Sex differences in cardiovascular disease - Impact on care and outcomes

Challenges of the heterogeneous nutrition response: interpreting the group mean

Extensive research demonstrates unequivocally that nutrition plays a fundamental role in maintaining health and preventing disease. In parallel nutrition research provides evidence that the risks and benefits of diet and lifestyle choices do not affect people equally, as people are inherently variable in their responses to nutrition and associated interventions to maintain health and prevent disease. To simplify the inherent complexity of human subjects and their nutrition, with the aim of managing expectations for dietary guidance required to ensure healthy populations and individuals, nutrition researchers often seek to group individuals based on commonly used criteria. This strategy relies on demonstrating meaningful conclusions based on comparison of group mean responses of assigned groups. Such studies are often confounded by the heterogeneous nutrition response. Commonly used criteria applied in grouping study populations and individuals to identify mechanisms and determinants of responses to nutrition often contribute to the problem of interpreting the results of group comparisons. Challenges of interpreting the group mean using diverse populations will be discussed with respect to studies in human subjects, in vivo and in vitro model systems. Future advances in nutrition research to tackle inter-individual variation require a coordinated approach from funders, learned societies, nutrition scientists, publishers and reviewers of the scientific literature. This will be essential to develop and implement improved study design, data recording, analysis and reporting to facilitate more insightful interpretation of the group mean with respect to population diversity and the heterogeneous nutrition response.

Prohibitin: a prime candidate for a pleiotropic effector that mediates sex differences in obesity, insulin resistance, and metabolic dysregulation

Adipocytes and macrophages, the two major constituents of adipose tissue, exhibit sex differences and work in synergy in adipose tissue physiology and pathophysiology, including obesity-linked insulin resistance and metabolic dysregulation. Sex steroid hormones play a major role in sex differences in adipose tissue biology. However, our knowledge of the molecules that mediate these effects in adipose tissue remains limited. Consequently, it remains unclear whether these effector molecules in different adipose and immune cell types are distinct or if there are also pleiotropic effectors. Recently, a protein named prohibitin (PHB) with cell compartment- and tissue-specific functions has been found to play a role in sex differences in adipose and immune functions. Transgenic (Tg) mouse models overexpressing PHB (PHB-Tg) and a phospho-mutant PHB (mPHB-Tg) from the fatty acid binding protein-4 (Fabp-4) gene promoter display sex-neutral obesity; however, obesity-related insulin resistance and metabolic dysregulation are male-specific. Intriguingly, with aging, the male PHB-Tg mice developed hepatic steatosis and subsequently liver tumors whereas the male mPHB-Tg mice developed lymph node tumors and splenomegaly. Unlike the male transgenic mice, the female PHB-Tg and mPHB-Tg mice remain protected from obesity-related metabolic dysregulation and tumor development. In conclusion, the sex-dimorphic metabolic and immune phenotypes of PHB-Tg and mPHB-Tg mice have revealed PHB as a pleiotropic effector of sex differences in adipose and immune functions. In this mini-review, we will discuss the pleiotropic attributes of PHB and potential mechanisms that may have contributed to the sex-dimorphic metabolic phenotypes in PHB-Tg and mPHB-Tg mice, which warrant future research. We propose that PHB is a prime candidate for a pleiotropic mediator of sex differences in adipose and immune functions in both physiology and pathophysiology, including obesity, insulin resistance, and metabolic dysregulation.

Downregulation of microRNA-155 stimulates sevoflurane-mediated cardioprotection against myocardial ischemia/reperfusion injury by binding to SIRT1 in mice

OBJECTIVE

The inhaled sevoflurane has been demonstrated to protect against myocardial ischemia/reperfusion (I/R) injury. However, the relative mechanisms of sevoflurane-mediated cardioprotection remain largely unknown. This study intends to explore the effect of miR-155 on the sevoflurane-mediated cardioprotection by regulating Sirtuin 1 (SIRT1) in mouse models of myocardial I/R.

