Emerging role of adipokines as mediators in atherosclerosis

The correlation between indirect calorimetry data and the metabolic syndrome development in men and women

Objectives

To investigate the indirect calorimetric findings in subjects with Metabolic Syndrome (MetS) compared to those without MetS and explore the potential parameters for predicting MetS in susceptible individuals.

Methods

Data was collected from a cross-sectional study conducted during the second phase of The Mashhad Stroke and Heart Atherosclerotic Disorder (MASHAD) study, which involved 1,014 participants. The presence of MetS was determined using the National Cholesterol Education Program Adult Treatment Panel III criteria. The study involved taking anthropometric measurements, blood samples, and indirect calorimetry measurements.

Results

The study showed significant differences in MetS criteria between the groups with and without MetS. According to the results in men, an increase in resting metabolic rate (RMR)/weight decreased the likelihood of developing MetS. However, an increase in protein oxidation raised the probability of developing MetS. Moreover, an increased RMR/weight or RMR/ body surface area (BSA) decreased the likelihood of developing MetS in women. Based on the logistic regression analysis, men with a higher RMR/Weight had a lower risk of developing MetS. Conversely, an increase in protein oxidation can increase the risk of MetS. However, women with higher RMR/Weight and RMR/BSA had a reduced risk of developing MetS.

Conclusions

These findings suggest that variations in RMR and macronutrient oxidations may play a role in the development of MetS. Assessing RMR and macronutrient oxidation through indirect calorimetry could potentially be used as predictive parameters for MetS. Further research is needed to better understand the underlying mechanisms and implications of these findings.

Low breast density is associated with epicardial adipose tissue volume and coronary artery disease

PURPOSE

Epicardial adipose tissue volume (EATv), is well correlated with coronary artery disease (CAD), however not reported clinically. Breast density, measured on mammography, has shown promise as a reflector of cardiometabolic risk, with less dense breasts indicating greater proportion of adipose tissue. We aimed to evaluate the association between breast density, EATv and CAD.

METHOD

Retrospective, cross-sectional study including 153 women who had both clinically indicated coronary computed tomography angiogram (CCTA) and mammography. EATv was quantified using semi-automated software. Breast density was visually assessed by standard 4-level BI-RADS grading (low: BI-RADS A-B, high: BI-RADS CD). CAD was categorised as presence/absence of coronary artery plaque and severity was quantified using CAD-RADS score.

RESULTS

Among 153 patients (mean age 62 ± 10), 103 (67.3 %) had low breast density (high breast adiposity). Low breast density patients were older, had greater rates of hypertension, higher mean BMI (p < 0.001) and EATv (106.6 ± 43.0 ml vs 81.0 ± 31.6 ml, p < 0.001). EATv was predictive of low breast density (OR: 1.02[1.01-1.03], p = 0.006), independent of age and hypertension. Low breast density was strongly associated with presence of CAD (prevalence 75 % vs 48 %, OR: 3.21[1.58-6.53], p = 0.001) independent of EATv, and modifiable (OR: 2.69[1.24-5.92], p = 0.012) and non-modifiable (OR: 2.42[1.04-5.85], p = 0.047) cardiovascular risk factors. Low breast density made up a higher proportion of mild (76.5 %), moderate (73.9 %) and severe (80.0 %) CAD.

CONCLUSIONS

Low breast density is associated with higher EATv and independently associated with CAD presence beyond EATv and other cardiovascular risk factors. Mammographic breast density may therefore have value as an early risk identification tool for CAD in women.

Semaglutide modulates prothrombotic and atherosclerotic mechanisms, associated with epicardial fat, neutrophils and endothelial cells network

BACKGROUND

Obesity has increased in recent years with consequences on diabetes and other comorbidities. Thus, 1 out of 3 diabetic patients suffers cardiovascular disease (CVD). The network among glucose, immune system, endothelium and epicardial fat has an important role on pro-inflammatory and thrombotic mechanisms of atherogenesis. Since semaglutide, long-acting glucagon like peptide 1- receptor agonist (GLP-1-RA), a glucose-lowering drug, reduces body weight, we aimed to study its effects on human epicardial fat (EAT), aortic endothelial cells and neutrophils as atherogenesis involved-cardiovascular cells.

METHODS

EAT and subcutaneous fat (SAT) were collected from patients undergoing cardiac surgery. Differential glucose consumption and protein cargo of fat-released exosomes, after semaglutide or/and insulin treatment were analyzed by enzymatic and TripleTOF, respectively. Human neutrophils phenotype and their adhesion to aortic endothelial cells (HAEC) or angiogenesis were analyzed by flow cytometry and functional fluorescence analysis. Immune cells and plasma protein markers were determined by flow cytometry and Luminex-multiplex on patients before and after 6 months treatment with semaglutide.

RESULTS

GLP-1 receptor was expressed on fat and neutrophils. Differential exosomes-protein cargo was identified on EAT explants after semaglutide treatment. This drug increased secretion of gelsolin, antithrombotic protein, by EAT, modulated CD11b on neutrophils, its migration and endothelial adhesion, induced by adiposity protein, FABP4, or a chemoattractant. Monocytes and neutrophils phenotype and plasma adiposity, stretch, mesothelial, fibrotic, and inflammatory markers on patients underwent semaglutide treatment for 6 months showed a 20% reduction with statistical significance on FABP4 levels and an 80% increase of neutrophils-CD88.

