Plasma adiponectin and resistin levels as predictors of mortality in patients with acute myocardial infarction: data from infarction prognosis study registry. Coron Artery Dis. 2009;20:33-39. [PMID: 18997620 DOI: 10.1097/mca.0b013e328318ecb0]

The Role of Epicardial Adipose Tissue in Acute Coronary Syndromes, Post-Infarct Remodeling and Cardiac Regeneration

Epicardial adipose tissue (EAT) is a fat deposit surrounding the heart and located under the visceral layer of the pericardium. Due to its unique features, the contribution of EAT to the pathogenesis of cardiovascular and metabolic disorders is extensively studied. Especially, EAT can be associated with the onset and development of coronary artery disease, myocardial infarction and post-infarct heart failure which all are significant problems for public health. In this article, we focus on the mechanisms of how EAT impacts acute coronary syndromes. Particular emphasis was placed on the role of inflammation and adipokines secreted by EAT. Moreover, we present how EAT affects the remodeling of the heart following myocardial infarction. We further review the role of EAT as a source of stem cells for cardiac regeneration. In addition, we describe the imaging assessment of EAT, its prognostic value, and its correlation with the clinical characteristics of patients.

Body mass index and early outcomes after carotid endarterectomy

As the existing data on the correlation of adiposity with adverse outcomes of carotid endarterectomy (CEA) are inconsistent, the aim of the present study is to examine the correlation of an increased body mass index with 30-day complications after carotid endarterectomy. The cohort study comprises 1586 CEAs, performed at the Clinic for Vascular Surgery in Belgrade, from 2012-2017. Out of them, 550 CEAs were performed in patients with normal body mass index (18.5-24.9), 750 in overweight (25.0-29.9), and 286 in obese (≥30) patients. The association of overweight and obesity with early outcomes of carotid endarterectomy was assessed using univariate and multivariate logistic regression analysis. Overweight patients, in whom CEAs were performed, were significantly more frequently males, compared to normal weight patients-Odds Ratio (OR) 1.51 (95% confidence interval- 1.19-1.89). Moreover, overweight patients significantly more frequently had non-insulin-dependent diabetes mellitus-OR 1.44 (1.09-1.90), and more frequently used ACEI in hospital discharge therapy-OR 1.41 (1.07-1.84) than normal weight patients. Additionally, the CEAs in them were less frequently followed by bleedings-OR 0.37 (0.16-0.83). Compared to normal weight patients, obese patients were significantly younger-OR 0.98 (0.96-0.99), and with insulin-dependent and non-insulin-dependent diabetes mellitus-OR 1.83 (1.09-3.06) and OR 2.13 (1.50-3.01) respectively. They also more frequently had increased triglyceride levels-OR 1.36 (1.01-1.83), and more frequently used oral anticoagulants in therapy before the surgery-OR 2.16 (1.11-4.19). According to the results obtained, overweight and obesity were not associated with an increased death rate, transient ischemic attack (TIA), stroke, myocardial infarction, or with minor complications, and the need for reoperation after carotid endarterectomy. The only exception was bleeding, which was significantly less frequent after CEA in overweight compared to normal weight patients.

Prognostic role of inflammatory cytokines and novel adipokines in acute myocardial infarction: An updated and comprehensive review

Acute myocardial infarction (AMI) is one of the major causes of morbidity and mortality worldwide. The inflammation response during and after AMI is common and seems to play a key role in the peri-AMI period, related with ischaemia-reperfusion injury, adverse cardiac remodelling, infarct size and poor prognosis. In this article, we provide an updated and comprehensive overview of the most important cytokines and adipokines involved in the complex pathophysiology mechanisms in AMI, summarizing their prognostic role post-AMI. Data so far support that elevated levels of the major proinflammatory cytokines TNFα, IL-6 and IL-1 and the adipokines adiponectin, visfatin and resistin, are linked to high mortality and morbidity. In contrary, there is evidence that anti-inflammatory cytokines and adipokines as IL-10, omentin-1 and ghrelin can suppress the AMI-induced inflammatory response and are correlated with better prognosis. Mixed data make unclear the role of the novel adipokines leptin and apelin. After all, imbalance of pro-inflammatory and anti-inflammatory cytokines may result in worst AMI prognosis. The incorporation of these inflammation biomarkers in established prognostic models could further improve their prognostic power improving overall the management of AMI patients.

Inflammation and Cardiovascular Diseases in the Elderly: The Role of Epicardial Adipose Tissue

Human aging is a complex phenomenon characterized by a wide spectrum of biological changes which impact on behavioral and social aspects. Age-related changes are accompanied by a decline in biological function and increased vulnerability leading to frailty, thereby advanced age is identified among the major risk factors of the main chronic human diseases. Aging is characterized by a state of chronic low-grade inflammation, also referred as inflammaging. It recognizes a multifactorial pathogenesis with a prominent role of the innate immune system activation, resulting in tissue degeneration and contributing to adverse outcomes. It is widely recognized that inflammation plays a central role in the development and progression of numerous chronic and cardiovascular diseases. In particular, low-grade inflammation, through an increased risk of atherosclerosis and insulin resistance, promote cardiovascular diseases in the elderly. Low-grade inflammation is also promoted by visceral adiposity, whose accumulation is paralleled by an increased inflammatory status. Aging is associated to increase in epicardial adipose tissue (EAT), the visceral fat depot of the heart. Structural and functional changes in EAT have been shown to be associated with several heart diseases, including coronary artery disease, aortic stenosis, atrial fibrillation, and heart failure. EAT increase is associated with a greater production and secretion of pro-inflammatory mediators and neuro-hormones, so that thickened EAT can pathologically influence, in a paracrine and vasocrine manner, the structure and function of the heart and is associated to a worse cardiovascular outcome. In this review, we will discuss the evidence underlying the interplay between inflammaging, EAT accumulation and cardiovascular diseases. We will examine and discuss the importance of EAT quantification, its characteristics and changes with age and its clinical implication.

Differential prognostic value of resistin for cardiac death in patients with coronary artery disease according to the presence of metabolic syndrome

Resistin is associated with atherosclerosis progression by affecting inflammation and insulin resistance. There are controversial data regarding the prognostic value of resistin in stable coronary artery disease (CAD) patients. We prospectively investigated the long-term prognostic value of resistin in patients with stable CAD. A total 741 consecutive patients with stable CAD were followed for a median of 5.5 years. Serum resistin, lipids, high-sensitivity C-reactive protein (hsCRP) and interleukin-6 (IL-6) levels were measured at baseline. Primary endpoints were cardiac death and secondary hospitalizations for acute coronary syndrome, arrhythmic event or ischemic stroke. Follow-up data were obtained from 703 patients of whom 79 had a cardiac death (11.2%) and 205 (29.2%) met the secondary endpoints. Resistin was positively correlated with hsCRP (r = 0.159, p < 0.001) and IL-6 (r = 0.165, p = 0.002), and negatively with high-density lipoprotein-cholesterol (r = - 0.176, p < 0.001). Resistin levels could not predict cardiac death [HR 1.044; 95% CI 0.994-1.096; p = 0.087] neither secondary endpoints [HR 1.025; 95% CI 0.983-1.068; p = 0.250). Among 298 patients (42.4%) with metabolic syndrome (MS) resistin levels were independently associated with cardiac death after adjustment for conventional risk factors [HR 1.121; 95% CI 1.045-1.204; p = 0.002). Further adjustment for ejection fraction of left ventricle (LVEF) did not change the association (HR 1.145; 95% CI 1.057-1.240; p = 0.001). Patients with resistin values ≥ 7.6 ng/mL (median level) had 2.8 times higher risk of cardiac death compared to those with resistin levels < 7.6 ng/mL after adjustment for traditional risk factors and LVEF (HR 2.882; 95% CI 1.311-6.336; p = 0.008). Resistin is independently associated with cardiac death in patients with stable CAD and MS.