METHODS

Left anterior descending coronary artery ligation was used to induce models of myocardial I/R in mice. The I/R mice were treated with sevoflurane, sevoflurane + mimics negative control (NC) or sevoflurane + miR-155 mimics. The expression of microRNA-155 (miR-155) and SIRT1 was examined by quantitative real-time polymerase chain reaction and Western blot assay. Then cardiac functions and hemodynamic alterations were evaluated. Evans blue-2,3,5-triphenyltetrazolium chloride and terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling assay staining methods were adopted to evaluate infarct size and cardiomyocyte apoptosis, respectively.

RESULTS

In the I/R mice, miR-155 was expressed at a high level and SIRT1 at a low level. SIRT1 was confirmed to be a target gene of miR-155. The treatment of sevoflurane could reduce miR-155 expression and increased SIRT1 expression in the myocardial tissues, under which conditions, cardiac functions were promoted, accompanied by reduced infarct size and inhibited cardiomyocyte apoptosis. In response to miR-155 upregulation, the sevoflurane-treated I/R mice showed reduced cardiac functions, and increased infarct size and cardiomyocyte apoptosis.

CONCLUSION

The findings obtained in this study provide evidence suggesting that miR-155 targets and negatively regulates SIRT1 expression, a mechanism by which the protection of sevoflurane is inhibited against myocardial I/R in mice.

Thyroid hormone protects cardiomyocytes from H2O2-induced oxidative stress via the PI3K-AKT signaling pathway

Oxidative stress plays an important role in the progression of cardiac diseases, including acute myocardial infarction, ischemia/reperfusion (I/R) injury and heart failure. Growing evidence indicates that thyroid hormone has protective properties against cardiovascular diseases. However, little is known about its effect on oxidative stress in cardiomyocytes or the underlying mechanisms. This study showed that T3 pretreatment in vivo significantly reduced cardiac dysfunction by increasing the left ventricular ejection function and ameliorating the pathological changes induced by I/R-induced injury. In an in vitro experiment, T3 inhibited apoptosis in H₂O₂-treated cardiomyocytes, as evidenced by the decreased expression of Bax, cleaved caspase 3 and 9, and increased expression of Bcl-2. In addition, oxidative stress observed in hearts of mice with I/R injury was significantly alleviated by T3 pretreatment, intracellular ROS and mitochondrial ROS overproduction were effectively inhibited, and similar results were also detected in H₂O₂-treated cardiomyocytes in vitro. T3 significantly increased antioxidant protein (Nrf2 and HO-1) expression levels, and inhibited NOX2 and NOX4 protein expression levels in H₂O₂-treated cardiomyocytes. Moreover, T3 preserved mitochondrial functions upon H₂O₂-induced oxidative stress by increasing mitochondrial membrane potential and promoting the expression of mitochondrial biogenesis genes. Notably, the PI3K/AKT signaling was significantly activated by T3 pretreatment in H₂O₂-induced cardiomyocytes. Together, these findings revealed that T3 could be served as potential therapeutic target for protection against cardiac oxidative stress injury through its antioxidant and anti-apoptosis effects, which are mediated by the activation of the PI3K/AKT signaling pathway.

Curcuminoids: Implication for inflammation and oxidative stress in cardiovascular diseases

It has been extensively verified that inflammation and oxidative stress play important roles in the pathogenesis of cardiovascular diseases (CVDs). Curcuminoids, from the plant Curcuma longa, have three major active ingredients, which include curcumin (curcumin I), demethoxycurcumin, and bisdemethoxycurcumin. Curcuminoids have been used in traditional medicine for CVDs' management and other comorbidities for centuries. Numerous studies had delineated their anti-inflammatory, antioxidative, and other medicinally relevant properties. Animal experiments and clinical trials have also demonstrated that turmeric and curcuminoids can effectively reduce atherosclerosis, cardiac hypertrophy, hypertension, ischemia/reperfusion injury, and diabetic cardiovascular complications. In this review, we introduce and summarize curcuminoids' molecular and biological significance, while focusing on their mechanistic anti-inflammatory/antioxidative involvements in CVDs and preventive effects against CVDs, and, finally, discuss relevant clinical applications.