CONCLUSION

Semaglutide increases endocrine activity of epicardial fat with antithrombotic properties. Moreover, this drug modulates the pro-inflammatory and atherogenic profile induced by the adiposity marker, FABP4, which is also reduced in patients after semaglutide treatment.

In silico package models for deriving values of solute parameters in linear solvation energy relationships

Environmental partitioning influences fate, exposure and ecological risks of chemicals. Linear solvation energy relationship (LSER) models may serve as efficient tools for estimating environmental partitioning parameter values that are commonly deficient for many chemicals. Nonetheless, scarcities of empirical solute parameter values of LSER models restricted the application. This study developed and evaluated in silico methods and models to derive the values, in which excess molar refraction, molar volume and logarithm of hexadecane/air partition coefficient were computed from density functional theory; dipolarity/polarizability parameter, solute H-bond acidity and basicity parameters were predicted by quantitative structure-activity relationship models developed with theoretical molecular descriptors. New LSER models on four physicochemical properties relevant with environmental partitioning (n-octanol/water partition coefficients, n-octanol/air partition coefficients, water solubilities, sub-cooled liquid vapour pressures) were constructed using the in silico solute parameter values, which exhibited comparable performance with conventional LSER models using the empirical solute parameter values. The package models for deriving the LSER solute parameter values, with advantages that they are free of instrumental determinations, may lay the foundation for high-throughput estimating environmental partition parameter values of diverse organic chemicals.

Alternate Day Fasting Improves Endothelial Function in Type 2 Diabetic Mice: Role of Adipose-Derived Hormones

Introduction

Intermittent fasting, including alternate day fasting (ADF), has grown in popularity as it can produce clinically significant metabolic benefits and is often considered to be easier to adhere to than other types of diets such as chronic calorie restriction. However, the effects of ADF on diabetes-associated vascular dysfunction, and the role of adipose-derived hormones, i.e., adipokines, in mediating its effects, remain largely unknown.

Objective

We aimed to test the hypothesis that ADF protects against diabetes-associated endothelial dysfunction, at least partly through modulating adipokine profiles.

Methods

Control mice (m Lepr db ) and diabetic mice (Leprdb ) were treated with 12-weeks of ADF. Glucose metabolism, endothelial function, and adipokine profile were assessed.

Results

ADF reduced fasting blood glucose level and homeostatic model assessment for insulin resistance (HOMA-IR), and improved insulin sensitivity. ADF improved endothelium-dependent vasorelaxation of small mesenteric arteries (SMA) of Leprdb mice. The improvement in endothelial function was largely attenuated by incubation with the nitric oxide synthase inhibitor, L-NAME. These ADF-induced metabolic and vascular benefits were accompanied by increased circulating adiponectin. Adenovirus-mediated adiponectin supplementation improved endothelial function in Leprdb mice, supporting endothelial protective roles in diabetes-associated endothelial dysfunction. Protein tyrosine nitration is a post-translational modification that serves as a marker of oxidative stress. Nitrotyrosine protein levels in SMA and mesenteric adipose tissue (MAT) were elevated in Leprdb mice. ADF reduced nitrotyrosine protein in SMA, but not in MAT, of Leprdb mice.

Conclusion

ADF exerts metabolic and endothelial protective benefits. The improvement of endothelial function was partly mediated by increased adiponectin, representing an important mechanism for the beneficial vascular effects resulting from ADF.

A network pharmacology analysis on drug-like compounds from Ganoderma lucidum for alleviation of atherosclerosis

Ganoderma lucidum (GL) is known as a potent alleviator against chronic inflammatory disease like atherosclerosis (AS), but its mechanisms against AS have not been unveiled. This research aimed to identify the key compounds(s) and mechanism(s) of GL against AS through network pharmacology. The compounds from GL were identified by gas chromatography-mass spectrum (GC-MS), and SwissADME screened their physicochemical properties. Then, the target(s) associated with the screened compound(s) or AS related targets were identified by public databases, and we selected the overlapping targets using a Venn diagram. The networks between overlapping targets and compounds were visualized, constructed, and analyzed by RStudio. Finally, we performed a molecular docking test (MDT) to explore key target(s), compound(s), on AutoDockVina. A total of 35 compounds in GL were detected via GC-MS, and 34 compounds (accepted by Lipinski's rule) were selected as drug-like compounds (DLCs). A total of 34 compounds were connected to the number of 785 targets, and DisGeNET and Online Mendelian Inheritance in Man (OMIM) identified 2,606 AS-related targets. The final 98 overlapping targets were extracted between the compounds-targets and AS-related targets. On Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment, the number of 27 signaling pathways were sorted out, and a hub signaling pathway (MAPK signaling pathway), a core gene (PRKCA), and a key compound (Benzamide, 4-acetyl-N-[2,6-dimethylphenyl]) were selected among the 27 signaling pathways via MDT. Overall, we found that the identified 3 DLCs from GL have potent anti-inflammatory efficacy, improving AS by inactivating the MAPK signaling pathway. PRACTICAL APPLICATIONS: Ganoderma lucidum (GL) has been used as a medicinal or edible mushroom for chronic inflammatory patients: diabetes mellitus and dyslipidemia, especially atherosclerosis (AS). Until now, the majority of mushroom research has been implemented regarding β-glucan derivatives with very hydrophilic physicochemical properties. It implies that β-glucan or its derivatives have poor bioavailability. Hence, we have involved GC-MS in identifying lipophilic compounds from GL, which filtered them in silico to sort drug-like compounds (DLCs). Then, we retrieved targets associated with the DLCs, and identified a key signaling pathway, key targets, and key compounds against AS. In this paper, we utilized bioinformatics and network pharmacology theory to understand the uncovered pharmacological mechanism of GL on AS. To sum things up, our analysis elucidates the relationships between signaling pathways, targets, and compounds in GL. Ultimately, this work provides biochemical evidence to identify the therapeutic effect of GL on AS, and a scientific basis for deciphering the key mechanism on DLCs of GL against AS.

