Leptin and atherosclerosis

Meta-Analysis and Network Analysis Differentially Detect Various Pro-Inflammatory Mediators and Risk Factors for Type 2 Diabetes in the Elderly

Type 2 diabetes (T2D) has a pathophysiological component that includes inflammation. Inflammation-sensitive marker measurement may be helpful in determining the risk of complications for both older T2D patients and the public. This study aimed to investigate the association between blood pro-inflammatory mediators and the characteristics of elderly patients with T2D using meta and network analyses. The Web of Science, Scopus, PubMed, and Cochrane Library databases were selected as study methodology. The Quality in Prognosis Studies (QUIPS) tool in the meta-analysis assessed the studies' methodological quality. The selected studies were statistically analyzed using the META-MAR tool based on the standardized mean difference (SMD). The selected studies included nine examinations involving 6399 old people [+>+55 years old, 65.9+±+4.09 (mean+±+SD)]. The meta-analysis showed that pro-inflammatory mediators (SMD 0.82) and patient-related variables [risk factors (SMD 0.71)] were significantly associated with T2D (p+<+0.05). Subgroup analysis revealed that tumor necrosis factor alpha (TNF-α; SMD 1.08), body mass index (SMD 0.64), high-density lipoprotein (HDL; SMD -0.61), body weight (SMD 0.50), and blood pressure (SMD 1.11) were factors significantly associated with T2D (p+<+0.05). Network analysis revealed that among patient characteristics, diastolic blood pressure and, among inflammatory mediators, leptin were the most closely associated factors with T2D in older adults. Moreover, network analysis showed that TNF-α and systolic blood pressure were most closely associated with leptin. Overall, alternate techniques, such as meta-analysis and network analysis, might identify different markers for T2D in older people. A therapeutic decision-making process needs to consider these differences in advance.

Associations of Adipokine Levels With Levels of Remnant Cholesterol: The Multi-Ethnic Study of Atherosclerosis

BACKGROUND

The metabolic syndrome phenotype of individuals with obesity is characterized by elevated levels of triglyceride-rich lipoproteins and remnant particles, which have been shown to be significantly atherogenic. Understanding the association between adipokines, endogenous hormones produced by adipose tissue, and remnant cholesterol (RC) would give insight into the link between obesity and atherosclerotic cardiovascular disease.

METHODS AND RESULTS

We studied 1791 MESA (Multi-Ethnic Study of Atherosclerosis) participants who took part in an ancillary study on body composition with adipokine levels measured (leptin, adiponectin, and resistin) at either visit 2 or visit 3. RC was calculated as non-high-density lipoprotein cholesterol minus low-density lipoprotein cholesterol, measured at the same visit as the adipokines, as well as subsequent visits 4 through 6. Multivariable-adjusted linear mixed-effects models were used to assess the cross-sectional and longitudinal associations between adipokines and log-transformed levels of RC. Mean±SD age was 64.5±9.6 years; mean±SD body mass index was 29.9±5.0 kg/m2; and 52.0% were women. In fully adjusted cross-sectional models that included body mass index, diabetes, low-density lipoprotein cholesterol, and lipid-lowering therapy, for each 1-unit increment in adiponectin, there was 14.6% (95% CI, 12.2-16.9) lower RC. With each 1-unit increment in leptin and resistin, there was 4.8% (95% CI, 2.7-7.0) and 4.0% (95% CI, 0.2-8.1) higher RC, respectively. Lower adiponectin and higher leptin were also associated with longitudinal increases in RC levels over median follow-up of 5 (interquartile range, 4-8) years.

CONCLUSIONS

Lower adiponectin and higher leptin levels were independently associated with higher levels of RC at baseline and longitudinal RC increase, even after accounting for body mass index and low-density lipoprotein cholesterol.

Leptin Is Associated with Testosterone, Nutritional Markers, and Vascular Muscular Dysfunction in Chronic Kidney Disease

Chronic kidney disease (CKD) causes specific hormonal disturbances, such as variations in leptin and testosterone levels and function. These disturbances can promote errors in signaling interaction and cellular information processing and can be implicated in the pathogenesis of atherosclerosis. This study investigates the factors that affect leptin in CKD patients and examines how leptin is related to markers of vascular disease. We conducted a cross-sectional study of 162 patients with CKD in pre-dialysis and dialysis stages. We recorded clinical and laboratory data, including leptin, testosterone, and subclinical atherosclerosis markers like brachial-ankle pulse wave velocity (ba PWV) in pre-dialysis CKD patients and flow-mediated vasodilation (FMD) and nitroglycerin-mediated vasodilation (NMD) in hemodialysis (HD) patients. Leptin was significantly correlated with testosterone in CKD pre-dialysis stages (p < 0.001) and also in HD (p = 0.026), with adipose tissue mass in pre-dialysis stages (p < 0.001), and also in HD (p < 0.001). In women HD patients, leptin correlated with NMD (p = 0.039; r = -0.379); in all HD patients, leptin correlated with C reactive protein (p = 0.007; r = 0.28) and parathormone (p = 0.039; r = -0.220). Our research emphasizes the connection between leptin, adipose tissue, and testosterone in all stages of CKD. Leptin was associated with NMD in HD women and correlated with inflammatory syndrome and parathyroid hormone in all HD patients.

Plasma proteomics for prediction of subclinical coronary artery calcifications in primary prevention

BACKGROUND AND AIMS

Recent developments in high-throughput proteomic technologies enable the discovery of novel biomarkers of coronary atherosclerosis. The aims of this study were to test if plasma protein subsets could detect coronary artery calcifications (CAC) in asymptomatic individuals and if they add predictive value beyond traditional risk factors.

METHODS

Using proximity extension assays, 1,342 plasma proteins were measured in 1,827 individuals from the Impaired Glucose Tolerance and Microbiota (IGTM) study and 883 individuals from the Swedish Cardiopulmonary BioImage Study (SCAPIS) aged 50-64 years without history of ischaemic heart disease and with CAC assessed by computed tomography. After data-driven feature selection, extreme gradient boosting machine learning models were trained on the IGTM cohort to predict the presence of CAC using combinations of proteins and traditional risk factors. The trained models were validated in SCAPIS.

RESULTS

The best plasma protein subset (44 proteins) predicted CAC with an area under the curve (AUC) of 0.691 in the validation cohort. However, this was not better than prediction by traditional risk factors alone (AUC = 0.710, P = .17). Adding proteins to traditional risk factors did not improve the predictions (AUC = 0.705, P = .6). Most of these 44 proteins were highly correlated with traditional risk factors.

CONCLUSIONS

A plasma protein subset that could predict the presence of subclinical CAC was identified but it did not outperform nor improve a model based on traditional risk factors. Thus, support for this targeted proteomics platform to predict subclinical CAC beyond traditional risk factors was not found.

PCSK9 and leptin plasma levels in anorexia nervosa

AIM

Proprotein convertase subtilisin/kexin type 9 (PCSK9) is a regulator of low-density-lipoprotein cholesterol (LDL-C), a major risk factor for cardiovascular (CV) disease. Since the hormone leptin has been suggested as having a role in CV risk regulation, possibly by modulating LDL receptor expression through the PCSK9 pathway, nutritional status may represent a potential regulator. Thus, evaluation of PCSK9 levels in human eating disorders appears to be of interest. In this report, we evaluate the lipoprotein profile, PCSK9, and leptin levels in subjects affected by anorexia nervosa (AN) to improve our understanding of the metabolic alterations in this disease.

METHODS AND RESULTS

We designed a case-control observational study, enrolling 20 anorexic adolescent females and 20 adolescent females without AN as the control group, age- and sex-matched. Subjects affected by AN showed lower BMI, total cholesterol, and LDL-C in comparison to the control group, with lipoprotein levels in the normal range. Furthermore, adolescent girls with AN show significantly higher PCSK9 (+24%, p < 0.005) and lower leptin levels (-43%, p < 0.01), compared to the control group.

CONCLUSIONS

The findings of increased levels of PCSK9 and reduced leptin levels among AN subjects warrant further research in order to unravel the role of the liver and adipose tissue in the management of PCSK9/LDL metabolism in adolescents affected by AN.

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.

Targeting systemic inflammation in metabolic disorders. A therapeutic candidate for the prevention of cardiovascular diseases?