Sex Differences in Ischemia/Reperfusion Injury: The Role of Mitochondrial Permeability Transition

Brain and heart ischemia are among the leading causes of death and disability in both men and women, but there are significant sex differences in the incidence and severity of these diseases. Ca²⁺ dysregulation in response to ischemia/reperfusion injury (I/RI) is a well-recognized pathogenic mechanism leading to the death of affected cells. Excess intracellular Ca²⁺ causes mitochondrial matrix Ca²⁺ overload that can result in mitochondrial permeability transition (MPT), which can have severe consequences for mitochondrial function and trigger cell death. Recent findings indicate that estrogens and their related receptors are involved in the regulation of MPT, suggesting that sex differences in I/RI could be linked to estrogen-dependent modulation of mitochondrial Ca²⁺. Here, we review the evidence supporting sex differences in I/RI and the role of estrogen and estrogen receptors in producing these differences, the involvement of mitochondrial Ca²⁺ overload in disease pathogenesis, and the estrogen-dependent modulation of MPT that may contribute to sex differences.

Melatonin: Another avenue for treating osteoporosis?

Melatonin is a signal molecule that modulates the biological circadian rhythms of vertebrates. Melatonin deficiency is thought to be associated with several disorders, including insomnia, cancer, and cardiovascular and neurodegenerative diseases. Accumulating evidence has also indicated that melatonin may be involved in the homeostasis of bone metabolism. Age-related reductions in melatonin are considered to be critical factors in bone loss and osteoporosis with aging. Thus, serum melatonin levels might serve as a biomarker for the early detection and prevention of osteoporosis. Compared to conventional antiosteoporosis medicines, which primarily inhibit bone loss, melatonin both suppresses bone loss and promotes new bone formation. Mechanistically, by activating melatonin receptor 2 (MT2), melatonin upregulates the gene expression of alkaline phosphatase (ALP), bone morphogenetic protein 2 (BMP2), BMP6, osteocalcin, and osteoprotegerin to promote osteogenesis while inhibiting the receptor activator of NF-kB ligand (RANKL) pathway to suppress osteolysis. In view of the distinct actions of melatonin on bone metabolism, we hypothesize that melatonin may be a novel remedy for the prevention and clinical treatment of osteoporosis.

A Novel Discovery: Holistic Efficacy at the Special Organ Level of Pungent Flavored Compounds from Pungent Traditional Chinese Medicine

Pungent traditional Chinese medicines (TCMs) play a vital role in the clinical treatment of hepatobiliary disease, gastrointestinal diseases, cardiovascular diseases, diabetes, skin diseases and so on. Pungent TCMs have a vastness of pungent flavored (with pungent taste or smell) compounds. To elucidate the molecular mechanism of pungent flavored compounds in treating cardiovascular diseases (CVDs) and liver diseases, five pungent TCMs with the action of blood-activating and stasis-resolving (BASR) were selected. Here, an integrated systems pharmacology approach is presented for illustrating the molecular correlations between pungent flavored compounds and their holistic efficacy at the special organ level. First, we identified target proteins that are associated with pungent flavored compounds and found that these targets were functionally related to CVDs and liver diseases. Then, based on the phenotype that directly links human genes to the body parts they affect, we clustered target modules associated with pungent flavored compounds into liver and heart organs. We applied systems-based analysis to introduce a pungent flavored compound-target-pathway-organ network that clarifies mechanisms of pungent substances treating cardiovascular diseases and liver diseases by acting on the heart/liver organ. The systems pharmacology also suggests a novel systematic strategy for rational drug development from pungent TCMs in treating cardiovascular disease and associated liver diseases.

Clinical Presentation, Quality of Care, Risk Factors and Outcomes in Women with Acute ST-Elevation Myocardial Infarction (STEMI): An Observational Report from Six Middle Eastern Countries

BACKGROUND

Most of the available literature on ST-Elevated myocardial infarction (STEMI) in women was conducted in the developed world and data from Middle-East countries was limited.