The impacts of C1q/TNF-related protein-15 and adiponectin on Interleukin-6 and tumor necrosis factor-α in primary macrophages of patients with coronary artery diseases

Atherosclerosis is a progressive inflammatory disease characterized by the accumulation of lipids in the arterial wall. Inflammation plays a key role in the pathogenesis of atherosclerosis and some previous studies have shown the role of adipokines during the inflammatory process of atherosclerosis. Therefore, the present study aimed to evaluate the impacts of adiponectin and CTRP15 on inflammatory cytokines secretions from THP1 and primary macrophages.

METHODS

THP1 monocytes were differentiated to macrophages and primary monocytes were then isolated from patients with coronary artery disease and controls who were differentiated to macrophages. Macrophages were treated with LPS, LPS+adiponectin, and LPS+CTRP15.

RESULTS

Adiponectin and CTRP15 have reduced IL-6 and TNF-α secretions from LPS-induced THP1 macrophages, and the CTRP15 indicated a more potent anti-inflammatory property compared to adiponectin. In addition, adiponectin reduced cytokines' expressions and secretions in primary macrophages of both patient and control groups. However, CTRP15 has only reduced cytokines' expressions and secretions in controls and it was not able to ameliorate inflammation in macrophages of CAD patients.

CONCLUSION

The results of the present study indicate anti-inflammatory impact of adiponectin and CTRP15, while this property was stronger for CTRP15. In addition, it seems likely that anti-inflammatory CTRP15's impact on macrophages in the CAD patients was weaker than macrophages from the controls.

HOMA-Adiponectin Closely Associates with Cardiometabolic Risk Markers in Middle-Aged Indians with Metabolic Syndrome

BACKGROUND

Unhealthy dietary habits and sedentary lifestyles have raised alarming concerns for the rising prevalence of metabolic syndrome (MetS) and associated cardiometabolic risk among Indians at an early age. Insulin resistance and adiposity are the important risk factors associated with MetS. The present study aimed to investigate the relationship between a modified marker of insulin resistance (homeostatic model assessment-adiponectin (HOMA-AD)) and cardiometabolic risk among middle-aged Indians.

METHODS

The study comprised of 144 subjects of age-group 31-50 years, where 83 subjects were diagnosed for MetS according to the guidelines given by the International Diabetes Federation. We measured cardiometabolic risk indicators such as fasting blood glucose (FPG), fasting plasma insulin (FPI), homeostatic model assessment- insulin resistance (HOMA-IR), adiponectin, high sensitivity C-reactive protein (hs-CRP), oxidized LDL (oxLDL), monocyte chemoattractant protein-1 (MCP-1), and atherogenic index, among others. We calculated HOMA-AD by the formula: [FPG (mmol/l) × FPI (µIU/ml)] / [22.5 × Adiponectin (µg/ml)].

RESULTS

HOMA-IR and HOMA-AD were highly increased (p<0.001) in the MetS subjects than controls. Adiponectin was significantly (p<0.01) lower whereas cardiac risk markers such as atherogenic index, hs-CRP, oxLDL, and MCP-1 were significantly (p<0.01) elevated in MetS group than controls. Linear regression showed positive and significant associations (p<0.01) of HOMA-AD with all the cardiometabolic risk markers except MCP-1. HOMA-AD showed higher AUC (0.806) than HOMA-IR (0.791) for predicting MetS.

CONCLUSION

HOMA-AD could be a surrogate adipokine-based marker correlated significantly with components of MetS and cardiometabolic risk indicators. It appeared to be a better predictor of MetS among middle-aged Indians than HOMA-IR.

L-4F Inhibits Oxidized Low-density Lipoprotein-induced Inflammatory Adipokine Secretion via Cyclic AMP/Protein Kinase A-CCAAT/Enhancer Binding Protein β Signaling Pathway in 3T3-L1 Adipocytes

Background:

Adipocytes behave like a rich source of pro-inflammatory cytokines including monocyte chemoattractant protein-1 (MCP-1). Oxidized low-density lipoprotein (oxLDL) participates in the local chronic inflammatory response, and high-density lipoprotein could counterbalance the proinflammatory function of oxLDL, but the underlying mechanism is not completely understood. This study aimed to evaluate the effect of apolipoprotein A-I mimetic peptide L-4F on the secretion and expression of MCP-1 in fully differentiated 3T3-L1 adipocytes induced by oxLDL and to elucidate the possible mechanisms.

Methods:

Fully differentiated 3T3-L1 adipocytes were incubated in the medium containing various concentration of L-4F (0–50 μg/ml) with oxLDL (50 μg/ml) stimulated, with/without protein kinase A (PKA) inhibitor H-89 (10 μmol/L) preincubated. The concentrations of MCP-1 in the supernatant, the mRNA expression of MCP-1, the levels of CCAAT/enhancer binding protein α (C/EBPα), and CCAAT/enhancer binding protein β (C/EBPβ) were evaluated. The monocyte chemotaxis assay was performed by micropore filter method using a modified Boyden chamber.