Resistin: Potential biomarker and therapeutic target in atherosclerosis

Resistin, a cysteine-rich secretory protein, has a pleiotropic role in humans. Resistin usually presents as trimer or hexamer in plasma, and targets specific receptors Toll Like Receptor 4 (TLR4) or Adenylyl Cyclase-Associated Protein 1 (CAP1). Upon binding to TLR4 and CAP1, resistin can trigger various intracellular signal transduction pathways to induce vascular inflammation, lipid accumulation, and plaque vulnerability. These pro-atherosclerotic effects of resistin appear in various cell types, including endothelial cells, vessel smooth muscle cells and macrophages, which cause diverse damages to cardiovascular system from dyslipidemia, atherosclerosis rupture and ventricular remodeling. In this review, we gather recent evidence about the pro- atherosclerotic effects of resistin and highlight it as a candidate therapeutic or diagnostic target for cardiovascular disease.

Pro-inflammatory Cytokines in Acute Coronary Syndromes

BACKGROUND

Over the last decades, the role of inflammation and immune system activation in the initiation and progression of coronary artery disease (CAD) has been established.

OBJECTIVES

The study aimed to present the interplay between cytokines and their actions preceding and shortly after ACS.

METHODS

We searched in a systemic manner the most relevant articles to the topic of inflammation, cytokines, vulnerable plaque and myocardial infarction in MEDLINE, COCHRANE and EMBASE databases.

RESULTS

Different classes of cytokines (intereleukin [IL]-1 family, Tumor necrosis factor-alpha (TNF-α) family, chemokines, adipokines, interferons) are implicated in the entire process leading to destabilization of the atherosclerotic plaque, and consequently, to the incidence of myocardial infarction. Especially IL-1 and TNF-α family are involved in inflammatory cell accumulation, vulnerable plaque formation, platelet aggregation, cardiomyocyte apoptosis and adverse remodeling following the myocardial infarction. Several cytokines such as IL-6, adiponectin, interferon-γ, appear with significant prognostic value in ACS patients. Thus, research interest focuses on the modulation of inflammation in ACS to improve clinical outcomes.

CONCLUSION

Understanding the unique characteristics that accompany each cytokine-cytokine receptor interaction could illuminate the signaling pathways involved in plaque destabilization and indicate future treatment strategies to improve cardiovascular prognosis in ACS patients.

Exercise and apulian hypocaloric diet affect adipokine changes and gastric banding-induced weight loss: A prospective study on severe obese subjects

Background

Adiponectin and Resistin correlate with insulin sensitivity and cardiovascular risk, respectively. This study aimed to identify lifestyle factors that modulate changes in Adiponectin and Resistin levels after gastric banding positioning (LapGB).

Materials and methods

Before (T0), 3 months (T3), 6 months (T6), and 12 months (T12) after LapGB, serum Adiponectin and Resistin levels were evaluated in a single-centre prospective study including a cohort of 27 non-diabetic obese subjects (S-Ob, BMI ≥35 kg/m²). After surgery, a dietitian checked the adherence of S-Ob to an Apulian hypocaloric diet (aphypoD)/physical activity (phA) and, according to their high or low compliance to aphypoD/phA, S-Ob were included in group 1 (n = 14) or 2 (n = 13) respectively. Serum Adiponectin and Resistin were also measured in 10 healthy controls.

Results

At baseline, Resistin levels were significantly higher and Adiponectin levels significantly lower in S-Ob than in controls. After surgery, group 1 showed a 50.2% excess weight loss (%EWL), significantly decreased Resistin levels at T12 and increased Adiponectin levels at both T6 and T12 as compared with baseline. Group 2 showed 24.6 %EWL at T12, decreased Adiponectin levels at T6 and T12 as compared with baseline, but unaltered Resistin levels. After surgery, group 1 followed aphypoD/phA, while group 2 did not.

Conclusions

LapGB fails to improve cardiovascular risk markers (Resistin) in S-Ob not improving lifestyle. Future studies might investigate these findings in a larger cohort and display whether aphypoD is more effective than other dietary intervention on cardiovascular risk in subjects undergoing LapGB or other Bariatric procedures.

•

Gastric banding (LapGB) plus a 12-month lifestyle program was followed by a % excess weight loss >40.

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Resistin significantly declined in subjects adhering to a 1-year LapGB/lifestyle intervention.

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In subjects not following any lifestyle program after surgery, Adiponectin unexpectedly decreased.

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LapGB fails to change cardiovascular risk or insulin sensitivity without a healthy lifestyle.

Prognostic value of adiponectin level in patients with coronary artery disease: a systematic review and meta-analysis

Background

Conflicting results on the prognostic value of blood adiponectin level in patients with coronary artery disease (CAD) have been reported. This meta-analysis aimed to investigate the prognostic value of elevated adiponectin level in CAD patients.

Methods

A comprehensive literature search was conducted in PubMed and Embase databases up to May 10, 2019. Studies evaluating the association between adiponectin level and major adverse cardiovascular events (death, stroke, acute coronary syndrome or coronary revascularisation), cardiovascular mortality, and all-cause mortality in CAD patients were included. Pooled multivariable adjusted risk ratios (RR) and 95% confidence intervals (CI) was calculated for the highest vs the lowest category of adiponectin level.

Results

Twelve studies including 10,974 CAD patients were included. Elevated adiponectin level was independently associated with higher risk of cardiovascular (RR 1.93; 95% CI 1.55–2.42; p < 0.001) and all-cause mortality (RR 1.96; 95% CI 1.64–2.34; p < 0.001) in CAD patients. However, CAD patients with higher adiponectin level did not significantly increase major cardiovascular events risk (RR 1.12; 95% CI 0.86–1.45; p = 0.407) after adjustment for potential confounders.

Conclusions

This meta-analysis indicates that elevated adiponectin level is an independent predictor of cardiovascular and all-cause mortality in CAD patients. Measurement of blood adiponectin level has potential to identify CAD patients who have high risk of death.