AIMS

To examine the clinical presentation, patient management, quality of care, risk factors and inhospital outcomes of women with acute STEMI compared with men using data from a large STEMI registry from the Middle East.

METHODS

Data were derived from the third Gulf Registry of Acute Coronary Events (Gulf RACE-3Ps), a prospective, multinational study of adults with acute STEMI from 36 hospitals in 6 Middle-Eastern countries. The study included 2928 patients; 296 women (10.1%) and 2632 men (89.9%). Clinical presentations, management and in-hospital outcomes were compared between the 2 groups.

RESULTS

Women were 10 years older and more likely to have diabetes mellitus, hypertension, and hyperlipidemia compared with men who were more likely to be smokers (all p<0.001). Women had longer median symptom-onset to emergency department (ED) arrival times (230 vs. 170 min, p<0.001) and ED to diagnostic ECG (8 vs. 6 min., p<0.001). When primary percutaneous coronary intervention (PPCI) was performed, women had longer door-to-balloon time (DBT) (86 vs. 73 min., p=0.009). When thrombolytic therapy was not administered, women were less likely to receive PPCI (69.7 vs. 76.7%, p=0.036). The mean duration of hospital stay was longer in women (6.03 ± 22.51 vs. 3.41 ± 19.45 days, p=0.032) and the crude in-hospital mortality rate was higher in women (10.4 vs. 5.2%, p<0.001). However, after adjustments, multivariate analysis revealed a statistically non-significant trend of higher inhospital mortality among women than men (6.4 vs. 4.6%), (p=0.145).

CONCLUSION

Our study demonstrates that women in our region have almost double the mortality from STEMI compared with men. Although this can partially be explained by older age and higher risk profiles in women, however, correction of identified gaps in quality of care should be attempted to reduce the high morbidity and mortality of STEMI in our women.

Inflammation, depression and cardiovascular disease in women: the role of the immune system across critical reproductive events

Women are at increased risk for developing depression and cardiovascular disease (CVD) across the lifespan and their comorbidity is associated with adverse outcomes that contribute significantly to rates of morbidity and mortality in women worldwide. Immune-system activity has been implicated in the etiology of both depression and CVD, but it is unclear how inflammation contributes to sex differences in this comorbidity. This narrative review provides an updated synthesis of research examining the association of inflammation with depression and CVD, and their comorbidity in women. Recent research provides evidence of pro-inflammatory states and sex differences associated with alterations in the hypothalamic-pituitary-adrenal axis, the renin-angiotensin-aldosterone system and the serotonin/kynurenine pathway, that likely contribute to the development of depression and CVD. Changes to inflammatory cytokines in relation to reproductive periods of hormonal fluctuation (i.e. the menstrual cycle, perinatal period and menopause) are highlighted and provide a greater understanding of the unique vulnerability women experience in developing both depressed mood and adverse cardiovascular events. Inflammatory biomarkers hold substantial promise when combined with a patient's reproductive and mental health history to aid in the prediction, identification and treatment of the women most at risk for CVD and depression. However, more research is needed to improve our understanding of the mechanisms underlying inflammation in relation to their comorbidity, and how these findings can be translated to improve women's health.

Non-ST elevation acute coronary syndrome in women and the elderly: recent updates and stones still left unturned

Despite the growing awareness of adverse events with acute coronary syndrome and vigilance to refine pharmacological and interventional therapies, the understanding of how these events present in and affect women and the elderly remains limited. Pathophysiological differences in these subgroups and under-representation in large trials create a medical gap in sex- and age-related outcomes and in our knowledge of how best to detect, diagnose, and treat acute coronary syndrome. This review provides a general overview of recent advances in non-ST elevation myocardial infarction management in women and the elderly and elucidates areas where further exploration is needed.