Results:

OxLDL stimulation induced a significant increase of MCP-1 expression and secretion in 3T3-L1 adipocytes, which were inhibited by L-4F preincubation in a dose-dependent manner. PKA inhibitor H-89 markedly reduced the oxLDL-induced MCP-1 expression, but no further decrease was observed when H-89 was used in combination with L-4F (50 μg/ml) (P > 0.05). OxLDL stimulation showed no significant effect on C/EBPα protein level but increased C/EBPβ protein level in a time-dependent manner. H-89 and L-4F both attenuated C/EBPβ protein level in oxLDL-induced 3T3-L1 adipocytes.

Conclusions:

OxLDL induces C/EBPβ protein synthesis in a time-dependent manner and enhances MCP-1 secretion and expression in 3T3-L1 adipocytes. L-4F dose-dependently counterbalances the pro-inflammatory effect of oxLDL, and cyclic AMP/PKA-C/EBPβ signaling pathway may participate in it.

Inhibitory Effect of Serotonin Antagonist on Leukocyte-Endothelial Interactions In Vivo and In Vitro

Background

Although 5-HT_2A serotonergic antagonists have been used to treat vascular disease in patients with diabetes mellitus or obesity, their effects on leukocyte-endothelial interactions have not been fully investigated. In this study, we assessed the effects of sarpogrelate hydrochloride (SRPO), a 5-HT_2A receptor inverse agonist, on leukocyte-endothelial cell interactions in obesity both in vivo and in vitro.

Methods and Findings

In the in vivo experiment, C57BL/6 mice were fed a high-fat high-fructose diet (HFFD), comprising 20% fat and 30% fructose, with or without intraperitoneal injection of 5 mg/kg/day SRPO for 4 weeks. The body weight, visceral fat weight, and serum monocyte chemoattractant protein-1 levels in the mice increased significantly with the HFFD, but these effects were prevented by chronic injections of SRPO. Intravital microscopy of the femoral artery detected significant leukocyte-endothelial interactions after treatment with HFFD, but these leukocyte-endothelial interactions were reduced in the mice injected with SRPO. In the in vitro experiment, pre-incubation of activated human umbilical vein endothelial cells (HUVECs) with platelet-rich plasma (PRP) induced THP-1 cell adhesion under physiological flow conditions, but the adhesion was reduced by pretreatment of PRP with SRPO. A fluorescent immunobinding assay showed that PRP induced significant upregulation of E-selectin in HUVECs, but this upregulation was reduced by pretreatment of PRP with SRPO. In other in vitro conditions, pre-incubation of THP-1 cells with phorbol 12-myristate 13-acetate increased the adhesion of THP-1 cells to activated HUVECs under rotational conditions, but this adhesion was reduced by pretreatment with SRPO. Western blotting analysis showed that protein kinase C α activation in THP-1 cells was inhibited by SRPO.

Conclusion

Our findings indicated that SRPO inhibits vascular inflammation in obesity via inactivation of platelets and leukocytes, and improvement of obese.

Role of omentin-1 and C-reactive protein in obese subjects with subclinical inflammation

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Relationship between insulin resistance and inflammatory markers in obese subjects was examined.

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This was investigated in 105 subjects without any clinically evident cardiovascular disease.

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Omentin-1 was associated with diabetes mellitus indirectly via insulin activity and obesity.

Background

While chronic subclinical inflammation is now considered to be a predisposing risk factor of cardiovascular diseases, the extent by which adipokines induce metabolic abnormalities in humans is not fully resolved. The purpose of this study was to examine the relationship between insulin resistance and serum inflammatory markers in obese subjects.

Methods

One hundred and five subjects without any clinically evident CVD were classified into 3 coronary risk levels according to Framingham risk score. Demographic and anthropometric variables were estimated. Serum levels of lipid profile, blood glucose, insulin, omentin-1 and high sensitivity-C reactive protein (hs-CRP) were measured in fasting blood samples. Insulin resistance indices were also calculated.

Results

29% and 62% of the study population were overweight and obese respectively by body mass index (BMI) measures. Almost half of the study population was considered diabetic. There was a tendency for a fall in serum omentin-1 concentrations with increasing coronary risk with a significant increase in hs-CRP levels in the same direction (p < 0.05). Age and fasting blood glucose were found to be independently associated with serum omentin-1 levels. BMI and fasting blood glucose were independent determinants of serum hs-CRP levels.

Conclusions

Omentin-1 might be associated with the development of diabetes mellitus indirectly via insulin activity and obesity. These findings may have important implications for the pathophysiology and therapy of diabetes mellitus by further longitudinal studies.

Serum adiponectin levels in patients with acute coronary syndromes: Serial changes and relation to infarct size

BACKGROUND

The role of adiponectin in patients with acute coronary syndromes is incompletely defined. This study investigated adiponectin levels in patients with acute coronary syndromes and the association between adiponectin and 30-day infarct size and 1-year clinical outcomes.

METHODS

Retrospective analysis of 120 participants with acute coronary syndromes enrolled in the Immediate Myocardial Metabolic Enhancement During Initial Assessment and Treatment in Emergency care Trial. Blood levels were tested three times within 24 h of onset of ischaemic symptoms. Infarct size was measured at 30 days. The 1-year clinical outcome was the composite of all-cause mortality or hospitalization for heart failure.