Cardiovascular disease (CVD) remains the leading cause of death and disability worldwide. While many factors can contribute to CVD, atherosclerosis is the cardinal underlying pathology, and its development is associated with several metabolic risk factors including dyslipidemia and obesity. Recent studies have definitively demonstrated a link between low-grade systemic inflammation and two relevant metabolic abnormalities: hypercholesterolemia and obesity. Interestingly, both metabolic disorders are also associated with endothelial dysfunction/activation, a proinflammatory and prothrombotic phenotype of the endothelium that involves leukocyte infiltration into the arterial wall, one of the earliest stages of atherogenesis. This article reviews the current literature on the intricate relationship between hypercholesterolemia and obesity and the associated systemic inflammation and endothelial dysfunction, and discusses the effectiveness of present, emerging and in-development pharmacological therapies used to treat these metabolic disorders with a focus on their effects on the associated systemic inflammatory state and cardiovascular risk.

Serum Adiponectin and Leptin Among Ghanaian Migrants in Amsterdam and Their Compatriots in Rural and Urban Ghana: The RODAM Study

Background

The rapidly rising cardiometabolic disease (CMD) burden in urbanizing sub-Saharan African populations and among sub-Saharan African migrants in Europe likely affects serum adiponectin and leptin levels, but this has not yet been quantified.

Objectives

To compare the serum levels of adiponectin and leptin among migrant, and non-migrant (urban and rural) populations of Ghanaian descent.

Methods

Cross-sectional analysis of serum leptin and adiponectin in the multi-centre Research on Obesity and Diabetes among African Migrants (RODAM) study. Logistic-regression models were used to examine the association between these adipocyte-derived hormones after stratification (sex, geographic area) and adjustments for potential confounders.

Results

A total of 2518 Ghanaians were included. Rural participants had the highest serum adiponectin and lowest leptin levels compared to Amsterdam and urban Ghanaians (P < .001). In fully adjusted models, participants living in urban Ghana had significantly higher odds of hyperleptinemia compared to rural participants (women-odds ratio 2.88; 95% CI, 1.12-7.38, P = .028 and men 43.52, 95% CI, 4.84-391.25, P < .001). Urban Ghanaian men also had higher odds of elevated leptin: adiponectin ratio (6.29, 95% CI, 1.43-27.62, P = .015). The odds of hyperleptinemia were only higher in Amsterdam Ghanaian men (10.56; 95% CI, 1.11-100.85, P = .041), but not in women (0.85; 95% CI, 0.30-2.41, P = .759). There was no significant association between hypoadiponectinemia and geographical location in both sexes.

Conclusion

Urbanization is associated with serum adiponectin and leptin levels after adjusting for confounding covariates in sub-Saharan Africans. These findings serve as a backdrop for further research on the role adipokines play in CMD epidemiology among Africans.

Leptin as predictor of cardiovascular events and high platelet reactivity in patients undergoing percutaneous coronary intervention

BACKGROUND AND AIMS

Leptin is a hormone involved in the regulation of food intake. Previous studies suggested an interplay between leptin, platelet aggregation, and cardiovascular outcome but this issue was not investigated in vivo in patients treated with percutaneous coronary intervention (PCI). We designed a study to evaluate the possible relation between leptin, cardiovascular outcome, and platelet reactivity (PR) in patients undergoing PCI.

METHODS

155 PCI patients had preprocedural measurements of PR and leptin plasma levels. The latter were assessed by ELISA. Hyperleptinemia was defined as leptin levels ≥14 ng/ml. PR was evaluated by the VerifyNowP2Y12 assay and expressed as P2Y12 reaction units (PRU). Patients were divided into three groups based on PR values and defined as low (LPR), normal (NPR), and high (HPR). Patients were followed for up 8 years. The primary endpoint was the incidence of Major Acute Cardiac Events (MACE) at long-term follow-up according to leptin groups. Secondary endpoints were the evaluation of leptin levels according to PR groups and the incidence of periprocedural myocardial infarction (PMI) according to leptin groups.

RESULTS

Long-term follow-up was completed in 140 patients. Patients with hyperleptinemia experienced a higher MACE rate than the normoleptinemic group (HR 2.3; CI 95% 1.14-4.6, P = 0.02). These results remained unchanged after adjusting for Body Mass Index, hypertension, and gender. Leptin levels were significantly different among groups of PR (P = 0.047). Leptin levels were higher in the HPR group (12.61 ± 16.58 ng/ml) compared to the LPR group (7.83 ± 8.87 ng/ml, P = 0.044) and NPR group (7.04 ± 7.03 ng/ml, P = 0.01). The rate of PMI was higher in hyperleptinemia patients (15.1% vs. 6.5%, P = 0.22).

CONCLUSIONS

This study suggests that high leptin levels are associated with a worse clinical outcome in patients undergoing PCI and with HPR. Further studies are needed to define better the pathophysiological pathways underlying this association.

PET Radiotracers in Atherosclerosis: A Review

Traditional atherosclerosis imaging modalities are limited to late stages of disease, prior to which patients are frequently asymptomatic. Positron emission tomography (PET) imaging allows for the visualization of metabolic processes underscoring disease progression via radioactive tracer, allowing earlier-stage disease to be identified. 2-deoxy-2-[fluorine-18]fluoro-D-glucose (18F-FDG) uptake largely reflects the metabolic activity of macrophages, but is unspecific and limited in its utility. By detecting areas of microcalcification, 18F-Sodium Fluoride (18F-NaF) uptake also provides insight into atherosclerosis pathogenesis. Gallium-68 DOTA-0-Tyr3-Octreotate (68Ga-DOTATATE) PET has also shown potential in identifying vulnerable atherosclerotic plaques with high somatostatin receptor expression. Finally, 11-carbon (11C)-choline and 18F-fluoromethylcholine (FMCH) tracers may identify high-risk atherosclerotic plaques by detecting increased choline metabolism. Together, these radiotracers quantify disease burden, assess treatment efficacy, and stratify risk for adverse cardiac events.

Adipokines in atherosclerosis: unraveling complex roles

Adipokines are biologically active factors secreted by adipose tissue that act on local and distant tissues through autocrine, paracrine, and endocrine mechanisms. However, adipokines are believed to be involved in an increased risk of atherosclerosis. Classical adipokines include leptin, adiponectin, and ceramide, while newly identified adipokines include visceral adipose tissue-derived serpin, omentin, and asprosin. New evidence suggests that adipokines can play an essential role in atherosclerosis progression and regression. Here, we summarize the complex roles of various adipokines in atherosclerosis lesions. Representative protective adipokines include adiponectin and neuregulin 4; deteriorating adipokines include leptin, resistin, thrombospondin-1, and C1q/tumor necrosis factor-related protein 5; and adipokines with dual protective and deteriorating effects include C1q/tumor necrosis factor-related protein 1 and C1q/tumor necrosis factor-related protein 3; and adipose tissue-derived bioactive materials include sphingosine-1-phosphate, ceramide, and adipose tissue-derived exosomes. However, the role of a newly discovered adipokine, asprosin, in atherosclerosis remains unclear. This article reviews progress in the research on the effects of adipokines in atherosclerosis and how they may be regulated to halt its progression.

Regulation of cardiovascular health and disease by visceral adipose tissue-derived metabolic hormones

Visceral adipose tissue (VAT) is a metabolic organ known to regulate fat mass, and glucose and nutrient homeostasis. VAT is an active endocrine gland that synthesizes and secretes numerous bioactive mediators called 'adipocytokines/adipokines' into systemic circulation. These adipocytokines act on organs of metabolic importance like the liver and skeletal muscle. Multiple preclinical and in vitro studies showed strong evidence of the roles of adipocytokines in the regulation of metabolic disorders like diabetes, obesity and insulin resistance. Adipocytokines, such as adiponectin and omentin, are anti-inflammatory and have been shown to prevent atherogenesis by increasing nitric oxide (NO) production by the endothelium, suppressing endothelium-derived inflammation and decreasing foam cell formation. By inhibiting differentiation of vascular smooth muscle cells (VSMC) into osteoblasts, adiponectin and omentin prevent vascular calcification. On the other hand, adipocytokines like leptin and resistin induce inflammation and endothelial dysfunction that leads to vasoconstriction. By promoting VSMC migration and proliferation, extracellular matrix degradation and inflammatory polarization of macrophages, leptin and resistin increase the risk of atherosclerotic plaque vulnerability and rupture. Additionally, the plasma concentrations of these adipocytokines alter in ageing, rendering older humans vulnerable to cardiovascular disease. The disturbances in the normal physiological concentrations of these adipocytokines secreted by VAT under pathological conditions impede the normal functions of various organs and affect cardiovascular health. These adipokines could be used for both diagnostic and therapeutic purposes in cardiovascular disease.

