Role of Leptin in Cardiovascular Diseases

Key Players in the Complex Pathophysiology of Obesity: A Cross-Talk Between the Obesogenic Genes and Unraveling the Metabolic Pathway of Action of Capsaicin and Orange Peel

Obesity is a widespread prevailing health concern with multifactorial causes. Among the various defined molecular targets associated with obesity, peroxisome proliferator activated receptor gamma, leptin, ghrelin, and adiponectin play crucial roles in fundamental processes including energy balance, adipose tissue biology, and metabolic health, making them particularly significant in the study of obesity.Capsaicin and orange peel exhibit promising anti-obesity properties through their thermogenic, metabolic, and anti-inflammatory effects. Potential pathways for therapeutic approaches in the management of obesity are provided by these targets. The lipid-lowering and anti-obesity benefits of specific plant species have been highlighted in Asian medicine. Due to the potential anti-obesity qualities, capsaicin, which is derived from chilli peppers, and orange peel extract has been focused in this review. Capsaicin causes apoptosis in preadipocytes and adipocytes and suppresses adipogenesis. Citrus fruits are a significant source of bioactive substances, primarily flavonoids. Due to their ability to reduce adipocyte development and cellular lipid content, citrus polyphenols are helpful in the control of obesity. This extensive analysis offers insights into new treatment approaches for the prevention and management of obesity and metabolic syndrome by examining the interactions of molecular variables in obesity as well as the possible anti-obesity advantages of capsaicin and orange peel extract.

miRNA and leptin signaling in metabolic diseases and at extreme environments

The burden of growing concern about the dysregulation of metabolic processes arises due to complex interplay between environment and nutrition that has great impact on genetics and epigenetics of an individual. Thereby, any abnormality at the level of food intake regulating hormones may contribute to the development of metabolic diseases in any age group due to malnutrition, overweight, changing lifestyle, and exposure to extreme environments such as heat stress (HS), cold stress, or high altitude (HA). Hormones such as leptin, adiponectin, ghrelin, and cholecystokinin regulate appetite and satiety to maintain energy homeostasis. Leptin, an adipokine and a pleiotropic hormone, play major role in regulating the food intake, energy gain and energy expenditure. Using in silico approach, we have identified the major genes (LEP, LEPR, JAK2, STAT3, NPY, POMC, IRS1, SOCS3) that play crucial role in leptin signaling pathway. Further, eight miRNAs (hsa-miR-204-5p, hsa-miR-211-5p, hsa-miR-30, hsa-miR-3163, hsa-miR-33a-3p, hsa-miR-548, hsa-miR-561-3p, hsa-miR-7856-5p) from TargetScan 8.0 database were screened out that commonly target these genes. The role of these miRNAs should be explored as they might play vital role in regulating the appetite, energy metabolism, metabolic diseases (obesity, type 2 diabetes, cardiovascular diseases, inflammation), and to combat extreme environments. The miRNAs regulating leptin signaling and appetite may be useful for developing novel therapeutics for metabolic diseases.

Inflammatory Biomarkers in Patients With Type 2 Diabetes Mellitus and Heart Failure With Preserved Ejection Faction

AIM

To verify the relationship between gene polymorphisms of tumor necrosis factor alpha (TNF-α) and interleukin-6 (IL-6) with inflammation markers and codependent metabolic variables in patients with type 2 diabetes mellitus and chronic heart failure (CHF).

MATERIAL AND METHODS

This study included 154 patients (mean age, 69.1±3.2 years). The control group consisted of 47 patients with metabolic syndrome (MS) without CHF; the 2nd group included 56 patients with CHF with preserved ejection fraction (CHFpEF); and the 3rd group consisted of 51 patients with CHF with reduced ejection fraction (CHFrEF). The rs1800629 polymorphism of the TNF-α gene (TNF-α: G308A) was studied in real time by the polymerase chain reaction (PCR) method and the rs1800795 polymorphism of the IL-6 gene (IL-6: 174 G>C) was studied by PCR with the electrophoretic detection. The frequencies of polymorphic alleles were compared with the clinical blood test results, plasma concentrations of C-reactive protein (CRP), TNF-α, leptin, and fibrinogen. Differences between the groups were determined using the F test. Relationships between individual studied parameters were identified using the regression analysis.

RESULTS

In most patients, the occurrence of gene polymorphisms was eident as increased plasma concentrations of biomarkers. An association was found between the TNF-α gene polymorphism (G308A) and an increase in plasma TNF-α and between the IL-6 gene polymorphism (174 C>G) and an increase in plasma CRP. In the CHFpEF group, the rs1800629 gene polymorphism was observed in 55% of patients, among whom 93% had increased TNF-α. The rs1800795 gene polymorphism was observed in 82% of CHFpEF patients, among whom 21% had increased CRP. In the CHFrEF group, the G308A transition in the TNF-α gene was observed in 53% of patients; an increase in the respective cytokine was noted in 67% of patients; the IL-6 gene polymorphism 174 C>G was found in 78%, however, only 14% of patients with this polymorphism had also increased CRP. In the control group, the TNF-α G308A gene polymorphism was found in 30% of patients, while an increase in free TNF-α was associated with this polymorphism in 50% of patients; the IL-6 174 C>G gene polymorphism was detected in 78%, while no increase in the CRP level was observed in this group. This demonstrates a high probability of the TNF-α G308A gene polymorphism occurrence in patients with CHF.

CONCLUSION

Inflammatory markers are important predictors of CHF. The most significant predictor was the TNF-α G308A gene polymorphism, which was observed in more than 50% of patients, the majority of whom had an increase in plasma TNF-α.

Identifying plasma proteomic signatures from health to heart failure, across the ejection fraction spectrum

Circulating proteins may provide insights into the varying biological mechanisms involved in heart failure (HF) with preserved ejection fraction (HFpEF) and reduced ejection fraction (HFrEF). We aimed to identify specific proteomic patterns for HF, by comparing proteomic profiles across the ejection fraction spectrum. We investigated 4210 circulating proteins in 739 patients with normal (Stage A/Healthy) or elevated (Stage B) filling pressures, HFpEF, or ischemic HFrEF (iHFrEF). We found 2122 differentially expressed proteins between iHFrEF-Stage A/Healthy, 1462 between iHFrEF-HFpEF and 52 between HFpEF-Stage A/Healthy. Of these 52 proteins, 50 were also found in iHFrEF vs. Stage A/Healthy, leaving SLITRK6 and NELL2 expressed in lower levels only in HFpEF. Moreover, 108 proteins, linked to regulation of cell fate commitment, differed only between iHFrEF-HFpEF. Proteomics across the HF spectrum reveals overlap in differentially expressed proteins compared to stage A/Healthy. Multiple proteins are unique for distinguishing iHFrEF from HFpEF, supporting the capacity of proteomics to discern between these conditions.

Leptin and ghrelin dynamics: unraveling their influence on food intake, energy balance, and the pathophysiology of type 2 diabetes mellitus

Purpose

Type 2 diabetes mellitus (T2DM) is a chronic metabolic disorder characterized by insulin resistance and impaired glucose homeostasis. In recent years, there has been growing interest in the role of hunger and satiety hormones such as ghrelin and leptin in the development and progression of T2DM. In this context, the present literature review aims to provide a comprehensive overview of the current understanding of how ghrelin and leptin influences food intake and maintain energy balance and its implications in the pathophysiology of T2DM.

Methods

A thorough literature search was performed using PubMed and Google Scholar to choose the studies that associated leptin and ghrelin with T2DM. Original articles and reviews were included, letters to editors and case reports were excluded.

Results

This narrative review article provides a comprehensive summary on mechanism of action of leptin and ghrelin, its association with obesity and T2DM, how they regulate energy and glucose homeostasis and potential therapeutic implications of leptin and ghrelin in managing T2DM.

Conclusion

Ghrelin, known for its appetite-stimulating effects, and leptin, a hormone involved in the regulation of energy balance, have been implicated in insulin resistance and glucose metabolism. Understanding the complexities of ghrelin and leptin interactions in the context of T2DM may offer insights into novel therapeutic strategies for this prevalent metabolic disorder. Further research is warranted to elucidate the molecular mechanisms underlying these hormone actions and to explore their clinical implications for T2DM prevention and management.

Plasma Leptin and Alzheimer Protein Pathologies Among Older Adults

Importance

Many epidemiologic studies have suggested that low levels of plasma leptin, a major adipokine, are associated with increased risk of Alzheimer disease (AD) dementia and cognitive decline. Nevertheless, the mechanistic pathway linking plasma leptin and AD-related cognitive decline is not yet fully understood.

Objective

To examine the association of plasma leptin levels with in vivo AD pathologies, including amyloid-beta (Aβ) and tau deposition, through both cross-sectional and longitudinal approaches among cognitively unimpaired older adults.

Design, Setting, and Participants

This was a longitudinal cohort study from the Korean Brain Aging Study for Early Diagnosis and Prediction of Alzheimer Disease. Data were collected from January 1, 2014, to December 31, 2020, and data were analyzed from July 11 to September 6, 2022. The study included a total of 208 cognitively unimpaired participants who underwent baseline positron emission tomography (PET) scans for brain Aβ deposition. For longitudinal analyses, 192 participants who completed both baseline and 2-year follow-up PET scans for brain Aβ deposition were included.