RESULTS

Using linear mixed models, log adiponectin levels decreased by -0.005 µg/mL per hour (p = 0.035). After stratifying the analysis by gender, there was no decrease in log adiponectin in men; however, levels decreased by -0.01 µg/mL per hour in women (p = 0.02). Results of multivariable regression models showed no association between log adiponectin and infarct size (β = -1.1, p = 0.64). Log adiponectin levels did not predict 1-year outcomes using Cox-proportional hazard models.

CONCLUSION

There was a small decrease in plasma adiponectin shortly after symptoms of ischaemia, more noticeable in women. No relationship was found between adiponectin and infarct size or clinical outcomes. This adds to evidence showing no clear association between adiponectin and adverse outcomes in patients with acute coronary syndromes.

Hyperleptinemia: implications on the inflammatory state and vascular protection in obese adolescents submitted to an interdisciplinary therapy

The low-grade systemic inflammation seen in obesity may affect the actions of some adipose tissue-derived adipokines that are involved in the regulation of vascular function. We sought to verify whether hyperleptinemia may influence the inflammatory and atherogenic responses in obese adolescents undergoing interdisciplinary therapy. Thirty-four obese adolescents underwent interdisciplinary therapy for 1 year. Subjects were considered hyperleptinemic if they had baseline values of leptin above 20 ng/mL for boys and 24 ng/mL for girls. Both groups showed an improvement in body composition and a reduction in carotid intima-media thickness. However, only subjects in the non-hyperleptinemic group showed an increase in adiponectin concentration after therapy. Moreover, leptin concentration was positively correlated with adiponectin and inversely correlated with PAI-1 in this group. Hyperleptinemic state may impair the attenuation of inflammation in obese adolescents undergoing interdisciplinary therapy, particularly by impeding the increase in adiponectin concentration, which is directly involved in vascular protection.

Role of endoplasmic reticulum stress in atherosclerosis and diabetic macrovascular complications

Age-related changes in endoplasmic reticulum (ER) are associated with stress of this cell organelle. Unfolded protein response (UPR) is a normal physiological reaction of a cell in order to prevent accumulation of unfolded and misfolded proteins in the ER and improve the normal ER function. However, in pathologic conditions such as atherosclerosis, obesity, and diabetes, ER function becomes impaired, leading to the development of ER stress. In chronic ER stress, defective posttranslational protein folding results in deposits of aberrantly folded proteins in the ER and the induction of cell apoptosis mediated by UPR sensors C/EBPα-homologous protein (CHOP) and inositol requiring protein-1 (IRE1). Since ER stress and ER-induced cell death play a nonredundant role in the pathogenesis of atherosclerosis and diabetic macrovascular complications, pharmaceutical targeting of ER stress components and pathways may be beneficial in the treatment and prevention of cardiovascular pathology.

The Impact of Full-Length, Trimeric and Globular Adiponectin on Lipolysis in Subcutaneous and Visceral Adipocytes of Obese and Non-Obese Women

Contribution of individual adiponectin isoforms to lipolysis regulation remains unknown. We investigated the impact of full-length, trimeric and globular adiponectin isoforms on spontaneous lipolysis in subcutaneous abdominal (SCAAT) and visceral adipose tissues (VAT) of obese and non-obese subjects. Furthermore, we explored the role of AMPK (5'-AMP-activated protein kinase) in adiponectin-dependent lipolysis regulation and expression of adiponectin receptors type 1 and 2 (AdipoR1 and AdipoR2) in SCAAT and VAT. Primary adipocytes isolated from SCAAT and VAT of obese and non-obese women were incubated with 20 µg/ml of: A) full-length adiponectin (physiological mixture of all adiponectin isoforms), B) trimeric adiponectin isoform or C) globular adiponectin isoform. Glycerol released into media was used as a marker of lipolysis. While full-length adiponectin inhibited lipolysis by 22% in non-obese SCAAT, globular isoform inhibited lipolysis by 27% in obese SCAAT. No effect of either isoform was detected in non-obese VAT, however trimeric isoform inhibited lipolysis by 21% in obese VAT (all p<0.05). Trimeric isoform induced Thr172 p-AMPK in differentiated preadipocytes from a non-obese donor, while globular isoform induced Ser79 p-ACC by 32% (p<0.05) and Ser565 p-HSL by 52% (p = 0.08) in differentiated preadipocytes from an obese donor. AdipoR2 expression was 17% and 37% higher than AdipoR1 in SCAAT of obese and non-obese groups and by 23% higher in VAT of obese subjects (all p<0.05). In conclusion, the anti-lipolytic effect of adiponectin isoforms is modified with obesity: while full-length adiponectin exerts anti-lipolytic action in non-obese SCAAT, globular and trimeric isoforms show anti-lipolytic activity in obese SCAAT and VAT, respectively.

Is the neck circumference an emergent predictor for inflammatory status in obese adults?

BACKGROUND

Plasminogen Activator Inhibitor 1 (PAI-1) is a prothrombotic adipokine involved in the coagulation cascade and fibrinolysis that associated with proinflammatory adipokines may increase the risk related to obesity. Anthropometric measures are commonly used in clinical practice and, currently, neck circumference (NC) has been used as a marker of cardiovascular risk that can favour inflammatory factors.

