine, liver, pancreas, adipose tissue and skeletal muscle) yield net improvements in insulin resistance, insulin secretion and insulin-independent glucose metabolism. In a subset of patients, post-bariatric hypoglycaemia can develop months to years after surgery, potentially reflecting the extreme effects of potent glucose reduction after surgery. This Review addresses the effects of bariatric surgery on glucose regulation and the potential mechanisms responsible for both the resolution of T2DM and the induction of hypoglycaemia.

Sex differences in interindividual gene expression variability across human tissues

Understanding phenotypic sex differences has long been a goal of biology from both a medical and evolutionary perspective. Although much attention has been paid to mean differences in phenotype between the sexes, little is known about sex differences in phenotypic variability. To gain insight into sex differences in interindividual variability at the molecular level, we analyzed RNA-seq data from 43 tissues from the Genotype-Tissue Expression project (GTEx). Within each tissue, we identified genes that show sex differences in gene expression variability. We found that these sex-differentially variable (SDV) genes are associated with various important biological functions, including sex hormone response, immune response, and other signaling pathways. By analyzing single-cell RNA sequencing data collected from breast epithelial cells, we found that genes with sex differences in gene expression variability in breast tissue tend to be expressed in a cell-type-specific manner. We looked for an association between SDV expression and Graves' disease, a well-known heavily female-biased disease, and found a significant enrichment of Graves' associated genes among genes with higher variability in females in thyroid tissue. This suggests a possible role for SDV expression in sex-biased disease. We then examined the evolutionary constraints acting on genes with sex differences in variability and found that they exhibit evidence of increased selective constraint. Through analysis of sex-biased eQTL data, we found evidence that SDV expression may have a genetic basis. Finally, we propose a simple evolutionary model for the emergence of SDV expression from sex-specific constraints.

Sex-specific differences in metabolic outcomes after sleeve gastrectomy and intermittent fasting in obese middle-aged mice

Despite the high prevalence of obesity among middle-aged subjects, it is unclear if sex differences in middle age affect the metabolic outcomes of obesity therapies. Accordingly, in this study, middle-aged obese female and male mice were randomized to one of three groups: sleeve gastrectomy (SG), sham surgery ad libitum (SH-AL), or sham surgery with weight matching to SG through intermittent fasting with calorie restriction (SH-IF). Comprehensive measures of energy and glucose homeostasis, including energy intake, body weight, energy expenditure, glucose and insulin tolerance, and interscapular brown adipose tissue (iBAT) sympathetic innervation density were obtained. At the end of 8 wk, SG and SH-IF females had better metabolic outcomes than their male counterparts. SG females had improved weight loss maintenance, preservation of fat-free mass (FFM), higher total energy expenditure (TEE), normal locomotor activity, and reduced plasma insulin and white adipose tissue (WAT) inflammatory markers. SH-IF females also had lower plasma insulin and WAT inflammatory markers, and higher TEE than SH-IF males, despite their lower FFM. In addition, SH-IF females had higher iBAT sympathetic nerve density than SG and SH-AL females, whereas there were no differences among males. Notably, SH-IF mice of both sexes had the most improved glucose tolerance, highlighting the benefits of fasting, irrespective of weight loss. Results from this study demonstrate that in middle-aged obese mice, female sex is associated with better metabolic outcomes after SG or IF with calorie restriction. Clinical studies are needed to determine if sex differences should guide the choice of obesity therapies.NEW & NOTEWORTHY SG or IF with calorie restriction produces better metabolic outcomes in females than in males. IF with calorie restriction prevents metabolic adaptation, even in the face of fat-free mass loss. IF with calorie restriction in females only, is associated with increased iBAT sympathetic innervation, which possibly mitigates reductions in energy expenditure secondary to fat-free mass loss. Lastly, IF leads to better glucose homeostasis than SG, irrespective of sex.

Sex Differences in Cardiovascular Impact of Early Metabolic Impairment: Interplay between Dysbiosis and Adipose Inflammation

The evolving view of gut microbiota has shifted toward describing the colonic flora as a dynamic organ in continuous interaction with systemic physiologic processes. Alterations of the normal gut bacterial profile, known as dysbiosis, has been linked to a wide array of pathologies. Of particular interest is the cardiovascular-metabolic disease continuum originating from positive energy intake and high-fat diets. Accumulating evidence suggests a role for sex hormones in modulating the gut microbiome community. Such a role provides an additional layer of modulation of the early inflammatory changes culminating in negative metabolic and cardiovascular outcomes. In this review, we will shed the light on the role of sex hormones in cardiovascular dysfunction mediated by high-fat diet-induced dysbiosis, together with the possible involvement of insulin resistance and adipose tissue inflammation. Insights into novel therapeutic interventions will be discussed as well. SIGNIFICANCE STATEMENT: Increasing evidence implicates a role for dysbiosis in the cardiovascular complications of metabolic dysfunction. This minireview summarizes the available data on the sex-based differences in gut microbiota alterations associated with dietary patterns leading to metabolic impairment. A role for a differential impact of adipose tissue inflammation across sexes in mediating the cardiovascular detrimental phenotype following diet-induced dysbiosis is proposed. Better understanding of this pathway will help introduce early approaches to mitigate cardiovascular deterioration in metabolic disease.