Exposure

Plasma leptin levels as assessed by enzyme-linked immunosorbent assay.

Main Outcomes and Measures

Baseline levels and longitudinal changes of global Aβ and AD-signature region tau deposition measured by PET scans.

Results

Among the 208 participants, the mean (SD) age was 66.0 (11.3) years, 114 were women (54.8%), and 37 were apolipoprotein E ε4 carriers (17.8%). Lower plasma leptin levels had a significant cross-sectional association with greater brain Aβ deposition (β = -0.04; 95% CI, -0.09 to 0.00; P = .046), while there was no significant association between plasma leptin levels and tau deposition (β = -0.02; 95% CI, -0.05 to 0.02; P = .41). In contrast, longitudinal analyses revealed that there was a significant association between lower baseline leptin levels and greater increase of tau deposition over 2 years (β = -0.06; 95% CI, -0.11 to -0.01; P = .03), whereas plasma leptin levels did not have a significant association with longitudinal change of Aβ deposition (β = 0.006; 95% CI, 0.00-0.02; P = .27).

Conclusions and Relevance

The present findings suggest that plasma leptin may be protective for the development or progression of AD pathology, including both Aβ and tau deposition.

Effect and mechanisms of Gambi-jung against high-fat diet-induced cardiac apoptosis in mice

Obesity is associated with an increased risk of cardiovascular disease. Gambi-jung (GBJ), a modified herbal formula of Taeumjowi-tang, induces weight loss in high-fat diet (HFD)-fed obese mice. Meanwhile, concerns have been raised regarding Ephedra sinica Stapf (ES), the primary herb of GBJ, having potential adverse cardiovascular effects. However, there have been no reports on the effects of ES and ephedrine-containing products on obesity-induced cardiac apoptosis. Therefore, to investigated the effect of GBJ and ES on HFD-induced cardiac apoptosis, we utilized Western blot analysis, TUNEL-staining, and histological staining of heart tissues from HFD-fed obese mice. Western blot analysis showed that there were significant changes in the protein levels of anti-apoptotic markers (B-cell lymphoma (BCL) protein 2 (BCL-2), BCL-XL, and X-linked inhibitor of apoptosis protein) and pro-apoptotic markers (Fas, Fas-associated protein with death domain, BCL-2 agonist of cell death, BCL-2 associated X, cytochrome C, and cleaved caspase-9) in the heart of HFD-fed mice. In contrast administration of 250 mg/kg GBJ for 12 weeks significantly reversed the protein levels related to the apoptosis signaling pathway, which was greater than that of ES administration. Furthermore, GBJ-treated mice had markedly decreased number of TUNEL-stained apoptotic cells compared to the HFD group. Moreover, GBJ improved the mitochondrial function by regulating the genes expression of uncoupling protein 2, peroxisome proliferator-activated receptor-γ coactivator-1α, optic atrophy protein 1, and fission protein 1. Notably, hematoxylin and eosin histological staining showed no changes in the heart tissues of GBJ- and ES-treated mice, indicating that long-term administration of GBJ and ES did not exert any adverse effects on the cardiac tissue. The present study lays the foundation to support the efficacy of GBJ in protecting cardiac cell apoptosis induced by HFD feeding, as well as to verify the cardiac safety of GBJ administration.

Occupational Risk for Coronary Artery Disease in Shift Workers - A Systematic Review

BACKGROUND

Coronary artery disease (CAD) prevention in shift workers (SWs) poses a significant challenge worldwide, as CAD remains a major cause of mortality and disability. In the past, SWs were found at higher risk of CAD than non-s SWs. Nevertheless, the pathogenic mechanism between shift work and CAD to date is unclear. This systematic review aims to enhance understanding of the risk of CAD occurrence in SWs.

METHODS

A systematic literature review was conducted from January 2013 to December 2023. MEDLINE/Pubmed databases were used initially, and additional relevant studies were searched from references. Shift work was defined as any schedule outside traditional shifts, including the night shift.

RESULTS

Fifteen pertinent papers were categorized into risk assessment or risk management. Findings demonstrated an increased risk of CAD among SWs compared to non-SWs, with an increased CAD risk observed for both shift work and night shift work.

DISCUSSION

Duration-response associations indicate that greater shift exposure is linked to higher CAD risk. SWs incur an increased risk of CAD through the atherosclerotic process. As shift work duration increases as the risk of atherosclerosis is higher, workers demonstrate a higher prevalence and severity of coronary artery plaques.

CONCLUSIONS

The evidence-based results underscore the increased risk of CAD in SWs and are sufficient for proposing guidelines aimed at reducing the risk of CAD in SWs and at managing people with CAD in return to work characterized by disrupted circadian rhythms.

Unraveling Adipose Tissue Dysfunction: Molecular Mechanisms, Novel Biomarkers, and Therapeutic Targets for Liver Fat Deposition

Adipose tissue (AT), once considered a mere fat storage organ, is now recognized as a dynamic and complex entity crucial for regulating human physiology, including metabolic processes, energy balance, and immune responses. It comprises mainly two types: white adipose tissue (WAT) for energy storage and brown adipose tissue (BAT) for thermogenesis, with beige adipocytes demonstrating the plasticity of these cells. WAT, beyond lipid storage, is involved in various metabolic activities, notably lipogenesis and lipolysis, critical for maintaining energy homeostasis. It also functions as an endocrine organ, secreting adipokines that influence metabolic, inflammatory, and immune processes. However, dysfunction in WAT, especially related to obesity, leads to metabolic disturbances, including the inability to properly store excess lipids, resulting in ectopic fat deposition in organs like the liver, contributing to non-alcoholic fatty liver disease (NAFLD). This narrative review delves into the multifaceted roles of WAT, its composition, metabolic functions, and the pathophysiology of WAT dysfunction. It also explores diagnostic approaches for adipose-related disorders, emphasizing the importance of accurately assessing AT distribution and understanding the complex relationships between fat compartments and metabolic health. Furthermore, it discusses various therapeutic strategies, including innovative therapeutics like adipose-derived mesenchymal stem cells (ADMSCs)-based treatments and gene therapy, highlighting the potential of precision medicine in targeting obesity and its associated complications.

Role of Leptin in Obesity, Cardiovascular Disease, and Type 2 Diabetes

Diabetes mellitus (DM) is a highly prevalent disease worldwide, estimated to affect 1 in every 11 adults; among them, 90-95% of cases are type 2 diabetes mellitus. This is partly attributed to the surge in the prevalence of obesity, which has reached epidemic proportions since 2008. In these patients, cardiovascular (CV) risk stands as the primary cause of morbidity and mortality, placing a substantial burden on healthcare systems due to the potential for macrovascular and microvascular complications. In this context, leptin, an adipocyte-derived hormone, plays a fundamental role. This hormone is essential for regulating the cellular metabolism and energy balance, controlling inflammatory responses, and maintaining CV system homeostasis. Thus, leptin resistance not only contributes to weight gain but may also lead to increased cardiac inflammation, greater fibrosis, hypertension, and impairment of the cardiac metabolism. Understanding the relationship between leptin resistance and CV risk in obese individuals with type 2 DM (T2DM) could improve the management and prevention of this complication. Therefore, in this narrative review, we will discuss the evidence linking leptin with the presence, severity, and/or prognosis of obesity and T2DM regarding CV disease, aiming to shed light on the potential implications for better management and preventive strategies.

Deletion, but not heterozygosity, of eNOS raises blood pressure and aggravates nephropathy in BTBR ob/ob mice

INTRODUCTION

ob/ob mice are a leptin-deficient type 2 diabetes mellitus model, which, on a BTBR background, mimics glomerular pathophysiology of diabetic nephropathy (DN). Since leptin deficiency reduces blood pressure (BP), and endothelial nitric oxide synthase (eNOS) lowers BP and is kidney protective, we attempted to develop a more robust DN model by introducing eNOS deficiency in BTBR ob/ob mice.

METHODS

Six experimental groups included littermate male and female BTBR ob/ob or wild-type for ob (control) as well as wild-type (WT), heterozygote (HET) or knockout (KO) for eNOS. Systolic BP (by automated tail-cuff) and GFR (by FITC sinistrin plasma kinetics) were determined in awake mice at 27-30 weeks of age followed by molecular and histological kidney analyses.

RESULTS

Male and female ob/ob WT presented hyperglycemia and larger body and kidney weight, GFR, glomerular injury, and urine albumin to creatinine ratio (UACR) despite modestly lower BP vs control WT. These effects were associated with higher tubular injury score and renal mRNA expression of NGAL only in males, whereas female ob/ob WT unexpectedly had lower KIM-1 and COL1A1 expression vs control WT, indicating sex differences. HET for eNOS did not consistently alter BP or renal outcome in control or ob/ob. In comparison, eNOS KO increased BP (15-25 mmHg) and worsened renal markers of injury, inflammation and fibrosis, GFR, UACR, and survival rates, as observed in control and, more pronounced, in ob/ob mice and independent of sex.

CONCLUSIONS

Deletion, but not heterozygosity, of eNOS raises blood pressure and aggravates nephropathy in BTBR ob/ob mice.