OBJECTIVE

To verify the possible correlations between prothrombotic and pro/anti-inflammatory markers with anthropometric measurements in obese.

SUBJECTS AND METHODS

  A total of 43 obese adults were enrolled. The variables include body mass, stature, body mass index (BMI), NC, chest circumference (CC), abdominal circumference (AC), hip circumference (HC), blood pressure and blood collection used to assess the level of adipokines.

RESULTS

The sample was stratified by BMI. PAI-1 levels were positively correlated with body mass (r=0.31, p=0.04), NC (r=0.43, p=0.004), CC (r=0.40, p=0.004), AC (r=0.37, p=0.01), diastolic blood pressure (r=0.35, p=0.03), leptin/adiponectin ratio (r=0.36, p=0.01) and negatively correlated with adiponectin (r=-0.34, p=0.02). In stepwise multiple linear regression analysis, NC showed to be an independent predictor to PAI-1 when adjusted for gender and BMI, according to the age (β=0.47, p=0.02 and β=0.42, p=0.02 respectively).

CONCLUSION

In conclusion, NC could be suggested as an independent predictor higher PAI-1. This association can be a new screening of persons at an enhanced cardiovascular risk and inflammation in this obese population, so useful in clinical practice.

Association of adiponectin with blood pressure in healthy people

OBJECTIVE

With the increasing prevalence of diseases related to obesity, metabolic syndrome and its key player adiponectin are now attracting considerable attention. Hypoadiponectinaemia is reported to be a risk factor for hypertension and associated with endothelial dysfunction, which is closely related to complications of obesity such as hypertension. As there is limited information regarding serum adiponectin levels in normotensive people, we undertook the large-scale study to determine the association of adiponectin with blood pressure (BP) in mainly normotensive people.

DESIGN, PATIENTS AND MEASUREMENTS

In 21 100 Japanese adults (12 363 men and 8737 women) who had no apparent diseases, we examined the relationship between the serum adiponectin concentration and BP by performing a questionnaire survey, physical measurements and measurement of laboratory parameters including the serum adiponectin level.

RESULTS

Subjects with hypoadiponectinaemia had higher systolic and diastolic BPs as already reported. And interestingly, subjects with higher adiponectin had lower systolic and diastolic BP. According to linear regression analysis, adiponectin showed a significant negative correlation with systolic and diastolic BP independently of the other variables. Analysis of covariance according to adiponectin quintiles showed that systolic and diastolic BP in highest adiponectin quintile was significantly lower than in other quintiles.

CONCLUSIONS

This study revealed that there were significant trends toward lower systolic and diastolic BP with higher adiponectin not only in hypertensive people but also in normotensive people.

Association of adipokines with cardiovascular risk factors in low birth weight children: a case-control study

Our aim was to investigate plasma levels of adiponectin, monocyte chemoattractant protein-1 (MCP-1) and plasminogen activator inhibitor-1 (PAI-1) in low birth weight (LBW) children and to determine correlations among these adipokines and birth weight and cardiovascular disease risk factors. In a case-control study, the concentrations of adiponectin, MCP-1 and PAI-1 were measured in 180 schoolchildren (ages 6-11 years). MCP-1 and PAI-1 levels were significantly elevated in LBW children. Conversely, adiponectin concentration was significantly reduced in these children. Similar findings were observed after adjustment for current age, gender and abdominal circumference. Because the children with LBW had altered adipokine levels, as well as higher abdominal circumference, HOMA-IR and systolic blood pressure (SBP), we evaluated the correlation among these variables. These analyses showed that adiponectin levels were inversely correlated with systolic blood pressure (SBP) (r = -0.501; P < 0.001), HOMA-IR (r = -0.293; P = 0.023) and waist circumference (r = -0.317; P = 0.014). The proinflammatory markers were positively correlated with HOMA-IR (PAI-1: r = 0.358; P = 0.005) and waist circumference (PAI-1: r = 0.571; P < 0.001 and MCP-1: r = 0.267; P = 0.039).

CONCLUSION

Adipokines levels were correlated with cardiovascular risk factors in LBW children, and these compounds could be involved in the mechanism that links birth weight to the development of cardiovascular diseases in adulthood.

Increased circulating ANG II and TNF-α represents important risk factors in obese saudi adults with hypertension irrespective of diabetic status and BMI

Central adiposity is a significant determinant of obesity-related hypertension risk, which may arise due to the pathogenic inflammatory nature of the abdominal fat depot. However, the influence of pro-inflammatory adipokines on blood pressure in the obese hypertensive phenotype has not been well established in Saudi subjects. As such, our study investigated whether inflammatory factors may represent useful biomarkers to delineate hypertension risk in a Saudi cohort with and without hypertension and/or diabetes mellitus type 2 (DMT2). Subjects were subdivided into four groups: healthy lean controls (age: 47.9±5.1 yr; BMI: 22.9±2.1 Kg/m²), non-hypertensive obese (age: 46.1±5.0 yr; BMI: 33.7±4.2 Kg/m²), hypertensive obese (age: 48.6±6.1 yr; BMI: 36.5±7.7 Kg/m²) and hypertensive obese with DMT2 (age: 50.8±6.0 yr; BMI: 35.3±6.7 Kg/m²). Anthropometric data were collected from all subjects and fasting blood samples were utilized for biochemical analysis. Serum angiotensin II (ANG II) levels were elevated in hypertensive obese (p<0.05) and hypertensive obese with DMT2 (p<0.001) compared with normotensive controls. Systolic blood pressure was positively associated with BMI (p<0.001), glucose (p<0.001), insulin (p<0.05), HOMA-IR (p<0.001), leptin (p<0.01), TNF-α (p<0.001) and ANG II (p<0.05). Associations between ANG II and TNF-α with systolic blood pressure remained significant after controlling for BMI. Additionally CRP (p<0.05), leptin (p<0.001) and leptin/adiponectin ratio (p<0.001) were also significantly associated with the hypertension phenotype. In conclusion our data suggests that circulating pro-inflammatory adipokines, particularly ANG II and, TNF-α, represent important factors associated with a hypertension phenotype and may directly contribute to predicting and exacerbating hypertension risk.

