Leptin receptors are expressed in coronary arteries, and hyperleptinemia causes significant coronary endothelial dysfunction

Signals From Inflamed Perivascular Adipose Tissue Contribute to Small-Vessel Dysfunction in Women With Human Immunodeficiency Virus

BACKGROUND

People with the human immunodeficiency virus (PWH) have microvascular disease. Because perivascular adipose tissue (PVAT) regulates microvascular function and adipose tissue is inflamed in PWH, we tested the hypothesis that PWH have inflamed PVAT that impairs the function of their small vessels.

METHODS

Subcutaneous small arteries were dissected with or without PVAT from a gluteal skin biopsy from 11 women with treated HIV (WWH) aged < 50 years and 10 matched women without HIV, and studied on isometric myographs. Nitric oxide (NO) and reactive oxygen species (ROS) were measured by fluorescence microscopy. Adipokines and markers of inflammation and ROS were assayed in PVAT.

RESULTS

PVAT surrounding the small arteries in control women significantly (P < .05) enhanced acetylcholine-induced endothelium-dependent relaxation and NO, and reduced contractions to thromboxane and endothelin-1. However, these effects of PVAT were reduced significantly (P < .05) in WWH whose PVAT released less adiponectin but more markers of ROS and inflammation. Moderation of contractions by PVAT were correlated positively with adipose adiponectin.

CONCLUSIONS

PVAT from WWH has oxidative stress, inflammation, and reduced release of adiponectin, which may contribute to enhanced contractions and therefore could promote small-artery dysfunction.

Sex-Specific Effects of Cholesteryl Ester Transfer Protein (CETP) on the Perivascular Adipose Tissue

Cholesteryl ester transfer protein (CETP) increases the atherosclerosis risk by lowering HDL-cholesterol levels. It also exhibits tissue-specific effects independent of HDL. However, sexual dimorphism of CETP effects remains largely unexplored. Here, we hypothesized that CETP impacts the perivascular adipose tissue (PVAT) phenotype and function in a sex-specific manner. PVAT function, gene and protein expression, and morphology were examined in male and female transgenic mice expressing human or simian CETP and their non-transgenic counterparts (NTg). PVAT exerted its anticontractile effect in aortas from NTg males, NTg females, and CETP females, but not in CETP males. CETP male PVAT had reduced NO levels, decreased eNOS and phospho-eNOS levels, oxidative stress, increased NOX1 and 2, and decreased SOD2 and 3 expressions. In contrast, CETP-expressing female PVAT displayed increased NO and phospho-eNOS levels with unchanged NOX expression. NOX inhibition and the antioxidant tempol restored PVAT anticontractile function in CETP males. Ex vivo estrogen treatment also restored PVAT function in CETP males. Moreover, CETP males, but not female PVAT, show increased inflammatory markers. PVAT lipid content increased in CETP males but decreased in CETP females, while PVAT cholesterol content increased in CETP females. CETP male PVAT exhibited elevated leptin and reduced Prdm16 (brown adipocyte marker) expression. These findings highlight CETP sex-specific impact on PVAT. In males, CETP impaired PVAT anticontractile function, accompanied by oxidative stress, inflammation, and whitening. Conversely, in females, CETP expression increased NO levels, induced an anti-inflammatory phenotype, and preserved the anticontractile function. This study reveals sex-specific vascular dysfunction mediated by CETP.

White-brown adipose tissue interplay in polycystic ovary syndrome: Therapeutic avenues

This study highlights the therapeutic potential of activating brown adipose tissue (BAT) for managing polycystic ovary syndrome (PCOS), a prevalent endocrine disorder associated with metabolic and reproductive abnormalities. BAT plays a crucial role in regulating energy expenditure and systemic insulin sensitivity, making it an attractive target for the treatment of obesity and metabolic diseases. Recent research suggests that impaired BAT function and mass may contribute to the link between metabolic disturbances and reproductive issues in PCOS. Additionally, abnormal white adipose tissue (WAT) can exacerbate these conditions by releasing adipokines and nonesterified fatty acids. In this review, we explored the impact of WAT changes on BAT function in PCOS and discussed the potential of BAT activation as a therapeutic strategy to improve PCOS symptoms. We propose that BAT activation holds promise for managing PCOS; however, further research is needed to confirm its efficacy and to develop clinically feasible methods for BAT activation.

Molecular and Cellular Mechanisms Underlying the Cardiac Hypertrophic and Pro-Remodelling Effects of Leptin

Since its initial discovery in 1994, the adipokine leptin has received extensive interest as an important satiety factor and regulator of energy expenditure. Although produced primarily by white adipocytes, leptin can be synthesized by numerous tissues including those comprising the cardiovascular system. Cardiovascular function can thus be affected by locally produced leptin via an autocrine or paracrine manner but also by circulating leptin. Leptin exerts its effects by binding to and activating specific receptors, termed ObRs or LepRs, belonging to the Class I cytokine family of receptors of which six isoforms have been identified. Although all ObRs have identical intracellular domains, they differ substantially in length in terms of their extracellular domains, which determine their ability to activate cell signalling pathways. The most important of these receptors in terms of biological effects of leptin is the so-called long form (ObRb), which possesses the complete intracellular domain linked to full cell signalling processes. The heart has been shown to express ObRb as well as to produce leptin. Leptin exerts numerous cardiac effects including the development of hypertrophy likely through a number of cell signaling processes as well as mitochondrial dynamics, thus demonstrating substantial complex underlying mechanisms. Here, we discuss mechanisms that potentially mediate leptin-induced cardiac pathological hypertrophy, which may contribute to the development of heart failure.

Role of Perturbated Hemostasis in MASLD and Its Correlation with Adipokines

The prevalence of metabolic dysfunction-associated steatotic liver disease (MASLD) continues to rise, making it one of the most prevalent chronic liver disorders. MASLD encompasses a range of liver pathologies, from simple steatosis to metabolic dysfunction-associated steatohepatitis (MASH) with inflammation, hepatocyte damage, and fibrosis. Interestingly, the liver exhibits close intercommunication with fatty tissue. In fact, adipose tissue could contribute to the etiology and advancement of MASLD, acting as an endocrine organ that releases several hormones and cytokines, with the adipokines assuming a pivotal role. The levels of adipokines in the blood are altered in people with MASLD, and recent research has shed light on the crucial role played by adipokines in regulating energy expenditure, inflammation, and fibrosis in MASLD. However, MASLD disease is a multifaceted condition that affects various aspects of health beyond liver function, including its impact on hemostasis. The alterations in coagulation mechanisms and endothelial and platelet functions may play a role in the increased vulnerability and severity of MASLD. Therefore, more attention is being given to imbalanced adipokines as causative agents in causing disturbances in hemostasis in MASLD. Metabolic inflammation and hepatic injury are fundamental components of MASLD, and the interrelation between these biological components and the hemostasis pathway is delineated by reciprocal influences, as well as the induction of alterations. Adipokines have the potential to serve as the shared elements within this complex interrelationship. The objective of this review is to thoroughly examine the existing scientific knowledge on the impairment of hemostasis in MASLD and its connection with adipokines, with the aim of enhancing our comprehension of the disease.

