Serum omentin-1 levels are inversely associated with the presence and severity of coronary artery disease in patients with metabolic syndrome

Omentin Modulates Chronic Cardiac Remodeling After Myocardial Infarction

Background: Omentin, a circulating adipokine, is downregulated in complications of obesity, including heart disease. Here, we investigated whether omentin modulates adverse cardiac remodeling in mice after myocardial infarction (MI). Methods and Results: Transgenic mice expressing the human omentin gene in fat tissue (OMT-Tg) and wild-type (WT) mice were subjected to permanent ligation of the left anterior descending coronary artery (LAD) to induce MI. OMT-Tg mice had a higher survival rate after permanent LAD ligation than WT mice. Moreover, OMT-Tg mice had lower heart weight/body weight (HW/BW) and lung weight/body weight (LW/BW) ratios at 4 weeks after coronary artery ligation compared with WT mice. OMT-Tg mice also showed decreased left ventricular diastolic diameter (LVDd) and increased fractional shortening (%FS) following MI. Moreover, an increase in capillary density in the infarct border zone and a decrease in myocardial apoptosis, myocyte hypertrophy, and interstitial fibrosis in the remote zone following MI, were more prevalent in OMT-Tg than WT mice. Finally, intravenous administration of adenoviral vectors expressing human omentin to WT mice after MI resulted in decreases in HW/BW, LW/BW, and LVDd, and an increase in %FS. Conclusions: Our findings document that human omentin prevents pathological cardiac remodeling after chronic ischemia, suggesting that omentin represents a potential therapeutic molecule for the treatment of ischemic heart disease.

The shared biomarkers and pathways of systemic lupus erythematosus and metabolic syndrome analyzed by bioinformatics combining machine learning algorithm and single-cell sequencing analysis

Background

Systemic lupus erythematosus (SLE) is one of the most prevalent systemic autoimmune diseases, and metabolic syndrome (MetS) is the most common metabolic disorder that contains hypertension, dyslipidemia, and obesity. Despite clinical evidence suggested potential associations between SLE and MetS, the underlying pathogenesis is yet unclear.

Methods

The microarray data sets of SLE and MetS were obtained from the Gene Expression Omnibus (GEO) database. To identify the shared genes between SLE and MetS, the Differentially Expressed Genes (DEGs) analysis and the weighted gene co-expression network analysis (WGCNA) were conducted. Then, the GO and KEGG analyses were performed, and the protein-protein interaction (PPI) network was constructed. Next, Random Forest and LASSO algorithms were used to screen shared hub genes, and a diagnostic model was built using the machine learning technique XG-Boost. Subsequently, CIBERSORT and GSVA were used to estimate the correlation between shared hub genes and immune infiltration as well as metabolic pathways. Finally, the significant hub genes were verified using single-cell RNA sequencing (scRNA-seq) data.

Results

Using limma and WGCNA, we identified 153 shared feature genes, which were enriched in immune- and metabolic-related pathways. Further, 20 shared hub genes were screened and successfully used to build a prognostic model. Those shared hub genes were associated with immunological and metabolic processes in peripheral blood. The scRNA-seq results verified that TNFSF13B and OAS1, possessing the highest diagnostic efficacy, were mainly expressed by monocytes. Additionally, they showed positive correlations with the pathways for the metabolism of xenobiotics and cholesterol, both of which were proven to be active in this comorbidity, and shown to be concentrated in monocytes.

Conclusion

This study identified shared hub genes and constructed an effective diagnostic model in SLE and MetS. TNFSF13B and OAS1 had a positive correlation with cholesterol and xenobiotic metabolism. Both of these two biomarkers and metabolic pathways were potentially linked to monocytes, which provides novel insights into the pathogenesis and combined therapy of SLE comorbidity with MetS.

Omentin-1: A newly discovered warrior against metabolic related diseases

INTRODUCTION

: Chronic metabolism-related diseases are challenging clinical problems. Omentin-1 is mainly expressed in stromal vascular cells of adipose tissue and can also be expressed in airway goblet cells, mesothelial cells, and vascular cells. Omentin-1 has been found to exert important anti-inflammatory, antioxidative and anti-apoptotic roles and to regulate endothelial dysfunction. Moreover, omentin-1 also has protective effects against cancer, atherosclerosis, type 2 diabetes mellitus, and bone metabolic diseases. The current review will discuss the therapeutic potential of omentin-1.

AREAS COVERED

: This review summarizes the biological actions of omentin-1 and provides an overview of omentin-1 in metabolic-related diseases. The relevant literature was derived from a PubMed search spanning 1998-2021 using these search terms: omentin-1, atherosclerosis, diabetes mellitus, bone, cancer, inflammation, and oxidative stress.

EXPERT OPINION

: As a novel adipocytokine, omentin-1 is a promising therapeutic target in metabolic-related diseases. Preclinical animal studies have shown encouraging results. Moreover, circulating omentin-1 has excellent potential as a noninvasive biomarker. In the future, strategies for regulating omentin-1 need to be investigated further in clinical trials in a large cohort.

Omentin as an Independent Predictor of Metabolic Syndrome and Obesity Among Adolescents in Northeast China

PURPOSE

We investigated the association of omentin with metabolic syndrome (MetS), MetS components, and obesity in adolescents.

METHODS

A total of 742 middle-school students from Liaoyang City were enrolled in this cross-sectional study using the stratified cluster sampling method. Clinical information and blood samples were collected, and serum omentin levels were measured using enzyme-linked immunosorbent assay.

RESULTS

Mean plasma omentin levels were lower in male than in female participants (88.25 (interquartile range 63.02-133.61) vs 99.46 (interquartile range 69.08-188.35) ng/L, P = 0.004). The participants were divided into four groups according to the quartile (Q) values of omentin from low to high. With increasing omentin levels from Q1 to Q4, the age of adolescents and the proportion of males gradually increased (P < 0.05), whereas the body mass index (BMI) (P < 0.05) and prevalence of MetS (P > 0.05) tended to decrease. Omentin levels were significantly and negatively correlated with waist circumference and BMI (correlation coefficients of -0.099 and -0.115, respectively). Regression analysis showed that omentin level was independently associated with the risk of MetS (Odds ratio, OR = 0.639, 95% confidence interval, CI (0.432, 0.945)), which was attributed to the association with central obesity (OR = 0.775, 95% CI (0.605, 0.993)) among MetS components. Increased omentin levels also indicated a reduced risk of obesity (OR = 0.700, 95% CI (0.563, 0.870)).