Obesity and risk of vascular disease: importance of endothelium-dependent vasoconstriction

Obesity has become a serious global health issue affecting both adults and children. Recent devolopments in world demographics and declining health status of the world's population indicate that the prevalence of obesity will continue to increase in the next decades. As a disease, obesity has deleterious effects on metabolic homeostasis, and affects numerous organ systems including heart, kidney and the vascular system. Thus, obesity is now regarded as an independent risk factor for atherosclerosis-related diseases such as coronary artery disease, myocardial infarction and stroke. In the arterial system, endothelial cells are both the source and target of factors contributing to atherosclerosis. Endothelial vasoactive factors regulate vascular homeostasis under physiological conditions and maintain basal vascular tone. Obesity results in an imbalance between endothelium-derived vasoactive factors favouring vasoconstriction, cell growth and inflammatory activation. Abnormal regulation of these factors due to endothelial cell dysfunction is both a consequence and a cause of vascular disease processes. Finally, because of the similarities of the vascular pathomechanisms activated, obesity can be considered to cause accelerated, 'premature' vascular aging. Here, we will review some of the pathomechanisms involved in obesity-related activation of endothelium-dependent vasoconstriction, the clinical relevance of obesity-associated vascular risk, and therapeutic interventions using 'endothelial therapy' aiming at maintaining or restoring vascular endothelial health.

LINKED ARTICLES

This article is part of a themed section on Fat and Vascular Responsiveness. To view the other articles in this section visit http://dx.doi.org/10.1111/bph.2012.165.issue-3.

Hypoadiponectinemia: A Link between Visceral Obesity and Metabolic Syndrome

Metabolic syndrome (MetS) represents a combination of cardiometabolic risk factors, including visceral obesity, glucose intolerance or type 2 diabetes, elevated triglycerides, reduced HDL cholesterol, and hypertension. MetS is rapidly increasing in prevalence worldwide as a consequence of the “epidemic” obesity, with a considerable impact on the global incidence of cardiovascular disease and type 2 diabetes. At present, there is a growing interest on the role of visceral fat accumulation in the occurrence of MetS. In this review, the effects of adipocytokines and other proinflammatory factors produced by fat accumulation on the occurrence of the MetS have been also emphasized. Accordingly, the “hypoadiponectinemia” has been proposed as the most interesting new hypothesis to explain the pathophysiology of MetS.

Serum adiponectin level is not only decreased in metabolic syndrome but also in borderline metabolic abnormalities

Objective:

Along with the increasing prevalence of obesity and related diseases, particularly atherosclerotic diseases, metabolic syndrome (MetS) is now a common and major public health issue in many countries around the world. Adiponectin, a protein secreted by the adipose tissue, has become recognized as a key player in the development of MetS. These days, not only MetS but also borderline metabolic/physiological abnormalities, such as impaired fasting glucose, high normal blood pressure and high normal plasma cholesterol, have been reported to be risk factors for atherosclerotic disease. Therefore, we undertook this study to determine the relationship between adiponectin and borderline metabolic/physiological abnormalities, as well as MetS.

Design:

A cross-sectional study performed from April 2007 to November 2009.

Subjects:

In 16 892 Japanese adults (10 008 men and 6884 women), we examined the relationship between the serum adiponectin concentration and borderline metabolic/physiological abnormalities or MetS by a questionnaire survey about medical treatment, body size measurement and measurement of laboratory parameters including the serum adiponectin concentration.

Results:

Adiponectin showed a significant negative correlation with the number of MetS components. In subjects without overt diabetes mellitus, hypertension or dyslipidemia, the adiponectin concentration also showed a significant negative correlation with the number of borderline metabolic abnormalities.

Conclusion:

The decrease of circulating adiponectin may start before the development of diabetes mellitus, hypertension, dyslipidemia or MetS. Adiponectin is an important biomarker for reflecting the adverse influence of visceral fat in persons with MetS, and also in these subclinical states.

Association of serum omentin-1 levels with coronary artery disease

AIM

Omentin-1, a novel adipokine expressed in visceral adipose tissue, is negatively correlated with insulin resistance and obesity. Decreased omentin-1 expression has been found in many chronic inflammatory diseases. However, the role of omentin-1 in coronary artery disease (CAD) has not been elucidated. The aim of the present study was to determine whether serum concentration of omentin-1 was independently associated with CAD.

METHODS

One hundred and fifty five patients with CAD were divided into two groups: acute coronary syndrome (ACS) and stable angina pectoris (SAP). A total of 52 healthy participants served as controls. Serum concentrations of omentin-1 and interleukin-6 (IL-6) were measured using ELISA. The association of omentin-1 with CAD and cardiovascular disease risk factors was evaluated.