Characterizing human mesenchymal stromal cells' immune-modulatory potency using targeted lipidomic profiling of sphingolipids

Cell therapies are expected to increase over the next decade owing to increasing demand for clinical applications. Mesenchymal stromal cells (MSCs) have been explored to treat a number of diseases, with some successes in early clinical trials. Despite early successes, poor MSC characterization results in lessened therapeutic capacity once in vivo. Here, we characterized MSCs derived from bone marrow (BM), adipose tissue and umbilical cord tissue for sphingolipids (SLs), a class of bioactive lipids, using liquid chromatography/tandem mass spectrometry. We found that ceramide levels differed based on the donor's sex in BM-MSCs. We detected fatty acyl chain variants in MSCs from all three sources. Linear discriminant analysis revealed that MSCs separated based on tissue source. Principal component analysis showed that interferon-γ-primed and unstimulated MSCs separated according to their SL signature. Lastly, we detected higher ceramide levels in low indoleamine 2,3-dioxygenase MSCs, indicating that sphingomyelinase or ceramidase enzymatic activity may be involved in their immune potency.

Ultrasonographic measurement of abdominal and gluteal-femoral fat thickness as a predictor for android/gynoid ratio

OBJECTIVE

To evaluate the use of ultrasonography (US) as an alternative to dual-energy x-ray absorptiometry (DXA) to predict the percentage ratio of android/gynoid (A/G) fat mass.

METHODS

This was a cross-sectional study. Twenty-eight participants included in the study underwent whole-body DXA examinations and the A/G ratio was calculated. Soft-tissue US was performed in several standardised anthropometric areas of the body. Correlation analysis between abdominal and gluteal-femoral fat thickness based on US and A/G ratio was conducted using the Pearson or Spearman test depending on the data normality. Multiple regression analysis using the backward stepwise method was performed to establish an equation for estimating the A/G ratio.

RESULTS

There was a strong and significant correlation between fat thickness in the six anthropometric areas and the A/G ratio in female participants. The analysis revealed three anthropometric areas: upper abdomen (S4), lower abdomen (S5), and mid-xiphoid-umbilical region (S7), that can accurately predict the A/G ratio by 82.3%. (P < 0.05). However, no such correlation was found in male participants.

CONCLUSIONS

US measurement of fat thickness can predict A/G ratio in the female population. However, this method is not recommended for men.

Global Proteome Profiling of the Temporal Cortex of Female Rats Exposed to Chronic Stress and the Western Diet

The increasing consumption of highly processed foods with high amounts of saturated fatty acids and simple carbohydrates is a major contributor to the burden of overweight and obesity. Additionally, an unhealthy diet in combination with chronic stress exposure is known to be associated with the increased prevalence of central nervous system diseases. In the present study, the global brain proteome approach was applied to explore protein alterations after exposure to the Western diet and/or stress. Female adult rats were fed with the Western diet with human snacks and/or subjected to chronic stress induced by social instability for 12 weeks. The consumption of the Western diet resulted in an obese phenotype and induced changes in the serum metabolic parameters. Consuming the Western diet resulted in changes in only 5.4% of the proteins, whereas 48% of all detected proteins were affected by chronic stress, of which 86.3% were down-regulated due to this exposure to chronic stress. However, feeding with a particular diet modified stress-induced changes in the brain proteome. The down-regulation of proteins involved in axonogenesis and mediating the synaptic clustering of AMPA glutamate receptors (Nptx1), as well as proteins related to metabolic processes (Atp5i, Mrps36, Ndufb4), were identified, while increased expression was detected for proteins involved in the development and differentiation of the CNS (Basp1, Cend1), response to stress, learning and memory (Prrt2), and modulation of synaptic transmission (Ncam1, Prrt2). In summary, global proteome analysis provides information about the impact of the combination of the Western diet and stress exposure on cerebrocortical protein alterations and yields insight into the underlying mechanisms and pathways involved in functional and morphological brain alterations as well as behavioral disturbances described in the literature.