The Role of Oxidative Stress Enhanced by Adiposity in Cardiometabolic Diseases

Cardiometabolic diseases (CMDs), including cardiovascular disease (CVD), metabolic syndrome (MetS), and type 2 diabetes (T2D), are associated with increased morbidity and mortality. The growing prevalence of CVD is mostly attributed to the aging population and common occurrence of risk factors, such as high systolic blood pressure, elevated plasma glucose, and increased body mass index, which led to a global epidemic of obesity, MetS, and T2D. Oxidant–antioxidant balance disorders largely contribute to the pathogenesis and outcomes of CMDs, such as systemic essential hypertension, coronary artery disease, stroke, and MetS. Enhanced and disturbed generation of reactive oxygen species in excess adipose tissue during obesity may lead to increased oxidative stress. Understanding the interplay between adiposity, oxidative stress, and cardiometabolic risks can have translational impacts, leading to the identification of novel effective strategies for reducing the CMDs burden. The present review article is based on extant results from basic and clinical studies and specifically addresses the various aspects associated with oxidant–antioxidant balance disorders in the course of CMDs in subjects with excess adipose tissue accumulation. We aim at giving a comprehensive overview of existing knowledge, knowledge gaps, and future perspectives for further basic and clinical research. We provide insights into both the mechanisms and clinical implications of effects related to the interplay between adiposity and oxidative stress for treating and preventing CMDs. Future basic research and clinical trials are needed to further examine the mechanisms of adiposity-enhanced oxidative stress in CMDs and the efficacy of antioxidant therapies for reducing risk and improving outcome of patients with CMDs.

Effects of the Follicular Menstrual Phase on Forearm Vascular Conductance in Abdominal Obese Premenopausal Women During Graded Handgrip Exercise

Purpose

Previous studies have reported a sympatholytic action of estrogen on the vasculature in response to increased sympathetic outflow, an effect most notable during exercise, providing for necessary increases in blood flow to working muscle. In contrast, elevated concentrations of progesterone can inhibit this action of estrogen, impairing increases in blood flow. We hypothesize that the peak concentration of estrogen during the proliferative portion of the follicular phase of the menstrual cycle in female humans will increase vascular conductance during exercise when the effects of progesterone are negligible. In addition, we hypothesize that overweight abdominally obese females will have an attenuated conductance response to dynamic exercise during the same menstrual phase.

Methods

Participants engaged in graded forearm exercise using an isotonic handgrip dynometer with sequential increases in resistance at a cadence of 30 contractions/minute until task failure. They performed exercise at time points of the menstrual cycle corresponding to low concentrations of both sex hormones and elevated estrogen, while progesterone remained low. Blood flow and vascular conductance were measured using Doppler ultrasound.

Results

This revealed a trend that abdominal obese women during a phase of low estrogen had a lower overall blood flow and vascular conductance response than healthy controls at matching resistance stages during rest and exercise. This group difference was attenuated during the proliferative phase with elevated circulating estrogen. There is not a statistically significant interaction between Ovarian Phase and Weight group (P = 0.778).

Conclusion

The results indicate that overweight women are at a disadvantage during exercise in increasing blood flow to working muscles, which can be detrimental to overall fitness improvement during the early and potentially late follicular phase of the menstrual cycle.

Medical and Surgical Obesity Treatments and Atherosclerosis: Mechanisms beyond Typical Risk Factors

PURPOSE OF REVIEW

This study aims to discuss the mechanisms by which GLP-1 agonists and bariatric surgery improve cardiovascular outcomes in severely obese patients.

RECENT FINDINGS

Recent studies have demonstrated that both GLP-1 agonist use and bariatric surgery reduce adverse cardiovascular outcomes. Improvements in traditional atherosclerosis risk factors in association with weight loss likely contribute, but weight loss-independent mechanisms are also suggested to have roles. We review the clinical and preclinical evidence base for cardiovascular benefit of LP-1 agonists and bariatric surgery beyond traditional risk factors, including improvements in endothelial function, direct impacts on atherosclerotic plaques, and anti-inflammatory effects.

Leptin in Atherosclerosis: Focus on Macrophages, Endothelial and Smooth Muscle Cells

Increasing adipose tissue mass in obesity directly correlates with elevated circulating leptin levels. Leptin is an adipokine known to play a role in numerous biological processes including regulation of energy homeostasis, inflammation, vascular function and angiogenesis. While physiological concentrations of leptin may exhibit multiple beneficial effects, chronically elevated pathophysiological levels or hyperleptinemia, characteristic of obesity and diabetes, is a major risk factor for development of atherosclerosis. Hyperleptinemia results in a state of selective leptin resistance such that while beneficial metabolic effects of leptin are dampened, deleterious vascular effects of leptin are conserved attributing to vascular dysfunction. Leptin exerts potent proatherogenic effects on multiple vascular cell types including macrophages, endothelial cells and smooth muscle cells; these effects are mediated via an interaction of leptin with the long form of leptin receptor, abundantly expressed in atherosclerotic plaques. This review provides a summary of recent in vivo and in vitro studies that highlight a role of leptin in the pathogenesis of atherosclerotic complications associated with obesity and diabetes.

The Interplay Between Adipose Tissue and Vasculature: Role of Oxidative Stress in Obesity

Cardiovascular diseases (CVDs) rank the leading cause of morbidity and mortality globally. Obesity and its related metabolic syndrome are well-established risk factors for CVDs. Therefore, understanding the pathophysiological role of adipose tissues is of great importance in maintaining cardiovascular health. Oxidative stress, characterized by excessive formation of reactive oxygen species, is a common cellular stress shared by obesity and CVDs. While plenty of literatures have illustrated the vascular oxidative stress, very few have discussed the impact of oxidative stress in adipose tissues. Adipose tissues can communicate with vascular systems, in an endocrine and paracrine manner, through secreting several adipocytokines, which is largely dysregulated in obesity. The aim of this review is to summarize current understanding of the relationship between oxidative stress in obesity and vascular endothelial dysfunction. In this review, we briefly describe the possible causes of oxidative stress in obesity, and the impact of obesity-induced oxidative stress on adipose tissue function. We also summarize the crosstalk between adipose tissue and vasculature mediated by adipocytokines in vascular oxidative stress. In addition, we highlight the potential target mediating adipose tissue oxidative stress.

Obesity-induced cognitive impairment in older adults: a microvascular perspective

Over two-thirds of individuals aged 65 and older are obese or overweight in the United States. Epidemiological data show an association between the degree of adiposity and cognitive dysfunction in the elderly. In this review, the pathophysiological roles of microvascular mechanisms, including impaired endothelial function and neurovascular coupling responses, microvascular rarefaction, and blood-brain barrier disruption in the genesis of cognitive impairment in geriatric obesity are considered. The potential contribution of adipose-derived factors and fundamental cellular and molecular mechanisms of senescence to exacerbated obesity-induced cerebromicrovascular impairment and cognitive decline in aging are discussed.

Association of Low Leptin with Poor 3-Month Prognosis in Ischemic Stroke Patients with Type 2 Diabetes

Background

Leptin, an adipokine, has effects on the cardiovascular system with both protective and harmful role. This study aimed to assess the relationship between leptin and 3-month prognosis in ischemic stroke patients with type 2 diabetes.

Patients and Methods

As a prospective single-center observational study, we collected consecutive first-ever acute ischemia stroke with type 2 diabetes mellitus from February 2019 to February 2020. Serum samples were obtained at admission, and leptin serum levels were tested by the ELISA method. Logistic regression models were used to assess leptin's prognostic value to predict the functional outcome and mortality within three months.

Results

Finally, two hundred and eleven patients were included, and the mean leptin serum level was 16.8 (SD. 6.9) ng/mL. At admission, 53.6% of those included patients (N=113) were defined as severe stroke (NIH Stroke Scale [NIHSS]>5). In multivariable models adjusted for other factors, leptin levels<11.6ng/mL (lowest quartile, Q1) related to severe stroke and the risk increased 175% (odds ratios [OR] =2.75; 95% confidence interval [CI]=2.13-3.38; P=0.002). Serum leptin levels on admission in patients with poor outcomes and nonsurvivors were significantly reduced (P<0.001 and P<0.001). Leptin levels <11.6ng/mL (lowest quartile, Q1) related to a higher risk of poor functional impairment (OR=5.13; 95% CI =3.25-6.86; P<0.001) and mortality (OR=3.19; 95% CI =2.03-4.25; P<0.001).

Conclusion

The data shows that leptin serum level is a useful prognostic biomarker in ischemic stroke patients with type 2 diabetes, and this relationship is negative.