Sodium-Glucose Cotransporter Protein 2 Inhibitors: Novel Application for the Treatment of Obesity-Associated Hypertension

Obesity is becoming increasingly prevalent in China and worldwide and is closely related to the development of hypertension. The pathophysiology of obesity-associated hypertension is complex, including an overactive sympathetic nervous system (SNS), activation of the renin-angiotensin-aldosterone system (RAAS), insulin resistance, hyperleptinemia, renal dysfunction, inflammatory responses, and endothelial function, which complicates treatment. Sodium-glucose cotransporter protein 2 (SGLT-2) inhibitors, novel hypoglycemic agents, have been shown to reduce body weight and blood pressure and may serve as potential novel agents for the treatment of obesity-associated hypertension. This review discusses the beneficial mechanisms of SGLT-2 inhibitors for the treatment of obesity-associated hypertension. SGLT-2 inhibitors can inhibit SNS activity, reduce RAAS activation, ameliorate insulin resistance, reduce leptin secretion, improve renal function, and inhibit inflammatory responses. SGLT-2 inhibitors can, therefore, simultaneously target multiple mechanisms of obesity-associated hypertension and may serve as an effective treatment for obesity-associated hypertension.

Evaluation of Metabolic and Cardiovascular Risk Measured by Laboratory Biomarkers and Cardiopulmonary Exercise Test in Children and Adolescents Recovered from Brain Tumors: The CARMEP Study

In recent decades, the improvement of treatments and the adoption of therapeutic protocols of international cooperation has led to an improvement in the survival of children affected by brain tumors. However, in parallel with the increase in survival, long-term side effects related to treatments have been observed over time, including the activation of chronic inflammatory processes and metabolic alterations, which can facilitate the onset of metabolic syndrome and increased cardiovascular risk. The aim of this study was to find possible statistically significant differences in the serum concentrations of early biomarkers of metabolic syndrome and in the results of cardiopulmonary exercise testing between survivors of childhood brain tumors and healthy controls. This is a prospective and observational study conducted on a group of 14 male patients who survived childhood brain tumors compared with the same number of healthy controls. The concentrations of early metabolic syndrome biomarkers [adiponectin, leptin, TNF-α, IL-1, IL-6, IL-10, endothelin-1, apolipoprotein B, and lipoprotein (a)] were measured and a cardiopulmonary exercise test (CPET) was performed. Results: Childhood brain tumor survivors performed worse on average than controls on the CPET. Furthermore, they showed higher endothelin-1 values than controls (p = 0.025). The CPET results showed an inverse correlation with leptin. The differences found highlight the greater cardiovascular risk of brain tumor survivors, and radiotherapy could be implicated in the genesis of this greater cardiovascular risk.

The solution structure of human leptin reveals a conformational plasticity important for receptor recognition

Leptin is a multi-potency cytokine that regulates various physiological functions, including weight control and energy homeostasis. Signaling of leptin is also important in many aging-related diseases. Leptin is required for the noncovalent crosslinking of different extracellular domains of leptin receptors, which is critical for receptor activation and downstream signaling. Nevertheless, the structure of intact apo-form leptin and the structural transition leptin undergoes upon receptor binding are not fully understood yet. Here, we determined the monomeric structure of wild-type human leptin by solution-state nuclear magnetic resonance spectroscopy. Leptin contains an intrinsically disordered region (IDR) in the internal A-B loop and the flexible helix E in the C-D loop, both of which undergo substantial local structural changes when leptin binds to its receptor. Our findings provide further insights into the molecular mechanisms of leptin signaling.

An Overview of the Mechanism behind Excessive Volume of Pericardial Fat in Heart Failure

Heart failure (HF) is a clinical syndrome characterized by myocardial dysfunction leading to inefficient blood filling or ejection. Regardless of the etiology, various mechanisms, including adipokine hypersecretion, proinflammatory cytokines, stem cell proliferation, oxidative stress, hyperglycemic toxicity, and autonomic nervous system dysregulation in the pericardial fat (PCF), contribute to the development of HF. PCF has been directly associated with cardiovascular disease, and an increased PCF volume is associated with HF. The PCF acts as neuroendocrine tissue that is closely linked to myocardial function and acts as an energy reservoir. This review aims to summarize each mechanism associated with PCF in HF.

Interaction between Selected Adipokines and Musculoskeletal and Cardiovascular Systems: A Review of Current Knowledge

Adipokines are substances secreted by adipose tissue that are receiving increasing attention. The approach to adipose tissue has changed in recent years, and it is no longer looked at as just a storage organ but its secretion and how it influences systems in the human body are also looked at. The role of adipokine seems crucial in developing future therapies for pathologies of selected systems. In this study, we look at selected adipokines, leptin, adiponectin, chemerin, resistin, omentin-1, nesfatin, irisin-1, visfatin, apelin, vaspin, heparin-binding EGF-like growth factor (HB-EGF), and TGF-β2, and how they affect systems in the human body related to physical activity such as the musculoskeletal and cardiovascular systems.

Obesity-related cardiometabolic indicators modify the associations of personal noise exposure with heart rate variability: A further investigation on the Study among Obese and Normal-weight Adults (SONA)

Elucidating the associations between environmental noise and heart rate variability (HRV) would be beneficial for the prevention and control of detrimental cardiovascular changes. Obese people have been found to manifest heightened susceptibility to the adverse effects of noise on HRV. However, the underlying mechanisms remain unclear. Based on 53 normal-weight and 44 obese young adults aged 18-26 years in Beijing, China, this study aimed to investigate the role of obesity-related cardiometabolic indicators for associations between short-term environmental noise exposure and HRV in the real-world context. The participants underwent personal noise exposure and ambulatory electrocardiogram monitoring using portable devices at 5-min intervals for 24 continuous hours. Obesity-related blood pressure, glucose and lipid metabolism, and inflammatory indicators were subsequently examined. Generalized mixed-effect models were used to estimate the associations between noise exposure and HRV parameters. The C-peptide, homeostasis model assessment of insulin resistance (HOMA-IR), and leptin levels were higher in obese participants compared to normal-weight participants. We observed amplified associations between short-term noise exposure and decreases in HRV among participants with higher C-peptide, HOMA-IR, and leptin levels. For instance, a 1 dB(A) increment in 3 h-average noise exposure level preceding each measurement was associated with changes of -0.20% (95%CI: -0.45%, 0.04%) and -1.35% (95%CI: -1.85%, -0.86%) in standard deviation of all normal to normal intervals (SDNN) among participants with lower and higher C-peptide levels, respectively (P for interaction <0.05). Meanwhile, co-existing fine particulate matter (PM2.5) could amplify the associations between noise and HRV among obese participants and participants with higher C-peptide, HOMA-IR, and leptin levels. The more apparent associations of short-term exposure to environmental noise with HRV and the effect modification by PM2.5 may be partially explained by the higher C-peptide, HOMA-IR, and leptin levels of obese people.

Obesity-Related Biomarkers Are Associated With Exercise Intolerance and HFpEF

BACKGROUND

Obesity and adiposity are associated with an increased risk of heart failure with preserved ejection fraction (HFpEF); yet, specific underlying mechanisms remain unclear. We sought to examine the association of obesity-related biomarkers including adipokines (leptin, resistin, adiponectin), inflammatory markers (CRP [C-reactive protein], IL-6 [interleukin-6]), and insulin resistance (HOMA-IR) with HFpEF status, exercise capacity, and cardiovascular outcomes.

METHODS

We studied 509 consecutive patients with left ventricular ejection fraction ≥50% and chronic dyspnea, who underwent clinically indicated cardiopulmonary exercise test with invasive hemodynamic monitoring between 2006 and 2017. We defined HFpEF based on the presence of elevated left ventricular filling pressures at rest or during exercise. Fasting blood samples collected at the time of the cardiopulmonary exercise test were used to assay obesity-related biomarkers. We examined the association of log-transformed biomarkers with HFpEF status and exercise traits using multivariable-adjusted logistic regression models.

RESULTS

We observed associations of obesity-related biomarkers with measures of impaired exercise capacity including peak VO2 (P≤0.002 for all biomarkers). The largest effect size was seen with leptin, where a 1-SD higher leptin was associated with a 2.35 mL/kg per min lower peak VO2 (β, -2.35±0.19; P<0.001). In addition, specific biomarkers were associated with distinct measures of exercise reserve including blood pressure (homeostatic model assessment of insulin resistance, leptin, adiponectin; P≤0.002 for all), and chronotropic response (CRP, IL-6, homeostatic model assessment of insulin resistance, leptin, and resistin; P<0.05 for all). Our findings suggest that among the obesity-related biomarkers studied, higher levels of leptin and CRP are independently associated with increased odds of HFpEF, with odds ratios of 1.36 (95% CI, 1.09-1.70) and 1.25 (95% CI, 1.03-1.52), respectively.

CONCLUSIONS

Specific obesity-related pathways including inflammation, adipokine signaling, and insulin resistance may underlie the association of obesity with HFpEF and exercise intolerance.