Renin–Angiotensin System in Liver Metabolism: Gender Differences and Role of Incretins

The impaired hepatic lipids and carbohydrates metabolism result in various metabolic disorders, including obesity, diabetes, insulin resistance, hyperlipidemia and metabolic syndrome. The renin–angiotensin system (RAS) has been identified in the liver and it is now recognized as an important modulator of body metabolic processes. This review is intended to provide an update of the impact of the renin–angiotensin system on lipid and carbohydrate metabolism, regarding gender difference and prenatal undernutrition, specifically focused on the role of the liver. The discovery of angiotensin-converting enzyme 2 (ACE2) has renewed interest in the potential therapeutic role of RAS modulation. RAS is over activated in non-alcoholic fatty liver disease (NAFLD) and hepatocellular carcinoma. Glucagon-like peptide-1 (GLP-1) has been shown to modulate RAS. The GLP-I analogue liraglutide antagonizes hepatocellular steatosis and exhibits liver protection. Liraglutide has a negative effect on the ACE/AngII/AT1R axis and a positive impact on the ACE2/Ang(1-7)/Mas axis. Activation of the ACE2/Ang(1-7)/Mas counter-regulatory axis is able to prevent liver injuries. Angiotensin(1-7) and ACE2 shows more favorable effects on lipid homeostasis in males but there is a need to do more investigation in female models. Prenatal undernutrition exerts long-term effects in the liver of offspring and is associated with a number of metabolic and endocrine alterations. These findings provide a novel therapeutic regimen to prevent and treat many chronic diseases by accelerating the effect of the ACE2/Ang1-7/Mas axis and inhibiting the ACE/AngII/AT1R axis.

Estrogenic Action in Stress-Induced Neuroendocrine Regulation of Energy Homeostasis

Estrogens are among important contributing factors to many sex differences in neuroendocrine regulation of energy homeostasis induced by stress. Research in this field is warranted since chronic stress-related psychiatric and metabolic disturbances continue to be top health concerns, and sex differences are witnessed in these aspects. For example, chronic stress disrupts energy homeostasis, leading to negative consequences in the regulation of emotion and metabolism. Females are known to be more vulnerable to the psychological consequences of stress, such as depression and anxiety, whereas males are more vulnerable to the metabolic consequences of stress. Sex differences that exist in the susceptibility to various stress-induced disorders have led researchers to hypothesize that gonadal hormones are regulatory factors that should be considered in stress studies. Further, estrogens are heavily recognized for their protective effects on metabolic dysregulation, such as anti-obesogenic and glucose-sensing effects. Perturbations to energy homeostasis using laboratory rodents, such as physiological stress or over-/under- feeding dietary regimen prevalent in today’s society, offer hints to the underlying mechanisms of estrogenic actions. Metabolic effects of estrogens primarily work through estrogen receptor α (ERα), which is differentially expressed between the sexes in hypothalamic nuclei regulating energy metabolism and in extrahypothalamic limbic regions that are not typically associated with energy homeostasis. In this review, we discuss estrogenic actions implicated in stress-induced sex-distinct metabolic disorders.

Families' healthcare experiences for children with inherited metabolic diseases: protocol for a mixed methods cohort study

INTRODUCTION

Children with inherited metabolic diseases (IMDs) often have complex and intensive healthcare needs and their families face challenges in receiving high-quality, family centred health services. Improvement in care requires complex interventions involving multiple components and stakeholders, customised to specific care contexts. This study aims to comprehensively understand the healthcare experiences of children with IMDs and their families across Canada.

METHODS AND ANALYSIS

A two-stage explanatory sequential mixed methods design will be used. Stage 1: quantitative data on healthcare networks and encounter experiences will be collected from 100 parent/guardians through a care map, 2 baseline questionnaires and 17 weekly diaries over 5-7 months. Care networks will be analysed using social network analysis. Relationships between demographic or clinical variables and ratings of healthcare experiences across a range of family centred care dimensions will be analysed using generalised linear regression. Other quantitative data related to family experiences and healthcare experiences will be summarised descriptively. Ongoing analysis of quantitative data and purposive, maximum variation sampling will inform sample selection for stage 2: a subset of stage 1 participants will participate in one-on-one videoconference interviews to elaborate on the quantitative data regarding care networks and healthcare experiences. Interview data will be analysed thematically. Qualitative and quantitative data will be merged during analysis to arrive at an enhanced understanding of care experiences. Quantitative and qualitative data will be combined and presented narratively using a weaving approach (jointly on a theme-by-theme basis) and visually in a side-by-side joint display.

ETHICS AND DISSEMINATION

The study protocol and procedures were approved by the Children's Hospital of Eastern Ontario's Research Ethics Board, the University of Ottawa Research Ethics Board and the research ethics boards of each participating study centre. Findings will be published in peer-reviewed journals and presented at scientific conferences.