CONCLUSION

Omentin is an independent predictor of MetS and obesity among adolescents in northeast China.

Relationship between circulating serum omentin-1 levels and nascent metabolic syndrome in patients with hypertension

The prevalence of metabolic syndrome (MetS) is more common in patients with hypertension and is associated with an increased risk of target organ damage and/or cardiovascular disease (CVD). Omentin-1 is a beneficial adipokine considered to play a role in MetS and MetS-related states such as obesity, diabetes, and coronary artery disease. The aim of this study was to determine the relationship between circulating omentin-1 levels and MetS uncomplicated by diabetes or CVD (nascent MetS) in patients with hypertension. In this study, 110 patients (54 men, 49%; average age: 49.72±11.32 years) treated for hypertension but without overt diabetes and/or CVD were enrolled. 66 patients were stratified into MetS (+) (group 1) and 44 patients into MetS (-) (group 2) according to the American Heart Association/National Heart, Lung, and Blood Institute criteria. The triglyceride glucose (TyG) index was used to assess insulin resistance. Circulating omentin-1 levels in venous blood samples were measured by an ELISA kit. Circulating omentin-1 levels in patients with MetS were significantly lower than in patients without MetS (46.35 ng/mL (42.70-57.70 ng/mL) vs 130.95 ng/mL (62.83-236.48 ng/mL), p<0.001). Omentin-1 was inversely correlated with TyG index (r=-0.204, p=0.033). In a multivariate logistic regression analysis, omentin-1, TyG index, and body mass index were independent predictors of MetS. A receiver operating characteristic curve analysis determined that the best cut-off value for omentin-1 in predicting MetS was 62.20 ng/mL and the area under the curve was 0.880 (95% CI 0.817 to 0.942, p<0.001). The findings of this study suggest that circulating omentin-1 levels are inversely related to the presence of MetS and may be a reliable marker to predict the development of MetS in patients with hypertension.

Val109Asp Polymorphism of the Omentin-1 Gene and Incidence of Knee Osteoarthritis in a Chinese Han Population: A Correlation Analysis

Objective

To investigate the correlation of the Val109Asp polymorphism of the omentin-1 gene with the risk and severity of knee osteoarthritis (KOA) in a Chinese Han population.

Methods

This study enrolled 383 patients with primary KOA and 460 healthy controls. The genotypes were determined by the detection of single nucleotide polymorphism. To explore the interaction between omentin-1 gene polymorphism and obesity and age, the body mass index (BMI) of 25 kg/m² and the age of 55 years old were preset as the cut-off value of stratified analysis. Furthermore, enzyme-linked immunosorbent assay was used to determine the levels of omentin-1, interleukin (IL)-1β, IL-6 in peripheral blood and synovial fluid and the contents of IL-1β, IL-6, metalloproteinase (MMP)-13 and collagen (COL)-II in the supernatant of knee joint cartilage tissue.

Results

The Val109Asp polymorphism of the omentin-1 gene showed no obvious correlation with KOA. Compared with Asp/Asp genotype carriers with BMI <25 kg/m² and age <55 years old, Val109 allele carriers with BMI≥25 kg/m² and age ≥55 years old had obviously increased risk of KOA (adjusted OR = 1.416, p = 0.042; adjusted OR = 1.735, p = 0.038, respectively). In the KOA group, only the omentin-1 levels were significantly lower in the plasma and synovial fluid of Ala/Ala genotype carriers than in those of Asp/Asp genotype carriers. Meanwhile, the proportion of patients with moderate–severe K-L Classification, the levels of IL-1β, IL-6 in synovial fluid and the expression levels of IL-1β, IL-6 and MMP-13 in cartilage tissue significantly increased (p < 0.05). By contrast, the expression level of COL-II in cartilage tissue significantly decreased (p < 0.05).

Conclusions

The Val109Asp polymorphism of the omentin-1 gene may not be the primary pathogenic factor of KOA in Chinese. The Val/Val genotype can be regarded as a potential biomarker for the risk of KOA progression.

Association Between Coronary Artery Disease and Plasma Omentin-1 Levels

Introduction: Omentin-1 is secreted from visceral adipose tissue that contributes to chronic inflammatory diseases’ pathogenesis, including cardiovascular events. In this case-control study, we will determine the association between plasma omentin and coronary artery disease (CAD).

Methods: This is a case-control study, conducted from June 2020 to April 2021 in the cardiology unit of a tertiary care hospital in Pakistan. Patients diagnosed with CAD (n = 300) within the last six months were included in the study. Another 300 participants without CAD and with similar demographic profiles were included in the control group. A blood sample of 5 ml was drawn from participants of both groups and sent to the laboratory to test for plasma omentin level.

Results: Plasma omentin level was significantly lower in patients with CAD compared to the patients without CAD (61.21 ± 10.21 ng/dL vs. 95.22 ± 12.21 ug/L; p-value: <0.0001). In both genders, the plasma omentin-1 was lower in patients with CAD compared to patients without CAD (p-value: <0.0001).

Conclusion: The present study revealed a negative association between omentin-1 and CAD. We speculate that low levels of omentin-1 might play a role in the pathogenesis of atherosclerosis. Therefore, plasma omentin-1 can be a potential biomarker to predict the development and progression of CAD.

The effects of spirulina under high-intensity interval training on levels of nesfatin-1, omentin-1, and lipid profiles in overweight and obese females: A randomized, controlled, single-blind trial

BACKGROUND

We investigated the effects of spirulina under high-intensity interval training (HIIT) on levels of nesfatin-1, omentin-1, and lipid profiles in overweight and obese females.

MATERIALS AND METHODS

This is a randomized, quasi-experimental controlled, single-blind with a pre- and post-test design, in which twenty overweight and obese women (body mass index = 29.32 ± 3.01 kg/m², age = 21.55 ± 1.76 years), were randomly divided into the following groups: HIIT + spirulina (n = 10) and HIIT + placebo (n = 10). Running anaerobic sprint test was used for HIIT protocol consisting of six intervals at 35 m maximal speed runs, with a rest of 10 s in each trial (3 times/week, 4 weeks). HIIT + spirulina group received 500 mg of the spirulina pills twice daily for 4 weeks and the second group took placebo.