Adipokines and Inflammation: Focus on Cardiovascular Diseases

It is well established that adipose tissue, apart from its energy storage function, acts as an endocrine organ that produces and secretes a number of bioactive substances, including hormones commonly known as adipokines. Obesity is a major risk factor for the development of cardiovascular diseases, mainly due to a low grade of inflammation and the excessive fat accumulation produced in this state. The adipose tissue dysfunction in obesity leads to an aberrant release of adipokines, some of them with direct cardiovascular and inflammatory regulatory functions. Inflammation is a common link between obesity and cardiovascular diseases, so this review will summarise the role of the main adipokines implicated in the regulation of the inflammatory processes occurring under the scenario of cardiovascular diseases.

Pharmacological management of vascular endothelial dysfunction in diabetes: TCM and western medicine compared based on biomarkers and biochemical parameters

Diabetes, a worldwide health concern while burdening significant populace of countries with time due to a hefty increase in both incidence and prevalence rates. Hyperglycemia has been buttressed both in clinical and experimental studies to modulate widespread molecular actions that effect macro and microvascular dysfunctions. Endothelial dysfunction, activation, inflammation, and endothelial barrier leakage are key factors contributing to vascular complications in diabetes, plus the development of diabetes-induced cardiovascular diseases. The recent increase in molecular, transcriptional, and clinical studies has brought a new scope to the understanding of molecular mechanisms and the therapeutic targets for endothelial dysfunction in diabetes. In this review, an attempt made to discuss up to date critical and emerging molecular signaling pathways involved in the pathophysiology of endothelial dysfunction and viable pharmacological management targets. Importantly, we exploit some Traditional Chinese Medicines (TCM)/TCM isolated bioactive compounds modulating effects on endothelial dysfunction in diabetes. Finally, clinical studies data on biomarkers and biochemical parameters involved in the assessment of the efficacy of treatment in vascular endothelial dysfunction in diabetes was compared between clinically used western hypoglycemic drugs and TCM formulas.

Von Willebrand Factor Deficiency Improves Hepatic Steatosis, Insulin Resistance, and Inflammation in Mice Fed High-Fat Diet

OBJECTIVE

The aim of this study was to investigate the effect of Von Willebrand factor (VWF) on high-fat diet (HFD)-induced hepatic steatosis, insulin resistance, and inflammation in mice.

METHODS

The expression of VWF was detected in obese mice. Wild-type and VWF knockout mice were fed a normal chow diet or an HFD, and then biomedical, histological, and metabolic analyses were conducted to identify pathologic alterations. Inflammatory cytokine levels and the number of hepatic macrophages were determined in these mice fed an HFD.

RESULTS

VWF expression was significantly increased in obese mice. VWF^-/- mice were less obese and had improved hepatic steatosis, balance of lipid metabolism, and insulin resistance in response to HFD. Furthermore, VWF deficiency attenuated HFD-induced systemic and hepatic inflammation. In addition, VWF deficiency rescued the abnormal accumulation of hepatic macrophages.

CONCLUSIONS

These data demonstrated VWF deficiency improves hepatic steatosis, insulin resistance, and inflammation. Furthermore, the protective effects are mediated via regulation of hepatic macrophages.

Mechanistic Links Between Obesity, Diabetes, and Blood Pressure: Role of Perivascular Adipose Tissue

Obesity is increasingly prevalent and is associated with substantial cardiovascular risk. Adipose tissue distribution and morphology play a key role in determining the degree of adverse effects, and a key factor in the disease process appears to be the inflammatory cell population in adipose tissue. Healthy adipose tissue secretes a number of vasoactive adipokines and anti-inflammatory cytokines, and changes to this secretory profile will contribute to pathogenesis in obesity. In this review, we discuss the links between adipokine dysregulation and the development of hypertension and diabetes and explore the potential for manipulating adipose tissue morphology and its immune cell population to improve cardiovascular health in obesity.

Functional Relationship between Leptin and Nitric Oxide in Metabolism

Leptin, the product of the ob gene, was originally described as a satiety factor, playing a crucial role in the control of body weight. Nevertheless, the wide distribution of leptin receptors in peripheral tissues supports that leptin exerts pleiotropic biological effects, consisting of the modulation of numerous processes including thermogenesis, reproduction, angiogenesis, hematopoiesis, osteogenesis, neuroendocrine, and immune functions as well as arterial pressure control. Nitric oxide (NO) is a free radical synthesized from L-arginine by the action of the NO synthase (NOS) enzyme. Three NOS isoforms have been identified: the neuronal NOS (nNOS) and endothelial NOS (eNOS) constitutive isoforms, and the inducible NOS (iNOS). NO mediates multiple biological effects in a variety of physiological systems such as energy balance, blood pressure, reproduction, immune response, or reproduction. Leptin and NO on their own participate in multiple common physiological processes, with a functional relationship between both factors having been identified. The present review describes the functional relationship between leptin and NO in different physiological processes.

Gene Expression and Cardiometabolic Phenotypes of Vitamin D-Deficient Overweight and Obese Black Children

Associations between whole blood transcriptome and clinical phenotypes in vitamin D-deficient overweight and obese children can provide insight into the biological effects of vitamin D and obesity. We determined differentially expressed genes (DEGs) in relation to body mass index (BMI) in vitamin D-deficient black children with a BMI ≥ 85th percentile and ascertained the cardiometabolic phenotypes associated with the DEGs. We examined whole-blood transcriptome gene expression by RNA sequencing and cardiometabolic profiling in 41, 10- to 18-year-old children. We found 296 DEGs in association with BMI after adjusting for age, race, sex, and pubertal status. Cardiometabolic phenotypes associated with the BMI-related DEGs, after adjusting for age, sex, pubertal status, and %total body fat, were (i) flow-mediated dilation (marker of endothelial function), (ii) c-reactive protein (marker of inflammation), and (iii) leptin (adipocytokine). Canonical pathways of relevance for childhood obesity and its phenotypes that were significantly associated with the BMI-related DEGs affected immune cell function/inflammation, vascular health, metabolic function, and cell survival/death; several immune and inflammatory pathways overlapped across the three phenotypes. We have identified transcriptome-based biomarkers associated with BMI in vitamin D-deficient, overweight and obese black children. Modulating effects of vitamin D supplementation on these biomarkers and their related phenotypes need further exploration.

Linking the metabolic syndrome and obesity with vitamin D status: risks and opportunities for improving cardiometabolic health and well-being

The global death toll from noncommunicable diseases is exceptionally high, reported to cause 71% of global deaths worldwide. Metabolic syndrome risk factors, especially excessive adiposity and obesity, are at the heart of the problem resulting in increased co-morbidities such as cardiometabolic diseases and cancer, increased health costs, poorer quality of life, and shortened survival. Vitamin D3 can positively reverse many of these adverse effects and outcomes through blocking signaling mechanisms that predispose to cardiometabolic and metastatic disease. As an affordable natural agent, vitamin D3 can be used to counteract obesity-induced inflammation, block early adipogenesis, enhance glucose uptake, counteract hyperleptinemia, ameliorate insulin resistance, and reduce hypertension. This is supported by data from in vitro, in vivo and epidemiological studies and clinical trials. We propose that everyone in general and obese patients in particular consider raising 25-hydroxyvitamin D levels through UVB exposure and/or supplemental vitamin D3 intake to reduce cardiometabolic and metastatic disease and increase longevity.