Evidence of Bariatric Surgery Benefits Cardiac Function in Non-HFpEF Patients with Obesity: a Meta-Analysis

BACKGROUND/OBJECTIVE

Nowadays, increasing clinical evidence on metabolic and weight-loss effects of bariatric surgery on improving cardiac structure in obese patients, but its application in improving the cardiac function of HF (heart failure) patients remains controversial. The objective of this meta-analysis was to assess the effects of BS on cardiac function by quantifying the changes of LVEF (left ventricular ejection fraction) and NYHA (New York Heart Association classification) after operations in non-HFpEF (heart failure and preserved ejection fraction) patients.

METHODS

Articles were searched using PubMed and Embase from inception to December 9, 2022, and the Minors scale was used for quality assessments. The included patients should be non-HFpEF and clinically severely obese, and their pre-operative and post-operative values of LVEF or NYHA should be reported.

RESULT

Nine studies involving 146 patients were eventually included with a final result showing that the cardiac functional parameters were improved in non-HFpEF patients. After a weighted mean follow-up time of 15.8 months, the mean NYHA decreased by 0.59 (I2 = 0; 95% CI 0.27 ~ 0.92; p = 0.003), and the mean LVEF increased by 7.49% (I2 = 0; 95% CI - 9.99 ~  - 4.99; p < 0.00001).

CONCLUSION

Bariatric surgery offers beneficial cardiac effects on non-HFpEF patients with obesity but failed to show a significant improvement in the pooled analysis for the changes of cardiac parameters. The improving degree may be related to the baseline BMI, the extent of BMI loss, and the baseline age. Future studies should focus on finding out the influencing factors of effectivenesses and defining the suitable crowd.

Adipokines and Their Role in Heart Failure: A Literature Review

Obesity is a major risk factor for heart failure (HF). The relationship between adipokines and HF has been implicated in many previous studies and reviews. However, this review article summarizes the basic role of major adipokines, such as apelin, adiponectin, chemerin, resistin, retinol-binding protein 4 (RBP4), vaspin, visfatin, plasminogen activator inhibitor-1, monocyte chemotactic protein-1, nesfatin-1, progranulin, leptin, omentin-1, lipocalin-2, and follistatin-like 1 (FSTL1), in the pathogenesis of HF. Apelin is reduced in patients with HF and upregulated following favorable left ventricular (LV) remodeling. Higher levels of adiponectin have been found in patients with HF compared to in control patients. Also, high plasma chemerin levels are linked to a higher risk of HF. Serum resistin is related to the severity of HF and associated with a high risk for adverse cardiac events. Evidence indicates that RBP4 can contribute to inflammation and damage heart muscle cells, potentially leading to HF. Vaspin might stop the progression of cardiac degeneration, fibrosis, and HF according to experiments on rats with experimental isoproterenol-induced chronic HF. The serum concentrations of visfatin are significantly lower in patients with systolic HF. Leptin levels were found to be correlated with low LV mass and myocardial stiffness, both of which are significant risk factors for the development of HF with preserved ejection fraction (HFpEF). Measuring serum omentin-1 levels appears to be a novel prognostic indicator for risk stratification in HF patients. Increased expression of neutrophil gelatinase-associated lipocalin in both systemic circulation and myocardium in clinical and experimental HF suggests that innate immune responses may contribute to the development of HF. FSTL1 was elevated in patients with HF with reduced ejection fraction and associated with an increase in the size of the left ventricle of the heart. However, other adipokines, such as plasminogen activator inhibitor-1, monocyte chemotactic protein-1, nesfatin-1, and progranulin, have not yet been studied for HF.

Leptin Mediates Prostate Stromal Cell Proliferation, Smooth Muscle Contraction, and Mitochondrial Function in Benign Prostate Hyperplasia

Introduction

Leptin is a metabolic peptide hormone produced by adipocytes, with proven roles in proliferation of prostate cancer cells and of prostate cells in animal models of benign prostatic hyperplasia (BPH). Thus, the role of leptin as a molecular link connecting BPH and lower urinary tract symptoms (LUTS) suggestive of BPH with metabolic symptoms appears feasible but is still unknown. In fact, a connection between metabolic syndrome and BPH is becoming increasingly evident from epidemiologic studies. Key factors of Lower urinary tract symptoms associated with benign prostatic hyperplasia (BPH/LUTS) are increased prostate smooth muscle tone, and prostate enlargement. Here, we examined the effects of leptin on contraction of human prostate smooth muscle and on growth of stromal cells.

Methods

We performed microarray analysis to identify genes (fold change ≥ 1.5) associated with BPH/LUTS progression, such as those involved in proliferation, apoptosis, and mitochondrial metabolism, in rat prostate tissue (data from GSE129561). We then used electric field stimulation (EFS) to induce frequency-dependent, neurogenic contractions of human prostate strips, which were enhanced by leptin. We also examined the effect of leptin on human prostate stromal cells (WPMY-1) and found increased cell proliferation and viability upon exposure. To explore the underlying mechanism, we conducted mitochondrial stress assay using near-infrared (NIR) fluorescent dye and flow cytometry (FACS) analysis and observed reduced cellular apoptosis and preserved mitochondrial membrane potential (∆ψM) after leptin treatment.

Results

Microarray analysis reveals that leptin regulates prostate smooth muscle contraction and stromal cell proliferation, shedding new light on its involvement in BPH/LUTS pathogenesis and mitochondrial function. We found that leptin enhanced the proliferation rate of prostate stromal cells relative to the control group (0.67 ± 0.05 vs 0.54 ± 0.08, p-value= 0.024). Moreover, leptin (100 ng/mL) potentiated the frequency-dependent, neurogenic contractions of prostate strips elicited by EFS (p= 0.047 between leptin and control group). We also show that leptin treatment increased the mitochondrial membrane potential of prostate stromal cells and inhibited mitochondrial apoptosis.

Discussion

Our results indicate that leptin stimulates the contractility and proliferation of smooth muscle and stromal cells in the human prostate, implying a potential role for leptin in exacerbating BPH/LUTS in obese men. Leptin modulation may be a beneficial therapeutic strategy for patients with metabolic syndrome and BPH/LUTS. Further studies are warranted to elucidate the mechanisms and implications of the leptin system in BPH/LUTS.

Impacts of Non-alcoholic Fatty Liver Disease on Acute Coronary Syndrome: Evidence and Controversies

PURPOSE OF REVIEW

Acute coronary syndrome (ACS) and non-alcoholic fatty liver disease (NAFLD) are two clinically common disease entities that share numerous risk factors. This review aimed to discuss the impacts of NAFLD on ACS.

RECENT FINDINGS

In an era of improved control of traditional risk factors, the substantial burden of cardiometabolic abnormalities has caused widespread concern. NAFLD is considered the hepatic component of metabolic syndrome, which can exert an impact on human health beyond the liver. Accumulating studies have demonstrated that NAFLD is closely related to cardiovascular disease, especially coronary artery disease. Interestingly, although recent data have suggested an association between NAFLD and the incidence and outcomes of ACS, the results are not consistent. In this review, we comprehensively summarized evidence and controversies regarding whether NAFLD is a contributor to either the development of ACS or worse outcomes in patients with ACS. The potential pathophysiological and molecular mechanisms involved in the impacts of NAFLD on ACS were also elucidated.

Which Comes First, Nonalcoholic Fatty Liver Disease or Arterial Hypertension?

Non-alcoholic fatty liver disease (NAFLD) and arterial hypertension (AH) are widespread noncommunicable diseases in the global population. Since hypertension and NAFLD are diseases associated with metabolic syndrome, they are often comorbid. In fact, many contemporary published studies confirm the association of these diseases with each other, regardless of whether other metabolic factors, such as obesity, dyslipidemia, and type 2 diabetes mellites, are present. This narrative review considers the features of the association between NAFLD and AH, as well as possible pathophysiological mechanisms.

Recent progress in leptin signaling from a structural perspective and its implications for diseases

As a multi-potency cytokine, leptin not only plays a crucial role in controlling weight and energy homeostasis but also participates in the metabolic balance in the human body. Leptin is a small helical protein with a molecular weight of 16 kDa. It can interact with multiple subtypes of its receptors to initiate intracellular signal transduction and exerts physiological effects. Disturbances in leptin signaling may lead to obesity and a variety of metabolic diseases. Leptin was also found to be a critical factor in many diseases of the elderly. In this review, we focus on recent advances in the structural and molecular mechanisms of leptin signaling through its receptors with the aim of a deeper understanding of leptin-related diseases.

Immunometabolism mRNA expression phenotypes and reprogramming of CD14 in T2DM with or without CVD

BACKGROUND/AIM

Type 2 diabetes mellitus (T2DM) and cardiovascular diseases (CVD) have a significant impact on the expression of genes in peripheral blood mononuclear cells (PBMCs). The primary objective of this study was to investigate the role of two signaling pathways, STAT1/6, and two important modulators of immunometabolism, leptin and PPARs, in the development of T2DM with and without CVD. Furthermore, the study aimed to assess the correlation between these factors and the dynamics of CD14 in PBMCs. This research was conducted within the context of a growing body of literature on the complex pathophysiology of T2DM and its association with CVD. Prior studies have indicated that T2DM is characterized by an imbalance in immunometabolism and the involvement of various signaling pathways.