RESULTS

There was a significant increase in serum levels of nesfatin-1 in HIIT + spirulina (P < 0.0001) but not in HIIT + placebo (P = 0.61) group. Furthermore, results indicated a significant difference between two groups with respect to serum levels of nesfatin-1 (P = 0.04). Serum levels of omentin-1 significantly increased in both groups (P < 0.05). However, there was no significant difference between two groups (P = 0.49). In addition, results showed no significant inter- and intra-group differences in total cholesterol levels, triglycerides, low-density lipoprotein cholesterol, and high-density lipoprotein cholesterol between groups (P > 0.05).

CONCLUSION

The spirulina under HIIT increased levels of nesfatin-1 and omentin-1 with no effects on the levels of lipid profiles in overweight and obese females.

Omentin attenuates angiotensin II-induced abdominal aortic aneurysm formation in apolipoprotein-E knockout mice

AIMS

Abdominal aortic aneurysm (AAA) is an increasing and life-threatening disease. Obesity contributes to an increased risk of AAA. Omentin is a circulating adipokine, which is downregulated in obese complications. Here we examined whether omentin could modulate angiotensin (Ang) II-induced AAA formation in apolipoprotein-E knockout (apoE-KO) mice.

METHODS AND RESULTS

ApoE-KO mice were crossed with transgenic mice expressing the human omentin gene in fat tissue (OMT-Tg mice) to generate ApoE-KO/OMT-Tg mice. ApoE-KO/OMT-Tg and apoE-KO mice were subjected to continuous Ang II infusion by using osmotic mini pumps. ApoE-KO/OMT-Tg mice exhibited a lower incidence of AAA formation and a reduced maximal diameter of AAA compared with apo-E KO mice. ApoE-KO/OMT-Tg mice showed attenuated disruption of medial elastic fibers in response to Ang II compared with apo-E KO mice. ApoE-KO/OMT-Tg mice also displayed reduced expression levels of matrix metalloproteinase (MMP) 9, MMP2 and pro-inflammatory genes in aortic walls compared with apo-E KO mice. Furthermore, systemic administration of omentin also attenuated AAA formation and disruption of medial elastic fibers in response to Ang II in apoE-KO mice. Treatment of human monocyte-derived macrophages with omentin protein attenuated expression of MMP9 and pro-inflammatory mediators, and MMP9 activation after stimulation with lipopolysaccharide (LPS). Treatment of human vascular smooth muscle cells with omentin protein reduced expression and activation of MMP2 after stimulation with tumor necrosis factor α. Omentin treatment increased phosphorylation levels of Akt in human macrophages and vascular smooth muscle cells. The suppressive effects of omentin on MMP9 and MMP2 expression were reversed by inhibition of integrin-αVβ3/PI3-kinase/Akt signaling in macrophages and vascular smooth muscle cells, respectively.

CONCLUSION

These data suggest that omentin acts as an adipokine that can attenuate Ang II-induced development of AAA through suppression of MMP9 and MMP2 expression and inflammatory response in the vascular wall.

Omentin-1: Protective impact on ischemic stroke via ameliorating atherosclerosis

Omentin-1, a newly identified adipokine, has recently been revealed as a novel biomarker for ischemic stroke (IS). Low circulating omentin-1 levels could indicate a high risk of IS, and elevated omentin-1 levels exert a favorable impact on cerebral ischemia. Furthermore, omentin-1 has anti-atherosclerotic, anti-inflammatory, and cardiovascular protective capabilities through the intracellular Akt/AMP-activated protein kinase (AMPK)/ nuclear factor-κB (NF-κB) and certain protein kinase (ERK, JNK, and p38) signaling pathways. Omentin-1 also alleviates endothelial cell dysfunction, improves revascularization via the Akt-endothelial nitric-oxide synthase (eNOS) regulatory axis, promotes endothelium-dependent vasodilation through endothelium-derived NO in an eNOS fashion, and inhibits VSMC proliferation by means of AMPK/ERK signaling pathways, VSMC migration via inactivation of the NADPH oxidase (NOX)/ROS/p38/HSP27 pathways and artery calcification via the PI3K-Akt pathway. These findings indicate that omentin-1 may be a negative mediator of IS. Pharmacologically, several lines of clinical evidence indicate that metformin and statins could elevate omentin-1 levels, although the specific mechanism has not been precisely delineated until now. This study is the first to summarize the comprehensive mechanisms between omentin-1 and atherosclerosis and to review the shielding effect of omentin-1 on IS. We shed light on omentin-1 as a novel therapeutic target for combating IS.

The effects of physical activity on adipokines in individuals with overweight/obesity across the lifespan: A narrative review

This narrative review summarizes current knowledge on the effects of physical activity (PA) on adipokine levels in individuals with overweight and obesity. Approximately 90 investigations including randomized control, cross-sectional and longitudinal studies that reported on the effects of a single session of PA (acute) or long-term PA (chronic) on adipokine levels in individuals with overweight/obesity were reviewed. The findings support the notion that there is consensus on the benefits of chronic exercise training-regardless of the mode (resistance vs. aerobic), intensity and cohort (healthy vs. diabetes)-on adipokine levels (such as tumour necrosis factor-alpha, interleukin-6, adiponectin, visfatin, omentin-1 and leptin). However, several confounding factors (frequency, intensity, time and type of exercise) can alter the magnitude of the effects of an acute exercise session. Available evidence suggests that PA, as a part of routine lifestyle behaviour, improves obesity complications by modulating adipokine levels. However, additional research is needed to help identify the most effective interventions to elicit the most beneficial changes in adipokine levels in individuals with overweight/obesity.