Cysteine 253 of UCP1 regulates energy expenditure and sex-dependent adipose tissue inflammation

Uncoupling protein 1 (UCP1) is a major regulator of brown and beige adipocyte energy expenditure and metabolic homeostasis. However, the widely employed UCP1 loss-of-function model has recently been shown to have a severe deficiency in the entire electron transport chain of thermogenic fat. As such, the role of UCP1 in metabolic regulation in vivo remains unclear. We recently identified cysteine-253 as a regulatory site on UCP1 that elevates protein activity upon covalent modification. Here, we examine the physiological importance of this site through the generation of a UCP1 cysteine-253-null (UCP1 C253A) mouse, a precise genetic model for selective disruption of UCP1 in vivo. UCP1 C253A mice exhibit significantly compromised thermogenic responses in both males and females but display no measurable effect on fat accumulation in an obesogenic environment. Unexpectedly, we find that a lack of C253 results in adipose tissue redox stress, which drives substantial immune cell infiltration and systemic inflammatory pathology in adipose tissues and liver of male, but not female, mice. Elevation of systemic estrogen reverses this male-specific pathology, providing a basis for protection from inflammation due to loss of UCP1 C253 in females. Together, our results establish the UCP1 C253 activation site as a regulator of acute thermogenesis and sex-dependent tissue inflammation.

Dihydroartemisinin improves hypercholesterolemia in ovariectomized mice via enhancing vectorial transport of cholesterol and bile acids from blood to bile

The increase of concentrations of total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C) in the serum of postmenopausal women is the important risk factor of the high morbidity of cardiovascular diseases of old women worldwide. To test the anti-hypercholesterolemia function of dihydroartemisinin (DHA) in postmenopausal women, ovariectomized (OVX) mice were generated, and DHA were administrated to OVX mice for 4 weeks. The blood and liver tissues were collected for biochemical and histological tests respectively. The mRNA and protein expression levels of genes related to metabolism and transport of cholesterol, bile acid and fatty acid in the liver or ileum were checked through qPCR and western blot. DHA could significantly reduce the high concentrations of TC and LDL-C in the serum and the lipid accumulation in the liver of ovariectomized mice. The expression of ABCG5/8 was reduced in liver of OVX mice, and DHA could up-regulate the expression of them. Genes of transport proteins for bile salt transport from blood to bile, including Slc10a1, Slco1b2 and Abcb11, were also significantly up-regulated by DHA. DHA also down-regulated the expression of Slc10a2 in the ileum of OVX mice to reduce the absorption of bile salts. Genes required for fatty acid synthesis and uptake, such as Fasn and CD36, were reduced in the liver of OVX mice, and DHA administration could significantly up-regulate the expression of them. These results demonstrated that DHA could improve hypercholesterolemia in OVX mice through enhancing the vectorial transport of cholesterol and bile acid from blood to bile.

Effects of Simultaneous Exposure to a Western Diet and Wheel-Running Training on Brain Energy Metabolism in Female Rats

BACKGROUND

In the pathogenesis of central nervous system disorders (e.g., neurodegenerative), an important role is attributed to an unhealthy lifestyle affecting brain energy metabolism. Physical activity in the prevention and treatment of lifestyle-related diseases is getting increasing attention.

METHODS

We performed a series of assessments in adult female Long Evans rats subjected to 6 weeks of Western diet feeding and wheel-running training. A control group of lean rats was fed with a standard diet. In all experimental groups, we measured physiological parameters (animal weights, body composition, serum metabolic parameters). We assessed the impact of simultaneous exposure to a Western diet and wheel-running on the cerebrocortical protein expression (global proteomic profiling), and in the second part of the experiment, we measured the cortical levels of protein related to brain metabolism (Western blot).

RESULTS

Western diet led to an obese phenotype and induced changes in the serum metabolic parameters. Wheel-running did not reduce animal weights or fat mass but significantly decreased serum glucose level. The global proteome analysis revealed that the altered proteins were functionally annotated as they were involved mostly in metabolic pathways. Western blot analysis showed the downregulation of the mitochondrial protein-Acyl-CoA dehydrogenase family member 9, hexokinase 1 (HK1)-enzyme involved in principal glucose metabolism pathways and monocarboxylate transporter 2 (MCT2). Wheel-running reversed this decline in the cortical levels of HK1 and MCT2.

CONCLUSION

The cerebrocortical proteome is affected by a combination of physical activity and Western diet in female rats. An analysis of the cortical proteins involved in brain energy metabolism provides a valuable basis for the deeper investigation of changes in the brain structure and function induced by simultaneous exposure to a Western diet and physical activity.