Overview and New Insights into the Metabolic Syndrome: Risk Factors and Emerging Variables in the Development of Type 2 Diabetes and Cerebrocardiovascular Disease

Metabolic syndrome (MetS) is considered a metabolic disorder that has been steadily increasing globally and seems to parallel the increasing prevalence of obesity. It consists of a cluster of risk factors which traditionally includes obesity and hyperlipidemia, hyperinsulinemia, hypertension, and hyperglycemia. These four core risk factors are associated with insulin resistance (IR) and, importantly, the MetS is known to increase the risk for developing cerebrocardiovascular disease and type 2 diabetes mellitus. The MetS had its early origins in IR and syndrome X. It has undergone numerous name changes, with additional risk factors and variables being added over the years; however, it has remained as the MetS worldwide for the past three decades. This overview continues to add novel insights to the MetS and suggests that leptin resistance with hyperleptinemia, aberrant mitochondrial stress and reactive oxygen species (ROS), impaired folate-mediated one-carbon metabolism with hyperhomocysteinemia, vascular stiffening, microalbuminuria, and visceral adipose tissues extracellular vesicle exosomes be added to the list of associated variables. Notably, the role of a dysfunctional and activated endothelium and deficient nitric oxide bioavailability along with a dysfunctional and attenuated endothelial glycocalyx, vascular inflammation, systemic metainflammation, and the important role of ROS and reactive species interactome are discussed. With new insights and knowledge regarding the MetS comes the possibility of new findings through further research.

Adipokines as an important link between hidradenitis suppurativa and obesity: a narrative review

Hidradenitis suppurativa (HS) is a chronic, recurrent, debilitating disorder of the pilosebaceous unit. Although its pathophysiology is not fully explained, inflammation seems to play an essential role in the development of HS. A link between obesity - often considered a state of chronic inflammation - and a higher prevalence of HS has been described. Nevertheless, the exact association is not well understood. Adipose tissue is a highly active endocrine organ that produces and secretes a variety of metabolically and immunologically active molecules called adipokines. The imbalances in concentrations of several adipokines in patients with HS have already been described. A shift towards the overproduction of proinflammatory adipokines (including leptin, resistin and visfatin) with the suppression of anti-inflammatory ones (adiponectin) has been noted. We conducted a review of the available data on adipokines in HS, concentrating on the described imbalances in adipokine concentrations, as well as possible implications in HS pathogenesis. Moreover, new, unstudied adipokines with possible implications in the development of HS are proposed.

Effects of Coffee Supplementation on Homocysteine and Leptin Levels: A Systematic Review and Meta-analysis of Clinical Trials

BACKGROUND

It has been reported that the consumption of antioxidant foods and beverages may benefit the development of cardiovascular risk factors. However, the impact of coffee consumption on some of these factors, such as homocysteine and leptin is controversial. Some clinical trials have suggested that coffee administration increases plasma total homocysteine levels, while others have found no significant changes in leptin concentrations.

OBJECTIVE

This study aimed to assess the effects of coffee supplementation on homocysteine and leptin concentrations in a meta-analysis of clinical trials.

METHODS

PubMed, Web of Science, Scopus, ClinicalTrials.gov, and Google Scholar databases were searched from inception to September 29, 2021. A fixed-effects model and the generic inverse variance weighting method were used for meta-analysis.

RESULTS

The meta-analysis demonstrated that coffee administration significantly increases homocysteine levels (WMD: 0.55 μmol/L, 95% CI: 0.17, 0.93, p = 0.005, I2 = 0%) but has no significant changes in leptin concentrations (WMD: 1.34 ng/mL, 95% CI: -0.78, 3.45, p = 0.21, I2 = 0%). Additionally, the sensitivity analysis was robust for both homocysteine and leptin levels.

CONCLUSION

The results of the present meta-analysis revealed that coffee supplementation raises serum homocysteine concentrations but has no effect on circulating leptin levels.

Effect of Intermittent Fasting, Probiotic-Fermented Camel Milk, and Probiotic-Fermented Camel Milk Incorporating Sukkari Date on Diet-Induced Obesity in Rats

Obesity causes metabolic syndrome disorders that are detrimental to health. The current study examined the effects of intermittent fasting (IF), fermented camel milk (FCM), and fermented camel milk incorporating 10% Sukkari date (FCM-D) on weight loss, blood profile, and antioxidant status in obese rats for 6 weeks. Subsequently, leptin and adiponectin levels and histopathological examination of adipose tissue were carried out. Results showed that IF with FCM or FCM-D decreased body weight by 0.92 and −5.45%, respectively. IF alone lowered non-fasting blood glucose (NFBG) and fasting blood glucose FBG after 6 weeks, whereas adding FCM or FCM-D reduced NFBG after 4 weeks. Intermittently fasting obese rats given FCM or FCM-D had the lowest blood glucose levels (BGL). The hypolipidemic effects of IF, FCM, and FCM-D on obese rats reduced triglycerides (TG), cholesterols (CHO), and their derivatives. FCM-D with IF presented a superior effect on lipid profile. A reduction rate of 40, 37, 66, and 40% for TG, CHO, low-density lipoprotein (LDL-c), and very low-density lipoprotein (VLDL-c), respectively, and an increase in HDL-C by 34% were noticed. Reductions of 40, 37, 66, and 40% for TG, CHO, LDL-c, and VLDL-c, respectively, and a 34% rise in high-density lipoprotein (HDL-C) were noted. Combining IF with FCM or FCM-D lowered the atherogenic index (AI) by 42% and 59%, respectively. Remarkably, treating rats with FCM+IF or FCM-D+IF effectively attenuated leptin and adiponectin levels. Malondialdehyde (MDA) was significantly decreased in a type-dependent manner. Implementing FCM-D or FCM with IF significantly attenuated reduced glutathione (GSH), superoxide dismutase (SOD), MDA, and catalase (CAT) levels. The most efficient treatment was giving FCM-D with IF. Histopathologically, adipocyte lipolysis increases free fatty acids (FFAs) and promotes inflammation. Only IF+FCM-D indicated no histopathological alteration except for a few focal areas of a few inflammatory cell infiltrations in the parenchyma. In conclusion, combining IF and Probiotic-FCM or Probiotic-FCM-D effectively accelerated weight loss, attenuated metabolic markers, and reversed histopathological alterations. Thus, IF combined with Probiotic-FCM or Probiotic-FCM-D is highly recommended for weight loss, strengthening antioxidative status, and preventing health disorders.

Leptin signaling and leptin resistance

With the prevalence of obesity and associated comorbidities, studies aimed at revealing mechanisms that regulate energy homeostasis have gained increasing interest. In 1994, the cloning of leptin was a milestone in metabolic research. As an adipocytokine, leptin governs food intake and energy homeostasis through leptin receptors (LepR) in the brain. The failure of increased leptin levels to suppress feeding and elevate energy expenditure is referred to as leptin resistance, which encompasses complex pathophysiological processes. Within the brain, LepR-expressing neurons are distributed in hypothalamus and other brain areas, and each population of the LepR-expressing neurons may mediate particular aspects of leptin effects. In LepR-expressing neurons, the binding of leptin to LepR initiates multiple signaling cascades including janus kinase (JAK)-signal transducers and activators of transcription (STAT) phosphatidylinositol 3-kinase (PI3K)-protein kinase B (AKT), extracellular regulated protein kinase (ERK), and AMP-activated protein kinase (AMPK) signaling, etc., mediating leptin actions. These findings place leptin at the intersection of metabolic and neuroendocrine regulations, and render leptin a key target for treating obesity and associated comorbidities. This review highlights the main discoveries that shaped the field of leptin for better understanding of the mechanism governing metabolic homeostasis, and guides the development of safe and effective interventions to treat obesity and associated diseases.