MATERIALS AND METHODS

Blood samples were collected from a total of 47 subjects, including 7 healthy volunteers, 20 individuals diagnosed with diabetes and cardiovascular disease (D.CVD) and another 20 individuals diagnosed with diabetes only (D). PBMCs were isolated from these samples, and the expression levels of leptin, PPARγ, PPARα, and CD14 genes were measured using Real-Time PCR.

RESULTS

The most relevant result showed that diabetic patients with CVD had significantly higher levels of leptin expression, which was positively correlated with STAT1 (r = 0.7497, p = 0.0001). On the other hand, diabetic patients without CVD had elevated PPARγ expression, which was strongly correlated with STAT6 (r = 0.8437, p = 0.0001). Interestingly, we found a significant increase in the PPARγ/ PPARα ratio in the D.CVD group compared to the D group (4.273 ± 0.9531; 7.52 ± 3.556, p = 0.0479). Moreover, CD14 expression was significantly reduced in this group compared to diabetic patients without CVD.

CONCLUSION

These findings suggested that the immunometabolic imbalance in T2DM was driven by a STAT1/Leptin phenotype in diabetic patients with CVD and by a STAT6/PPARγ phenotype in diabetic patients without CVD. Taking into account STAT1/Leptin and STAT6/PPARγ profiling could help clinicians identify novel therapeutic targets for T2DM and other related diseases.

A National Multicenter Study of Leptin and Leptin Receptor Deficiency and Systematic Review

CONTEXT

Homozygous leptin (LEP) and leptin receptor (LEPR) variants lead to childhood-onset obesity.

OBJECTIVE

To present new cases with LEP and LEPR deficiency, report the long-term follow-up of previously described patients, and to define, based on all reported cases in literature, genotype-phenotype relationships.

METHODS

Our cohort included 18 patients (LEP = 11, LEPR = 7), 8 of whom had been previously reported. A systematic literature review was conducted in July 2022. Forty-two of 47 studies on LEP/LEPR were selected.

RESULTS

Of 10 new cases, 2 novel pathogenic variants were identified in LEP (c.16delC) and LEPR (c.40 + 5G > C). Eleven patients with LEP deficiency received metreleptin, 4 of whom had been treated for over 20 years. One patient developed loss of efficacy associated with neutralizing antibody development. Of 152 patients, including 134 cases from the literature review in addition to our cases, frameshift variants were the most common (48%) in LEP and missense variants (35%) in LEPR. Patients with LEP deficiency were diagnosed at a younger age [3 (9) vs 7 (13) years, P = .02] and had a higher median body mass index (BMI) SD score [3.1 (2) vs 2.8 (1) kg/m2, P = 0.02], which was more closely associated with frameshift variants (P = .02). Patients with LEP deficiency were more likely to have hyperinsulinemia (P = .02).

CONCLUSION

Frameshift variants were more common in patients with LEP deficiency whereas missense variants were more common in LEPR deficiency. Patients with LEP deficiency were identified at younger ages, had higher BMI SD scores, and had higher rates of hyperinsulinemia than patients with LEPR deficiency. Eleven patients benefitted from long-term metreleptin, with 1 losing efficacy due to neutralizing antibodies.

Neuro-Vulnerability in Energy Metabolism Regulation: A Comprehensive Narrative Review

This comprehensive narrative review explores the concept of neuro-vulnerability in energy metabolism regulation and its implications for metabolic disorders. The review highlights the complex interactions among the neural, hormonal, and metabolic pathways involved in the regulation of energy metabolism. The key topics discussed include the role of organs, hormones, and neural circuits in maintaining metabolic balance. The review investigates the association between neuro-vulnerability and metabolic disorders, such as obesity, insulin resistance, and eating disorders, considering genetic, epigenetic, and environmental factors that influence neuro-vulnerability and subsequent metabolic dysregulation. Neuroendocrine interactions and the neural regulation of food intake and energy expenditure are examined, with a focus on the impact of neuro-vulnerability on appetite dysregulation and altered energy expenditure. The role of neuroinflammation in metabolic health and neuro-vulnerability is discussed, emphasizing the bidirectional relationship between metabolic dysregulation and neuroinflammatory processes. This review also evaluates the use of neuroimaging techniques in studying neuro-vulnerability and their potential applications in clinical settings. Furthermore, the association between neuro-vulnerability and eating disorders, as well as its contribution to obesity, is examined. Potential therapeutic interventions targeting neuro-vulnerability, including pharmacological treatments and lifestyle modifications, are reviewed. In conclusion, understanding the concept of neuro-vulnerability in energy metabolism regulation is crucial for addressing metabolic disorders. This review provides valuable insights into the underlying neurobiological mechanisms and their implications for metabolic health. Targeting neuro-vulnerability holds promise for developing innovative strategies in the prevention and treatment of metabolic disorders, ultimately improving metabolic health outcomes.

Long-term dietary nitrate supplementation slows the progression of established atherosclerosis in ApoE-/- mice fed a high fat diet

BACKGROUND AND AIMS

Atherosclerosis is associated with a reduction in the bioavailability and/or bioactivity of endogenous nitric oxide (NO). Dietary nitrate has been proposed as an alternate source when endogenous NO production is reduced. Our previous study demonstrated a protective effect of dietary nitrate on the development of atherosclerosis in the apoE-/- mouse model. However most patients do not present clinically until well after the disease is established. The aims of this study were to determine whether chronic dietary nitrate supplementation can prevent or reverse the progression of atherosclerosis after disease is already established, as well as to explore the underlying mechanism of these cardiovascular protective effects.

METHODS

60 apoE-/- mice were given a high fat diet (HFD) for 12 weeks to allow for the development of atherosclerosis. The mice were then randomized to (i) control group (HFD + 1 mmol/kg/day NaCl), (ii) moderate-dose group (HFD +1 mmol/kg/day NaNO3), or (iii) high-dose group (HFD + 10 mmol/kg/day NaNO3) (20/group) for a further 12 weeks. A group of apoE-/- mice (n = 20) consumed a normal laboratory chow diet for 24 weeks and were included as a reference group.

RESULTS

Long-term supplementation with high dose nitrate resulted in ~ 50% reduction in plaque lesion area. Collagen expression and smooth muscle accumulation were increased, and lipid deposition and macrophage accumulation were reduced within atherosclerotic plaques of mice supplemented with high dose nitrate. These changes were associated with an increase in nitrite reductase as well as activation of the endogenous eNOS-NO pathway.

CONCLUSION

Long-term high dose nitrate significantly attenuated the progression of established atherosclerosis in the apoE-/- mice fed a HFD. This appears to be mediated in part through a XOR-dependent reduction of nitrate to NO, as well as enhanced eNOS activation via increased Akt and eNOS phosphorylation.

The effects of physical exercise therapy on weight control: its regulation of adipocyte physiology and metabolic capacity

Factors associated with increased body mass, including dyslipidemia, hypertension, insulin resistance, vascular endothelial dysfunction and sleep disorders, may contribute to the exacerbation of cardiovascular disease. These health problems associated with obesity are caused by accumulated metabolism and physical and emotional stress. Lifestyle, especially exercise, is a major therapeutic strategy for the treatment and management of obesity-induced metabolic problems. Metabolic disease often co-occurs with abdominal obesity. Exercise is necessary for the treatment of obesity, diabetes and cardiovascular disease. A potential benefit of exercise is to promote fat burning and energy use increases both during exercise itself and in the post-exercise period. Exercise suppresses basal metabolic rate and also has many health benefits. Why should we exercise to lose weight? Does physical activity help lower blood pressure, blood cholesterol, and blood sugar? In this article, we review the positive effects of physical exercise on weight maintenance and weight loss, and the effectiveness of physical exercise on the treatment and prevention of metabolic syndrome.

Effects of Angiotensin Receptor-Neprilysin Inhibitors (ARNIs) on the Glucose and Fat Metabolism Biomarkers Leptin and Fructosamine

(1) Background: Heart failure with reduced ejection fraction (HFrEF) remains a major health burden. Angiotensin-Receptor-Neprilysin-Inhibitors (ARNIs) are an established HFrEF therapy which increases natriuretic peptide levels by inhibiting neprilysin. Leptin is a lipid metabolism parameter, which is also involved in glucose metabolism and is suggested to correlate with HF burden. While the hormone also seems to interact with neprilysin, potential associations with ARNI therapy have not been investigated yet. (2) Methods: To study this issue, we measured levels of leptin and fructosamine in consecutive 72 HFrEF patients before initiation of ARNI therapy and 3-6 months after initiation of therapy in two European centers. Biomarker levels were correlated with clinical parameters including ejection fraction, LVEF, and NYHA class. (3) Results: During a follow-up of up to 6 months, clinical parameters improved significantly (LVEF: 30.2 ± 7.8% to 37.6 ± 10.0%, (p < 0.001) and a significant improvement of the mean NYHA class with initial 32 patients in NYHA III or IV and 8 patients in NYHA class III/IV during the follow up (p < 0.001). The initial NT-proBNP levels of 2251.5 ± 2566.8 pg/mL significantly improved to 1416.7 ± 2145 pg/mL, p = 0.008) during follow up. ARNI therapy was also associated with an increase in leptin levels (17.5 ± 23.4 µg/L to 22.9 ± 29.3, p < 0.001) and furthermore, affected glucose metabolism indicated by elevation of fructosamine values (333.9 ± 156.8 µmol/L to 454.8 ± 197.8 µmol/L, p = 0.013). (4) Conclusion: while in the early phase of therapy, ARNI promotes clinical improvement of HFrEF, and it also seems to affect fat and glucose parameters, indicating significant metabolic implications of this therapy regime.