Adipose Tissue Immunomodulation: A Novel Therapeutic Approach in Cardiovascular and Metabolic Diseases

Adipose tissue is a critical regulator of systemic metabolism and bodily homeostasis as it secretes a myriad of adipokines, including inflammatory and anti-inflammatory cytokines. As the main storage pool of lipids, subcutaneous and visceral adipose tissues undergo marked hypertrophy and hyperplasia in response to nutritional excess leading to hypoxia, adipokine dysregulation, and subsequent low-grade inflammation that is characterized by increased infiltration and activation of innate and adaptive immune cells. The specific localization, physiology, susceptibility to inflammation and the heterogeneity of the inflammatory cell population of each adipose depot are unique and thus dictate the possible complications of adipose tissue chronic inflammation. Several lines of evidence link visceral and particularly perivascular, pericardial, and perirenal adipose tissue inflammation to the development of metabolic syndrome, insulin resistance, type 2 diabetes and cardiovascular diseases. In addition to the implication of the immune system in the regulation of adipose tissue function, adipose tissue immune components are pivotal in detrimental or otherwise favorable adipose tissue remodeling and thermogenesis. Adipose tissue resident and infiltrating immune cells undergo metabolic and morphological adaptation based on the systemic energy status and thus a better comprehension of the metabolic regulation of immune cells in adipose tissues is pivotal to address complications of chronic adipose tissue inflammation. In this review, we discuss the role of adipose innate and adaptive immune cells across various physiological and pathophysiological states that pertain to the development or progression of cardiovascular diseases associated with metabolic disorders. Understanding such mechanisms allows for the exploitation of the adipose tissue-immune system crosstalk, exploring how the adipose immune system might be targeted as a strategy to treat cardiovascular derangements associated with metabolic dysfunctions.

Association between Omentin-1 and Coronary Artery Disease: Pathogenesis and Clinical Research

Like other adipokines, omentin-1 is secreted from visceral adipose tissue and plays a vital role in the development of chronic inflammatory diseases, including cardiovascular events. Recent studies have shown that circulating omentin-1 levels are associated with various metabolic risk factors, such as high blood pressure, increased waist circumference, dyslipidemia, and glucose intolerance. The decrease in serum omentin level is an independent predictor of Coronary Artery Disease (CAD) and is associated with the severity of this disease. Since there is no relevant review in the literature, we aimed to summarize the studies on the relationship between omentin-1 and CAD.

Psoriatic Arthritis and Diabetes Mellitus: A Narrative Review

INTRODUCTION

Psoriatic arthritis (PsA) is a chronic immune-mediated inflammatory spondyloarthropathy associated with psoriasis. PsA is frequently associated with metabolic disorders including, obesity, metabolic syndrome, and diabetes mellitus (DM). Type 2 DM is among the most common metabolic disorders, with a prevalence ranging from 2.4 to 14.8% in the general population.

METHODS

We conducted a narrative review of the English-language studies from January 1989 to September 2019 investigating the risk of type 2 DM in patients with PsA, the pathogenic mechanism linking DM to PsA, and the effects on insulin sensitivity exerted by systemic therapies for PsA.

RESULTS

The prevalence of type 2 DM in patients with PsA ranges from 6.1 to 20.2%, generally higher when compared to the general population. The higher risk of DM is reported in women with more severe forms of PsA. Elevated serum levels of adipokines, including TNF-α, which inhibits the autophosphorylation of the insulin receptor and suppresses the expression of glucose transporter 4, favor insulin resistance and could partially explain the association between PsA and DM. Moreover, adiponectin and omentin, with insulin-sensitizing and anti-atherogenic properties, are decreased in patients with PsA. Some of the treatments for PsA could affect the glucose homeostasis. Systemic corticosteroids are known to impair insulin resistance, whereas apremilast (phosphodiesterase type 4 inhibitor) and TNF-α inhibitors could exert neutral effect or reduce the insulin-resistance. The role of IL-17 or IL-23 inhibitors has been marginally investigated.

CONCLUSIONS

Patients affected by PsA have a higher prevalence of type 2 DM compared with the general population. The mechanism linking PsA with DM has not been completely clarified, but some of the principal mediators could be TNF-α and adipokine, especially adiponectin and omentin. Apremilast and TNF-α inhibitor may have a favorable effect and could be safely used in patients with DM.

Mechanisms linking adipose tissue inflammation to cardiac hypertrophy and fibrosis

Adipose tissue is classically recognized as the primary site of lipid storage, but in recent years has garnered appreciation for its broad role as an endocrine organ comprising multiple cell types whose collective secretome, termed as adipokines, is highly interdependent on metabolic homeostasis and inflammatory state. Anatomical location (e.g. visceral, subcutaneous, epicardial etc) and cellular composition of adipose tissue (e.g. white, beige, and brown adipocytes, macrophages etc.) also plays a critical role in determining its response to metabolic state, the resulting secretome, and its potential impact on remote tissues. Compared with other tissues, the heart has an extremely high and constant demand for energy generation, of which most is derived from oxidation of fatty acids. Availability of this fatty acid fuel source is dependent on adipose tissue, but evidence is mounting that adipose tissue plays a much broader role in cardiovascular physiology. In this review, we discuss the impact of the brown, subcutaneous, and visceral white, perivascular (PVAT), and epicardial adipose tissue (EAT) secretome on the development and progression of cardiovascular disease (CVD), with a particular focus on cardiac hypertrophy and fibrosis.

Higher circulating omentin is associated with increased risk of primary cardiovascular events in individuals with diabetes

AIMS/HYPOTHESIS

Higher concentrations of the adipokine omentin are associated with lower levels of cardiometabolic risk factors in experimental and cross-sectional studies, but with higher risk of type 2 diabetes and cardiovascular diseases in population-based cohort studies. However, it is unknown whether high omentin concentrations are associated with increased risk of cardiovascular events in people with established diabetes. Therefore, the present study investigated the association between serum omentin concentrations and the risk of cardiovascular events in individuals with diabetes.

METHODS

This prospective study was based on participants of the German ESTHER cohort with diabetes and without previous cardiovascular event. The ESTHER cohort consists of individuals aged 50-75 years at baseline who were recruited by their general practitioners. After exclusion of individuals with serum C-reactive protein ≥10 mg/l (≥95.24 nmol/l), the final analysis population consisted of 933 individuals. At baseline, serum omentin concentrations were measured by ELISA. Cox regression models were fitted to estimate HRs and their corresponding 95% CIs for associations of omentin tertiles with a composite endpoint of cardiovascular events and separately with incident myocardial infarction, stroke and cardiovascular death.