Leptin-reactive antibodies are distinctly correlated with body composition parameters and metabolic risk indexes in children and adolescents

Studies have demonstrated the presence of low-affinity immunoglobulins (Igs) directed to leptin, a key hormone of the neuroendocrine axis that regulates appetite and metabolism, in adult healthy subjects, patients with obesity, and type 2 diabetes mellitus. In the present exploratory study, IgG leptin-reactive antibodies were analyzed for the first time in children and adolescents according to body mass index (BMI) and were correlated with biochemical profile (lipid profile, insulin, glucose, and leptin) and metabolic risk indexes [homeostasis model assessment for insulin resistance (HOMA-IR), homeostasis model assessment for β-cell function (HOMA-β), atherogenic index of plasma (AIP)]. One hundred and thirty-six participants were included (children n = 63, adolescents n = 73). An in-house enzyme-linked immunosorbent assay (ELISA) test was performed to measure IgG anti-leptin antibodies (free, total, and immune complexes). In adolescents, free and total IgG anti-leptin antibodies levels were higher in groups with overweight or obesity than in normal-weight group (P < 0.01), while in children, the total fractions were lower in groups with overweight and obesity than in normal weight (P < 0.02). Immune complexes percentage showed opposite correlations with BMI in children (r = 0.4004, P = 0.0473) and adolescents (r = -0.3983, P = 0.0133). IgG anti-leptin antibodies were also correlated with HOMA-IR in children (r = -0.4569, P = 0.0217) and adolescents (r = -0.3589, P = 0.0316), and with AIP (r = -0.3608, P = 0.0261) in adolescents. Our data suggest that the production and affinity of IgG anti-leptin antibodies can be affected by age, body composition, and metabolic conditions; additionally, in normal conditions, IgG anti-leptin antibodies may have a protective role in insulin resistance and cardiovascular events.

The Head-to-Toe Hormone: Leptin as an Extensive Modulator of Physiologic Systems

Leptin is a well-known hunger-sensing peptide hormone. The role of leptin in weight gain and metabolic homeostasis has been explored for the past two decades. In this review, we have tried to shed light upon the impact of leptin signaling on health and diseases. At low or moderate levels, this peptide hormone supports physiological roles, but at chronically higher doses exhibits detrimental effects on various systems. The untoward effects we observe with chronically higher levels of leptin are due to their receptor-mediated effect or due to leptin resistance and are not well studied. This review will help us in understanding the non-anorexic roles of leptin, including their contribution to the metabolism of various systems and inflammation. We will be able to get an alternative perspective regarding the physiological and pathological roles of this mysterious peptide hormone.

Cardiometabolic biomarkers in women with polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is the most common endocrine disorder in women of reproductive age. Apart from the reproductive problems, PCOS is also associated with metabolic disturbances, and therefore, it also affects adolescents and postmenopausal women with PCOS as well as their offspring and other first-degree relatives. Adolescents with PCOS show unfavorable cardiometabolic biomarkers more often than controls, such as overweight/obesity and hyperandrogenism, and studies also suggest an unfavorable lipid profile. During reproductive age, women with PCOS develop additional cardiometabolic biomarkers, such as hypertension, insulin resistance, and metabolic syndrome. Growing evidence also supports the important role of inflammatory cytokines in cardiovascular health in these women. During menopausal transition, some PCOS characteristics ameliorate, whereas other biomarkers increase, such as body mass index, insulin resistance, type 2 diabetes, and hypertension. Offspring of women with PCOS have a lower birth weight and a higher body mass index later in life than controls. In addition, fathers, mothers, and siblings of women with PCOS show unfavorable cardiometabolic biomarkers. Therefore, cardiovascular screening and follow-up of women with PCOS and their offspring and siblings are of utmost importance.

The cerebral artery in cynomolgus monkeys (Macaca fascicularis)

Cerebral artery structure has not been extensively studied in primates. The aim of this study was to examine the cerebrovascular anatomy of cynomolgus monkeys (Macaca fascicularis), which are one of the most commonly used primates in medical research on human diseases, such as cerebral infarction and subarachnoid hemorrhage. In this study, we investigated the anatomy and diameter of cerebral arteries from 48 cynomolgus monkey brain specimens. We found three anatomical differences in the vascular structure of this species compared to that in humans. First, the distal anterior cerebral artery is single. Second, the pattern in which both the anterior inferior cerebellar artery and posterior inferior cerebellar artery branch from the basilar artery is the most common. Third, the basilar artery has the largest diameter among the major arteries. We expect that this anatomical information will aid in furthering research on cerebrovascular disease using cynomolgus monkeys.

Fecal Microbiota Transplant in a Pre-Clinical Model of Type 2 Diabetes Mellitus, Obesity and Diabetic Kidney Disease

Diabetes mellitus (DM) burden encompasses diabetic kidney disease (DKD), the leading cause of end-stage renal disease worldwide. Despite compelling evidence indicating that pharmacological intervention curtails DKD progression, the search for non-pharmacological strategies can identify novel targets for drug development against metabolic diseases. One of those emergent strategies comprises the modulation of the intestinal microbiota through fecal transplant from healthy donors. This study sought to investigate the benefits of fecal microbiota transplant (FMT) on functional and morphological parameters in a preclinical model of type 2 DM, obesity, and DKD using BTBR^ob/ob mice. These animals develop hyperglycemia and albuminuria in a time-dependent manner, mimicking DKD in humans. Our main findings unveiled that FMT prevented body weight gain, reduced albuminuria and tumor necrosis factor-α (TNF-α) levels within the ileum and ascending colon, and potentially ameliorated insulin resistance in BTBR^ob/ob mice. Intestinal structural integrity was maintained. Notably, FMT was associated with the abundance of the succinate-consuming Odoribacteraceae bacteria family throughout the intestine. Collectively, our data pointed out the safety and efficacy of FMT in a preclinical model of type 2 DM, obesity, and DKD. These findings provide a basis for translational research on intestinal microbiota modulation and testing its therapeutic potential combined with current treatment for DM.

Ion channels in stem cells and their roles in stem cell biology and vascular diseases

Stem cell therapy may be a promising option for the treatment of vascular diseases. In recent years, significant progress has been made in stem cell research, especially in the mechanism of stem cell activation, homing and differentiation in vascular repair and reconstruction. Current research on stem cells focuses on protein expression and transcriptional networks. Ion channels are considered to be the basis for the generation of bioelectrical signals, which control the proliferation, differentiation and migration of various cell types. Although heterogeneity of multiple ion channels has been found in different types of stem cells, it is unclear whether the heterogeneous expression of ion channels is related to different cell subpopulations and/or different stages of the cell cycle. There is still a long way to go in clinical treatment by using the regulation of stem cell ion channels. In this review, we reviewed the main ion channels found on stem cells, their expression and function in stem cell proliferation, differentiation and migration, and the research status of stem cells' involvement in vascular diseases.

Plasma lipid profiles in early adulthood are associated with epigenetic aging in the Coronary Artery Risk Development in Young Adults (CARDIA) Study

Background

GrimAge acceleration (GAA), an epigenetic marker that represents physiologic aging, is associated with atherosclerotic cardiovascular disease. However, the associations between early adulthood lipid levels and GAA in midlife are unknown. Also, it is unknown whether GAA mediates the associations between lipid levels in young adults and subclinical atherosclerosis in midlife.

Results

We estimated measures of epigenetic age acceleration in 1118 White and Black participants from the Coronary Artery Risk Development in Young Adults (CARDIA) Study at examination years (Y) 15 and 20. We used multivariable regression models to examine associations of Y15 and Y20 GAA estimates with plasma lipid levels measured at prior examination years (Y0, Y5, and Y10) and concurrently: triglycerides (TG), low-density lipoprotein cholesterol (LDL-C), and high-density lipoprotein cholesterol (HDL-C) levels. Mediation analysis was used to assess the extent to which GAA may mediate associations between plasma lipids and coronary artery calcification (CAC). In our study each 1-SD higher cumulative TG level was associated with an average 0.73 ± 0.12 years older GAA. Each 1-SD higher cumulative HDL-C level was associated with an average 0.57 ± 0.17 years younger GAA. Stratified analyses showed that the associations between TG and GAA were stronger among female and Black participants and the associations between HDL-C and GAA were stronger among female and White participants. GAA statistically mediated 17.4% of the association of cumulative TG with CAC.