Adiponectin and insulin resistance are related to restenosis and overall new PCI in subjects with normal glucose tolerance: the prospective AIRE Study

Background

In patients with Normal Glucose Tolerance (NGT) some causes of ischemic heart disease (IHD) were not completely investigated. The role both of metabolic milieu and adipokines in IHD progression was not fully investigated. Our aim was to assess the link between adipokines plasma levels, insulin resistance (IR) and IHD in NGT patients undergoing Percutaneous Coronary Intervention (PCI).

Methods

AIRE is a single-center prospective longitudinal observational study investigating the IHD outcome of NGT subjects who underwent coronary revascularization by PCI in a third level cardiology center at A.O. dei Colli Hospital, University of Campania “Luigi Vanvitelli”. Six hundred seventy-nine subjects hospitalized in 2015 for coronary arteriography not suffering from Acute Coronary Syndrome (ACS) in the previous 4 weeks, as well as from all conditions could affect glycemic plasma levels and IR status, were assessed for eligibility. Fifty-four patients with neither history of diabetes nor Altered Fasting Glucose (AFG)/Impaired Fasting Glucose (IGT) after Oral Glucose Tolerance Test (OGTT) were finally enrolled. Primary endpoint was the assessment of the relationship of adipokines and HOMA-IR with the occurrence of restenosis in NGT subjects. As secondary endpoint we assessed the association of the same adipokines and IR with overall ACS events after PCI in NGT subjects.

Results

The 54 NGT patients enrolled were mainly males (85%), with a median age of 60 years [IQR 58–63 years]. Only 4 patients (7.4%) experimented restenosis. Median follow-up was equal to 29.5 months [IQR 14.7–34 months]. Adiponectin levels were independently associated to restenosis (OR 0.206; 95% CI 0.053–0.796; p = 0.000). Instead HOMA-IR and adiponectin appeared independently associated both to de novo IHD (OR 9.6*10¹³; 95% CI 3.026–3.08*10²⁷; p = 0.042 and OR 0.206; 95% CI 0.053–0.796; p = 0.000, respectively) and overall new PCI (OR 1.5*10¹¹; 95% CI 2.593–8.68*10²¹; p = 0.042 and OR 0.206; 95% CI 0.053–0.796; p = 0.000, respectively). Moreover, we fixed a potential cut-off for adiponectin for risk of restenosis (≤ 8.5 µg/mL) and overall new PCI (≤ 9.5 µg/mL).

Conclusion

IR and cytokines play a role in progression of any stage of IHD also in NGT subjects. Our results in this setting of patients, though the relatively small sample size, represent a novelty. Future studies on larger populations are needed to analyze more in depth adipokines and insulin resistance role on IHD progression in non-diabetic people.

Electronic supplementary material

The online version of this article (10.1186/s12933-019-0826-0) contains supplementary material, which is available to authorized users.

Circulating adiponectin levels are paradoxically associated with mortality rate. A systematic review and meta-analysis

CONTEXT

Some studies have surprisingly indicated that serum adiponectin is positively related to mortality rate, thus casting doubts on its role as a therapeutic target for cardiovascular disease.

OBJECTIVE

To summarize evidence about direction, strength and modulators of this controversial association.

DATA SOURCES

MEDLINE, Web of Science, CINHAL, Cochrane Library and Scopus from inception through June 2018.

STUDY SELECTION

English-language prospective studies reporting the association between adiponectin and all-cause or cardiovascular mortality.

DATA EXTRACTION

Two investigators independently extracted data and assessed study quality using standard criteria following the Preferred Reporting Items for Systematic Reviews and Meta-analyses and The Newcastle-Ottawa Scale, respectively. Pooled hazard ratios (HRs) (95% confidence intervals-CIs) were derived using a fixed or random effects models when appropriated and were expressed for one standard deviation (SD) increment of adiponectin.

DATA SYNTHESIS

We identified fifty-five (n=61,676 subjects) and twenty-eight (n=43,979 subjects) studies for all-cause and cardiovascular mortality, respectively. Pooled HRs, were 1.24 (1.17-1.31) and 1.28 (1.19-1.37) for all-cause and cardiovascular mortality, respectively. Similar results were obtained also for High Molecular Weight adiponectin. When meta-analyses were restricted to studies reporting data on natriuretic peptides a 43% and 28% reduction on a log scale of these associations were observed after natriuretic peptides adjustment.

CONCLUSIONS

Our results strongly points to a paradoxical association between high adiponectin levels and increased mortality rate, which is partly modulated by natriuretic peptides.

The Anti-Inflammatory Effects of Testosterone

Low plasma testosterone (T) levels correlated with metabolic syndrome, cardiovascular diseases, and increased mortality risk. T exerts a significant effect on the regulation of adipose tissue accumulation, and in the glucose and lipids metabolism. Adipocytes are the primary source of the most important adipokines responsible for inflammation and chronic diseases. This review aims to analyze the possible effect of T on the regulation of the proinflammatory cytokines secretion.

A systematic literature search on MEDLINE, Google Scholar, and Cochrane using the combination of the following keywords: “testosterone” with “inflammation,” “cytokines,” “adiponectin, CRP, IL-1B, IL-6, TNFα, leptin” was conducted. Sixteen articles related to the effect of low T level and 18 to the effect of T therapy on proinflammatory cytokine were found.

T exerts a significant inhibitory effect on adipose tissue formation and the expression of various adipocytokines, such as leptin, TNF-α, IL-6, IL-1, and is positively correlated with adiponectin level, whereas a low T level is correlated with increased expression of markers of inflammation. Further studies are necessary to investigate the role of T, integrated with weight loss and physical activity, on its action on the mechanisms of production and regulation of proinflammatory cytokines.

Increased serum resistin level is associated with coronary heart disease

To explore the relationship between the serum resistin level and different types of coronary heart diseases (CHD). Literature was retrieved by formal searching of PubMed, Web of Science, Google Scholar, the Cochrane Library, Wanfang Data, China Biological Medicine Database (SinoMed) and China National Knowledge Infrastructure (CNKI) and by hand searching of reference lists of related articles. RevMan5.3 statistical software was utilized for processing and analysis. A total of 22 literatures involving 2070 subjects were included. Meta-analysis showed that the level of serum resistin in the patients with stable angina (SA), unstable angina(UA) or acute myocardial infarction (AMI) were significantly higher than those of normal controls, respectively [SMD(95% CI) were 1.97(1.15, 2.79), 2.54(1.76, 3.31), and 3.62(2.62, 4.62), all P<0.00001]. Serum resistin level in patients with UA or AMI was higher than those in patients with SA, respectively [SMD=0.90, 95CI(0.28,1.52), P=0.005], [SMD=2.28, 95%CI(0.74, 3.82), P=0.004]. The level of serum resistin in patients with AMI was also higher than those in patients with UA [SMD=1.22, 95%CI(0.58, 1.85), P=0.0002]. The study demonstrated that increased serum resistin level is significantly associated with the severity of CHD.