The Local Regulation of Vascular Function: From an Inside-Outside to an Outside-Inside Model

Our understanding of the regulation of vascular function, specifically that of vasomotion, has evolved dramatically over the past few decades. The classic conception of a vascular system solely regulated by circulating hormones and sympathetic innervation gave way to a vision of a local regulation. Initially by the so-called, autacoids like prostacyclin, which represented the first endothelium-derived paracrine regulator of smooth muscle. This was the prelude of the EDRF-nitric oxide age that has occupied vascular scientists for nearly 30 years. Endothelial cells revealed to have the ability to generate numerous mediators besides prostacyclin and nitric oxide (NO). The need to classify these substances led to the coining of the terms: endothelium-derived relaxing, hyperpolarizing and contracting factors, which included various prostaglandins, thromboxane A2, endothelin, as well numerous candidates for the hyperpolarizing factor. The opposite layer of the vascular wall, the adventitia, eventually and for a quite short period of time, enjoyed the attention of some vascular physiologists. Adventitial fibroblasts were recognized as paracrine cells to the smooth muscle because of their ability to produce some substances such as superoxide. Remarkably, this took place before our awareness of the functional potential of another adventitial cell, the adipocyte. Possibly, because the perivascular adipose tissue (PVAT) was systematically removed during the experiments as considered a non-vascular artifact tissue, it took quite long to be considered a major source of paracrine substances. These are now being integrated in the vast pool of mediators synthesized by adipocytes, known as adipokines. They include hormones involved in metabolic regulation, like leptin or adiponectin; classic vascular mediators like NO, angiotensin II or catecholamines; and inflammatory mediators or adipocytokines. The first substance studied was an anti-contractile factor named adipose-derived relaxing factor of uncertain chemical nature but possibly, some of the relaxing mediators mentioned above are behind this factor. This manuscript intends to review the vascular regulation from the point of view of the paracrine control exerted by the cells present in the vascular environment, namely, endothelial, adventitial, adipocyte and vascular stromal cells.

Exercise for Prevention and Relief of Cardiovascular Disease: Prognoses, Mechanisms, and Approaches

This review is aimed at summarizing the new findings about the multiple benefits of exercise on cardiovascular disease (CVD). We pay attention to the prevalence and risk factors of CVD and mechanisms and recommendations of physical activity. Physical activity can improve insulin sensitivity, alleviate plasma dyslipidemia, normalize elevated blood pressure, decrease blood viscosity, promote endothelial nitric oxide production, and improve leptin sensitivity to protect the heart and vessels. Besides, the protective role of exercise on the body involves not only animal models in the laboratory but also clinical studies which is demonstrated by WHO recommendations. The general exercise intensity for humans recommended by the American Heart Association to prevent CVD is moderate exercise of 30 minutes, 5 times a week. However, even the easiest activity is better than nothing. What is more, owing to the different physical fitness of individuals, a standard exercise training cannot provide the exact treatment for everyone. So personalization of exercise will be an irresistible trend and bring more beneficial effects with less inefficient physical activities. This paper reviews the benefits of exercise contributing to the body especially in CVD through the recent mechanism studies.

Leptinemia is Associated With Peripheral Artery Disease

BACKGROUND

Leptin, adiponectin, and resistin are in a class of hormones called adipokines that are produced by adipocytes and have been implicated in the causal pathway of atherosclerosis. We examined the association between adipokine levels and peripheral artery disease (PAD), hypothesizing that after adjusting for fat mass, leptin and resistin would be higher, whereas adiponectin would be lower, in patients with PAD.

METHODS

A cross-sectional sample of 179 predominately male (97%) vascular surgery outpatients was recruited from the San Francisco Veterans Affairs Medical Center (SFVAMC). PAD was defined as either an ankle-brachial index < 0.9 plus symptoms of claudication or prior revascularization for symptomatic PAD (n = 141). Controls had an ankle-brachial index ≥0.9 and no history of atherosclerotic disease (n = 38). Adipokines were assayed using commercially available ELISA kits and values were log-transformed. Fat mass was measured using bioelectrical impedance.

RESULTS

In an analysis adjusting for body mass index (BMI) and atherosclerotic risk factors, higher serum leptin was associated with PAD (OR 2.54, 95% CI 1.07-6.01, P = 0.03), whereas high molecular weight adiponectin was inversely associated, though not significantly (OR 0.60, 95% CI 0.33-1.08, P = 0.09). Resistin was not associated with PAD. Sensitivity analyses using fat mass/height² rather than BMI yielded similar results.

CONCLUSIONS

These results indicate that after adjusting for BMI or fat mass, serum leptin levels are positively and independently associated with PAD, whereas high molecular weight adiponectin might be inversely associated. Using a more representative, nonveteran sample, further investigations should focus on the potential role of adipokines in the pathophysiology of PAD as well as determine whether leptin levels have clinical utility in predicting PAD outcomes.

The interplay between adipose tissue and the cardiovascular system: is fat always bad?

Obesity is a risk factor for cardiovascular disease (CVD). However, clinical research has revealed a paradoxically protective role for obesity in patients with chronic diseases including CVD, suggesting that the biological 'quality' of adipose tissue (AT) may be more important than overall AT mass or body weight. Importantly, AT is recognised as a dynamic organ secreting a wide range of biologically active adipokines, microRNAs, gaseous messengers, and other metabolites that affect the cardiovascular system in both endocrine and paracrine ways. Despite being able to mediate normal cardiovascular function under physiological conditions, AT undergoes a phenotypic shift characterised by acquisition of pro-oxidant and pro-inflammatory properties in cases of CVD. Crucially, recent evidence suggests that AT depots such as perivascular AT and epicardial AT are able to modify their phenotype in response to local signals of vascular and myocardial origin, respectively. Utilisation of this unique property of certain AT depots to dynamically track cardiovascular biology may reveal novel diagnostic and prognostic tools against CVD. Better understanding of the mechanisms controlling the 'quality' of AT secretome, as well as the communication links between AT and the cardiovascular system, is required for the efficient management of CVD.

A study of the correlation of insulin resistance and leptin with inflammatory factors and vascular endothelial injury in T2DM patients with CHD

The purpose of this study was to explore the correlation of insulin resistance (IR) and leptin with inflammatory factors and vascular endothelial injury in patients with type 2 diabetes mellitus (T2DM) complicated with coronary heart disease (CHD) was explored. One hundred and fifty normal patients (normal group), 150 patients with pure T2DM (T2DM group) and 150 patients with T2DM complicated with coronary heart disease (T2DM + CHD group) were selected from Xi'an No. 5 Hospital. All the participants met our inclusion criteria. Age, body mass index, waist-to-hip ratio, blood lipid and fasting plasma glucose (FPG), of all the subjects were measured. Chemiluminescent immunoassay was adopted for the detection of FPG and double-antibody sandwich method was used for the determination of fasting plasma leptin, and assay of high-sensitivity C-reactive protein (hs-CRP), interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α). Insulin resistance index (IRI) was used to evaluate IR and enzyme-linked immunosorbent assay was adopted for the detection of von Willebrand factor (vWF) and endothelin (ET-1). Compared with the control group, patients in the T2DM + CHD group and those in the T2DM group had higher homeostasis model assessment-IR, and higher assay of plasma leptin, hs-CRP, IL-6 and TNF-α (P<0.05), and lower vascular endothelial function (P<0.05). Moreover, compared with the T2DM group, T2DM + CHD group had higher plasma leptin, and higher assay of hs-CRP, IL-6 and TNF-α (P<0.05). IRI was positively correlated with hs-CRP (r=0.521, P=0.001), IL-6 (r=0.359, P=0.001) and TNF-α (r=0.386, P=0.001), leptin was positively correlated with hs-CRP (r=0.305, P=0.001), IL-6 (r=0.259, P=0.002) and TNF-α (r=0.429, P=0.001), and IRI had no correlation with ET-1 (r=0.058, P=0.734) and vWF (r=0.047, P=0.812), that is, it had no direct correlation with vascular endothelial function. Level of leptin was positively correlated with ET-1 (r=0.366, P=0.001) and vWF (r=0.471, P=0.001), that is, it was negatively correlated with vascular endothelial function. Our results showed that leptin, hs-CRP, IL-6 and TNF-α are involved in the occurrence and development of CHD in patients with T2DM. IR has no direct correlation with the occurrence and development of CHD in patients with T2DM.