Conclusions

High TG and low HDL-C in early adulthood are associated with accelerated epigenetic aging by midlife. Increased epigenetic age acceleration may partially mediate the associations between high TG levels and the presence of subclinical atherosclerosis.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13148-021-01222-2.

Adherence to a Mediterranean Diet Is Associated with Lower Depressive Symptoms among U.S. Adults

Depression is a leading cause of disability, yet current prevention and treatment approaches have only had modest effects. It is important to better understand the role of dietary patterns on depressive symptoms, which may help prevent depression or complement current treatments. This study examined whether adherence to a Mediterranean diet (Med Diet), determined by the Alternate Med Diet score (aMED), was associated with depressive symptoms in a representative sample of U.S. adults. The aMED score (range 0–9) was calculated from a 24-h diet recall with gender-specific quartiles (Q) estimated. The Patient Health Questionnaire-9 (PHQ-9) was used to define depressive symptoms, which was dichotomized as no to mild (0–9) versus moderate to severe symptoms (10–27). Logistic regression was used to investigate the association between quartiles of aMED and depressive symptoms when controlling for sociodemographics, total calories, and the time of year of diet recall; 7.9% of the sample had moderate to severe depressive symptoms. Compared to individuals with the lowest aMED (Q1), individuals in Q3 and Q4 had 40% and 45% lower odds of moderate to severe depressive symptoms (odds ratio [OR] = 0.60, 95% confidence interval [CI]: 0.50, 0.74; OR = 0.55, 95% CI: 0.36, 0.84, respectively). This study provides modest support of Med Diet’s role in supporting positive mental health.

Serum Tenascin-C and Alarin Levels Are Associated with Cardiovascular Diseases in Type 2 Diabetes Mellitus

BACKGROUND

Tenascin-C (TNC), an extracellular matrix glycoprotein, is elevated in inflammatory and cardiovascular pathologies, whereas alarin, a novel orexigenic peptide, participates in insulin resistance and glycometabolism. The roles of these molecules in individuals with cardiovascular disease (CVD) and type 2 diabetes mellitus (T2DM), clinical conditions associating with metabolic disorders, and chronic inflammation, remain controversial. Our study aimed at determining the potential role of TNC and alarin in CVD adult patients with T2DM.

METHODS

This was a cross-sectional study. Basic and clinical information for 250 patients with T2DM were analyzed. Based on their cardiovascular disease status, participants were assigned into the CVD and non-CVD groups. Serum TNC and alarin levels were assessed by enzyme-linked immunosorbent assay (ELISA).

RESULTS

Serum TNC and alarin concentrations in the CVD group were significantly higher than those of the non-CVD group. Moreover, serum TNC levels were positively correlated with age, waist circumference, and waist-hip ratio; however, they were negatively correlated with TC, LDL-C, and eGFR levels. Alarin levels were positively correlated with BMI, waist circumference, and hip circumference. In logistic regression models, TNC and alarin were also established to be independent determinants for CVD in T2DM patients and their increases were associated with CVD severity. Receiver operating characteristic (ROC) curve analysis showed that the area under curve (AUC) values for TNC and alarin were 0.68 and 0.67, respectively. TNC and alarin were good predictors of CVD occurrence. When the cutoff value for TNC was 134.05 pg/mL, its sensitivity was 69.47% while its specificity was 61.29%. When the cutoff value for alarin was 142.69 pg/mL, sensitivity and specificity were 38.95% and 90.97%, respectively.

CONCLUSION

Elevated TNC and alarin levels are independently associated with the occurrence and severity of CVD in T2DM individuals. Therefore, these two biomarkers are potential diagnostic and prognostic indicators for CVD in diabetics.

Impact of Different Adipose Depots on Cardiovascular Disease

ABSTRACT

Adipose tissue (AT)-derived factors contribute to the regulation of cardiovascular homeostasis, thereby playing an important role in cardiovascular health and disease. In obesity, AT expands and becomes dysfunctional, shifting its secretory profile toward a proinflammatory state associated with deleterious effects on the cardiovascular system. AT in distinct locations (ie, adipose depots) differs in crucial phenotypic variables, including inflammatory and secretory profile, cellular composition, lipolytic activity, and gene expression. Such heterogeneity among different adipose depots may explain contrasting cardiometabolic risks associated with different obesity phenotypes. In this respect, central obesity, defined as the accumulation of AT in the abdominal region, leads to higher risk of cardiometabolic alterations compared with the accumulation of AT in the gluteofemoral region (ie, peripheral obesity). The aim of this review was to provide an updated summary of clinical and experimental evidence supporting the differential roles of different adipose depots in cardiovascular disease and to discuss the molecular basis underlying the differences of adipose depots in the regulation of cardiovascular function.

Changes of omentin-1 and chemerin during 4 weeks of lifestyle intervention and 1 year follow-up in children with obesity

AIMS

Data about the influence of short-term lifestyle intervention in children with obesity on long-term follow-up body weight, adipokines and cardiometabolic risk parameters is scarce.

METHODS

In a subgroup of the LOGIC-trial (Long-term Effects of Lifestyle Intervention in Obesity and Genetic Influence in Children), we assessed anthropometry (BMI, BMI-SDS (Standard Deviation Score), adipokines (omentin-1, chemerin, leptin, adiponectin) and cardiometabolic risk parameters, (e.g. hsCRP) in children with overweight/obesity after 4 weeks of lifestyle intervention (n = 156, 14.0 ± 1.8 yrs) and after one year follow-up (n = 50). Data were compared to normal weight children (JuvenTUM school cohort; n = 152, 13.3 ± 0.7 yrs).

RESULTS

Short-term lifestyle intervention was associated with a significant reduction in BMI and BMI-SDS (p < 0.001), with significant reductions in hsCRP, leptin, and chemerin levels, and an increase in adiponectin and omentin-1 levels (p < 0.001 for all). After one year follow-up a significant reduction in BMI and BMI-SDS was observed in children from the LOGIC-trial (p < 0.001). Improvements in adiponectin (p = 0.025) and chemerin levels (p = 0.027) were seen in children with clear weight loss success (BMI-SDS reduction ≥ 0.2), whereas children with no or only mild weight loss success showed an increase in leptin levels (p < 0.001). An increase in omentin-1 levels was observed after 1 year independent of weight change (p < 0.001).

CONCLUSION

Effects of short-term weight reduction on mean BMI and BMI-SDS persist over one year. Improvements in omentin-1 levels were independent of short-term or long-term weight loss.

TRIAL REGISTRATION

ClinicalTrials.gov: LOGIC-trial: NCT01067157, JuvenTUM-trial: NCT00988754.

Glutamine supplementation can reduce some atherosclerosis markers after exhaustive exercise in young healthy males

OBJECTIVES

Glutamine can be beneficial to athletes for its antiinflammatory and antioxidant effects. The present study was designed to investigate the effect of glutamine supplementation on some atherosclerosis markers after exhaustive exercise in young healthy males.

METHODS

In an intervention study, 30 healthy males (case = 15 and control = 15) were randomly assigned into two groups. For 14 d, the intervention group received 0.3 g of glutamine per kilogram of body weight per day, with 25 g of sugar in 250 mL of water, and the control group received 25 g of sugar per 250 mL of water. At the end of the intervention, the participants completed one session of exhaustive exercise, and then fasting blood samples were taken to test serum levels of atherosclerosis markers.

RESULTS

In the intervention group, the serum levels of leptin, cholesterol, and oxidized low-density lipoprotein were lower than in the control group after 2 wk of glutamine supplementation (P < 0.05). Interleukin-6 serum levels were lower in the intervention group compared to the control group after supplementation, but not significantly. Serum levels of leptin, interleukin-6, cholesterol, and oxidized low-density lipoprotein, as well as the ratio of oxidized low-density lipoprotein to high-density lipoprotein, were significantly decreased in the intervention group compared to the control group after exhaustive exercise (P < 0.05).