The Adiponectin Paradox for All-Cause and Cardiovascular Mortality

Basic science studies have shown beneficial effects of adiponectin on glucose homeostasis, chronic low-grade inflammation, apoptosis, oxidative stress, and atherosclerotic processes, so this molecule usually has been considered a salutary adipokine. It was therefore quite unexpected that large prospective human studies suggested that adiponectin is simply a marker of glucose homeostasis, with no direct favorable effect on the risk of type 2 diabetes and cardiovascular disease. But even more unforeseen were data addressing the role of adiponectin on the risk of death. In fact, a positive, rather than the expected negative, relationship was reported between adiponectin and mortality rate across many clinical conditions, comprising diabetes. The biology underlying this paradox is unknown. Several explanations have been proposed, including adiponectin resistance and the confounding role of natriuretic peptides. In addition, preliminary genetic evidence speaks in favor of a direct role of adiponectin in increasing the risk of death. However, none of these hypotheses are based on robust data, so further efforts are needed to unravel the elusive role of adiponectin on cardiometabolic health and, most important, its paradoxical association with mortality rate.

Serum resistin is causally related to mortality risk in patients with type 2 diabetes: preliminary evidences from genetic data

Resistin has been firmly associated with all-cause mortality. We investigated, whether, in patients with type 2 diabetes (T2D), this association is sustained by a cause-effect relationship. A genotype risk score (GRS), created by summing the number of resistin increasing alleles of two genome-wide association studies (GWAS)-derived single nucleotide polymorphisms (SNPs), serum resistin measurements and all-cause death records were obtained in 1,479 (403 events/12,454 person-years), patients with T2D from three cohorts, Gargano Heart Study-prospective design (n = 350), Gargano Mortality Study (n = 698) and Foggia Mortality Study (n = 431), from Italy. GRS was strongly associated with serum resistin in a non-linear fashion (overall p = 3.5 * 10^-7) with effect size modest for GRS = 1 and 2 and much higher for GRS >3, with respect to GRS = 0. A significant non-linear association was observed also between GRS and all-cause mortality (overall p = 3.3 * 10^-2), with a low effect size for GRS = 1 and 2, and nearly doubled for GRS ≥ 3, with respect to GRS = 0. Based on the above-reported associations, each genetic equivalent SD increase in log-resistin levels showed a causal hazard ratio of all-cause mortality equal to 2.17 (95%CI: 1.22-3.87), thus providing evidence for a causal role of resistin in shaping the risk of mortality in diabetic patients.

Linking resistin, inflammation, and cardiometabolic diseases

Adipose tissue secretes a variety of bioactive substances that are associated with chronic inflammation, insulin resistance, and an increased risk of type 2 diabetes mellitus. While resistin was first known as an adipocyte-secreted hormone (adipokine) linked to obesity and insulin resistance in rodents, it is predominantly expressed and secreted by macrophages in humans. Epidemiological and genetic studies indicate that increased resistin levels are associated with the development of insulin resistance, diabetes, and cardiovascular disease. Resistin also appears to mediate the pathogenesis of atherosclerosis by promoting endothelial dysfunction, vascular smooth muscle cell proliferation, arterial inflammation, and the formation of foam cells. Thus, resistin is predictive of atherosclerosis and poor clinical outcomes in patients with cardiovascular disease and heart failure. Furthermore, recent evidence suggests that resistin is associated with atherogenic dyslipidemia and hypertension. The present review will focus on the role of human resistin in the pathogeneses of inflammation and obesity-related diseases.

Association between serum resistin level and outcomes in kidney transplant recipients

Resistin is an adipocytokine that is associated with inflammation, coronary artery disease, and other types of cardiovascular disease among patients with normal kidney function. However, little is known about the association of resistin with outcomes in kidney transplant recipients. We collected socio-demographic and clinical parameters, medical and transplant history, and laboratory data from 988 prevalent kidney transplant recipients enrolled in the Malnutrition-Inflammation in Transplant-Hungary Study (MINIT-HU study). Serum resistin levels were measured at baseline. Associations between serum resistin level and death with a functioning graft over a 6-year follow-up period were examined in unadjusted and adjusted models. The mean±SD age of the study population was 51 ± 13 years, among whom 57% were men and 21% were diabetics. Median serum resistin concentrations were significantly higher in patients who died with a functioning graft as compared to those who did not die during the follow-up period (median [IQR]: 22[15-26] vs. 19[14-22] ng/ml, respectively; P < 0.001). Higher serum resistin level was associated with higher mortality risk in both unadjusted and fully adjusted models: HRs (95% CI): 1.33(1.16-1.54) and 1.21(1.01-1.46), respectively. In prevalent kidney transplant recipients, serum resistin was an independent predictor of death with a functioning graft.

Segmental peri-coronary epicardial adipose tissue volume and coronary plaque characteristics

AIMS

Epicardial adipose tissue (EAT) has been proposed to modulate underlying coronary plaque features. The study aimed to determine the relation between segmental EAT (sEAT) volume, assessed by cardiac magnetic resonance (CMR), and underlying coronary plaque characteristics, as estimated by multidetector computed tomography (CT) (MDCT).

METHODS AND RESULTS

The study included 32 male patients with stable angina pectoris and 11 age-matched healthy controls. For each CAD patient, sEAT volume around 8 coronary segments (3 in left anterior descending artery, 3 in right coronary artery, and 2 in left circumflex artery) was quantified by CMR. By MDCT, plaques in each coronary segment were characterized in terms of plaque volume, type, CT attenuation, and severity of luminal stenosis. Serum levels of adipokines were measured. Total EAT volume was significantly higher in CAD patients than in control group. Serum resistin showed significant correlation with EAT volume (r = 0.69, P < 0.001). Analysis of 256 coronary segments showed larger sEAT volume with increasing luminal stenosis of the corresponding segment (mild: 8.2 cm(3); moderate: 11 cm(3); severe: 11.8 cm(3), P < 0.001). sEAT volume was larger in segments with mixed than those with calcified or non-calcified plaques (12.1 vs. 10.2 vs. 9.5 cm(3), respectively, P = 0.015). sEAT volume was larger in segments with low CT attenuation non-calcified plaques compared with non-calcified plaques with CT attenuation >30 HU (10.5 vs. 8.2 mm(3), P < 0.001).

CONCLUSION

Peri-coronary epicardial adipose tissue volume is significantly associated with the extent and severity of coronary atherosclerosis and may be a determinant of plaque vulnerability.

Diabetic cardiomyopathy: is resistin a culprit?

Cardiovascular disease, including heart failure (HF), is the major cause of death in patients with diabetes. A contributing factor to the occurrence of HF in such patients is the development of diabetic cardiomyopathy. Recent evidence demonstrates that perturbations associated with adipokines secretion and signaling result in lusitropic and inotropic defects in diabetic cardiomyopathy. This perspective editorial will discuss the central role of resistin, a recently discovered adipokine, in the maladaptive cardiac phenotype seen in diabetic hearts. Given the pleiotropic effects of resistin, strategies targeting the control of resistin levels may constitute a potentially viable therapeutic utility in patients with diabetes and diabetes-induced cardiovascular diseases.

Association between resistin levels and all-cause and cardiovascular mortality: a new study and a systematic review and meta-analysis

Context

Studies concerning the association between circulating resistin and mortality risk have reported, so far, conflicting results.