Mesenteric fat cryolipolysis attenuates insulin resistance in the Ossabaw swine model of the metabolic syndrome

BACKGROUND

The rising prevalence of insulin resistance (IR), metabolic syndrome, and type 2 diabetes are associated with increases in abdominal mesenteric fat. Adipocytes are sensitive to low temperatures, making cryolipolysis of mesenteric fat an attractive treatment modality to potentially reduce IR.

OBJECTIVES

We aimed to determine whether (1) cryolipolysis is safe in reducing the volume of the mesenteric fat and (2) reduction in mesenteric fat volume reduces indices of IR and glycemic dysfunction.

SETTING

Indiana University School of Medicine.

METHODS

A novel cooling device and method delivered cryolipolysis in a controlled manner to avoid tissue ablative temperatures. Ossabaw pigs (n = 8) were fed a high-fat diet for 9 months to develop visceral obesity, IR, and metabolic syndrome. Following laparotomy, mesenteric fat cryolipolysis (MFC) was performed in 5 pigs, while 3 served as sham surgery controls. The volume of the mesenteric fat was measured by computed tomography and compared with indices of glucose intolerance before and at 3 and 6 months postprocedure.

RESULTS

MFC safely reduced mesenteric fat volume by ∼30% at 3 months, which was maintained at 6 months. Body weight did not change in either the MFC or sham surgery control groups. Measure of glycemic control, insulin sensitivity, and blood pressure significantly improved after MFC compared with sham controls.

CONCLUSION

MFC reduces the volume of mesenteric fat and improves glycemic control in obese, IR Ossabaw pigs, without adverse effects.

Smooth Muscle Cells from a Rat Model of Obesity and Hyperleptinemia Are Partially Resistant to Leptin-Induced Reactive Oxygen Species Generation

The aim of this study was to evaluate the effect of leptin on reactive oxygen species’ (ROS) generation of smooth muscle cells (SMCs) from a rat model of obesity and hyperleptinemia. Obesity and hyperleptinemia were induced in rats by a sucrose-based diet for 24 weeks. ROS generation was detected by using dichloro-dihydrofluorescein (DCF), a fluorescent ROS probe in primary SMCs culture. An increase in plasma leptin and oxidative stress markers was observed in sucrose-fed (SF) rats. At baseline SMCs from SF rats showed a more than twofold increase in fluorescence intensity (FI) compared to that obtained in control (C) cells. When the C cells were treated with 20 ng leptin, the FI increased by about 200%, whereas the leptin-induced FI in the SF cells increased only by 60%. In addition, sucrose feeding increased the levels of p22phox and gp91phox, subunits of Nox as an O2•− source in SMCs. Treatment of cells with leptin significantly increased p22phox and gp91phox levels in C cells and did not affect SF cells. Regarding STAT3 phosphorylation and the content of PTP1B and SOCS3 as protein markers of leptin resistance, they were found to be significantly increased in SF cells. These results suggest that SF aortic SMCs are partially resistant to leptin-induced ROS generation.

Functionally Significant Variants in Genes Associated with Abdominal Obesity: A Review

The high prevalence of obesity and of its associated diseases is a major problem worldwide. Genetic predisposition and the influence of environmental factors contribute to the development of obesity. Changes in the structure and functional activity of genes encoding adipocytokines are involved in the predisposition to weight gain and obesity. In this review, variants in genes associated with adipocyte function are examined, as are variants in genes associated with metabolic aberrations and the accompanying disorders in visceral obesity.

Effect of the interaction between the visceral-to-subcutaneous fat ratio and aldosterone on cardiac function in patients with primary aldosteronism

Primary aldosteronism is the most frequent secondary hypertensive disease and is characterized by an elevated risk for cardiovascular disease. The current standard treatments are adrenalectomy and/or administration of mineralocorticoid receptor blockers, both of which are effective at ameliorating hypertension via intervention for hyperaldosteronism. However, both of these approaches have side effects and contraindications, and mineralocorticoid receptor blockers also have limited preventive efficacy against cardiovascular events. Recently, in vitro experiments have shown that aldosterone regulation is closely related to abdominal fat accumulation and that there is crosstalk between aldosterone and visceral fat tissue accumulation. We previously reported that this interaction was clinically significant in renal dysfunction; however, its effects on the heart remain unclear. Here, we analyzed data from 49 patients with primary aldosteronism and 29 patients with essential hypertension to examine the potential effect of the interaction between the ratio of visceral-to-subcutaneous fat tissue volume and the plasma aldosterone concentration on echocardiographic indices, including the tissue Doppler-derived E/e' ratio. A significant interaction was found in patients with primary aldosteronism (p < 0.05), indicating that patients with the combination of a high plasma aldosterone concentration and high visceral-to-subcutaneous fat ratio show an increased E/e' ratio, which is a well-known risk factor for future cardiovascular events. Our results confirm the clinical importance of the interaction between aldosterone and abdominal fat tissue, suggesting that an improvement in the visceral-to-subcutaneous fat ratio may be synergistically and complementarily effective in reducing the elevated risk of cardiovascular disease in patients with primary aldosteronism when combined with conventional therapies for reducing aldosterone activity. A significant effect of the interaction between plasma aldosterone concentration and the visceral-to-subcutaneous fat ratio on the tissue Doppler-derived E/e' ratio in patients with primary aldosteronism.

Interplay between obesity and aging on myocardial geometry and function: Role of leptin-STAT3-stress signaling

BACKGROUND

Uncorrected obesity facilitates premature aging and cardiovascular anomalies. This study examined the interaction between obesity and aging on cardiac remodeling and contractile function.

METHODS

Cardiac echocardiographic geometry, function, morphology, intracellular Ca²⁺ handling, oxidative stress (DHE fluorescence), STAT3 and stress signaling were evaluated in young (3-mo) and old (12- and 18-mo) lean and leptin deficient ob/ob obese mice. Cardiomyocytes from young and old lean and ob/ob mice were treated with leptin (1 nM) for 4 h in vitro prior to assessment of mechanical and biochemical properties. High fat diet (45% calorie from fat) and the leptin receptor mutant db/db obese mice at young and old age were evaluated for comparison.

RESULTS

Our results displayed reduced survival in ob/ob mice. Obesity but less likely older age dampened echocardiographic, geometric, cardiomyocyte function and intracellular Ca²⁺ properties, elevated O₂^- and p^47phox NADPH oxidase levels with a more pronounced geometric change at older age. Immunoblot analysis revealed elevated p^47phox NADPH oxidase and dampened phosphorylation of STAT3, with a more pronounced response in old ob/ob mice, the effects were restored by leptin. Obesity and aging inhibited phosphorylation of Akt, eNOS, AMPK, and p38 while promoting phosphorylation of JNK and IκB. Leptin reconciled cardiomyocyte dysfunction, O₂^- yield, p^47phox upregulation, STAT3 dephosphorylation and stress signaling in ob/ob mice although its action on stress signaling cascades were lost at old age. High fat diet-induced and db/db obesity displayed aging-associated cardiomyocyte anomalies reminiscent of ob/ob model albeit lost leptin response.

CONCLUSIONS

Our data suggest disparate age-associated obesity response in cardiac remodeling and contractile dysfunction due to phosphorylation of Akt, eNOS and stress signaling-related oxidative stress.

Association between sedentary time and plasma leptin levels in middle-aged and older adult population in Taiwan: A community-based, cross-sectional study

Background

Association of sedentary behavior and plasma leptin levels is a popular topic in recent research. Aged populations often suffer from cardiometabolic diseases, and leptin is considered a novel marker for many cardiometabolic diseases. To further explore this topic, our research investigates the relationship between sedentary time and serum leptin levels in middle-aged and older populations.

Methods

A total of 396 middle-aged and older adult Taiwanese participants were included in this study. We recorded their self-reported sitting time as sedentary time. Participants were categorized into low leptin, medium leptin group, and high leptin groups according to the tertile of serum leptin level in the study. We also analyzed the anthropometric and cardiometabolic parameters between the three groups. Spearman's correlation coefficient was used to analyze the correlation between leptin level, sedentary time, and other cardiometabolic risk factors. The relationsip between leptin and sedentary time was also shown in a scatter plot. Multivariate linear regression was performed to determine the association between serum leptin levels and sedentary time after adjusting for age, sex, alcohol consumption, smoking, triglycerides, body mass index (BMI), fasting plasma glucose, systolic blood pressure, uric acid, creatinine, and alanine transaminase (ALT).

Results

In our study, data from a total of 396 participants were analyzed. The average age of participants was 64.75 (±8.75) years, and ~41.4% were male. A longer period of sedentary time was observed in the high leptin group. A positive correlation was found between serum leptin level and sedentary time in Spearman's correlation, in all BMI groups. Serum leptin levels were positively associated with sedentary time (B = 0.603, p = 0.016) in the multivariate linear regression after adjusting for age, sex, alcohol consumption, smoking, triglycerides, BMI, fasting plasma glucose, systolic blood pressure, uric acid, creatinine, and ALT.