Gender difference in the relationship between lipid accumulation product index and pulse pressure in nondiabetic Korean adults: The Korean National Health and Nutrition Examination Survey 2013-2014

The present study was conducted to assess the association between the lipid accumulation product index (LAP) and pulse pressure (PP) by gender in nondiabetic Korean adults. This study used the data of 8,240 nondiabetic adults (3,577 men and 4,663 women) aged ≥ 20 years from the Korean National Health and Nutrition Examination Survey 2013-2014. Key findings from the study were as follows: first, the mean values of age for the overall population, men, and women were 49.59 ± 15.73 years, 49.26 ± 16.04 years, and 49.85 ± 15.47 years, respectively. Second, in women (n = 4,663), after adjustment for related variables and with quartile 1 of LAP as a reference, the odds ratios (ORs) of high PP (PP > 60 mmHg) were significantly higher in quartile 3 [1.735 (95% confidence interval [CI], 1.064-2.831)] and quartile 4 of LAP [2.271 (95% CI, 1.325-3.893)]. Third, high PP in men (n = 3,577) was not associated with the quartiles of LAP. Forth, after adjustment for related variables, the PP level was positively associated with the quartiles of LAP in women (p < .001) but not in men (p = .400). PP was positively associated with LAP in nondiabetic Korean women but not in men.

Cross-comparison of systemic and tissue-specific metabolomes in a mouse model of Leigh syndrome

INTRODUCTION

The value of metabolomics in multi-systemic mitochondrial disease research has been increasingly recognized, with the ability to investigate a variety of biofluids and tissues considered a particular advantage. Although minimally invasive biofluids are the generally favored sample type, it remains unknown whether systemic metabolomes provide a clear reflection of tissue-specific metabolic alterations.

OBJECTIVES

Here we cross-compare urine and tissue-specific metabolomes in the Ndufs4 knockout mouse model of Leigh syndrome-a complex neurometabolic MD defined by progressive focal lesions in specific brain regions-to identify and evaluate the extent of common and unique metabolic alterations on a systemic and brain regional level.

METHODS

Untargeted and semi-targeted multi-platform metabolomics were performed on urine, four brain regions, and two muscle types of Ndufs4 KO (n≥19) vs wildtype (n≥20) mice.

RESULTS

Widespread alterations were evident in alanine, aspartate, glutamate, and arginine metabolism in Ndufs4 KO mice; while brain-region specific metabolic signatures include the accumulation of branched-chain amino acids, proline, and glycolytic intermediates. Furthermore, we describe a systemic dysregulation in one-carbon metabolism and the tricarboxylic acid cycle, which was not clearly reflected in the Ndufs4 KO brain.

CONCLUSION

Our results confirm the value of urinary metabolomics when evaluating MD-associated metabolites, while cautioning against mechanistic studies relying solely on systemic biofluids.

Hepatic Fat in Early Childhood Is Independently Associated With Estimated Insulin Resistance: The Healthy Start Study

BACKGROUND

Fatty liver disease is a common metabolic abnormality in adolescents with obesity but remains understudied in early childhood.

OBJECTIVES

To describe hepatic fat deposition in prepubertal children and examine cross-sectional associations with metabolic markers and body composition.

METHODS

Data were from 286 children ages 4 to 8 years old in the Healthy Start Study, a longitudinal prebirth cohort in Colorado (USA). Assessments included magnetic resonance imaging to quantify hepatic and abdominal fats, fasting blood draws to measure metabolic markers, and air displacement plethysmography to measure body composition (fat mass and fat-free mass).

RESULTS

The median (interquartile range) for hepatic fat was 1.65% (1.24%, 2.11%). Log-transformed hepatic fat was higher in Hispanic [mean (95% CI): 0.63 (0.52, 0.74)] vs non-Hispanic white children [0.46 (0.38, 0.53), P = 0.01] and children with overweight/obesity [0.64 (0.49, 0.79)] vs normal-weight [0.47 (0.40, 0.53), P = 0.02]. Higher log-hepatic fat was associated with higher insulin [β (95% CI): 1.47 (0.61, 2.33) uIU/mL, P = 0.001] and estimated insulin resistance (homeostatic model assessment) [0.40 (0.20, 0.60), P < 0.001] in the full sample and glucose [5.53 (2.84, 8.21) mg/dL, P < 0.001] and triglycerides [10.92 (2.92,18.91) mg/dL, P = 0.008] in boys, in linear regression models adjusted for sociodemographics, maternal/perinatal confounders, and percentage body fat. Log-hepatic fat was also associated with abdominal subcutaneous adipose tissue [SAT; 7.37 (1.12,13.60) mm2, P = 0.02] in unadjusted models, but this was attenuated and insignificant after adjusting for confounders.

CONCLUSIONS

While hepatic fat was low in children 4 to 8 years old, it was independently associated with estimated insulin resistance and exhibited sex-specific associations with glucose and triglycerides, suggesting hepatic fat may be an early indicator of metabolic dysfunction in youth.