Objective

To investigate the association between resistin and both all-cause and cardiovascular (CV) mortality risk by 1) analyzing data from the Gargano Heart Study (GHS) prospective design (n=359 patients; 81 and 58 all-cause and CV deaths, respectively); 2) performing meta-analyses of all published studies addressing the above mentioned associations.

Data Source and Study Selection

MEDLINE and Web of Science search of studies reporting hazard ratios (HR) of circulating resistin for all-cause or CV mortality.

Data Extraction

Performed independently by two investigators, using a standardized data extraction sheet.

Data Synthesis

In GHS, adjusted HRs per one standard deviation (SD) increment in resistin concentration were 1.28 (95% CI: 1.07-1.54) and 1.32 (95% CI: 1.06-1.64) for all-cause and CV mortality, respectively. The meta-analyses included 7 studies (n=4016; 961 events) for all-cause mortality and 6 studies (n=4,187: 412 events) for CV mortality. Pooled HRs per one SD increment in resistin levels were 1.21 (95% CI: 1.03-1.42, Q-test p for heterogeneity<0.001) and 1.05 (95% CI: 1.01-1.10, Q-test p for heterogeneity=0.199) for all-cause and CV mortality, respectively. At meta-regression analyses, study mean age explained 9.9% of all-cause mortality studies heterogeneity. After adjusting for age, HR for all-cause mortality was 1.24 (95% CI: 1.06-1.45).

Conclusions

Our results provide evidence for an association between circulating resistin and mortality risk among high-risk patients as are those with diabetes and coronary artery disease.

Adiponectin/resistin levels and insulin resistance in children: a four country comparison study

Background

There are few reports on the effects of ethnicity or gender in the association between adipocytokines and insulin resistance in children of different ages. This study assessed associations between serum concentrations of adiponectin/resistin and parameters of insulin resistance in children from 4 different countries.

Methods

A total of 2,290 children were analyzed in this study; each was from one of 4 different countries (Japan, Thailand, Italy and USA), and grouped according to age (8–11 years old in Group 1 and 12–15 years old in Group 2).

Results

Adioponectin was higher in female than in male children, and in Group 1 than in Group 2. Generally, adiponectin was lower in Asian as compared to Italian and American children. These tendencies remained even after adjustment for body mass index (BMI) or waist circumstance (WC). Among older children (Group 2), resistin was higher in female than in male children. Significant correlations by non-parametric univariate correlation coefficients and Spearman’s rank correlation coefficients were found between adiponectin and homeostasis model assessment of insulin resistance (HOMA-IR), and fasting serum insulin levels in young Japanese, Italian, and American female children(p < 0.01, p < 0.05, p < 0.05, respectively). Correlations between serum adiponectin and HOMA-IR were also found among older male Italian, American, and Thai children (p < 0.05, p < 0.001, p < 0.001, respectively). In multiple regression analysis by forced entry method, adiponectin correlated with HOMA-IR in Italian and American male children, and in all older female children regardless of country of origin. There was no correlation between resistin and markers of insulin resistance in children from any of the countries.

Conclusions

We conclude that serum adiponectin concentrations are lower in Asian as compared to Italian and American children, and that adiponectin but not resistin contributes to differences in markers for insulin resistance in children from different populations.

Adiponectin is associated with increased mortality in patients with already established cardiovascular disease: a systematic review and meta-analysis

BACKGROUND

The overall quantitative estimate on the possible association of adiponectin concentrations with mortality in patients with cardiovascular diseases (CVD) has not been reported.

METHODS

We performed a systematic review and meta-analysis of prospective studies to evaluate the overall quantitative estimates on the adiponectin levels for risk of mortality in patients with CVD. MEDLINE, EMBASE, CINAHL, and the Cochrane Library (up to Mar 22, 2014) were used to search for studies evaluating the effect of adiponectin levels on mortality in patients with CVD. Random-effect models were selected to estimate overall effect estimates.

RESULTS

Data from 14063 CVD patients enrolled in 15 prospective cohort and 1 nested case control studies were collated. The meta-analyses showed strong positive association of adiponectin with all-cause (n=14 studies, overall pooled effect estimate=1.45 [95% CI, 1.17-1.79]) and cardiovascular (n=11 studies, overall pooled effect estimate=1.69 [1.35-2.10]) mortality, for the highest tertile of adiponectin levels versus the lowest tertile. Subgroup analyses show study characteristics (including effect estimate, mean age, study location, sample sizes, gender, durations of follow-up, types of primary event, and acute or chronic CVD) did not substantially influence these positive associations.

CONCLUSIONS

Our results showed that increased baseline plasma adiponectin levels are significantly associated with elevated risk of all-cause and cardiovascular mortality in subjects with CVD. These positive associations may have been amplified by adjustment for potential intermediates or residual confounding, and their basis requires further investigation.

Adipokines as a novel link between obesity and atherosclerosis

The traditional perception of adipose tissue as a storage organ of fatty acids has been replaced by the notion that adipose tissue is an active endocrine organ, releasing various adipokines that are involved in the pathogenesis of obesity-related metabolic disturbances. Obesity is a well-known risk factor for atherosclerosis, and accelerates atherosclerosis by many mechanisms such as increase in blood pressure and glucose level, abnormal lipid profiles, and systemic inflammation. Furthermore, growing evidence suggests that some adipokines directly mediate the process of atherosclerosis by influencing the function of endothelial cells, arterial smooth muscle cells, and macrophages in vessel walls. In obese patients, the secretion and coordination of such adipokines is abnormal, and the secretion of specific adipokines increases or decreases. Accordingly, the discovery of new adipokines and elucidation of their functions might lead to a new treatment strategy for metabolic disorders related to obesity, including cardiovascular diseases.

Resistin in rodents and humans

Obesity is characterized by excess accumulation of lipids in adipose tissue and other organs, and chronic inflammation associated with insulin resistance and an increased risk of type 2 diabetes. Obesity, type 2 diabetes, and cardiovascular diseases are major health concerns. Resistin was first discovered as an adipose-secreted hormone (adipokine) linked to obesity and insulin resistance in rodents. Adipocyte-derived resistin is increased in obese rodents and strongly related to insulin resistance. However, in contrast to rodents, resistin is expressed and secreted from macrophages in humans and is increased in inflammatory conditions. Some studies have also suggested an association between increased resistin levels and insulin resistance, diabetes and cardiovascular disease. Genetic studies have provided additional evidence for a role of resistin in insulin resistance and inflammation. Resistin appears to mediate the pathogenesis of atherosclerosis by promoting endothelial dysfunction, vascular smooth muscle cell proliferation, arterial inflammation, and formation of foam cells. Indeed, resistin is predictive of atherosclerosis and poor clinical outcomes in patients with coronary artery disease and ischemic stroke. There is also growing evidence that elevated resistin is associated with the development of heart failure. This review will focus on the biology of resistin in rodents and humans, and evidence linking resistin with type 2 diabetes, atherosclerosis, and cardiovascular disease.