Perivascular Adipose Tissue as a Relevant Fat Depot for Cardiovascular Risk in Obesity

Obesity is associated with increased risk of premature death, morbidity, and mortality from several cardiovascular diseases (CVDs), including stroke, coronary heart disease (CHD), myocardial infarction, and congestive heart failure. However, this is not a straightforward relationship. Although several studies have substantiated that obesity confers an independent and additive risk of all-cause and cardiovascular death, there is significant variability in these associations, with some lean individuals developing diseases and others remaining healthy despite severe obesity, the so-called metabolically healthy obese. Part of this variability has been attributed to the heterogeneity in both the distribution of body fat and the intrinsic properties of adipose tissue depots, including developmental origin, adipogenic and proliferative capacity, glucose and lipid metabolism, hormonal control, thermogenic ability, and vascularization. In obesity, these depot-specific differences translate into specific fat distribution patterns, which are closely associated with differential cardiometabolic risks. The adventitial fat layer, also known as perivascular adipose tissue (PVAT), is of major importance. Similar to the visceral adipose tissue, PVAT has a pathophysiological role in CVDs. PVAT influences vascular homeostasis by releasing numerous vasoactive factors, cytokines, and adipokines, which can readily target the underlying smooth muscle cell layers, regulating the vascular tone, distribution of blood flow, as well as angiogenesis, inflammatory processes, and redox status. In this review, we summarize the current knowledge and discuss the role of PVAT within the scope of adipose tissue as a major contributing factor to obesity-associated cardiovascular risk. Relevant clinical studies documenting the relationship between PVAT dysfunction and CVD with a focus on potential mechanisms by which PVAT contributes to obesity-related CVDs are pointed out.

Polycystic ovarian syndrome-associated cardiovascular complications: An overview of the association between the biochemical markers and potential strategies for their prevention and elimination

Polycystic ovarian syndrome (PCOS) is associated with multiple cardiovascular risk factors (CVRF) including endothelial dysfunction (ED) and presence of metabolic syndrome (MS). The probable reason suggested for elevated CVRF in PCOS is oxidative stress (OS), which is an integral factor in cardiometabolic complications (CMC) seen in PCOS women. The interrelated mechanisms by which CVRF instigate clinical manifestation plays a crucial role in identification of a strategy to treat different comorbidities in PCOS. The existing treatment for PCOS mostly focuses on management of individual disorders, however, therapeutic strategies or novel targets to address cardiovascular complications in PCOS deserve extensive analysis.

Oxidative and inflammatory signals in obesity-associated vascular abnormalities

Obesity is associated with increased cardiovascular morbidity and mortality in part due to vascular abnormalities such as endothelial dysfunction and arterial stiffening. The hypertension and other health complications that arise from these vascular defects increase the risk of heart diseases and stroke. Prooxidant and proinflammatory signaling pathways as well as adipocyte-derived factors have emerged as critical mediators of obesity-associated vascular abnormalities. Designing treatments aimed specifically at improving the vascular dysfunction caused by obesity may provide an effective therapeutic approach to prevent the cardiovascular sequelae associated with excessive adiposity. In this review, we discuss the recent evidence supporting the role of oxidative stress and cytokines and inflammatory signals within the vasculature as well as the impact of the surrounding perivascular adipose tissue (PVAT) on the regulation of vascular function and arterial stiffening in obesity. In particular, we focus on the highly plastic nature of the vasculature in response to altered oxidant and inflammatory signaling and highlight how weight management can be an effective therapeutic approach to reduce the oxidative stress and inflammatory signaling and improve vascular function.

Cardiovascular consequences of metabolic syndrome

The metabolic syndrome (MetS) is defined as the concurrence of obesity-associated cardiovascular risk factors including abdominal obesity, impaired glucose tolerance, hypertriglyceridemia, decreased HDL cholesterol, and/or hypertension. Earlier conceptualizations of the MetS focused on insulin resistance as a core feature, and it is clearly coincident with the above list of features. Each component of the MetS is an independent risk factor for cardiovascular disease and the combination of these risk factors elevates rates and severity of cardiovascular disease, related to a spectrum of cardiovascular conditions including microvascular dysfunction, coronary atherosclerosis and calcification, cardiac dysfunction, myocardial infarction, and heart failure. While advances in understanding the etiology and consequences of this complex disorder have been made, the underlying pathophysiological mechanisms remain incompletely understood, and it is unclear how these concurrent risk factors conspire to produce the variety of obesity-associated adverse cardiovascular diseases. In this review, we highlight current knowledge regarding the pathophysiological consequences of obesity and the MetS on cardiovascular function and disease, including considerations of potential physiological and molecular mechanisms that may contribute to these adverse outcomes.

Uterine artery leptin receptors during the ovarian cycle and pregnancy regulate angiogenesis in ovine uterine artery endothelial cells†

Leptin regulates body weight, reproductive functions, blood pressure, endothelial function, and fetoplacental angiogenesis. Compared to the luteal phase, the follicular phase and pregnancy are physiological states of elevated estrogen, angiogenesis, and uterine blood flow (UBF). Little is known concerning regulation of uterine artery (UA) angiogenesis by leptin and its receptors. We hypothesized that (1) ex vivo expression of leptin receptors (LEPR) in UA endothelium (UAendo) and UA vascular smooth muscle (UAvsm) is elevated in pregnant versus nonpregnant (Luteal and Follicular) sheep; (2) in vitro leptin treatments differentially modulate mitogenesis in uterine artery endothelial cells from pregnant (P-UAECs) more than in nonpregnant (NP-UAECs) ewes; and (3) LEPR are upregulated in P-UAECs versus NP-UAECs in association with leptin activation of phospho-STAT3 signaling. Local UA adaptations were evaluated using a unilateral pregnant sheep model where prebreeding uterine horn isolation (nongravid) restricted gravidity to one horn. Immunolocalization revealed LEPR in UAendo and UAvsm from pregnant and nonpregnant sheep. Contrary to our hypothesis, western analysis revealed that follicular UAendo and UAvsm LEPR were greater than luteal, nongravid, gravid, and control pregnant. Compared to pregnant groups, LEPR were elevated in renal artery endothelium of follicular and luteal sheep. Leptin treatment significantly increased mitogenesis in follicular phase NP-UAECs and P-UAECs, but not luteal phase NP-UAECs. Although UAEC expression of LEPR was similar between groups, leptin treatment only activated phospho-STAT3 in follicular NP-UAECs and P-UAECs. Thus, leptin may play an angiogenic role particularly in preparation for the increased UBF during the periovulatory period and subsequently to meet the demands of the growing fetus.

Activation of Nrf2-Antioxidant Signaling by 1,25-Dihydroxycholecalciferol Prevents Leptin-Induced Oxidative Stress and Inflammation in Human Endothelial Cells