AMP-activated protein kinase sparks the fire of cardioprotection against myocardial ischemia and cardiac ageing

AMP-activated protein kinase (AMPK) is a pivotal regulator of some endogenous defensive molecules in various pathological processes, particularly myocardial ischemia (MI), a high risk of myocardial infarction. Thereby it is of great significance to explore the inherent mechanism between AMPK and myocardial infarction. In this review, we first introduce the structure and role of AMPK in the heart. Next, we introduce the mechanisms of AMPK in the heart; followed by the energy regulation of AMPK in MI. Lastly, the attention will be expanded to some potential directions and further perspectives. The information compiled here will be helpful for further research and drug design in the future before AMPK might be considered as a therapeutic target of MI.

Sex Differences in the Prenatal Programming of Adult Metabolic Syndrome by Maternal Androgens

Context

Growing preclinical evidence suggests that hormonal programming by androgens in utero may contribute to cardiovascular disease risk in adult offspring. However, the effect of prenatal androgens on cardiometabolic outcomes in the human population, especially their potential differential impact on male vs female offspring, has not been well studied.

Design

Adult offspring (n = 274) of mothers enrolled in the New England birth cohorts of the Collaborative Perinatal Project were assessed at ages 39 to 50. Androgen bioactivity was measured in maternal serum during the third trimester using a receptor-mediated luciferase expression bioassay. Metabolic syndrome (MetS) using Adult Treatment Panel III criteria was assessed in adult offspring. Bioactive androgens were analyzed as quartiles, with the lowest quartile (Q1) defined as the reference. Generalized estimating equations were used to evaluate the relationship of maternal bioactive androgens on offspring MetS risk overall and by sex, controlling for potential confounders and intrafamilial correlation.

Results

Mean age and body mass index of adult offspring were 44.7 ± 2.6 years and 29.7 ± 6.7 kg/m2, respectively. Participants born to mothers with the highest quartile (Q4) compared with Q1 of bioactive androgens had higher risk for MetS [adjusted odds ratio (aOR): 2.53(1.07 to 6.02)]. Stratified by sex, this association was found to be significant among women [Q4 vs Q1; aOR: 4.06 (1.10 to 14.93)] but not men [Q4 vs Q1; aOR: 1.67 (0.53 to 5.26)]. Women born to mothers with the highest levels of maternal bioactive androgens also demonstrated a 4.84-fold increased odds for having hypertension [Q4 vs Q1; aOR: 4.84 (1.12 to 20.85)].

Conclusion

Higher levels of maternal androgens were associated with increased risk for incident MetS in adult offspring, an effect that was significant in women but not men.

Effect of melatonin on attenuating the isoflurane-induced oxidative damage is related to PKCα/Nrf2 signaling pathway in developing rats

Isoflurane, an inhalational anesthesia, has frequently been used in pediatric anesthesia. However, research indicates that isoflurane can induce oxidative stress and affect neural and cognitive development. Melatonin, an endogenous hormone that exhibits antioxidant functions, can play a neuroprotective role by activating the PKCα/Nrf2 signaling pathway in response to oxidative stress. This study aims to determine whether the effect of melatonin on isoflurane-induced oxidative stress is related to activation of the PKCα/Nrf2 signaling pathway. Rat pups at postnatal day 7 were treated with control or 1.5% isoflurane for 4 h after pretreatment for 15 min with either melatonin (10 mg/kg i.p.) or 1% ethanol. The hematoxylin and eosin staining and transmission electron microscopic examination were used for observation of histopathology. The oxidative stress-related indicators were detected by using assay kits. The western blotting, immunohistochemistry and immunofluorescence were used to detect the activation of PKCα/Nrf2 signaling pathway. Results showed that isoflurane induced nerve damage in the hippocampus, and melatonin could reduce this injury. Oxidative stress-related indicators suggested that isoflurane can significantly increase reactive oxygen species and malondialdehyde levels, and decrease superoxide dismutase and glutathione activity compared with the control group, whereas melatonin ameliorated these indices. Expression of proteins associated with the PKCα/Nrf2 signaling pathway indicated that the neuroprotective effect of melatonin is related to activation of the PKCα/Nrf2 signaling pathway. These results suggest that the attenuating effect of melatonin on isoflurane-induced oxidative stress is related to activation of the PKCα/Nrf2 signaling pathway. These findings promote further research into underlying mechanisms and effective treatments to attenuate anesthesia neurotoxicity.