The association of resistin with coronary disease in the general population

AIMS

To explore the association between resistin expression and the incidence of ischemic heart disease in the general population.

METHODS

A follow-up study of 6636 adults recruited randomly from the general population.

RESULTS

The serum resistin concentration was higher in women (6.1 ng/mL; CI95%=6.0-6.2) than in men (5.6 ng/mL; CI95%=5.5-5.7). Individuals in the 5th quintile or higher of resistin (RQ5) were younger (P＜0.001) and had a lower prevalence of arterial hypertension (P＜0.001), abdominal obesity (P＜0.001), diabetes (P＜0.001) and dyslipidemia (P＜0.001). The cardiovascular risk estimated by the Framingham function was also lower in the RQ5 subgroup (P＜0.001); however, the prevalence of smoking was higher (P＜0.001), as was the prevalence of low HDL cholesterol (P＜0.001). After 3.5 years of follow-up, the RQ5 subgroup had a higher incidence of acute myocardial infarction (AMI, RR=1.9; CI95%=1.01-3.54). In the population without diabetes, the RQ5 subgroup had a higher risk of AMI (RR=2.4; CI95%=1.10-5.17), and the risk of AMI was highest in women in this group (4.97; CI95%=1.33-18.57). The risk levels were significant in the Cox models adjusted for age, sex and smoking; and the hazard ratio was 2.5 for AMI (CI95%=1.29-4.70) in the sample of patients matched by sex and smoking status.

CONCLUSIONS

Resistin may be a risk marker for ischemic heart disease in the general population. The serum resistin concentration is higher in women, and the associated increase in the risk of AMI based on the resistin level is also higher in women than in men.

Resistin and all-cause and cardiovascular mortality: effect modification by adiponectin in end-stage kidney disease patients

BACKGROUND

Resistin is a major adipose tissue cytokine implicated in insulin resistance, inflammation and vascular damage. This cytokine is raised in patients with end-stage kidney disease (ESKD) but the relationship between resistin and major clinical outcomes has not been investigated in this population.

METHODS

We studied the mutual relationship between resistin and the two major adipokines (adiponectin and leptin) and the interaction between resistin and adiponectin (ADPN) and all-cause and cardiovascular (CV) mortality in a cohort of 231 haemodialysis patients followed up for 57 ± 44 months.

RESULTS

Plasma resistin was substantially raised in ESKD patients when compared with healthy subjects (P < 0.001). On univariate analysis, resistin was related inversely to ADPN (r = -0.14, P = 0.04) and directly to C-reactive protein (r = 0.15, P = 0.03), but was largely independent of leptin (r = 0.08, P = 0.24) and the HOMA-IR index (r = -0.04, P = 0.51). During the follow-up, 165 patients died (96 for CV causes). On both univariate (all-cause mortality: P = 0.004; CV mortality P < 0.001) and multivariate (all-cause mortality: P = 0.01; CV mortality P < 0.001) Cox regression analyses, the effect of resistin on study outcomes was closely dependent on ADPN levels. There was a consistent excess risk for all-cause (P = 0.002) and CV mortality (P = 0.003) by plasma resistin (20 ng/mL) in patients in the first ADPN tertile, but no risk excess for these outcomes was apparent in patients in the third tertile.

CONCLUSION

This study indicates that resistin predicts death and fatal CV events depending on plasma ADPN levels. These findings underscore the importance of the interaction among adipokines for the prediction of adverse clinical outcomes in ESKD.

Resistin level in coronary artery disease and heart failure: the central role of kidney function

OBJECTIVES

The aim of this study was to evaluate resistin levels in patients with coronary artery disease (CAD) with or without chronic heart failure, in order to define its independent predictor.

METHODS

One hundred and seven outpatients with CAD were enrolled in the study and divided into three groups: CAD without left-ventricular systolic dysfunction (group 1); CAD with left-ventricular dysfunction without heart failure symptoms (group 2); CAD with overt heart failure (group 3). Plasma resistin was determined by ELISA.

RESULTS

Resistin progressively increased from group 1 (10.7±5.0 ng/ml) to groups 2 (11.8±5.8 ng/ml) and 3 (17.0±6.8 ng/ml), with the difference reaching statistical significance in group 3 versus groups 1 and 2 (P=0.001). A multivariable model of analysis demonstrated that the best predictor of plasma resistin level was the estimated glomerular filtration rate (P<0.001), indicating that reduction of kidney function was the main cause of the adipokine increase observed in patients with CAD and overt heart failure.

CONCLUSIONS

Our data confirm the rise of resistin plasma levels previously described in patients affected by chronic heart failure; however, in our study, this relationship seemed to be mediated mainly by the level of kidney function, and only partially by the severity of ventricular dysfunction.

Serum resistin, cardiovascular disease and all-cause mortality in patients with type 2 diabetes

Background

High serum resistin has been associated with increased risk of cardiovascular disease in the general population, Only sparse and conflicting results, limited to Asian individuals, have been reported, so far, in type 2 diabetes. We studied the role of serum resistin on coronary artery disease, major cardiovascular events and all-cause mortality in type 2 diabetes.

Methods

We tested the association of circulating resistin concentrations with coronary artery disease, major cardiovascular events (cardiovascular death, non-fatal myocardial infarction and non-fatal stroke) and all-cause mortality in 2,313 diabetic patients of European ancestry from two cross-sectional and two prospective studies. In addition, the expression of resistin gene (RETN) was measured in blood cells of 68 diabetic patients and correlated with their serum resistin levels.

Results

In a model comprising age, sex, smoking habits, BMI, HbA1c, and insulin, antihypertensive and antidyslipidemic therapies, serum resistin was associated with coronary artery disease in both cross-sectional studies: OR (95%CI) per SD increment = 1.35 (1.10–1.64) and 1.99 (1.55–2.55). Additionally, serum resistin predicted incident major cardiovascular events (HR per SD increment = 1.31; 1.10–1.56) and all-cause mortality (HR per SD increment = 1.16; 1.06–1.26). Adjusting also for fibrinogen levels affected the association with coronary artery disease and incident cardiovascular events, but not that with all cause-mortality. Finally, serum resistin was positively correlated with RETN mRNA expression (rho = 0.343).

Conclusions

This is the first study showing that high serum resistin (a likely consequence, at least partly, of increased RETN expression) is a risk factor for cardiovascular disease and all-cause mortality in diabetic patients of European ancestry.

Effect of soybean protein on novel cardiovascular disease risk factors: a randomized controlled trial

BACKGROUND/OBJECTIVES

Cardiovascular disease (CVD) is the leading cause of death in the United States and the world. Clinical trials have suggested that soybean protein lowers lipids and blood pressure. The effect of soybean protein on novel CVD risk factors has not been well studied. The objective of this study was to examine the effect of soybean protein on biomarkers of inflammation, endothelial dysfunction and adipocytokines.