Conclusion

Prolonged sedentary time can be an independent risk factor for high serum leptin levels, and high leptin levels can be a novel marker in future healthcare to screen the individual with prolonged sedentary time. Furthermore, based on our study, future research can further explore the relationship between leptin levels and health promotion, especially decreasing sedentary time in the middle-aged and elder population, which is vulnerable to cardiometabolic diseases.

The impact of exercise and dietary interventions on circulating leptin and adiponectin in individuals who are overweight and those with obesity: A systematic review and meta-analysis

The effects of exercise training (Ex), dietary interventions (DIs), and a combination of Ex and DI (Ex + DI) on leptin and adiponectin have been established. However, less is known regarding the comparisons of Ex with DI and of Ex + DI with either Ex or DI alone. The aim of the present meta-analysis is to compare the effects of Ex with those of DI and those of Ex + DI with those of either Ex or DI alone on circulating leptin and adiponectin in individuals who are overweight and those with obesity. PubMed, Web of Science, and MEDLINE were searched to identify original articles, published through June 2022, that compared the effects of Ex with those of DI and/or the effects of Ex + DI with those of Ex and/or DI on leptin and adiponectin in individuals with BMIs (in kg/m²) of ≥25 and aged 7-70 y. Standardized mean differences (SMDs), weighted mean differences, and 95% CIs were calculated using random-effect models for outcomes. Forty-seven studies, comprising 3872 participants who were overweight and those with obesity, were included in the current meta-analysis. DI reduced the concentration of leptin (SMD: -0.30; P = 0.001) and increased the concentration of adiponectin (SMD: 0.23; P = 0.001) compared with Ex, as did Ex + DI (leptin: SMD: -0.34; P = 0.001; adiponectin: SMD: 0.37; P = 0.004) compared with Ex alone. However, Ex + DI did not affect the concentration of adiponectin (SMD: 0.10; P = 0.11) and led to inconsistent and nonsignificant changes in the concentration of leptin (SMD: -0.13; P = 0.06) compared with DI alone. Subgroup analyses showed that age, BMI, duration of intervention, type of supervision, quality of the study, and magnitude of energy restriction are sources of heterogeneity. Our results suggest that Ex alone was not as effective as DI or Ex + DI for decreasing leptin and increasing adiponectin in individuals with overweight and obesity. However, Ex + DI was not more effective than DI alone, suggesting that diet plays a critical role in beneficially altering the concentrations of leptin and adiponectin. This review was registered at PROSPERO as CRD42021283532.

Obesity and Risk for Lymphoma: Possible Role of Leptin

Obesity, which is considered a pandemic due to its high prevalence, is a risk factor for many types of cancers, including lymphoma, through a variety of mechanisms by promoting an inflammatory state. Specifically, over the last few decades, obesity has been suggested not only to increase the risk of lymphoma but also to be associated with poor clinical outcomes and worse responses to different treatments for those diseases. Within the extensive range of proinflammatory mediators that adipose tissue releases, leptin has been demonstrated to be a key adipokine due to its pleotropic effects in many physiological systems and diseases. In this sense, different studies have analyzed leptin levels and leptin/leptin receptor expressions as a probable bridge between obesity and lymphomas. Since both obesity and lymphomas are prevalent pathophysiological conditions worldwide and their incidences have increased over the last few years, here we review the possible role of leptin as a promising proinflammatory mediator promoting lymphomas.

Cytokine database of stress and metabolic disorders (CdoSM): a connecting link between stress and cardiovascular disease, hypertension, diabetes and obesity

The risk of metabolic diseases is greatly increased by both chronic and acute stress. Irrespective of the cause, chronic or acute stress has the capacity to alter an individual's cytokine profile. For instance, it has been observed that stress significantly increased concentrations of IL 1 beta, IL 6 and TNF alpha. Alteration in cytokine profiles increase the likelihood of dysregulated metabolism, which subsequently acts as a driving force in the development of disorders, such as cardiovascular disease (CVD), hypertension, diabetes and obesity. Considering the dynamic and versatile role of cytokines in health and disease, an in-depth computational analysis (qualitative and quantitative) was performed to study the role of cytokines as an immuno-molecular link between rising stress levels and an increase in CVD, hypertension, diabetes and obesity. Upon a qualitative comparative analysis of cytokine profiles, a total of 14 cytokines (IL-6, TNF-alpha, IFN-gamma, IL-10, etc.) were observed to be commonly involved in stress and aforementioned four metabolic disorders. Further analysis of quantitative studies has revealed that the cytokine profile for coronary artery disease (CAD) showed remarkable increase in a couple of cytokines. IL 9 registered an increase of 67 percent to reach a concentration of 75 pg/mL. IL 3, on the other hand, was absent in control candidates but reached 56 ± 14 pg/mL in CAD patients. In case of diabetes, IFN-gamma showed an increase of 290 pg/mL. For obesity it was observed that both MCP-1 and IL-1 beta fell by 12.2 pg/mL to reach 44.4 pg/mL in obese patients. A fall of approximately 50 pg/mL was observed in the concentration of VEGF in obese patients. Similarly, hypertension was marked by reduction in concentration of several cytokines - MCP-1 and VEGF being a couple of them. Apart from performing an analysis of cytokine profiles, an innovative database [Cytokine database of Stress and Metabolic disorders (CdoSM)-https://www.akbi-nsut.co.in/] has also been created comprising cytokines involved in stress and the aforementioned metabolic disorders. Upon accessing the database, a user can find the list cytokines associated with a particular condition along with information on cytokine receptor/s; related research articles; cytokine concentration in control v/s diseased candidates for some specific cytokines and the Uniprot ID for the respective cytokine. Database can be accessed by the link-https://www.akbi-nsut.co.in/.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13205-022-03375-0.

Evaluation of Circulating MicroRNAs and Adipokines in Breast Cancer Survivors with Arm Lymphedema

Breast cancer-related lymphedema (BCRL) is a form of secondary lymphedema that is characterized by abnormal swelling of one or both arms due to the accumulation of lymph fluid in the interstitial tissue spaces, resulting from obstruction of the lymphatic vessels due to surgery insults, radiotherapy, or chemotherapy. Due to the multifactorial nature of this condition, the pathogenesis of secondary lymphedema remains unclear and the search for molecular factors associated with the condition is ongoing. This study aimed to identify serum microRNAs and adipokines associated with BCRL. Blood was collected from 113 breast cancer survivors and processed to obtain serum for small RNA-sequencing (BCRL vs. non-BCRL, n = 7 per group). MicroRNAs that were differentially expressed (fold change >1.5, p < 0.05) between lymphedema cases and those without lymphedema were further quantified in a validation cohort through quantitative reverse transcription PCR (BCRL n = 16, non-BCRL, n = 83). Leptin and adiponectin levels were measured in a combined cohort (BCRL n = 23, non-BCRL n = 90) using enzyme-linked immunosorbent assays. Two of the most significantly upregulated microRNAs, miR-199a-3p and miR-151a-3p, were strongly correlated with the onset of lymphedema and diabetes mellitus in the BCRL group. Leptin levels were higher in the BCRL cohort compared to the non-BCRL cohort (p < 0.05). A metabolic syndrome biomarker, the adiponectin/leptin ratio, was found to be lower in the BCRL group than in the non-BCRL group (median: 0.28 vs. 0.41, p < 0.05). Extensive studies on the mechanisms of the identified microRNAs and association of leptin with arm lymphedema may provide new insights on the potential biomarkers for lymphedema that should be followed up in a prospective cohort study.

Highlights of mechanisms and treatment of obesity-related hypertension

The prevalence of obesity has increased two to three times from 1975 to 2015. Large-scale epidemiological and longitudinal prospective studies link obesity with hypertension. Research suggests that excessive weight gain, particularly when associated with visceral adiposity, may account for as much as 65% to 75% of the risk of incident hypertension. Also, exercise and bariatric/metabolic surgery significantly lowers blood pressure, whereas weight gain increases blood pressure, thus establishing a firm link between these two factors. The mechanisms underpinning obesity-related hypertension are complex and multifaceted, and include, but are not limited to, renin-angiotensin-aldosterone system/sympathetic nervous system overactivation, overstimulation of adipokines, insulin resistance, immune dysfunction, structural/functional renal, cardiac, and adipocyte changes. Though weight loss is the mainstay of treatment for obesity-related hypertension, it is often not a feasible long-term solution. Therefore, it is recommended that aggressive treatment with multiple antihypertensive medications combined with diet and exercise be used to lower blood pressure and prevent complications. The research regarding the mechanisms and treatment of obesity-related hypertension has moved at a blistering pace over the past ten years. Therefore, the purpose of this expert review is two-fold: to discuss the pathophysiological mechanisms underlying obesity-related hypertension, and to revisit pharmacotherapies that have been shown to be efficacious in patients with obesity-related hypertension.