Background: Obesity is associated with hyperleptinemia and endothelial dysfunction. Hyperleptinemia has been reported to induce both oxidative stress and inflammation by increasing reactive oxygen species production.Objective: The objective of this study was to determine the effects of 1,25-dihydroxycholecalciferol [1,25(OH)₂D₃] against leptin-induced oxidative stress and inflammation in human endothelial cells.Methods: Small interfering RNA (siRNA) were used to knock down the expression of vitamin D receptor (VDR) in human umbilical vein endothelial cells (HUVECs). HUVECs were pretreated for 4 h with physiologic (10^-10 M) or supraphysiologic (10^-7 M) concentrations of 1,25(OH)₂D₃ and exposed to leptin (10 ng/mL). Superoxide anion production and translocation of nuclear factor (erythroid-derived 2)-like 2 (NRF2) and nuclear transcription factor κB (NF-κB) subunit p65 to the nucleus and the activation of their target genes were quantified.Results: Pretreatment of HUVECs with 1,25(OH)₂D₃ prevented the leptin-induced increase in superoxide anion production (P < 0.05). Pretreatment with 1,25(OH)₂D₃ further increased NRF2 translocation to the nucleus (by 3-fold; P < 0.05) and increased mRNA expression of superoxide dismutase 2 (SOD2; by 2-fold), glutathione peroxidase (GPX; by 3-fold), NAD(P)H dehydrogenase (quinone) 1 (NQO1; by 4-fold), and heme oxygenase 1 (HMOX1; by 2-fold) (P < 0.05). Leptin doubled the translocation of NF-κB (P < 0.05) to the nucleus and increased (P < 0.05) the upregulation of vascular inflammatory mediators such as monocyte chemoattractant protein 1 (MCP1; by 1-fold), transforming growth factor β (TGF β by 1-fold), and vascular cell adhesion molecule 1 (VCAM1; by 4-fold) (P < 0.05), which were prevented (P < 0.05) by pretreatment with 1,25(OH)₂D₃ Protective effects of 1,25(OH)₂D₃ were confirmed to be VDR dependent by using VDR siRNA.Conclusion: Pretreatment with 1,25(OH)₂D₃ in the presence of a high concentration of leptin has a beneficial effect on HUVECs through the regulation of mediators of antioxidant activity and inflammation.

Obesity and Cardiovascular Disease: a Risk Factor or a Risk Marker?

In the USA, 69 % of adults are either overweight or obese and 35 % are obese. Obesity is associated with an increased incidence of various cardiovascular disorders. Obesity is a risk marker for cardiovascular disease, in that it is associated with a much higher prevalence of comorbidities such as diabetes, hypertension, and metabolic syndrome, which then increase the risk for cardiovascular disease. However, in addition, obesity may also be an independent risk factor for the development of cardiovascular disease. Furthermore, although obesity has been shown to be an independent risk factor for several cardiovascular diseases, it is often associated with improved survival once the diagnosis of the cardiovascular disease has been made, leading to the term "obesity paradox." Several pathways linking obesity and cardiovascular disease have been described. In this review, we attempt to summarize the complex relationship between obesity and cardiovascular disorders, in particular coronary atherosclerosis, heart failure, and atrial fibrillation.

The paracrine control of vascular motion. A historical perspective

During the last quarter of the past century, the leading role the endocrine and nervous systems had on the regulation of vasomotion, shifted towards a more paracrine-based regulation. This begun with the recognition of endothelial cells as active players of vascular control, when the vessel's intimal layer was identified as the main source of prostacyclin and was followed by the discovery of an endothelium-derived smooth muscle cell relaxing factor (EDRF). The new position acquired by endothelial cells prompted the discovery of other endothelium-derived regulatory products: vasoconstrictors, generally known as EDCFs, endothelin, and other vasodilators with hyperpolarizing properties (EDHFs). While this research was taking place, a quest for the discovery of the nature of EDRF carried back to a research line commenced a decade earlier: the recently found intracellular messenger cGMP and nitrovasodilators. Both were smooth muscle relaxants and appeared to interact in a hormonal fashion. Prejudice against an unconventional gaseous molecule delayed the acceptance that EDRF was nitric oxide (NO). When this happened, a new era of research that exceeded the vascular field commenced. The discovery of the pathway for NO synthesis from L-arginine involved the clever assembling of numerous unrelated observations of different areas of knowledge. The last ten years of research on the paracrine regulation of the vascular wall has shifted to perivascular fat (PVAT), which is beginning to be regarded as the fourth layer of the vascular wall. Starting with the discovery of an adipose-derived relaxing substance (ADRF), the role that different adipokines have on the paracrine control of vasomotion is now filling the research activity of many vascular pharmacology labs, and surprising interactions between the endothelium, PVAT and smooth muscle are being unveiled.

Caloric Restriction as a Strategy to Improve Vascular Dysfunction in Metabolic Disorders

Caloric restriction (CR) has proved to be the most effective and reproducible dietary intervention to increase healthy lifespan and aging. A reduction in cardiovascular disease (CVD) risk in obese subjects can be already achieved by a moderate and sustainable weight loss. Since pharmacological approaches for body weight reduction have, at present, a poor long-term efficacy, CR is of great interest in the prevention and/or reduction of CVD associated with obesity. Other dietary strategies changing specific macronutrients, such as altering carbohydrates, protein content or diet glycemic index have been also shown to decrease the progression of CVD in obese patients. In this review, we will focus on the positive effects and possible mechanisms of action of these strategies on vascular dysfunction.

Adiponectin, Leptin, and Fatty Acids in the Maintenance of Metabolic Homeostasis through Adipose Tissue Crosstalk

Metabolism research has made tremendous progress over the last several decades in establishing the adipocyte as a central rheostat in the regulation of systemic nutrient and energy homeostasis. Operating at multiple levels of control, the adipocyte communicates with organ systems to adjust gene expression, glucoregulatory hormone exocytosis, enzymatic reactions, and nutrient flux to equilibrate the metabolic demands of a positive or negative energy balance. The identification of these mechanisms has great potential to identify novel targets for the treatment of diabetes and related metabolic disorders. Herein, we review the central role of the adipocyte in the maintenance of metabolic homeostasis, highlighting three critical mediators: adiponectin, leptin, and fatty acids.

Leptin augments coronary vasoconstriction and smooth muscle proliferation via a Rho-kinase-dependent pathway

Leptin has been implicated as a key upstream mediator of pathways associated with coronary vascular dysfunction and disease. The purpose of this investigation was to test the hypothesis that leptin modifies the coronary artery proteome and promotes increases in coronary smooth muscle contraction and proliferation via influences on Rho kinase signaling. Global proteomic assessment of coronary arteries from lean swine cultured with obese concentrations of leptin (30 ng/mL) for 3 days revealed significant alterations in the coronary artery proteome (68 proteins) and identified an association between leptin treatment and calcium signaling/contraction (four proteins) and cellular growth and proliferation (35 proteins). Isometric tension studies demonstrated that both acute (30 min) and chronic (3 days, serum-free media) exposure to obese concentrations of leptin potentiated depolarization-induced contraction of coronary arteries. Inhibition of Rho kinase significantly reduced leptin-mediated increases in coronary artery contractions. The effects of leptin on the functional expression of Rho kinase were time-dependent, as acute treatment increased Rho kinase activity while chronic (3 day) exposure was associated with increases in Rho kinase protein abundance. Proliferation assays following chronic leptin administration (8 day, serum-containing media) demonstrated that leptin augmented coronary vascular smooth muscle proliferation and increased Rho kinase activity. Inhibition of Rho kinase significantly reduced these effects of leptin. Taken together, these findings demonstrate that leptin promotes increases in coronary vasoconstriction and smooth muscle proliferation and indicate that these phenotypic effects are associated with alterations in the coronary artery proteome and dynamic effects on the Rho kinase pathway.

Obesity Related Coronary Microvascular Dysfunction: From Basic to Clinical Practice

Obesity related coronary microvascular disease is a medical entity which is not yet fully elucidated. The pathophysiological basis of coronary microcirculatory dysfunction consists of a heterogeneous group of disorders with individual morphologic/functional/clinical presentation and prognosis. Coronary microcirculatory changes include mechanisms connected with vascular dysfunction, as well as extravascular and vasostructural changes in responses to neural, mechanical, and metabolic factors. Cardiometabolic changes that include obesity, dyslipidemia, diabetes mellitus type II, and hypertension are associated with atherosclerosis of epicardial coronary arteries and/or microvascular coronary dysfunction, with incompletely understood underlying mechanisms. In obesity, microvascular disease is mediated via adipokines/cytokines causing chronic, subclinical inflammation with (a) reduced NO-mediated dilatation, (b) changed endothelial- and smooth muscle-dependent vasoregulating mechanisms, (c) altered vasomotor control with increased sympathetic activity, and (d) obesity related hypertension with cardiomyocytes hypertrophy and impaired cardiac vascular adaptation to metabolic needs. From a clinical point of view it can present itself in acute or chronic form with different prognosis, as a practice problem for real-life diagnosis and treatment.