SUBJECTS/METHODS

The effect of 8 weeks of 40 g of soybean protein supplement (89.3 mg isoflavones), 40 g of milk protein supplement and 40 g of complex carbohydrate placebo was examined in a randomized, placebo-controlled, double-blind, three-phase crossover trial among adults in New Orleans, Louisiana and Jackson, Mississippi. Plasma levels of inflammation biomarkers (C-reactive protein, interleukin-6, tumor necrosis factor-α), endothelial dysfunction biomarkers (E-selectin, intercellular adhesion molecule-1, vascular cell adhesion molecule-1, thrombomodulin) and adipocytokines (high-molecular weight adiponectin, leptin, resistin) were measured at baseline and at the end of each intervention using immunoturbidimetric and enzyme-linked immunosorbent assay techniques.

RESULTS

Soy protein supplementation resulted in a significant mean net change (95% confidence interval) in plasma E-selectin of -3.93 ng/ml (-7.05 to -0.81 ng/ml; P=0.014) compared with milk protein, and in plasma leptin of -2089.8 pg/ml (-3689.3 to -490.3 pg/ml; P=0.011) compared with carbohydrate. There were no significant changes in any other risk factors.

CONCLUSIONS

Soy protein supplementation may reduce levels of E-selectin and leptin. Further research is warranted to investigate the mechanisms through which protein may confer protective effects on novel CVD risk factors.

Leptin promotes osteoblast differentiation and mineralization of primary cultures of vascular smooth muscle cells by inhibiting glycogen synthase kinase (GSK)-3β

In this study, we begin to investigate the underlying mechanism of leptin-induced vascular calcification. We found that treatment of cultured bovine aortic smooth muscle cells (BASMCs) with leptin (0.5-4 μg/ml) induced osteoblast differentiation in a dose-dependent manner. Furthermore, we found that leptin significantly increased the mRNA expression of osteopontin and bone sialoprotein, while down-regulating matrix gla protein (MGP) expression in BASMCs. Key factors implicated in osteoblast differentiation, including members of the Wnt signaling pathway, were examined. Exposure to leptin enhanced phosphorylation of GSK-3β on serine-9 thereby inhibiting activity and promoting the nuclear accumulation of β-catenin. Transfection of BASMCs with an adenovirus that expressed constitutively active GSK-3β (Ad-GSK-3β S9A) resulted in a >2-fold increase in GSK-3β activity and a significant decrease in leptin-induced alkaline phosphatase (ALP) activity. In addition, qRT-PCR analysis showed that GSK-3β activation resulted in a significant decrease in the expression of osteopontin and bone sialoprotein, but a marked increase in MGP mRNA expression. When taken together, our results suggest a mechanism by which leptin promotes osteoblast differentiation and vascular calcification in vivo.

Adipocytokine levels mark endothelial function in normotensive individuals

Background

Endothelial dysfunction is an independent risk factor for cardiovascular events. Inflammatory mediators released by the adipose tissue can lead to local insulin resistance and endothelial dysfunction. This study addressed the relationship of adipocytokines with endothelial function and blood pressure.

Methods

In 92 newly diagnosed, drug-naïve essential hypertensive patients (HT, mean age 49 yrs) without organ damage and 66 normotensive subjects (NT, mean age 47 yrs), by an automated system, we measured endothelium-dependent and -independent vasodilation as brachial artery flow-mediated dilation before and after administration of glyceryl-trinitrate. Retinol binding protein-4 (RBP4) and resistin levels were determined by ELISA and RIA, respectively. Oxidative stress was evaluated by measuring serum malondyaldehyde (MDA).

Results

Flow-mediated dilation was significantly (p = 0.03) lower in HT (5.3 ± 2.6%) than NT (6.1 ± 3.1%), while response to glyceryl-trinitrate (7.5 ± 3.7% vs 7.9 ± 3.4%) was similar. RBP4 (60.6 ± 25.1 vs 61.3 ± 25.9 μg/ml), resistin (18.8 ± 5.3 vs 19.9 ± 6.1 ng/ml) and MDA levels (2.39 ± 1.26 vs 2.08 ± 1.17 nmol/ml) were not different in HT and NT.

RBP4 (r = −0.25; p = 0.04) and resistin levels (r = −0.29; p = 0.03) were related to flow-mediated dilation in NT, but not in HT (r = −0.03 and r = −0.10, respectively). In NT, multivariate analysis including RBP4 and confounders showed that only BMI or waist circumference remained related to flow- mediated dilation. In the multivariate model including resistin and confounders, BMI, age and resistin were significantly related to flow-mediated dilation, while only age significant correlated with this parameter when BMI was replaced by waist circumference.

Conclusions

Adipocytokine levels may be independent predictors of endothelial dysfunction in the peripheral circulation of healthy subjects, providing a pathophysiological link between inflammation from adipose tissue and early vascular alterations.

Resistin and cardiovascular disease

Resistin has been implicated in coronary atherosclerotic disease and congestive heart failure. Recent studies have extended its involvement in peripheral artery disease. Despite some controversial data, the mainstream clinical literature supports that resistin is associated with both coronary and peripheral artery diseases including ischemic stroke. In this review, the multiple roles of resistin as screening, diagnostic, and prognostic marker for cardiovascular disease are discussed. The independence of resistin in disease prediction and diagnosis appears complicated by its confounders, such as C-reactive protein. A clear-cut biomarker function of resistin in cardiovascular disease needs be clarified by additional large-scale, well-designed prospective studies.

[Effects of resistin on hepatic fibrosis: possible mechanisms in non-alcoholic fatty liver disease in in vitro and in vivo]

To investigate the effects and possible mechanisms of resistin on hepatic fibrosis in non-alcoholic fatty liver disease, this review used an in vivo model utilizing Wistar rats with a high fat diet. Recombinant resistin was selected to play role in hepatic stellate cells in the HSC-T6 cell line. We observed the degrees of hepatic fibrosis, measured the levels of Liver fibrosis spectrum and detected expression levels of resistin mRNA and protein in liver tissue as well as the expression levels of TGFβ-1 and TNF-α mRNA in HSC-T6. The results showed that expression of resistin in rat liver tissue and the degree of hepatic fibrosis increased over time with a high fat diet. Along with the increased concentration of resistin and levels of fibrosis index, TGFβ-1and TNF-α also increased in HSC-T6 cells. Compared with the control group, significant differences were found between each group, suggesting resistin by proinflammatory cytokine TNF-α and TGF-β1 induced the occurrence and development of NAFLD in hepatic fibrosis.

Association of resistin with heart failure and mortality in patients with stable coronary heart disease: data from the heart and soul study

BACKGROUND

Resistin is a pro-inflammatory signaling molecule that is thought to contribute to atherosclerosis. We sought to evaluate whether resistin is predictive of worse cardiovascular outcomes among ambulatory patients with stable coronary heart disease (CHD).

METHODS AND RESULTS

We measured baseline serum resistin in 980 participants with documented CHD. After a mean follow-up of 6.1 (range, 0.1 to 9.0) years, 358 (36.5%) were hospitalized for myocardial infarction or heart failure or had died. As compared with participants who had resistin levels in the lowest quartile, those with resistin levels in the highest quartile were at an increased risk of heart failure (hazard ratio [HR], 2.06; 95% confidence interval [CI], 1.26-3.39) and death (HR, 1.56; 95% CI, 1.11-2.18), adjusted for age, sex, and race. Further adjustments for obesity, hypertension, insulin resistance, dyslipidemia, and renal dysfunction eliminated these associations. Resistin levels were not associated with an increased risk of non-fatal myocardial infarction (unadjusted HR, 1.18; 95% CI, 0.68-2.05).