RESULTS

During 14 years of follow-up, 228 individuals experienced a primary cardiovascular event (myocardial infarction, stroke or cardiovascular death). After comprehensive adjustment for age, sex, BMI, metabolic and lifestyle factors and medication use, HRs (95% CIs) for the 2nd and 3rd tertile of omentin compared with the 1st tertile were: 1.24 (95% CI 0.86, 1.79) and 1.63 (1.15, 2.32) (p_trend = 0.005) for the composite cardiovascular endpoint; 1.39 (0.78, 2.47) and 1.71 (0.98, 2.99) (p_trend = 0.065) for incident myocardial infarction; 1.40 (0.78, 2.53) and 2.05 (1.17, 3.58) (p_trend = 0.010) for incident stroke; and 1.43 (0.85, 2.40) and 1.72 (1.04, 2.83) (p_trend = 0.040) for cardiovascular death. Effect estimates and p values were almost unaltered after additional adjustment for adiponectin.

CONCLUSIONS/INTERPRETATION

Higher omentin concentrations are associated with an increased risk for cardiovascular events in individuals with diabetes after adjustment for multiple cardiovascular risk factors. Given data from preclinical studies, it appears possible that this association reflects a compensatory, but insufficient upregulation of omentin concentrations as a response to stimuli that increase cardiovascular risk.

Impact of serum omentin-1 concentrations on functional outcome among acute intracerebral hemorrhage patients

BACKGROUND

Reduced serum omentin-1 concentrations might be related to an increased risk for poor functional outcome after acute ischemic stroke. We intended to explore whether serum omentin-1 could be a promising prognostic biomarker for acute intracerebral hemorrhage.

METHODS

A total of 104 consecutive patients with hemorrhagic stroke underwent 90-day follow-up. The modified Rankin scale score >2 was evaluated as worse prognosis. A multivariable logistic model was conFig.d for assessing the relationship between serum omentin-1 concentrations and functional outcome.

RESULTS

Serum omentin-1 concentrations, with the median value of 147.9 ng/ml (interquartile range, 114.7-199.8 ng/ml), were substantially declined with rising modified Rankin scale scores (P < 0.001). Serum omentin-1 concentrations <147.9 ng/ml was independently related to higher risk of 90-day worse prognosis (odds ratio, 3.789; 95% confidence interval, 1.819-8.608; P = 0.018). Under receiver operating characteristic curve, an optimal value of serum omentin-1 concentrations was selected as 179.7 ng/ml, which yielded 0.88 sensitivity value and 0.70 specificity value for discriminating patients at risk of 90-day worse prognosis (area under curve, 0.82; 95% confidence interval, 0.73-0.89).

CONCLUSIONS

Lower serum omentin-1 concentrations are closely associated with poor functional outcome after hemorrhagic stroke, substantializing serum omentin-1 as a potential prognostic biomarker for acute intracerebral hemorrhage.

New Insights into Adipokines as Potential Biomarkers for Type-2 Diabetes Mellitus

A large number of studies have been focused on investigating serum biomarkers associated with risk or diagnosis of type-2 diabetes mellitus. In the last decade, promising studies have shown that circulating levels of adipokines could be used as a relevant biomarker for diabetes mellitus progression as well as therapeutic future targets. Here, we discuss the possible use of recently described adipokines, including apelin, omentin-1, resistin, FGF-21, neuregulin-4 and visfatin, as early biomarkers for diabetes. In addition, we also include recent findings of other well known adipokines such as leptin and adiponectin. In conclusion, further studies are needed to clarify the pathophysiological significance and clinical value of these biological factors as potential biomarkers in type-2 diabetes and related dysfunctions.

Plasma omentin levels are associated with vascular endothelial function in patients with type 2 diabetes at elevated cardiovascular risk

AIMS

Omentin is an adipokine that has protective effects against cardiovascular damage. Previous studies showed an inverse relationship between omentin and obesity, diabetes, and cardiovascular disease. This study aimed to investigate the association between omentin and vascular endothelial function in patients with type 2 diabetes (T2D).

METHODS

The subjects were 425 patients with T2D and 223 non-diabetic controls. Fasting plasma omentin levels were measured by enzyme-linked immunosorbent assay, and the endothelium-dependent, flow-mediated dilatation (FMD) was measured by ultrasonography.

RESULTS

Plasma omentin levels were higher, while FMD was lower in participants with T2D than in non-diabetic controls. No significant correlation was found between plasma omentin levels and FMD in either non-diabetic controls or participants with T2D on multivariate analysis. However, stratified analysis in T2D patients revealed that plasma omentin levels were independently and positively associated with FMD in high cardiovascular risk subgroups according to age (≥65 years), estimated glomerular filtration rate (<60 mL/min/1.73 m²), or preexisting cardiovascular diseases but not in low-risk subgroups.

CONCLUSIONS

Plasma omentin levels are independently associated with endothelial function in subgroups of patients with T2D at elevated cardiovascular risk. This study suggests a protective role of omentin against endothelial dysfunction, particularly in high-risk patients.

Anti-Inflammatory and Pro-Inflammatory Adipokine Profiles in Children on Vegetarian and Omnivorous Diets

Adipose tissue is a highly active endocrine organ that secrets many pro-inflammatory as well anti-inflammatory adipokines. The aim of the study was to assess serum adipokine profile in prepubertal vegetarian and omnivorous children. Sixty-two children on a vegetarian diet and fifty-five children on an omnivorous diet, aged 5 to 10 years, were studied. Dietary assessment was performed using a nutritional software program. Body composition was measured by dual-energy X-ray absorptiometry. Serum concentrations of adipokines: leptin, soluble leptin receptor (sOB-R), adiponectin (total and high molecular weight), resistin, visfatin, vaspin, and omentin were determined by immunoenzymatic assays. Both studied groups of children were comparable in terms of age, weight, height, body mass index, and body composition. Vegetarians had a lower (p = 0.017) leptin/sOB-R ratio and lower serum concentrations of resistin (p = 0.051), compared with omnivores. Average levels of other adipokines did not differ between both groups of children. However, we observed significantly higher ratios of anti-inflammatory to pro-inflammatory adipokines: adiponectin/leptin 0.70 (0.37–0.93) vs 0.39 (0.28–0.74), p = 0.005, and omentin/leptin 0.40 (0.23–0.83) vs. 0.33 (0.15–0.48), p = 0.011 in vegetarians compared with omnivores. A well-planned vegetarian diet might beneficially affect the adipokine profile and inflammatory status expressed by the ratios of anti-inflammatory to pro-inflammatory adipokines in prepubertal children.