CONCLUSIONS

Glutamine supplementation has beneficial effects for athletes, particularly those doing strenuous physical exercise, through reducing atherosclerosis-related biomarkers and elevating serum adiponectin levels, and it can potentially play a role in decreasing the initiation and progression of atherosclerosis.

The interplay between statins and adipokines. Is this another explanation of statins' 'pleiotropic' effects?

Statin therapy comprises an integral part of secondary and to a lesser extent of primary cardiovascular disease prevention. This is attributed not only to their lipid-lowering properties, but as well to a plethora of pleiotropic actions. Recently, the cytokines secreted by adipose tissue, the so-called adipokines, have been proved to play a critical role in various pathophysiological functions, among which inflammation and atherosclerosis development and vulnerability. The aim of this literature review was to summarize the effects of statins and the underlying mechanisms on the circulating levels of the most common adipokines regulating atherosclerosis process, as a part of their pleiotropic function. Up to now, robust evidence implicates a significant statin-induced reduction of pro-inflammatory adipokines IL-6, TNF-a and visfatin. Weak evidence from limited, small and mostly non-randomized studies suggest increased levels of anti-inflammatory adipokines apelin, vaspin and omentin-1 after statin therapy. In the rest of most known adipokines, statins have shown either controversial (adiponectin, retinol binding protein-4 and fetuin-A) or negligible effects (leptin and resistin) on their circulating levels. Therefore, statins may favourably alter the balance of inflammatory/anti-inflammatory adipokines, implicating a novel atheroprotective mechanism. However, the interplay between statins and adipokines is still not fully elucidated and its potential clinical relevance is warranted.

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.

The New Kid on the Block: The Mechanisms of Action of Hyperleptinemia in Coronary Artery Disease and Atherosclerosis

Leptin is an adipocytokine that consists of 167 amino acids. It functions as a regulator of hunger and energy expenditure. Leptin loses its ability to carry out its physiological function at high serum levels, and many studies have associated this loss of function with the development of coronary artery disease (CAD). This literature review aims to outline the steps by which leptin leads to CAD and atherosclerosis. Two independent researchers extracted animal and human studies from PubMed and Google Scholar databases. We applied PubMed search builder options: pathology, pathophysiology, metabolism, and physiology to focus the search results. This study concluded that the mechanism by which leptin might lead to CAD via pressor and depressor effects on vascular tone, enhancing atherosclerotic plaques, and through numerous single nucleotide polymorphisms, the most common being that of the leptin receptor gene rs113701. 

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.

Browning of White Adipose Tissue as a Therapeutic Tool in the Fight against Atherosclerosis

Despite continuous medical advances, atherosclerosis remains the prime cause of mortality worldwide. Emerging findings on brown and beige adipocytes highlighted that these fat cells share the specific ability of non-shivering thermogenesis due to the expression of uncoupling protein 1. Brown fat is established during embryogenesis, and beige cells emerge from white adipose tissue exposed to specific stimuli like cold exposure into a process called browning. The consecutive energy expenditure of both thermogenic adipose tissues has shown therapeutic potential in metabolic disorders like obesity and diabetes. The latest data suggest promising effects on atherosclerosis development as well. Upon cold exposure, mice and humans have a physiological increase in brown adipose tissue activation and browning of white adipocytes is promoted. The use of drugs like β3-adrenergic agonists in murine models induces similar effects. With respect to atheroprotection, thermogenic adipose tissue activation has beneficial outcomes in mice by decreasing plasma triglycerides, total cholesterol and low-density lipoproteins, by increasing high-density lipoproteins, and by inducing secretion of atheroprotective adipokines. Atheroprotective effects involve an unaffected hepatic clearance. Latest clinical data tend to find thinner atherosclerotic lesions in patients with higher brown adipose tissue activity. Strategies for preserving healthy arteries are a major concern for public health.

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.

Leptin in Leanness and Obesity: JACC State-of-the-Art Review

Leptin has emerged over the past 2 decades as a key hormone secreted by adipose tissue that conveys information on energy stores. Leptin is considered an important regulator of both neuroendocrine function and energy homeostasis. Numerous studies (mainly preclinical and much less in humans) have investigated the mechanisms of leptin's actions both in the healthy state as well as in a wide range of metabolic diseases. In this review, the authors present leptin physiology and review the main findings from animal studies, observational and interventional studies, and clinical trials in humans that have investigated the role of leptin in metabolism and cardiometabolic diseases (energy deficiency, obesity, diabetes, cardiovascular diseases, nonalcoholic fatty liver disease). The authors discuss the similarities and discrepancies between animal and human biology and present clinical applications of leptin, directions for future research, and current approaches for the development of the next-generation leptin analogs.

TSP-1 (Thrombospondin-1) Deficiency Protects ApoE-/- Mice Against Leptin-Induced Atherosclerosis

OBJECTIVE

Hyperleptinemia, hallmark of obesity, is a putative pathophysiologic trigger for atherosclerosis. We previously reported a stimulatory effect of leptin on TSP-1 (thrombospondin-1) expression, a proatherogenic matricellular protein implicated in atherogenesis. However, a causal role of TSP-1 in leptin-driven atherosclerosis remains unknown. Approach and Results: Seventeen-weeks-old ApoE-/- and TSP-1-/-/ApoE-/- double knockout mice, on normocholesterolemic diet, were treated with or without murine recombinant leptin (5 µg/g bwt, IP) once daily for 3 weeks. Using aortic root morphometry and en face lesion assay, we found that TSP-1 deletion abrogated leptin-stimulated lipid-filled lesion burden, plaque area, and collagen accumulation in aortic roots of ApoE-/- mice, shown via Oil red O, hematoxylin and eosin, and Masson trichrome staining, respectively. Immunofluorescence microscopy of aortic roots showed that TSP-1 deficiency blocked leptin-induced inflammatory and smooth muscle cell abundance as well as cellular proliferation in ApoE-/- mice. Moreover, these effects were concomitant to changes in VLDL (very low-density lipoprotein)-triglyceride and HDL (high-density lipoprotein)-cholesterol levels. Immunoblotting further revealed reduced vimentin and pCREB (phospho-cyclic AMP response element-binding protein) accompanied with augmented smooth muscle-myosin heavy chain expression in aortic vessels of leptin-treated double knockout versus leptin-treated ApoE-/-; also confirmed in aortic smooth muscle cells from the mice genotypes, incubated ± leptin in vitro. Finally, TSP-1 deletion impeded plaque burden in leptin-treated ApoE-/- on western diet, independent of plasma lipid alterations.

CONCLUSIONS

The present study provides evidence for a protective effect of TSP-1 deletion on leptin-stimulated atherogenesis. Our findings suggest a regulatory role of TSP-1 on leptin-induced vascular smooth muscle cell phenotypic transition and inflammatory lesion invasion. Collectively, these results underscore TSP-1 as a potential target of leptin-induced vasculopathy.

Working and safety profiles of JAK/STAT signaling inhibitors. Are these small molecules also smart?

The Janus kinase (JAK)/signal transducers and activators of transcription (STAT) pathway is an important intracellular route through which many different extracellular soluble molecules, by reaching membrane receptors, can signal the nucleus. The spectrum of soluble molecules that use the JAK/STAT pathway through their corresponding receptors is quite large (almost 50 different molecules), and includes some cytokines involved in the pathogenesis of many immune-mediated diseases. Such diseases, when left untreated, present an evident hyperactivation of JAK/STAT signaling. Therefore, given the pathogenetic role of JAK/STAT, drugs known as JAK inhibitors (JAKi), that target one or more JAKs, have been developed to counteract JAK/STAT signal hyperactivation. As some hematological malignancies present an intrinsic JAK/STAT hyperactivation due to a JAK mutation, some JAKi have also been successfully used in this context. Regulatory agencies for drug administration in different countries have already approved a few JAKi in the setting of either immune-mediated diseases or hematological malignancies. Aim of this review is to describe the physiology of intracellular JAK/STAT pathway signaling and the pathological conditions associated to its dysregulation. Then, the rationale for targeting JAK in rheumatic autoimmune diseases is discussed, along with clinical data from registration studies showing the efficacy of these drugs. Finally, the excellent safety profile of JAKi is discussed in the context of the apparent poor specificity of JAK/STAT pathway signal.