Sex, gender and venous thromboembolism: do we care enough?

: The role of sex and gender in determining clinical presentation, diagnostic approach and outcomes of venous thromboembolism is not fully and systematically addressed, except for hormone-related events in women. A lack of knowledge is also apparent regarding drug prescription patterns, physician bias, enrolment in clinical studies and analysis of sex-related confounders in preclinical and clinical studies. As was shown for cardiovascular disease, ignoring sex and gender in medicine can have important impact on outcomes, including mortality. In this review, we seek to address some aspects of venous thromboembolism such as epidemiology and clinical presentation, recurrence, risk factors, animal studies, safety and efficacy of antithrombotic drugs, highlighting what is known and what is not regarding the role of sex and gender, and hoping to focus some interest and to promote the inclusion of these variables in all future studies on venous thromboembolism.

Cabbage (Brassica oleracea var. capitata) Protects against H2O2-Induced Oxidative Stress by Preventing Mitochondrial Dysfunction in H9c2 Cardiomyoblasts

Oxidative stress plays an important role in the progression of cardiac diseases, including ischemia/reperfusion injury, myocardial infarction, and heart failure. Growing evidence indicates that cabbage has various pharmacological properties against a wide range of diseases, such as cardiovascular diseases, hepatic diseases, and cancer. However, little is known about its effects on oxidative stress in cardiomyocytes or the underlying mechanisms. Therefore, the present study examined the effects of cabbage extract on oxidative stress in H9c2 cardiomyoblasts. Cell viability, reactive oxygen species (ROS) production, apoptosis, mitochondrial functions, and expression levels of mitogen-activated protein kinase (MAPK) proteins were analyzed to elucidate the antioxidant effects of this extract. Cabbage extract protected against H₂O₂-induced cell death and did not elicit any cytotoxic effects. In addition, cabbage extract suppressed ROS production and increased expression of antioxidant proteins (SOD-1, catalase, and GPx). Cabbage extract also inhibited apoptotic responses and activation of MAPK proteins (ERK1/2, JNK, and p-38) in oxidative stress-exposed H9c2 cells. Notably, cabbage extract preserved mitochondrial functions upon oxidative stress. These findings reveal that cabbage extract protects against oxidative stress and suggest that it can be used as an alternative therapeutic strategy to prevent the oxidative stress in the heart.

Stable Ischemic Heart Disease in Women

PURPOSE OF THE REVIEW

Paradoxically, although women have a lower burden of coronary atherosclerosis, they experience more symptoms, more frequent hospitalizations, and a worse prognosis compared to men. This is in part due to biological variations in pathophysiology between the two sexes, and in part related to inadequate understanding of these differences, subconscious referral bias, and suboptimal application of existing women-specific guidelines. We sought to review the contemporary literature and provide an update on risk assessment, diagnosis, and management of IHD in women.

RECENT FINDINGS

IHD in women is often secondary to diffuse non-obstructive atherosclerosis, coronary spasm, inflammation, and endothelial and microvascular dysfunction, and less commonly due to the male pattern of flow-limiting epicardial stenosis. Both IHD patterns likely represent sex-specific manifestations of the same disease process. Additionally, there is a differential expression of risk factors and symptoms between men and women. Application of male-pattern IHD risk factors and presentation to women contributes to under-recognition, under-testing, and under-treatment of IHD in women compared to men. Traditional diagnostic evaluation has focused on detection of epicardial disease, amenable to revascularization. Our improved understanding of sex-specific pathophysiology of IHD has enabled us to also develop tools for detection of microvascular disease. Advances in stress MRI, flow quantification on stress PET, and provocative invasive angiography have filled this void and offer important diagnostic and prognostic information. Despite our improved understanding of sex-specific differences in presentation, risk factors, pathophysiology, diagnostic testing, and management strategies of IHD, women with IHD continue to experience worse outcomes than men. This disparity underscores the need for improved research and understanding of biological sex differences, elimination of subconscious gender bias in referral patterns, and improved application of existing research into clinical practice.