RESULTS

Serum omentin-1 levels were lower in patients with ACS or SAP compared with controls (ACS, 113.08±61.43 ng/mL; SAP, 155.41±66.89 ng/mL; control, 254.00±72.9 ng/mL; P<0.01). Patients with ACS also had lower serum concentrations of omentin-1 compared with patients with SAP (P<0.01). Serum concentration of omentin-1 was negatively correlated with body mass index (r=-0.17, P<0.05) and serum IL-6 concentration (r=-0.19, P<0.05). Furthermore, multiple logistic regression analysis showed that serum omentin-1 concentrations were independently correlated with CAD.

CONCLUSION

The findings suggest that serum concentrations of omentin-1 are related to CAD.

Insulin resistance and other metabolic risk factors in the pathogenesis of hepatocellular carcinoma

Coinciding with the increased incidence of hepatocellular carcinoma (HCC), there has been a significant increase in the global incidence of obesity and diabetes mellitus (DM), the two major risk factors for nonalcoholic steatohepatitis (NASH). There are many causes of HCC, and nonalcoholic fatty liver disease/NASH is now emerging as a leading risk factor owing to the epidemic of obesity and type 2 DM. The mechanisms leading to HCC in obesity and type 2 DM likely involve interactions between several signaling pathways, including oxidative stress, inflammation, oncogenes, adiponectins, and insulin resistance associated with visceral adiposity and diabetes.

Relationship of autonomic imbalance and circadian disruption with obesity and type 2 diabetes in resistant hypertensive patients

Background

Hypertension, diabetes and obesity are not isolated findings, but a series of interacting interactive physiologic derangements. Taking into account genetic background and lifestyle behavior, AI (autonomic imbalance) could be a common root for RHTN (resistant hypertension) or RHTN plus type 2 diabetes (T2D) comorbidity development. Moreover, circadian disruption can lead to metabolic and vasomotor impairments such as obesity, insulin resistance and resistant hypertension. In order to better understand the triggered emergence of obesity and T2D comorbidity in resistant hypertension, we investigated the pattern of autonomic activity in the circadian rhythm in RHTN with and without type 2 diabetes (T2D), and its relationship with serum adiponectin concentration.

Methods

Twenty five RHTN patients (15 non-T2D and 10 T2D, 15 males, 10 females; age range 34 to 70 years) were evaluated using the following parameters: BMI (body mass index), biochemical analysis, serum adiponectinemia, echocardiogram and ambulatory electrocardiograph heart rate variability (HRV) in time and frequency domains stratified into three periods: 24 hour, day time and night time.

Results

Both groups demonstrated similar characteristics despite of the laboratory analysis concerning T2D like fasting glucose, HbA1c levels and hypertriglyceridemia. Both groups also revealed disruption of the circadian rhythm: inverted sympathetic and parasympathetic tones during day (parasympathetic > sympathetic tone) and night periods (sympathetic > parasympathetic tone). T2D group had increased BMI and serum triglyceride levels (mean 33.7 ± 4.0 vs 26.6 ± 3.7 kg/m² - p = 0.00; 254.8 ± 226.4 vs 108.6 ± 48.7 mg/dL - p = 0.04), lower levels of adiponectin (6729.7 ± 3381.5 vs 10911.5 ± 5554.0 ng/mL - p = 0.04) and greater autonomic imbalance evaluated by HRV parameters in time domain compared to non-T2D RHTN patients. Total patients had HRV correlated positively with serum adiponectin (r = 0.37 [95% CI -0.04 - 1.00] p = 0.03), negatively with HbA1c levels (r = -0.58 [95% CI -1.00 - -0.3] p = 0.00) and also adiponectin correlated negatively with HbA1c levels (r = -0.40 [95% CI -1.00 - -0.07] p = 0.02).

Conclusion

Type 2 diabetes comorbidity is associated with greater autonomic imbalance, lower adiponectin levels and greater BMI in RHTN patients. Similar circadian disruption was also found in both groups indicating the importance of lifestyle behavior in the genesis of RHTN.

Inflammation and reactive oxygen species in cardiovascular disease

Reactive oxygen species (ROS) have long been proposed to be mediators of experimental cardiovascular pathology. There is also a wealth of data indicating that ROS are involved in clinical cardiovascular pathology. However, multiple clinical studies have shown little benefit from anti-oxidant treatments, whereas nearly all experimental studies have shown a marked effect of anti-oxidant therapy. One reason for this discrepancy is that ROS are produced through multiple different mechanisms of which some are clinically beneficial; thus, in a defined experimental system where predominately pathological ROS are generated does not mimic a clinical setting where there are likely to be multiple ROS generating systems producing beneficial and pathological ROS. Simple inhibition of ROS would not be expected to have the same result in these two situations; ergo, it is important to understand the molecular mechanism underlying the production of ROS so that clinical treatments can be tailored to target the pathological production of ROS. One such example of this in cardiovascular biology is tissue specific inflammation-mediated ROS generation. This and the following series of articles discuss the current understanding of the role of ROS in cardiovascular disease, specifically focusing on the molecular mechanisms of ROS generation and the actions of ROS within the cardiovascular system. Although there are still many areas with regard to the effects of ROS in the cardiovascular system that are not completely understood, there is a wealth of data suggesting that blocking pathological ROS production is likely to have beneficial clinical effects compared to traditional anti-oxidants.