Obesity and Diabetes Mellitus Adversely Affect Outcomes after Cardiac Surgery in Children's Hospitals

OBJECTIVE

To assess how obesity or diabetes mellitus impacts outcomes in patients undergoing cardiac surgery in pediatric hospitals.

DESIGN

A multi-institutional, matched case-control study of the Pediatric Health Information System database was performed.

SETTING

Tertiary children's hospitals in the United States.

PATIENTS

All cardiac surgical cases in patients with obesity or diabetes mellitus between 2004 and 2012 were included. Cases were matched to controls by age, sex, race, and Risk Adjustment for Congenital Heart Surgery score.

OUTCOME MEASURES

Mortality, surgical complications, and hospital utilization. Differences in outcome measures were assessed by chi-square and Mann-Whitney tests. P value < .05 was significant.

RESULTS

Six hundred twenty-nine cardiac surgical cases (median age 17 years [IQR 12-32]) with obesity or diabetes mellitus were matched to 629 controls. Cases demonstrated lower median household income than those in the control group ($38,031 [IQR $31,900-$48,844] vs. ($41,896 [IQR $32,854-$56,020], P < .001). Mortality was similar between cases and controls (22% vs. 1.9%, P =.692). Surgical complications occurred similarly between cases and controls (13.5% vs. 12.4%, P = .535). Cases had longer intensive care unit length of stay than controls (3 vs. 2 days, P = .001), resulting in longer overall hospital length of stay (5 vs. 4 days, P < .001). Cases also had a higher odds of undergoing mechanical ventilation for >96 hours (OR 2.0, 95% CI 1.1-3.7) and higher rate of total parenteral nutrition use (7.2% vs. 4.5%, P = .040). Median hospital charges were higher in cases (clinical: $6,696 vs. $5,872; laboratory: $14,168 vs. $12,251; pharmacy: $12,971 vs. $10,426; imaging: $6,259 vs. $5,660; P ≤ .030 for all).

CONCLUSIONS

The presence of obesity or diabetes mellitus was associated with increased postoperative morbidity, hospital utilization, and cost in patients undergoing cardiac surgery in pediatric hospitals.

Better prognosis in overweight/obese coronary heart disease patients with high plasma levels of leptin

Background and aim

The involvement of leptin in atherosclerosis is very complex, including inflammation, the oxidative stress and thrombosis. Leptin has atherogenic and also antiatherogenic actions. In obesity elevated leptin levels are not sufficient to prevent disturbances of energy balance, suggesting that obese people are leptin resistant. The aim of the study was to investigate the relationship between baseline plasma levels of leptin and the incidence of new ischemic events in patients with CHD.

Methods

Plasma levels of leptin in fifty nine consecutive patients (29 men and 30 women) with CHD hospitalized in the County Emergency Clinical Hospital of Cluj-Napoca were measured using commercially available ELISA at admission. Patients with active infectious disease, neoplasia, acute coronary syndrome, stroke, hepatic or renal failure and severe heart failure were excluded The relationship between leptin levels and incident cardiovascular events (angina, nonfatal myocardial infarction or heart failure) over two years follow-up was studied using MEDCALC version 9.6.

Results

73.6% patients with CHD were overweight or suffered of obesity. There were no significant differences between women and men regarding the plasma levels of leptin, the body mass index (BMI), the number of rehospitalizations, rehospitalizations/patient, diabetes mellitus, hypertension or dyslipidemia. Only in women plasma levels of leptin are correlated with BMI. As compared with men with overweight and obesity (BMI≥25kg/m²), plasma levels of leptin were significantly higher in women with overweight and obesity (3905.97±463.91 pg/ml vs 1835.17±533.9 pg/ml) (p<0.002). Patient gender could not be demonstrated to influence prognosis. During the two years we recorded one or more readmissions in 26 patients (44%). The analysis of time till readmission using Kaplan-Meier curves, showed that leptin level (cut-off 2000 pg/ml, HR 0.38, 95% CI 0.17–0.83; p=0.01) and BMI (cut-off 28 kg/m², HR 0.3164, 95% CI 0.145–0.0689; p<0.01) were significantly associated with prognosis.

Conclusion

Patients with plasma levels of leptin >2000 pg/ml and BMI >28kg/m² had a better prognosis, suggesting a protective role of leptin in overweight/mild obesity.

Insights into the molecular mechanisms of diabetes-induced endothelial dysfunction: focus on oxidative stress and endothelial progenitor cells

Diabetes mellitus is a heterogeneous, multifactorial, chronic disease characterized by hyperglycemia owing to insulin insufficiency and insulin resistance (IR). Recent epidemiological studies showed that the diabetes epidemic affects 382 million people worldwide in 2013, and this figure is expected to be 600 million people by 2035. Diabetes is associated with microvascular and macrovascular complications resulting in accelerated endothelial dysfunction (ED), atherosclerosis, and cardiovascular disease (CVD). Unfortunately, the complex pathophysiology of diabetic cardiovascular damage is not fully understood. Therefore, there is a clear need to better understand the molecular pathophysiology of ED in diabetes, and consequently, better treatment options and novel efficacious therapies could be identified. In the light of recent extensive research, we re-investigate the association between diabetes-associated metabolic disturbances (IR, subclinical inflammation, dyslipidemia, hyperglycemia, dysregulated production of adipokines, defective incretin and gut hormones production/action, and oxidative stress) and ED, focusing on oxidative stress and endothelial progenitor cells (EPCs). In addition, we re-emphasize that oxidative stress is the final common pathway that transduces signals from other conditions-either directly or indirectly-leading to ED and CVD.

Obesity and coronary microvascular disease - implications for adipose tissue-mediated remote inflammatory response

It is believed that obesity has detrimental effects on the coronary circulation. These include immediate changes in coronary arterial vasomotor responsiveness and the development of occlusive large coronary artery disease. Despite its critical role in regulating myocardial perfusion, the altered behavior of coronary resistance arteries, which gives rise to coronary microvascular disease (CMD) is poorly understood in obesity. A chronic, low-grade vascular inflammation has been long considered as one of the main underlying pathology behind CMD. The expanded adipose tissue and the infiltrating macrophages are the major sources of pro-inflammatory mediators that have been implicated in causing inadequate myocardial perfusion and, in a long term, development of heart failure in obese patients. Much less is known the mechanisms regulating the release of these cytokines into the circulation that enable them to exert their remote effects in the coronary microcirculation. This mini review aims to examine recent studies describing alterations in the vasomotor function of coronary resistance arteries and the role of adipose tissue-derived pro-inflammatory cytokines and adipokines in contributing to CMD in obesity. We provide examples of regulatory mechanisms by which adipokines are released from adipose tissue to exert their remote inflammatory effects on coronary microvessels. We identify some of the important challenges and opportunities going forward.

Differential Role of Leptin and Adiponectin in Cardiovascular System

Leptin and adiponectin are differentially expressed adipokines in obesity and cardiovascular diseases. Leptin levels are directly associated with adipose tissue mass, while adiponectin levels are downregulated in obesity. Although significantly produced by adipocytes, leptin is also produced by vascular smooth muscle cells and cardiomyocytes. Plasma leptin concentrations are elevated in cases of cardiovascular diseases, such as hypertension, congestive heart failure, and myocardial infarction. As for the event of left ventricular hypertrophy, researchers have been stirring controversy about the role of leptin in this form of cardiac remodeling. In this review, we discuss how leptin has been shown to play an antihypertrophic role in the development of left ventricular hypertrophy through in vitro experiments, population-based cross-sectional studies, and longitudinal cohort studies. Conversely, we also examine how leptin may actually promote left ventricular hypertrophy using in vitro analysis and human-based univariate and multiple linear stepwise regression analysis. On the other hand, as opposed to leptin's generally detrimental effects on the cardiovascular system, adiponectin is a cardioprotective hormone that reduces left ventricular and vascular hypertrophy, oxidative stress, and inflammation. In this review, we also highlight adiponectin signaling and its protective actions on the cardiovascular system.