Protein Carbamylation: A Marker Reflecting Increased Age-Related Cell Oxidation

Carbamylation is a post-translational modification of proteins that may partake in the oxidative stress-associated cell damage, and its increment has been recently proposed as a “hallmark of aging”. The molecular mechanisms associated with aging are related to an increased release of free radicals. We have studied whether carbamylated proteins from the peripheral blood of healthy subjects are related to oxidative damage and aging, taking into account the gender and the immune profile of the subjects. The study was performed in healthy human volunteers. The detection of protein carbamylation and malondialdehyde (MDA) levels was evaluated using commercial kits. The immune profile was calculated using parameters of immune cell function. The results show that the individuals from the elderly group (60–79 years old) have increased carbamylated protein and MDA levels. When considered by gender, only men between 60 and 79 years old showed significantly increased carbamylated proteins and MDA levels. When those subjects were classified by their immune profile, the carbamylated protein levels were higher in those with an older immune profile. In conclusion, the carbamylation of proteins in peripheral blood is related to age-associated oxidative damage and to an aging functional immunological signature. Our results suggest that carbamylated proteins may play an important role at the cellular level in the aging process.

Relationships between sedentary behaviour, physical activity levels and red blood cell distribution width in children and adolescents

Background: Red blood cell distribution width (RDW) is a biomarker for cardiovascular disease(CVD). RDW is associated with sedentary behavior (SB) and physical activity (PA) in adults.To date, no study has evaluated this association in children. The purpose of this study was to evaluate the association between RDW and SB and PA levels of children and adolescents.

Methods: This observational study included data from participants aged 12-20 years in the 2003–2006 National Health and Nutrition Examination Survey (NHANES). SB and PA were measured using accelerometers. Activity levels were classified into intensity categories. Sex specific multivariable regression analyses (adjusted for covariates) were used to explore the associations between SB, PA and RDW.

Results: The study included 2143 children and adolescents (1080 boys and 1063 girls). In the fully adjusted regression model for boys, SB was positively associated with RDW (β =0.116,P=0.004) while moderate PA was negatively associated with RDW (β =-0.082, P=0.048). In girls, there were no significant associations between activity levels and RDW.

Conclusion: This study provides preliminary evidence of the association between SB, moderate intensity PA and RDW in boys, but not in girls. Further research to determine the mechanisms associated with this relationship and underlying sex differences is warranted.

Identifying the Critical Gaps in Research on Sex Differences in Metabolism Across the Life Span

The National Institutes of Health (NIH) Office of Research in Women's Health now functions under a mandate calling for the systematic inclusion of both female and male cells, animals, and human subjects in all types of research, so that sex as a biological variable is understood in health and disease. Sex-specific data can improve disease prevention, diagnosis, and treatment as well as reduce inequities. Inclusion of women in research studies has modestly improved over the last 20 years, yet preclinical research is still primarily done using male animal models and male-derived cells, with the result that many conclusions are made based on incomplete and sex-biased data. There are important, yet poorly studied, sex differences in cardiometabolic disease. To begin to address these sex differences, the Center for Women's Health Research at the University of Colorado held its inaugural National Conference, "Sex Differences Across the Lifespan: A Focus on Metabolism," in September 2016 (cwhr@ucdenver.edu). Research to address the important goal of understanding key sex differences in cardiometabolic disease across the life span is lacking. The goal of this article is to discuss the current state of research addressing sex differences in cardiometabolic health across the life span, to outline critical research gaps that must be addressed in response to NIH mandates, and, importantly, to develop strategies to address sex as a biological variable to understand disease mechanisms as well as develop diagnostic and therapeutic modalities.