Subcutaneous adipose tissue biology in metabolic syndrome

Metabolic syndrome (MetS) is a common global problem that comprises the cardio-metabolic cluster and predisposes to both diabetes and cardiovascular diseases. Although the pathogenic mechanisms have not been elucidated, both increased inflammation and insulin resistance play a pivotal role. It appears that both monocyte/macrophages and adipose tissue (AT) conspire to accentuate both the pro-inflammatory state and increased insulin resistance. Whilst there are scant data on visceral adipose tissue (VAT) and epicardial adipose tissue (EAT) biology, there are data on subcutaneous adipose tissue (SAT) dysregulation. There is a significant increase in macrophages and crown-like structures in the SAT of patients with MetS. With respect to adipokines, there is an increase in plasma leptin, plasminogen activator inhibitor-1, retinol-binding protein-4 (RBP-4), chemerin, serum amyloid-A, C-reactive protein (CRP), interleukin-1, -6, -8, lipopolysaccharide, fetuin A (FetA) and a decrease in adiponectin and omentin-1. All of the abnormalities in plasma were also confirmed for SAT-secreted adipokines except for adiponectin and RBP-4 which derive largely from VAT. As many of these biomediators correlate with both insulin resistance and increased inflammation, we can posit that dysregulation of SAT is detrimental and contributes to both the pathogenesis of MetS and its sequalae. Furthermore, as future directions, much work is needed with respect to VAT/EAT biology, autophagy, sirtuins, the gut microbiome, browning of AT, to further elucidate this common syndrome and identify potential therapeutic targets to forestall its serious complications.

Role of Omentin, Vaspin, Cardiotrophin-1, TWEAK and NOV/CCN3 in Obesity and Diabetes Development

Adipose tissue releases bioactive mediators called adipokines. This review focuses on the effects of omentin, vaspin, cardiotrophin-1, Tumor necrosis factor-like Weak Inducer of Apoptosis (TWEAK) and nephroblastoma overexpressed (NOV/CCN3) on obesity and diabetes. Omentin is produced by the stromal-vascular fraction of visceral adipose tissue. Obesity reduces omentin serum concentrations and adipose tissue secretion in adults and adolescents. This adipokine regulates insulin sensitivity, but its clinical relevance has to be confirmed. Vaspin is produced by visceral and subcutaneous adipose tissues. Vaspin levels are higher in obese subjects, as well as in subjects showing insulin resistance or type 2 diabetes. Cardiotrophin-1 is an adipokine with a similar structure as cytokines from interleukin-6 family. There is some controversy regarding the regulation of cardiotrophin-1 levels in obese -subjects, but gene expression levels of cardiotrophin-1 are down-regulated in white adipose tissue from diet-induced obese mice. It also shows anti-obesity and hypoglycemic properties. TWEAK is a potential regulator of the low-grade chronic inflammation characteristic of obesity. TWEAK levels seem not to be directly related to adiposity, and metabolic factors play a critical role in its regulation. Finally, a strong correlation has been found between plasma NOV/CCN3 concentration and fat mass. This adipokine improves insulin actions.

Role of Adipokines in Cardiovascular Disease

Cardiovascular disease (CVD) is the greatest cause of death, accounting for nearly one-third of all deaths worldwide. The increase in obesity rates over 3 decades is widespread and threatens the public health in both developed and developing countries. Obesity, the excessive accumulation of visceral fat, causes the clustering of metabolic disorders, such as type 2 diabetes, dyslipidemia, and hypertension, culminating in the development of CVD. Adipose tissue is not only an energy storage organ, but an active endocrine tissue producing various biologically active proteins known as adipokines. Since leptin, a central regulator of food intake and energy expenditure, was demonstrated to be an adipose-specific adipokine, attention has focused on the identification and characterization of unknown adipokines to clarify the mechanisms underlying obesity-related disorders. Numerous adipokines have been identified in the past 2 decades; most adipokines are upregulated in the obese state. Adipokines such as tumor necrosis factor (TNF)-α, interleukin (IL)-6, IL-1β, and resistin are pro-inflammatory, and exacerbate various metabolic and cardiovascular diseases. However, a small number of adipokines, including adiponectin, are decreased by obesity, and generally exhibit antiinflammatory properties and protective functions against obesity-related diseases. Collectively, an imbalance in the production of pro- and antiinflammatory adipokines in the obese condition results in multiple complications. In this review, we focus on the pathophysiologic roles of adipokines with cardiovascular protective properties.

Obesity-Induced Changes in Adipose Tissue Microenvironment and Their Impact on Cardiovascular Disease

Obesity is causally linked with the development of cardiovascular disorders. Accumulating evidence indicates that cardiovascular disease is the collateral damage of obesity-driven adipose tissue dysfunction that promotes a chronic inflammatory state within the organism. Adipose tissues secrete bioactive substances, referred to as adipokines, which largely function as modulators of inflammation. The microenvironment of adipose tissue will affect the adipokine secretome, having actions on remote tissues. Obesity typically leads to the upregulation of proinflammatory adipokines and the downregulation of anti-inflammatory adipokines, thereby contributing to the pathogenesis of cardiovascular diseases. In this review, we focus on the microenvironment of adipose tissue and how it influences cardiovascular disorders, including atherosclerosis and ischemic heart diseases, through the systemic actions of adipokines.