Untargeted metabolomics reveals sex-specific differences in lipid metabolism of adult rats exposed to dexamethasone in utero

Prenatal stress through glucocorticoid (GC) exposure leads to an increased risk of developing diseases such as cardiovascular disease, metabolic syndrome and hypertension in adulthood. We have previously shown that administration of the synthetic glucocorticoid, dexamethasone (Dex), to pregnant Wistar-Kyoto dams produces offspring with elevated blood pressures and disrupted circadian rhythm signaling. Given the link between stress, circadian rhythms and metabolism, we performed an untargeted metabolomic screen on the livers of offspring to assess potential changes induced by prenatal Dex exposure. This metabolomic analysis highlighted 18 significantly dysregulated metabolites in females and 12 in males. Pathway analysis using MetaboAnalyst 4.0 highlighted key pathway-level metabolic differences: glycerophospholipid metabolism, purine metabolism and glutathione metabolism. Gene expression analysis revealed significant upregulation of several lipid metabolism genes in females while males showed no dysregulation. Triglyceride concentrations were also found to be significantly elevated in female offspring exposed to Dex in utero, which may contribute to lipid metabolism activation. This study is the first to conduct an untargeted metabolic profile of liver from GC exposed offspring. Corroborating metabolic, gene expression and lipid profiling results demonstrates significant sex-specific lipid metabolic differences underlying the programming of hepatic metabolism.

Pathophysiology of Physical Inactivity-Dependent Insulin Resistance: A Theoretical Mechanistic Review Emphasizing Clinical Evidence

The modern lifestyle has a negative impact on health. It is usually accompanied by increased stress levels and lower physical activity, which interferes with body homeostasis. Diabetes mellitus is a relatively common metabolic disorder with increasing prevalence globally, associated with various risk factors, including lower physical activity and a sedentary lifestyle. It has been shown that sedentary behavior increases the risk of insulin resistance, but the intermediate molecular mechanisms are not fully understood. In this mechanistic review, we explore the possible interactions between physical inactivity and insulin resistance to help better understand the pathophysiology of physical inactivity-dependent insulin resistance and finding novel interventions against these deleterious pathways.

Dietary carbohydrates interact with AMY1 polymorphisms to influence the incidence of type 2 diabetes in Korean adults

The relationship between AMY1 single nucleotide polymorphisms (SNPs), dietary carbohydrates, and the risk of type 2 diabetes is unclear. We aimed to evaluate this association using an ongoing large-scale prospective study, namely the Korean Genome and Epidemiology Study. We selected six genetic variants of the AMY1 gene: rs10881197, rs4244372, rs6696797, rs1566154, rs1930212, and rs1999478. Baseline dietary data were obtained using a semi-quantitative food frequency questionnaire. Type 2 diabetes was defined according to the criteria of the World Health Organization and American Diabetes Association. During an average follow-up period of 12 years (651,780 person-years), 1082 out of 4552 (23.8%) patients had type 2 diabetes. Three AMY1 SNPs were significantly associated with diabetes incidence among patients with carbohydrate intake > 65% of total energy: rs6696797, rs4244372, and rs10881197. In multivariable Cox models, Korean women with the rs6696797 AG or AA genotype had 28% higher incidence of type 2 diabetes (hazard ratio 1.28, 95% confidence interval 1.06-1.55) than Korean women with the rs6696797 GG genotype. We did not observe significant associations between AMY1 SNPs, dietary carbohydrates, and diabetes incidence in Korean men. We conclude that AMY1 genetic variants and dietary carbohydrate intake influence the incidence of type 2 diabetes in Korean women only. Korean women who are minor carriers of the AMY1 rs6696797, rs4244372, and rs10881197 genotypes may benefit from a low-carbohydrate diet to prevent the future risk of type 2 diabetes.

Impaired fasting glucose, type 2 diabetes mellitus, and lifetime risk of cardiovascular disease among women and men: the Rotterdam Study

INTRODUCTION

Data on sex-specific lifetime risk of cardiovascular disease (CVD) across the glycemic spectrum, in particular in impaired fasting glucose (IFG) state, are scarce. Whether overweight/obesity modifies the CVD burden also remains unclear.

RESEARCH DESIGN AND METHODS

Using a prospective population-based Rotterdam Study, normoglycemia, IFG, and type 2 diabetes mellitus (T2D) were defined. First incident cases of coronary heart disease, heart failure, and stroke during a follow-up time until January 1, 2015 were identified and formed the composite CVD end point. The remaining lifetime risks of CVD were estimated in each glucose category at 55, 65, 75, and 85 years of age, using a modified version of survival analysis adjusted for the competing risk of death.