Cerebral hemodynamics in obesity: relationship with sex, age, and adipokines in a cohort-based study

Overweight and obesity are well-known independent risk factors for stroke in the general population although uncertain in the case of the elderly, according to the obesity paradox. Little is known about underlying mechanisms. Our study aims to assess whether there is a relationship between excess body weight (measured as waist circumference) and poor cerebral hemodynamics (measured by transcranial Doppler parameters: basal, mean flow velocity (MFV), and dynamic, cerebrovascular reserve (CvR) in the right middle cerebral artery (RMCA)). A possible underlying molecular mechanism was analyzed via plasma leptin, adiponectin, TNF-α, IL-6, VCAM, and CRP levels. One hundred sixty-five subjects were included. Bivariate and multivariate regression showed a linear correlation between waist circumference and hemodynamics in RMCA, with clear gender effects: MFV (global NS, men β - 0.26 p < 0.01; women NS), CvR (global: β - 0.15 p < 0.01; men: β - 0.29 p < 0.01, women: β - 0.19 p < 0.09). For subjects above 65 years, there is no significant relationship between AbP and cerebral hemodynamics. In multivariate regression models, only leptin correlated independently with MFV in RMCA (β 7.24, p < 0.01) and CvR (β - 0.30, p < 0.01). In both cases, waist circumference remains significantly related to both parameters. There is an inverse linear correlation between excess body weight and cerebral hemodynamics, independent of other vascular risk factors and clearly influenced by gender. This relation disappears in the elderly population. Leptin might play a role in this relationship. Nevertheless, there must be another associated mechanism, not identified in this study.

Effect of atorvastatin versus rosuvastatin on inflammatory biomarkers and LV function in type 2 diabetic patients with dyslipidemia

BACKGROUND

Statins are potential drugs for decreasing risk of atherosclerotic cardiovascular complications in type 2 diabetic (T2D) patients.

PURPOSE

To examine the efficacy of both rosuvastatin (ROSUVA) and atorvastatin (ATORVA) on LV function and markers of inflammation in T2D patients with dyslipidemia.

METHODS

One hundred-sixty T2D patients were assigned to receive either atorvastatin (ATORVA group, n = 80, 40 mg) or rosuvastatin (ROSUVA group, n = 80, 10 mg), daily for 6 months. Blood was collected for biochemical analysis. The prevalence of left ventricular abnormalities was determined by echocardiography and two-dimensional Speckle-Strain to assess Global Longitudinal Strain (GLS).

RESULTS

ROSUVA vs. ATORVA resulted in significant (p < 0.001) reduction in HbA1c % (9.13 vs 2.35%), LDL-C (22.23% vs. 14.75%), triglycerides (13.56 % vs. 8.21 %), total cholesterol (16.10 % vs. 10.81 %), atherogenic index (18.08. % vs. 10.97%), hs-CRP (23.51 % vs.18.96%), sortilin (33.33 % % vs. 15.08 %), and leptin (31.81 % vs. 23.17 %) but increased adiponectin (97.99 % vs.76.47.1 %) and HDL-C (76.47 % vs. 0.21 %) compared with baseline, respectively. Negative correlations between adiponectin and each of hs-CRP, HbA1c%, total cholesterol, LDL-C, atherogenic index and leptin were found. Also, left ventricular functions were correlated with adiponectin, lipids, HbA1c% and hs-CRP. The areas under receiver operating characteristic curve (AUC) showed that hs-CRP, leptin, sortlin, leptin, and adiponectin were good predictors for cardiovascular events.

CONCLUSION

ROSUVA is more efficacious in improving lipid profile, atherogenic index and modulation of inflammatory biomarkers in dyslipidemic T2D patients compared with ATROVA. However, both statins are equivalent as cardioprotective agents in dyslipidemic T2D patients.

Naringin attenuates high glucose-induced injuries and inflammation by modulating the leptin-JAK2/STAT3 pathway in H9c2 cardiac cells

INTRODUCTION

Our previous study showed that naringin (NRG) protects cardiomyocytes against high glucose (HG)-induced injuries by inhibiting p38 mitogen-activated protein kinase (MAPK). Leptin induces hypertrophy in rat cardiomyocytes via p38/MAPK activation. The present study aimed to test the hypothesis that leptin-Janus kinase 2 (JAK2)/signal transducers and activators of transcription 3 (STAT3), which are responsible for leptin's functions, are involved in HG-induced injuries and cardioprotective effects of NRG in cardiomyocytes.

MATERIAL AND METHODS

H9c2 cells were exposed to HG for 24 h to establish a cardiomyocyte injury model. Cells were pretreated with NRG and other drugs before exposure to HG. Protein expression was measured by western blot analysis. Cell viability was detected by Cell Counting Kit-8 assay. Apoptotic cells were assessed by Hoechst 33258 staining assay. Intracellular reactive oxygen species levels were determined by dichlorofluorescein diacetate staining. Mitochondrial membrane potential was evaluated using JC-1. An enzyme-linked immunosorbent assay was performed to determine the inflammatory cytokines.

RESULTS

NRG significantly attenuated HG-induced increases in leptin and Ob-R expression. Pretreatment with either a leptin antagonist (LA) or NRG markedly ameliorated HG-induced elevation of phosphorylated (p)-JAK2 and p-STAT3, respectively. Pretreatment with NRG, LA, Ob-R antagonist, or AG490 clearly alleviated HG-induced injuries and inflammation.

CONCLUSIONS

This study provides new evidence of the NRG protective effects of H9c2 cells against HG-induced injuries possibly via modulation of the leptin-JAK2/STAT3 pathway.

Effect of Leptin on Chronic Inflammatory Disorders: Insights to Therapeutic Target to Prevent Further Cardiovascular Complication

In response to obesity-associated chronic inflammatory disorders, adipose tissue releases a biologically active peptide known as leptin. Leptin activates the secretion of chemical mediators, which contribute to the pathogenesis of chronic inflammatory disorders, such as rheumatoid arthritis (RA), systemic lupus erythematosus (SLE) and psoriasis. Conversely, adiposity and obesity are the major aggravating risk factors in the pathogenesis of metabolic syndrome (MetS), including type II diabetes mellitus and obesity-associated hypertension. Elevated level of leptin in obesity-associated hypertension causes an increase in the production of aldosterone, which also results in elevation of arterial blood pressure. Hyperleptinemia is associated with the progress of the atherosclerosis through secretion of pro-inflammatory cytokines, like interleukin 6 (IL-6), tumor necrosis factor α (TNF-α), IL-17, and other cytokines to promote inflammation. The release of those cytokines leads to chronic inflammatory disorders and obesity-associated MetS. Thus, the aberrant leptin level in both MetS and chronic inflammatory disorders also leads to the complication of cardiovascular diseases (CVD). Therapeutic target of leptin regarding its pro-inflammatory effect and dysregulated sympathetic nervous system activity may prevent further cardiovascular complication. This review mainly assesses the mechanism of leptin on the pathogenesis and further cardiovascular risk complication of chronic inflammatory disorders.

Leptin as a Key between Obesity and Cardiovascular Disease

Obesity increases the risk of cardiovascular disease through various influencing factors. Leptin, which is predominantly secreted by adipose tissue, regulates satiety homeostasis and energy balance, and influences cardiovascular functions directly and indirectly. Leptin appears to play a role in heart protection in leptin-deficient and leptin-receptor-deficient rodent model experiments. Hyperleptinemia or leptin resistance in human obesity influences the vascular endothelium, cardiovascular structure and functions, inflammation, and sympathetic activity, which may lead to cardiovascular disease. Leptin is involved in many processes, including signal transduction, vascular endothelial function, and cardiac structural remodeling. However, the dual (positive and negative) regulator effect of leptin and its receptor on cardiovascular disease has not been completely understood. The protective role of leptin signaling in cardiovascular disease could be a promising target for cardiovascular disease prevention in obese patients.

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.