Unsettled Issues and Future Directions for Research on Cardiovascular Diseases in Women

Biological sex (being female or male) significantly influences the course of disease. This simple fact must be considered in all cardiovascular diagnosis and therapy. However, major gaps in knowledge about and awareness of cardiovascular disease in women still impede the implementation of sex-specific strategies. Among the gaps are a lack of understanding of the pathophysiology of women-biased coronary artery disease syndromes (spasms, dissections, Takotsubo syndrome), sex differences in cardiomyopathies and heart failure, a higher prevalence of cardiomyopathies with sarcomeric mutations in men, a higher prevalence of heart failure with preserved ejection fraction in women, and sex-specific disease mechanisms, as well as sex differences in sudden cardiac arrest and long QT syndrome. Basic research strategies must do more to include female-specific aspects of disease such as the genetic imbalance of 2 versus one X chromosome and the effects of sex hormones. Drug therapy in women also needs more attention. Furthermore, pregnancy-associated cardiovascular disease must be considered a potential risk factor in women, including pregnancy-related coronary artery dissection, preeclampsia, and peripartum cardiomyopathy. Finally, the sociocultural dimension of gender should be included in research efforts. The organization of gender medicine must be established as a cross-sectional discipline but also as a centered structure with its own research resources, methods, and questions.

Sex-Related Differences in Vasomotor Function in Patients With Angina and Unobstructed Coronary Arteries

BACKGROUND

Coronary vasomotor dysfunction is an important mechanism for angina in patients with unobstructed coronary arteries.

OBJECTIVES

The purpose of this study was to determine sex differences in the prevalence and clinical presentation of vasomotor dysfunction in a European population and to examine sex differences in the dose of acetylcholine leading to a positive acetylcholine provocation test (ACH test).

METHODS

Between 2007 and 2014, we included 1,379 consecutive patients with stable angina, unobstructed coronaries and ACH test performed for epicardial vasospasm or coronary microvascular dysfunction (CMD) due to microvascular spasm. The predictive value of sex, risk factors, symptoms, and noninvasive test results was analyzed by means of logistic regression.

RESULTS

The mean patient age was 62 years, and 42% were male. There were 813 patients (59%) with a pathological ACH test, 33% for CMD and 26% for epicardial vasospasm. A pathological test was more common in females (70% vs. 43%; p < 0.001). In a multivariable logistic regression model the sex difference was statistically significant with a female-male odds ratio for CMD and epicardial vasospasm of 4.2 (95% confidence interval: 3.1 to 5.5; p < 0.001) and 2.3 (95% confidence interval: 1.7 to 3.1; p < 0.001), respectively. Effort-related symptoms, but neither risk factors nor noninvasive stress tests, contributed to predicting a pathological test. Female patients were more sensitive to acetylcholine with vasomotor dysfunction occurring at lower ACH doses compared with male patients.

CONCLUSIONS

Vasomotor dysfunction is frequent in patients with angina and unobstructed coronaries in a European population. Female patients have a higher prevalence of vasomotor dysfunction (especially CMD) compared with male patients. A pathological ACH test was observed at lower ACH doses in women compared with men.

Androgens and cardiovascular disease in women and men

Cardiovascular disease is the leading cause of death in both women and men. Its pathogenesis is multifactorial, with sex hormones playing an important role. Androgens have both direct and indirect effects on the vasculature. This review summarizes evidence on the association of both endogenous and exogenous androgens with subclinical and overt cardiovascular disease in women and men. Concerning women, both high and low levels of endogenous androgens have been associated with cardiovascular disease, while other studies have reported no association. Adiposity, impaired glucose metabolism, dyslipidemia and estrogen levels may mediate the observed associations. Regarding testosterone therapy in women, there have been no large prospective studies on cardiovascular outcomes. Concerning men, most studies indicate that low levels of circulating testosterone are associated with increased rates of cardiovascular disease in the general population; the causality, however, of this association remains to be proven. Testosterone replacement therapy in men with symptoms of hypogonadism and low serum testosterone merits caution with regard to cardiovascular safety, as evidence is still conflicting.