RESULTS

Among 5698 women and 3803 men free of CVD at baseline, the mean age was 64.5 years (SD 9.6) and 60.0% of participants were women. At age 55 years, the remaining lifetime risk of any CVD event among women was 55.1% (95% CI 48.3 to 61.9) for IFG, compared with 52.7% (95% CI 49.5 to 55.9) for normoglycemia and 61.5% (95% CI 54.7 to 68.3) for T2D. For men, the remaining lifetime risk of any CVD event was 62.1% (95% CI 55.2 to 69.1) for IFG, compared with 59.1% (95% CI 55.5 to 62.7) for normoglycemia and 60.3% (95% CI 53.1 to 67.5) for T2D. At age 55 years, the lifetime risk for incident CVD was higher, although not statistically significant, among women and men with IFG who were overweight or had obesity compared with normal-weight women and men.

CONCLUSION

IFG carried a large lifetime risk for incident CVD among both women and men compared with normoglycemia. In particular among men, the risk was comparable to that of T2D. Overweight/Obesity modifies the risk and conferred a larger burden of lifetime CVD risk among women and men with IFG.

Homologous recombination is reduced in female embryonic stem cells by two active X chromosomes

The reactivation of X-linked genes is observed in some primary breast tumors. Two active X chromosomes are also observed in female embryonic stem cells (ESCs), but whether double doses of X-linked genes affect DNA repair efficiency remains unclear. Here, we establish isogenic female/male ESCs and show that the female ESCs are more sensitive to camptothecin and have lower gene targeting efficiency than male ESCs, suggesting that homologous recombination (HR) efficiency is reduced in female ESCs. We also generate Xist-inducible female ESCs and show that the lower HR efficiency is restored when X chromosome inactivation is induced. Finally, we assess the X-linked genes with a role in DNA repair and find that Brcc3 is one of the genes involved in a network promoting proper HR. Our findings link the double doses of X-linked genes with lower DNA repair activity, and this may have relevance for common diseases in female patients, such as breast cancer.

Vitamin D equilibrium affects sex-specific changes in lipid concentrations during Christian Orthodox fasting

We aimed to evaluate sex differences in changes of lipid profiles in a cohort of metabolically healthy adults following Orthodox fasting (OF), as well as to assess a potential role of vitamin D status in mediating these variations. 45 individuals (24 premenopausal females, 53.3 %) with mean age 48.3 ± 9.1 years and mean Body Mass Index 28.7 ± 5.8 kg/m² were prospectively followed for 12 weeks. Anthropometry, dietary and biochemical data regarding serum lipids, and vitamin D status were collected at baseline, 7 weeks after the implementation of OF, and 5 weeks after fasters returned to their standard dietary habits (12 weeks from baseline). According to 25-hydroxy-vitamin D [25(OH)D] measurements, participants were divided into two groups: those with concentrations above and below the median of values. Females with 25(OH)D concentrations below the median manifested a non-significant reduction by approximately 15 % in total and low-density lipoprotein cholesterol during the fasting period, followed by a significant increase 5 weeks after OF cessation (170.7 vs. 197.5 and 99.6 vs. 121.0 mg/dl respectively, p < 0.001). In contrast, males with 25(OH)D levels below the median demonstrated an inverse, non-significant trend of increase in lipid concentrations during the whole study period. Our findings suggest strikingly different inter-gender lipid responses to a dietary model of low-fat, mediated by vitamin D status. Further studies are necessary to reveal the underlying mechanisms and assess the importance of these differences with respect to cardiovascular health and the benefit of vitamin D supplementation strategies.

Healthy eating index patterns in adults by sex and age predict cardiometabolic risk factors in a cross-sectional study

BACKGROUND

Associations between diet and cardiometabolic disease (CMD) risk may vary in men and women owing to sex differences in eating habits and physiology. The current secondary analysis sought to determine the ability of sex differences in dietary patterns to discriminate groups with or without CMD risk factors (CMDrf) in the adult population and if this was influenced by age.

METHODS

Diet patterns and quality were evaluated using 24 h recall-based Healthy Eating Index (HEI-2015) in free-living apparently healthy men (n = 184) and women (n = 209) 18-65 y of age with BMIs of 18-44 kg/m2. Participants were stratified into low- and high-CMDrf groups based on the presence/absence of at least one CMDrf: BMI > 25 kg/m2; fasting triglycerides > 150 mg/dL; HDL cholesterol < 50 mg/dL-women or < 40 mg/dL-men; HOMA > 2; HbA1c > 5.7. Sex by age dietary patterns were stratified by multivariate analyses, with metabolic variable associations established by stepwise discriminant analysis.

RESULTS

Diet quality increased with age in both sexes (P < 0.01), while women showed higher fruit, vegetable and saturated fat intake as a percentage of total energy (P < 0.05). The total-HEI score (i.e. diet quality) was lower in the high-CMDrf group (P = 0.01), however, diet quality parameters predicted CMDrf presence more accurately when separated by sex. Lower 'total vegetable' intake in the high-CMDrf group in both sexes, while high-CMDrf men also had lower 'total vegetables', 'greens and beans' intake, and high-CMDrf women had lower 'total fruits', 'whole-fruits', 'total vegetables', 'seafood and plant-proteins', 'fatty acids', and 'saturated fats' intakes (P < 0.05). Moreover, 'dairy' intake was higher in high-CMDrf women but not in men (sex by 'dairy' interaction P = 0.01). Sex by age diet pattern models predicted CMDrf with a 93 and 89% sensitivity and 84 and 92% specificity in women and men, respectively.