Differential effects of leptin and adiponectin in endothelial angiogenesis

Obesity is a major health burden with an increased risk of cardiovascular morbidity and mortality. Endothelial dysfunction is pivotal to the development of cardiovascular disease (CVD). In relation to this, adipose tissue secreted factors termed "adipokines" have been reported to modulate endothelial dysfunction. In this review, we focus on two of the most abundant circulating adipokines, that is, leptin and adiponectin, in the development of endothelial dysfunction. Leptin has been documented to influence a multitude of organ systems, that is, central nervous system (appetite regulation, satiety factor) and cardiovascular system (endothelial dysfunction leading to atherosclerosis). Adiponectin, circulating at a much higher concentration, exists in different molecular weight forms, essentially made up of the collagenous fraction and a globular domain, the latter being investigated minimally for its involvement in proinflammatory processes including activation of NF-κβ and endothelial adhesion molecules. The opposing actions of the two forms of adiponectin in endothelial cells have been recently demonstrated. Additionally, a local and systemic change to multimeric forms of adiponectin has gained importance. Thus detailed investigations on the potential interplay between these adipokines would likely result in better understanding of the missing links connecting CVD, adipokines, and obesity.

Polycystic Ovary Syndrome: Important Underrecognised Cardiometabolic Risk Factor in Reproductive-Age Women

Polycystic ovary syndrome (PCOS) is the most common endocrine disorder amongst women of reproductive age. Although PCOS is diagnosed exclusively based on reproductive criteria, it is also a metabolic disorder. Insulin resistance, impaired glucose tolerance, type 2 diabetes mellitus, obesity, and dyslipidemia are more common in women with PCOS than in age-comparable women without PCOS. Many of the metabolic abnormalities that manifest in PCOS are worsened by the concurrent incidence of obesity. However, some of these metabolic perturbations occur even in lean women with PCOS and therefore are rightfully recognized as intrinsic to PCOS. The intrinsic factors that produce these metabolic disturbances are reviewed in this paper. The consequences of obesity and the other metabolic aberrations are also discussed. The metabolic perturbations in PCOS patients lead to chronic low-grade inflammation and to cardiovascular impairments that heighten the risk of having cardiovascular disease. Even though many studies have shown an elevation in surrogate biomarkers of cardiovascular disease in PCOS women, it is still not clear to what extent and magnitude the elevation precipitates more frequent and earlier events.

Leptin mediates the increase in blood pressure associated with obesity

Obesity is associated with increased blood pressure (BP), which in turn increases the risk of cardiovascular diseases. We found that the increase in leptin levels seen in diet-induced obesity (DIO) drives an increase in BP in rodents, an effect that was not seen in animals deficient in leptin or leptin receptors (LepR). Furthermore, humans with loss-of-function mutations in leptin and the LepR have low BP despite severe obesity. Leptin's effects on BP are mediated by neuronal circuits in the dorsomedial hypothalamus (DMH), as blocking leptin with a specific antibody, antagonist, or inhibition of the activity of LepR-expressing neurons in the DMH caused a rapid reduction of BP in DIO mice, independent of changes in weight. Re-expression of LepRs in the DMH of DIO LepR-deficient mice caused an increase in BP. These studies demonstrate that leptin couples changes in weight to changes in BP in mammalian species.

Resveratrol improves high-fructose-induced vascular dysfunction in rats

High levels of fructose in the diet results in metabolic abnormalities and vascular disorders. In this study, the effect of resveratrol (RES) on vascular relaxation and contraction responses was examined in the aorta of high-fructose (HFr)-fed rats. mRNA expressions of aortic sirtuin 1 (SIRT1), GLUT5, and aldolase B were also investigated. Rats were given fructose (30%) and (or) RES (50 mg·L−1) in their drinking water for 8 weeks. In the HFr-fed rats, plasma levels of arginine and the ratio of arginine:asymmetric dimethylarginine (ADMA) decreased, whereas leptin levels increased. Decreased relaxation and increased contractile responses were detected in aortic rings. However, the aortic expressions of SIRT1, GLUT5, and aldolase B remained unchanged. RES treatment restored HFr-induced vascular dysfunction without improvements in insulin resistance. Treatment of HFr-fed rats with RES increased plasma levels of arginine and the l-arginine:ADMA ratio, and decreased plasma levels of leptin. RES increased SIRT1 expression, but decreased the expression of GLUT5 and aldolase B in aortas from HFr-fed rats. These results suggest that RES contributes to the restoration of HFr-induced vascular dysfunction in rats, at least in part, by up-regulation of SIRT 1 and down-regulation of GLUT5 and aldolase B in the aorta. Moreover, RES may have a positive influence on vasculature by partly restoring the plasma arginine:ADMA ratio and leptin levels.

Association of plasma leptin, homocysteine and nitric oxide levels with the presence and unstability of coronary artery disease

AIM

Leptin and total homocysteine (tHcy) may participate in the pathogenesis of coronary artery disease (CAD) through nitric oxide (NO) depletion. We sought to investigate whether leptin, tHcy and NO are suitable predictors of CAD.

PATIENTS & METHODS

This study contained 50 control subjects and 50 stable and 50 unstable angina patients. Plasma leptin, tHcy and NO levels were determined using enzyme immunoassay, HPLC fluorescence and spectrophotometric methods, respectively. Other conventional risk factors were also determined.

RESULTS

Leptin and tHcy levels were highest in unstable angina patients, followed by stable angina patients and then controls (p < 0.001). Controls had significantly higher NO than patients (p <0.001). Leptin and tHcy had a positive and NO a negative association with the presence of CAD.

CONCLUSIONS

Some athrogenic effects of leptin may be mediated by affecting tHcy and NO levels. Plasma leptin, tHcy and NO levels showed significant contribution to CAD prediction and discrimination.

Inhibition of leptin-induced vascular extracellular matrix remodelling by adiponectin

Vascular extracellular matrix (ECM) remodelling, which is the result of disruption in the balance of ECM synthesis and degradation, induces vessel fibrosis and thereby leads to hypertension. Leptin is known to promote tissue fibrosis, while adiponectin has recently been demonstrated to be anti-fibrogenic in tissue fibrosis. In this study, we aimed to evaluate the leptin-antagonist function of adiponectin and to further elucidate the mechanisms through which adiponectin dampens leptin signalling in vascular smooth muscle cells, thus preventing excess ECM production, in our already established 3D co-culture vessel models. Our 3D co-culture vessel model, which mimics true blood vessels, is composed of vascular endothelial cells, vascular smooth muscle cells and collagen type I. We validated the profibrogenic effects of leptin and analysed matrix metalloproteinase 2 (MMP2), MMP9, tissue inhibitor of metalloproteinase 1 (TIMP1) and collagen types II/IV secretion in 3D vessel models. The protective/inhibitory effects of adiponectin were re-analysed by inhibiting adiponectin receptor 1 (AdipoR) and AdipoR2 expression in endothelial cells using RNAi technology. In the 3D vessel models, adiponectin blocked the leptin-stimulated secretion of collagen types II/IV and TIMP1 while significantly increasing MMP2/9 activity. In endothelial cells, adiponectin induced phosphorylation of AMPK, thereby suppressing leptin-mediated STAT3 phosphorylation through induction of SOCS3 in smooth muscle cells. Our findings indicate that adiponectin disrupted the leptin-induced vascular ECM remodelling via AdipoR1 and enhanced AMPK signalling in endothelial cells, which, in turn, promoted SOCS3 up-regulation in smooth muscle cells to repress leptin-stimulated phosphorylation of STAT3.