Omentin Val109Asp polymorphism and risk of coronary artery disease

Background Omentin is an adipocytokine with antiinflammatory properties. It has been reported to be involved in atherosclerosis and coronary artery disease. We aimed to investigate the association of omentin Val109Asp polymorphism with coronary artery disease in an Iranian population. Methods For a case-control study, 400 individuals were recruited: 200 with coronary artery disease and 200 healthy controls. Patients with coronary artery disease were diagnosed by angiography as having at least one main coronary artery with more than 50% stenosis. Genotyping of Val109Asp was carried out using a polymerase chain reaction DNA-restriction fragment length polymorphism technique. Results There was no association between Val109Asp polymorphism and the risk of coronary artery disease in our study population ( p = 0.20). However, when subgroup analysis was performed according to sex, there was a significant difference in the distribution of alleles between groups for men ( p = 0.031, odds ratio = 0.57, 95% confidence interval: 0.35-0.95) but not for women ( p = 0.88, odds ratio = 1.03, 95% confidence interval: 0.66-1.61). Conclusions Our results indicate that the Asp allele of Val109Asp (T allele of rs2274907) is more frequent among men with coronary artery disease than healthy men, so it is possibly a risk factor for coronary artery disease in men only. The difference in association between men and women may be due to the different distribution and metabolism of adipose tissue in men and women. More studies with larger sample sizes and in different populations are required to validate our study results.

Plasma Omentin-1 Level as a Predictor of Good Coronary Collateral Circulation

Aims: Coronary collateral circulation (CCC) is crucial during an acute ischemic attack. Evidences showed that omentin-1 exhibited remarkable antiatherogenic effects and ischemia-induced revascularization. The aim of this study was to investigate the relationship between plasma omentin-1 levels and CCC in patients with ≥ 90% angiography-proven coronary occlusion.

Methods: 142 patients with ≥ 90% luminal diameter stenosis in at least one major epicardial coronary artery were recruited. Among them, 79 patients with Rentrop 0–1 grade were classified into the poor CCC group and 63 patients with Rentrop 2–3 grade were included into the good CCC group. The association between plasma omentin-1 levels and CCC status was assessed.

Results: Plasma omentin-1 level was significantly higher in patients with good CCC than those with poor CCC (566.57 ± 26.90 vs. 492.38 ± 19.70 ng/mL, p = 0.024). Besides, omentin-1 was positively correlated with total cholesterol (TC), high-density lipoprotein, and gensini score but inversely with hyperlipidemia and body mass index (all p values < 0.05). Multivariate regression analysis indicated that omentin-1 [odds ratio (OR) = 1.002, 95% confidence interval (CI): 1.000 – 1.004, p = 0.041)], TC, the number of the diseased vessels, a higher frequency of left circumflex artery and right coronary artery, chronic total occlusion, and gensini score remained as the independent predictors of good CCC.

Conclusion: Higher plasma omentin-1 level was associated with better CCC development. Our findings suggest that omentin-1 may be an alternative marker for adequate CCC in patients with ≥ 90% coronary occlusion.

Adipokines in psoriasis: An important link between skin inflammation and metabolic alterations

Psoriasis is a chronic inflammatory skin disease most common in Europe, North America, and Australia. The etiology and pathomechanisms underlying the evolution and persistence of the skin alterations are increasingly being understood and have led to the development of effective anti-psoriatic therapies. Apart from the skin manifestations, psoriasis is associated with the metabolic syndrome (MetS), known to increase the risk of type 2 diabetes mellitus and cardiovascular disorders. Research of the last years demonstrated a dysregulated adipokine balance as an important link between inflammation, MetS, and consequential disorders. This article describes selected adipokines and their potential role in both metabolic comorbidity and skin inflammation in psoriasis.

Adipocytokines in Cardiovascular and Metabolic Diseases

Obesity, particularly excess visceral fat accumulation, is highly associated with the development of metabolic syndrome and atherosclerotic cardiovascular disease. Adipose tissue produces a variety of secreted proteins, referred to as adipocytokines, which directly affect nearby or remote organs. Dysregulation of adipocytokines caused by obese conditions contributes to the pathogenesis of various metabolic and cardiovascular disorders. This review focuses on the significance of several adipocytokines that potentially exert beneficial actions on obesity-related diseases, including atherosclerosis and ischemic heart disease.

Assessment of Serum Concentrations of Ghrelin, Obestatin, Omentin-1, and Apelin in Children with Type 1 Diabetes

The increasing knowledge on the functions of gastric peptides and adipokines in the body allows the assumption of their major role linking the process of food intake, nutritional status, and body growth, largely through the regulation of glucose metabolism and insulin resistance. The aim of the study was the assessment of serum levels of selected gastric peptides and adipocytokines in children with type 1 diabetes, with respect to the disease duration. The study involved 80 children aged 4-18 years (M/F -37/43). Children with type 1 diabetes (n = 46) were compared to the control group (n = 34). The study group was divided into 4 subgroups: (I) patients with newly diagnosed type 1 diabetes, after an episode of ketoacidosis (n = 10), (II) patients with type 1 diabetes of duration no longer than 5 years (n = 9), (III) patients with 5 to 10 years of DT1 (n = 20), and (IV) patients with type 1 diabetes of duration longer than 10 years (n = 7). The concentrations of gastric peptide and adipocytokines across all subgroups were lower than in the control group. The differences were statistically significant (p < 0.0001), which may be of importance in the development of the disease complications.

New Insights into the Role of Metformin Effects on Serum Omentin-1 Levels in Acute Myocardial Infarction: Cross-Sectional Study

Background. Serum omentin-1 level was low in the most types of ischemic heart disease compared to normal subjects; it also dependently correlated with coronary heart disease; thus, omentin-1 is regarded as a novel biomarker in IHD. Objective. The aim of the present study was to establish the links between omentin-1 and acute myocardial infarction in metformin patients. Subjects and Methods. A cross-sectional study was performed on eighty-five patients with type II DM and acute MI. They are divided as follows: Group I, 62 patients with type II DM who received metformin prior to onset of acute MI; Group II, 23 patients with type II DM who did not receive metformin prior to onset of acute MI; and Group III, 30 normal healthy controls. Venous blood was drawn from each participant for determination of lipid profile, plasma omentin-1, cardiac troponin-I (cTn-I) and other routine tests. Results. Patients that presented with acute MI that received metformin show a significant difference in all biochemical parameters (p < 0.001); metformin increases serum omentin-1 level and decreases serum cardiac troponin-I level compared with control subjects and nonmetformin treated patients. Conclusion. Metformin pharmacotherapy increases omentin-1 serum levels and may be regarded as a potential agent in the prevention of the occurrences of acute MI in diabetic patients.