CONCLUSIONS

Sex and age differences in dietary patterns classified participants with and without accepted CMDrfs, supporting an association between specific diet components and CMD risk that differs by sex. Including sex specific dietary patterns into health assessments may provide targeted nutritional guidance to reduce the burden of cardiovascular disease.

TRIAL REGISTRATION

ClinicalTrials.gov : NCT02367287 . ClinicalTrials.gov : NCT02298725 .

IL-2Rβγ signalling in lymphocytes promotes systemic inflammation and reduces plasma cholesterol in atherosclerotic mice

BACKGROUND AND AIMS

The relationship between inflammation and lipid metabolism is complex and bidirectional. Lymphocyte-driven inflammation has been shown to modulate both atherosclerotic plaque development and cholesterol levels, but the mechanisms are incompletely understood.

METHODS

The cardiometabolic effects of IL-2Rβγ signalling in atherosclerotic Apoe-/- mice were investigated by treatment with an agonistic IL-2Rβγ-targeting IL-2/anti-IL-2 complex or a monoclonal anti-CD122 (IL-2Rβ) blocking antibody.

RESULTS

Administration of IL-2Rβγ agonistic IL-2/anti-IL-2 complexes to Apoe-/- mice augmented opposing arms of the adaptive immune system. Expansion of effector/memory T cells and increased levels of circulating pro-inflammatory cytokines were observed along with elevated levels of regulatory T cells and IL-10. Notably, IL-2/anti-IL-2 treatment did not affect plaque size but decreased levels of plasma cholesterol. The cholesterol lowering effect of IL-2Rβγ agonism was not affected by anti-CD8 or anti-NK1.1 depleting antibody treatment but was contingent on the presence of adaptive immunity. Expression of multiple liver X receptor (LXR)-related genes, including Pltp and Srebp1c in the liver, was decreased by IL-2/anti-IL-2 treatment. Although IL-2Rβγ agonism lowered cholesterol levels, blocking IL-2Rβγ signalling using an anti-CD122 monoclonal antibody did not impact cholesterol levels or plaque burden in Apoe-/- mice.

CONCLUSIONS

Elevated IL-2Rβγ signalling results in activation of both inflammatory and regulatory lymphocytes with a net zero effect on atherosclerosis and decreased plasma cholesterol levels. Changes in cholesterol levels were associated with reductions in hepatic LXR-related gene expression. Further studies are needed to investigate the clinical significance of IL-2 mediated modulation of hepatic LXR signalling in inflammatory disorders.

Sex and gender in cardiovascular medicine: presentation and outcomes of acute coronary syndrome

Although health disparities in women presenting with acute coronary syndrome (ACS) have received growing attention in recent years, clinical outcomes from ACS are still worse for women than for men. Women continue to experience higher patient and system delays and receive less aggressive invasive treatment and pharmacotherapies. Gender- and sex-specific variables that contribute to ACS vulnerability remain largely unknown. Notwithstanding the sex differences in baseline coronary anatomy and function, women and men are treated the same based on guidelines that were established from experimental and clinical trial data over-representing the male population. Importantly, younger women have a particularly unfavourable prognosis and a plethora of unanswered questions remains in this younger population. The present review summarizes contemporary evidence for gender and sex differences in vascular biology, clinical presentation, and outcomes of ACS. We further discuss potential mechanisms and non-traditional risk conditions modulating the course of disease in women and men, such as unrecognized psychosocial factors, sex-specific vascular and neural stress responses, and the potential impact of epigenetic modifications.

Sex difference in blood pressure, a combinatorial consequence of the differential in RAAS components, sex hormones and time course

The longitudinal increment of blood pressure (BP) with age is attributed to lifestyle, internal and external environments. It is not limited to systemic brain-derived neurotrophic factor (BDNF), signaling to allow the individuals to better adapt to the developmental and environmental change. This regulation is necessary for all lives, regardless of sex. Basic levels of renin-angiotensin- aldosterone system (RAAS) components in males and females define the fundamental sex difference in BP, which may be set by prenatal programming and profoundly influence BP after birth. The innate sex difference in BP is magnified during puberty growth and further modified by menopause. At the age of 70 or older, blood pressure was similar in men and women. The understanding of the prenatal setup and development of sexual dimorphism in BP may provide preventative therapeutic strategies, including timing and drugs, for individuals with abnormal BP.