Sex Differences in Adiposity and Cardiovascular Diseases

Body fat distribution is a well-established predictor of adverse medical outcomes, independent of overall adiposity. Studying body fat distribution sheds insights into the causes of obesity and provides valuable information about the development of various comorbidities. Compared to total adiposity, body fat distribution is more closely associated with risks of cardiovascular diseases. The present review specifically focuses on the sexual dimorphism in body fat distribution, the biological clues, as well as the genetic traits that are distinct from overall obesity. Understanding the sex determinations on body fat distribution and adiposity will aid in the improvement of the prevention and treatment of cardiovascular diseases (CVD).

The Acute Effects of Leptin on the Contractility of Isolated Rat Atrial and Ventricular Cardiomyocytes

Leptin is a pleiotropic peptide playing an important role in the regulation of cardiac functions. It is not clear whether leptin directly modulates the mechanical function of atrial cardiomyocytes. We compared the acute effects of leptin on the characteristics of mechanically non-loaded sarcomere shortening and cytosolic Ca2+ concentration ([Ca2+]i) transients in single rat atrial and ventricular cardiomyocytes. We also studied the functional properties of myosin obtained from cardiomyocytes using an in vitro motility assay and assessed the sarcomeric protein phosphorylation. Single cardiomyocytes were exposed to 5, 20, and 60 nM leptin for 60 min. In ventricular cardiomyocytes, 60 nM leptin depressed sarcomere shortening amplitude and decreased the rates of shortening and relaxation. These effects were accompanied by a decrease in the phosphorylation of cMyBP-C, an increase in Tpm phosphorylation, and a slowdown of the sliding velocity of thin filaments over myosin in the in vitro motility assay. In contrast, in atrial cardiomyocytes, the phosphorylation of cMyBP-C and TnI increased, and the characteristics of sarcomere shortening did not change. Leptin had no effect on the characteristics of [Ca2+]i transients in ventricular cardiomyocytes, while 5 nM leptin prolonged [Ca2+]i transients in atrial cardiomyocytes. Thus, leptin-induced changes in contractility of ventricular cardiomyocytes may be attributed to the direct effects of leptin on cross-bridge kinetics and sarcomeric protein properties rather than changes in [Ca2+]i. We also suggest that the observed differences between atrial and ventricular cardiomyocytes may be associated with the peculiarities of the expression of leptin receptors, as well as signaling pathways in the atrial and ventricular myocardium.

Heart failure and osteoporosis: common pathogenetic components

This literature review reflects modern ideas about the combination of heart failure (HF) and osteoporosis, common risk factors for these diseases, and pathophysiological mechanisms of metabolic bone diseases in HF. Despite a growing number of studies on the combined cardiovascular and skeletal system pathology, the relationship between a decrease in bone mineral density and HF risk remains poorly understood. Both conditions are common causes of disability, death, prolonged hospitalizations and a significant reduction in quality of life, while its combination exacerbates their course and increases the incidence of adverse outcomes, which is a heavy burden for a patient and health care in general. Keywords: heart failure, osteoporosis, bone mineral density, bone metabolism.

Hypolipidemic activity and safety evaluation of a rhamnan-type sulfated polysaccharide-chromium (III) complex

BACKGROUND

Hyperlipidaemia is a chronic disorder characterized by imbalance of energy metabolism and high blood lipid level. The rhamnan-type sulfated polysaccharide is an excellent metal-ion chelating ligands. In this study, hypolipidemic activity and safety evaluation of a rhamnan-type sulfated polysaccharide-chromium (III) complex (RSPC) were studied.

METHODS

Scanning electron microscopy (SEM) and atomic force microscopy (AFM) were used to characterize the structure of RSPC. The effects of the RSPC on lipid metabolism in hyperlipidemic mice were evaluated by lipid contents, histopathological observation, immunofluorescent analysis, and adipocytokine levels. Moreover, sub-acute toxicity evaluation of RSPC was carried out on ICR mice.

RESULTS

SEM and AFM further demonstrated formation of the polysaccharide-chromium (III) complex and revealed the intertwined network of RSPC. The RSPC significantly (p < 0.05) regulated lipid levels in the mice. The RSPC inhibited over-growth of adipocytes and reduced inflammatory infiltration induced by hyperlipidemia. The RSPC promoted differentiation of white adipose tissue into beige adipocytes and increased expression of uncoupling protein 1 (UCP1), thereby eliminating fat accumulation. Moreover, RSPC (5 mg/kg for mice; equivalent to 924 µg/d for adults) promoted secretion of adiponectin and suppressed resistin, leptin, and tumor necrosis factor alpha. Sub-acute toxicity evaluation showed that 1500 mg/kg of RSPC exhibited no apparent adverse effects on the mice.

CONCLUSION

These results indicated that RSPC could be safely used to prevent hyperlipidemia and inflammation and may provide a new idea for the prevention of hyperlipidaemia and the related metabolic disorders.

Adipose Tissue Inflammation and Pulmonary Dysfunction in Obesity

Obesity is a chronic disease caused by an excess of adipose tissue that may impair health by altering the functionality of various organs, including the lungs. Excessive deposition of fat in the abdominal area can lead to abnormal positioning of the diaphragm and consequent reduction in lung volume, leading to a heightened demand for ventilation and increased exposure to respiratory diseases, such as chronic obstructive pulmonary disease, asthma, and obstructive sleep apnoea. In addition to mechanical ventilatory constraints, excess fat and ectopic deposition in visceral depots can lead to adipose tissue dysfunction, which promotes metabolic disorders. An altered adipokine-secretion profile from dysfunctional adipose tissue in morbid obesity fosters systemic, low-grade inflammation, impairing pulmonary immune response and promoting airway hyperresponsiveness. A potential target of these adipokines could be the NLRP3 inflammasome, a critical component of the innate immune system, the harmful pro-inflammatory effect of which affects both adipose and lung tissue in obesity. In this review, we will investigate the crosstalk between adipose tissue and the lung in obesity, highlighting the main inflammatory mediators and novel therapeutic targets in preventing pulmonary dysfunction.

Central and cardiac stress resiliences consistently linked to integrated immuno-neuroendocrine responses across stress models in male mice

Stress resilience, and behavioural and cardiovascular impacts of chronic stress, are theorised to involve integrated neuro-endocrine/inflammatory/transmitter/trophin signalling. We tested for this integration, and whether behaviour/emotionality, together with myocardial ischaemic tolerance, are consistently linked to these pathways across diverse conditions in male C57Bl/6 mice. This included: Restraint Stress (RS), 1 hr restraint/day for 14 days; Chronic Unpredictable Mild Stress (CUMS), 7 stressors randomised over 21 days; Social Stress (SS), 35 days social isolation with brief social encounters in final 13 days; and Control conditions (CTRL; un-stressed mice). Behaviour was assessed via open field (OFT) and sucrose preference (SPT) tests, and neurobiology from frontal cortex (FC) and hippocampal transcripts. Endocrine factors, and function and ischaemic tolerance in isolated hearts, were also measured. Model characteristics ranged from no behavioural or myocardial changes with homotypic RS, to increased emotionality and cardiac ischaemic injury (with apparently distinct endocrine/neurobiological profiles) in CUMS and SS models. Highly integrated expression of HPA axis, neuro-inflammatory, BDNF, monoamine, GABA, cannabinoid and opioid signalling genes was confirmed across conditions, and consistent/potentially causal correlations identified for: i) Locomotor activity (noradrenaline, ghrelin; FC Crhr1, Tnfrsf1b, Il33, Nfkb1, Maoa, Gabra1; hippocampal Il33); ii) Thigmotaxis (adrenaline, leptin); iii) Anxiety-like behaviour (adrenaline, leptin; FC Tnfrsf1a; hippocampal Il33); iv) Depressive-like behaviour (ghrelin; FC/hippocampal s100a8); and v) Cardiac stress-resistance (noradrenaline, leptin; FC Il33, Tnfrsf1b, Htr1a, Gabra1, Gabrg2; hippocampal Il33, Tnfrsf1a, Maoa, Drd2). Data support highly integrated pathway responses to stress, and consistent adipokine, sympatho-adrenergic, inflammatory and monoamine involvement in mood and myocardial disturbances across diverse conditions.

Remodeling and Fibrosis of the Cardiac Muscle in the Course of Obesity-Pathogenesis and Involvement of the Extracellular Matrix

Obesity is a growing epidemiological problem, as two-thirds of the adult population are carrying excess weight. It is a risk factor for the development of cardiovascular diseases (hypertension, ischemic heart disease, myocardial infarct, and atrial fibrillation). It has also been shown that chronic obesity in people may be a cause for the development of heart failure with preserved ejection fraction (HFpEF), whose components include cellular hypertrophy, left ventricular diastolic dysfunction, and increased extracellular collagen deposition. Several animal models with induced obesity, via the administration of a high-fat diet, also developed increased heart fibrosis as a result of extracellular collagen accumulation. Excessive collagen deposition in the extracellular matrix (ECM) in the course of obesity may increase the stiffness of the myocardium and thereby deteriorate the heart diastolic function and facilitate the occurrence of HFpEF. In this review, we include a rationale for that process, including a discussion about possible putative factors (such as increased renin–angiotensin–aldosterone activity, sympathetic overdrive, hemodynamic alterations, hypoadiponectinemia, hyperleptinemia, and concomitant heart diseases). To address the topic clearly, we include a description of the fundamentals of ECM turnover, as well as a summary of studies assessing collagen deposition in obese individuals.