Differential behaviour of epicardial adipose tissue-secretomes with high and low orosomucoid levels from patients with cardiovascular disease in H9C2 cells

Epicardial adipose tissue releases orosomucoid (ORM), an acute phase protein with multiple modulatory and protective properties. We aimed to identify the effect of EAT-supernatants according to their ORM levels on H9C2 cells. H9C2 were cultured with EAT-secretomes or ORM protein itself on a Real-Time Cell Analyser. Secretome proteins identification was performed by LC-mass spectrometry according to their ORM levels. Two of them were validated by ELISA in EAT-supernatants from 42 patients. ORM effect on H9C2 and neonatal rat cardiomyocytes apoptosis under hypoxia with or without fatty acid treatment was determined by Annexin-V flow cytometry measurement. Caspase-3 expression levels were determined by western blot in H9C2. Our results showed a differential effect of EAT-secretomes according their ORM levels. Although additional secreted proteins can contribute to their beneficial effects, ORM reduced hypoxia-induced apoptosis through caspase-3 inhibition. Our data showed the cardioprotective role of ORM and suggest that its quantification on EAT secretomes might help us to find new secreted factors with a cardioprotective role.

The protective functions of omentin in cardiovascular diseases

Adipose tissue is considered as a large gland that can produce paracrine and endocrine hormones. Growing evidence suggests that adipocytes may link obesity to cardiovascular diseases (CVD). Adipose tissue produces a large number of mediators, which affect metabolism, inflammation and coagulation. Omentin, a novel adipocytokine, has come into the center of interest due to its favorable effects on inflammation, glucose homeostasis and CVD. The present review provides a concise and general overview on the roles of omentin in CVD. The knowledge of these concepts may provide a new strategy to reduce disease risks on CVD in the future.

Adipokines, Vascular Wall, and Cardiovascular Disease

Epidemiological evidence has shown that abdominal obesity is closely associated with the development of cardiovascular (CV) disease, suggesting that it might be considered as an independent CV risk factor. However, the pathophysiological mechanisms responsible for the association between these 2 clinical entities remain largely unknown. Adipocytes are considered able to produce and secrete chemical mediators known as “adipokines” that may exert several biological actions, including those on heart and vessels. Of interest, a different adipokine profile can be observed in the plasma of patients with obesity or metabolic syndrome compared with healthy controls. We consider the main adipokines, focusing on their effects on the vascular wall and analyzing their role in CV pathophysiology.

Omentin-1 promotes the growth of neural stem cells via activation of Akt signaling

Omentin is a novel adipokine, which is expressed in and released from omental adipose tissue. In the present study, the effect of omentin on neural stem cells (NSCs) was investigated. NSCs are a subtype of stem cell in the nervous system, which are able to self‑renew and generate neurons and glia for repairing neural lesions. Mouse NSCs were isolated and cultured in vitro. Treatment with recombinant omentin for 3 and 5 days significantly increased the size of NSC neurospheres (P<0.01) and enhanced NSC cell viability in normal conditions. In addition, omentin protected against the decrease in cell viability induced by the pro‑inflammatory cytokine tumor necrosis factor‑α. In the NSCs, incubation of omentin for 2, 4, 6, 8 and 16 h enhanced the phosphorylation of Akt at the Thr308 site and of AS160 at the Ser318 site, peaking 6 h after treatment. Additionally, treatment with LY294002 (10 µM), a specific inhibitor of phosphatidylinositol 3‑kinase/Akt signaling, eliminated the omentin‑induced increase in neurosphere size and cell viability. Overall, the present study provided the first evidence, to the best of our knowledge, that omentin promotes the growth and survival of NSCs in vitro through activation of the Akt signaling pathway. These results may contribute to the understanding of the role of omentin in the nervous system.

Plasma levels of omentin-1 and visfatin in senile patients with coronary heart disease and heart failure

OBJECTIVE

To investigate the alteration of plasma levels of omentin-1 and visfatin in elderly patients with coronary heart disease (CHD) and heart failure.

METHODS

Plasma omentin-1 and visfatin levels were measured in 90 subjects (29 stable angina pectoris (SAP) cases, 30 unstable angina pectoris (UAP) cases and 31 age- and sex-matched healthy controls (age ≥ 60 years) by enzyme-linked immunosorbent assay methods. According to the New York Heart Association classification, 59 CHDs were divided into three groups: functional I class, 11 cases; functional II/III class, 36 cases; and functional IV class, 12 cases.

RESULTS

The plasma level of omentin-1 in CHD patients was significantly lower than that of the control group. Omentin-1in SAP group and UAP group were significantly lower compared to the control group (there was no statistical significance between UAP group and SAP group; P >0.05). The plasma level of visfatin in CHD patients was significantly higher than that of the control group. Similarly, visfatin in SAP group and UAP group were all significantly higher compared to the control group, while there was no statistical significance between UAP group, and SAP group. The plasma omentin-1 level was negatively correlated with SBP (r=-0.264, P<0.05), positively correlated with HDL-c level (r=0.271, P<0.05); the plasma visfatin level was positively correlated with TC (r=0.292,P<0.05), negatively correlated with HDL-c level (r=-0.266,P<0.05). There was a negative correlation between plasma omentin-1 and visfatin levels (r=-0.280, P<0.05). Moreover, multiple linear stepwise regression analysis showed that omentin-1 and visfatin levels might be affected by HDL-c level. Logistic regression analysis showed that visfatin could be an independent risk factor of CHD.

CONCLUSIONS

Decreased levels of omentin-1 and increased levels of visfatin may be involved in the occurrence and development of CHD. Omentin-1 and visfatin, independently, may be protective and pro-inflammatory cytokines. Additionally, both omentin-1 and visfatin may be related to lipid metabolism. Visfatin may be an independent risk factor of CHD.

Omentin on a four-pronged fork: another reason why obesity erodes cardiovascular survival

Adipose tissue is now acknowledged as not just an energy storage tissue, but also as an endocrine organ that produces bioactive adipokines. Omentin is an adipokine that is gaining interest due to reports of reduced circulating plasma levels in obesity and blood vessel diseases. An emerging cardioprotective role for omentin is discussed.