Serum leptin levels are positively associated with aortic stiffness in patients with chronic kidney disease stage 3-5

Leptin potentially exerts atherogenic effects.This study evaluated the relationship between serum leptin levels and aortic stiffness in patients with stage 3-5 chronic kidney disease (CKD). Totally 205 participants were enrolled. Fasting blood sample were checked and serum leptin were measured by enzyme immunoassay. Aortic stiffness was measured as the carotid-femoral pulse wave velocity (cfPWV). 73 (35.6%) of 205 patients showed cfPWV >10 m/s were defined as aortic stiffness group. Compared with the remaining patients, the aortic stiffness group had high prevalence of diabetes mellitus, older age, higher waist circumference, body fat mass, systolic blood pressure, fasting glucose, and higher serum leptin level. In multivariable logistic regression analysis the independent predictors of cfPWV >10 m/s included leptin levels (odds ratio [OR]: 1.061, 95% confidence interval [CI]: 1.027-1.095, P < 0.001), age (OR: 1.064, 95% CI: 1.033-1.096, P< 0.001), and systolic blood pressure (OR: 1.021, 95% CI: 1.006-1.037, P = 0.006). Multivariable forward stepwise linear regression analysisshowed a positive association between log-transformed leptin levels and log-cfPWV (β = 0.192, adjusted R² change = 0.042, P = 0.001). Thus, aortic stiffness is positively correlated with serum leptin levels in patients with stage 3-5 CKD.Abbreviations: BUN, blood urea nitrogen; cfPWV, carotid-femoral pulse wave velocity; CI, confidence interval; CKD, chronic kidney disease; Cre, creatinine; DBP, diastolic blood pressure; DM, diabetes mellitus; eGFR, estimated glomerular filtration rate; LDL-C, low-density lipoprotein cholesterol; OR, odds ratio; SBP, systolic blood pressure; TCH, total cholesterol; TG, triglycerides.

Association between plasma leptin/adiponectin ratios with the extent and severity of coronary artery disease

Background

Leptin can have a direct effect on endothelial and vascular smooth muscle cells and high level of leptin is involved in the pathogenesis of atherosclerosis. This study aimed to determine the relationship between leptin/adiponectin (L/A) ratio and the extent and severity of coronary artery disease (CAD).

Methods

This case-control study was conducted in an educational hospital in Ilam, Iran from June 2014 to September 2015. Totally 300 participants including 150 patients with CAD (case group) and 150 healthy individuals (control group) were selected and their plasma leptin, adiponectin and leptin/adiponectin ratio was measured. The extent and severity of coronary artery disease were assayed based on the number of involved vessels and Gensini score (GS) and the relation between scores and L/A findings were compared between cases and controls.

Results

Totally, 300 participants including 150 (42.7% male), mean age 59.5 ± 11.4 years as cases and 150 (50.7% male), mean age 59.8 ± 10.7 as controls were analyzed. Plasma level of leptin and L/A ratio were higher in cases compared to controls, but level of adiponectin was significantly lower in CAD patients than the control group. More number of involved coronary vessels was significantly correlated to higher level of plasma leptin, L/A ratio and lower level of adiponectin among case group. Moreover, adiponectin was negatively and leptin or L/A ratio were positively correlated with number of involved vessels. 7.3% of cases had only one involved vessel, 42.7% had two involved vessels, and 50% of total patients had involved vessels and the mean ± SD of GS in the case group was 23.6 ± 6.9.

Conclusions

Plasma levels of leptin, and adiponectin can indicate the extent of coronary artery diseases but leptin may be a better marker of extent of CAD than either L/A ratio or adiponectin separately.

The association between serum inflammatory biomarkers and incident hypertension among postmenopausal women in the Buffalo OsteoPerio Study

Several serum inflammatory biomarkers have been associated with blood pressure and hypertension prevalence in cross-sectional studies. Few of these associations have been evaluated prospectively. We examined associations for 10 serum inflammatory biomarkers with incident hypertension among 471 postmenopausal women (mean age = 65) in the Buffalo OsteoPerio Study. Concentrations of C-reactive protein, interleukin (IL)-2, IL-4, IL-6, IL-8, IL-10, tumor necrosis factor (TNF)-α, monocyte chemoattractant protein (MCP)-1, adiponectin, and leptin were measured using multiplexed sandwich immunoassays on fasting serum samples collected at baseline (1997–2001). Incident hypertension (195 cases) was defined as physician-diagnosed hypertension and treatment with medication identified on annual mailed health surveys during follow-up (mean 10 years). Cox regression was used to estimate hazard ratios (HR) and 95% confidence intervals (CI) between log-transformed biomarkers (per 1-SD) and hypertension. When adjusted for age, leptin was significantly associated with hypertension risk (HR=1.55, 95% CI: 1.04, 2.29), however, the association was attenuated and not significant after adjustment for demographic and lifestyle factors, including BMI. Significant (P<0.10) interactions were observed for smoking (never, ever) with CRP (HR: Never, 1.31; Ever, 0.91; P=0.06) and MCP-1 (HR: Never, 0.59; Ever, 5.11; P=0.004); for BMI (<25, ≥25) with MCP-1(HR: <25, 3.45; ≥25, 0.95; P=0.07); for systolic BP with IL-10 (HR: <120, 0.85; 120–139, 1.11; P=0.07); and for diastolic BP with MCP-1 (HR: <80, 1.29; 80–89, 0.84; P=0.03) and with adiponectin (HR: <80, 0.86; 80–89, 1.50; P=0.03). This study adds needed understanding on prospective associations between several serum inflammatory biomarkers and hypertension risk in older postmenopausal women, among whom hypertension burden is substantial.

Bariatric Surgery-Induced Changes in Intima-Media Thickness and Cardiovascular Risk Factors in Class 3 Obesity: A 3-Year Follow-Up Study

OBJECTIVE

The impact of weight loss induced by bariatric surgery (BS) and nonsurgical approaches on cardiovascular risk factors (CVRFs) has not been fully elucidated. We assessed the effects of BS and a nonsurgical approach on carotid intima-media thickness (CIMT) and CVRFs in participants with class 3 obesity.

METHODS

A total of 87 participants with obesity (59 women; 46 [37-52] years old; BMI, 43 [40-47]) and 75 controls were recruited; 21 (25%) participants with obesity underwent BS. BMI, blood pressure, cholesterol, triglycerides, fasting plasma glucose, C-reactive protein, CIMT, and Framingham Risk Score were measured at baseline and at 3-year follow-up. Independent factors for reduction in CIMT were analyzed. The literature on the effects of BS and CIMT was reviewed.

RESULTS

After BS, BMI decreased from 45.45 to 27.28 (P < 0.001), and mean CIMT decreased from 0.64 mm (0.56-0.75 mm) to 0.54 mm (0.46-0.65) mm (P < 0.012), equivalent to 0.005 mm/kg of weight lost. At 3-year follow-up, participants who had undergone BS had similar CIMT and CVRFs to the control group. No changes in CVRFs were seen related to the nonsurgical approach. BMI reduction after BS had the strongest independent association with decreased CIMT.

CONCLUSIONS

Weight loss after BS decreases CIMT and CVRFs in middle-aged participants with class 3 obesity, resulting in CIMT similar to that observed in lean participants.

Using proximity extension proteomics assay to discover novel biomarkers associated with circulating leptin levels in patients with type 2 diabetes

We aimed to discover novel associations between leptin and circulating proteins which could link leptin to the development of cardiovascular disease in patients with type 2 diabetes (T2DM). In a discovery phase, we investigated associations between 88 plasma proteins, assessed with a proximity extension assay, and plasma leptin in a cohort of middle-aged patients with T2DM. Associations passing the significance threshold of a False discovery rate of 5% (corresponding to p < 0.0017) were replicated in patients with T2DM in an independent cohort. We also investigated if proteins mediated the longitudinal association between plasma leptin and the incidence of major cardiovascular events (MACE). One protein, adipocyte fatty acid binding protein (A-FABP), was significantly associated with leptin in both the discovery phase [95% CI (0.06, 0.17) p = 0.00002] and the replication cohort [95% CI (0.12, 0.39) p = 0.0003]. Multiplicative interaction analyses in the two cohorts suggest a stronger association between A-FABP and leptin in men than in women. In longitudinal analyses, the association between leptin and MACE was slightly attenuated after adding A-FABP to the multivariate model. Our analysis identified a consistent association between leptin and A-FABP in two independent cohorts of patients with T2DM, particularly in men.Trial registration: ClinicalTrials.gov identifier NCT01049737.