CONCLUSIONS

Elevated serum resistin is associated with higher rates of mortality and hospitalization for heart failure. However, this appears to be explained by the association of resistin with traditional measures of cardiovascular risk. Thus, serum resistin does not add prognostic information among high-risk persons with established CHD.

Resistin levels in lupus and associations with disease-specific measures, insulin resistance, and coronary calcification

OBJECTIVE

To evaluate levels of resistin in female subjects with systemic lupus erythematosus (SLE) compared to age and race-matched controls and to determine the relationship between resistin and systemic inflammation, disease measures, and coronary artery calcification (CAC).

METHODS

Resistin levels were measured on stored samples from 159 women with SLE and 70 controls as an extension of a previous cross-sectional study. Spearman correlations and multivariable regressions were used to examine whether resistin levels were associated with SLE, disease-specific and inflammatory markers, insulin resistance, and CAC.

RESULTS

In a multivariable linear regression model, a diagnosis of SLE was significantly associated with higher resistin levels independent of age, race, renal function, body mass index (BMI), high-sensitivity CRP (hsCRP), hypertension, diabetes, and steroid use. In SLE, resistin levels correlated positively with Systemic Lupus International Collaborating Clinics Damage Index, glomerular filtration rate (GFR), hsCRP, erythrocyte sedimentation rate, homocysteine, and disease duration (all p < 0.03). Resistin level did not correlate with markers of insulin resistance or body adiposity, including homeostatic model assessment or BMI. Resistin levels were significantly elevated in SLE cases with CAC compared to cases without CAC (16.58 vs 13.10 ng/ml, respectively; p = 0.04). In multivariate logistic regression, the association was not present after adjustment for age, race, and GFR.

CONCLUSION

SLE was independently associated with higher resistin levels. Among subjects with SLE, higher resistin level correlated positively with renal dysfunction, inflammatory markers, and disease damage but not with insulin resistance or BMI. SLE cases with CAC had higher resistin levels than cases without CAC; however, this relationship was dependent on other established risk factors.

Association of adiponectin, resistin, and vascular inflammation: analysis with 18F-fluorodeoxyglucose positron emission tomography

OBJECTIVE

Adiponectin and resistin are adipokines that are linked to obesity, inflammation, and atherosclerosis. (18)F-Fluorodeoxyglucose (FDG) positron emission tomography is a promising imaging technique that can be used to evaluate vascular inflammation.

METHODS AND RESULTS

We measured adiponectin and resistin levels, as well as traditional cardiovascular risk factors, in 60 obese subjects and 60 nonobese controls. In addition, we compared carotid intima-media thickness and target-to-background ratio (TBR) measured using (18)F-fluorodeoxyglucose-positron emission tomography/computed tomography. The mean TBR values were significantly higher in the obese group compared with normal subjects, although their mean carotid intima-media thickness levels were not significantly different. Serum adiponectin levels showed a significant negative correlation with mean TBR values (r = -0.215, P = 0.020), whereas resistin levels were positively correlated with mean TBR values (r = 0.214, P = 0.021). Multiple linear regression analysis showed that mean TBR values were independently associated with body mass index, high-sensitivity C-reactive protein, and resistin levels (R(2) = 0.308).

CONCLUSIONS

Adiponectin and resistin may be useful as biomarkers to reflect vascular inflammation. In particular, resistin levels were independently associated with vascular inflammation even after adjusting for other cardiovascular risk factors.

Resistin contributes to neointimal formation via oxidative stress after vascular injury

Resistin may play a major potential role in vascular remodelling and may contribute to atherogenesis. However, the role of VSMC (vascular smooth muscle cell)-derived resistin in neointimal formation is not well understood. We hypothesize that endogenous resistin derived from VSMCs may contribute to neointimal formation after vascular injury. VSMCs from thoracic aorta of adult Wistar rats were cultured. The carotid artery from adult Wistar rats was injured by balloon catheter. Resistin significantly increased migration and proliferation of VSMCs. Resistin siRNA (small interfering RNA) and resistin antibody significantly inhibited migration and proliferation of VSMCs induced by conditioned medium from stretched VSMCs. Resistin protein and mRNA expression significantly increased at 14 days after carotid injury. Resistin siRNA and NAC (N-acetylcysteine) significantly reduced resistin protein and mRNA expression induced by balloon injury. Carotid artery injury increased ROS (reactive oxygen species) production. Treatment with NAC and resistin siRNA decreased ROS production. The neointimal area was significantly increased after carotid injury and was significantly reduced by resistin siRNA and NAC. In conclusion, resistin increases migration and proliferation of VSMCs, and expression of resistin in carotid artery significantly increases after injury. Resistin siRNA attenuates neointimal formation after carotid injury partly through an antioxidative mechanism. Resistin may play a pivotal role in the pathogenesis of neointimal thickening after mechanical injury.

Whole blood transcriptomics in cardiac surgery identifies a gene regulatory network connecting ischemia reperfusion with systemic inflammation

Background

Cardiac surgery with cardiopulmonary bypass (CS/CPB) is associated with increased risk for postoperative complications causing substantial morbidity and mortality. To identify the molecular mechanisms underlying CS/CPB-induced pathophysiology we employed an integrative systems biology approach using the whole blood transcriptome as the sentinel organ.

Methodology/Principal Findings

Total RNA was isolated and globin mRNA depleted from whole blood samples prospectively collected from 10 patients at time points prior (0), 2 and 24 hours following CS/CPB. Genome-wide transcriptional analysis revealed differential expression of 610 genes after CS/CPB (p<0.01). Among the 375 CS/CPB-upregulated genes, we found a gene-regulatory network consisting of 50 genes, reminiscent of activation of a coordinated genetic program triggered by CS/CPB. Intriguingly, the highly connected hub nodes of the identified network included key sensors of ischemia-reperfusion (HIF-1alpha and C/EBPbeta). Activation of this network initiated a concerted inflammatory response via upregulation of TLR-4/5, IL1R2/IL1RAP, IL6, IL18/IL18R1/IL18RAP, MMP9, HGF/HGFR, CalgranulinA/B, and coagulation factors F5/F12 among others. Differential regulation of 13 candidate genes including novel, not hitherto CS/CBP-associated genes, such as PTX3, PGK1 and Resistin, was confirmed using real-time quantitative RT-PCR. In support of the mRNA data, differential expression of MMP9, MIP1alpha and MIP1beta plasma proteins was further confirmed in 34 additional patients.

Conclusions

Analysis of blood transcriptome uncovered critical signaling pathways governing the CS/CPB-induced pathophysiology. The molecular signaling underlying ischemia reperfusion and inflammatory response is highly intertwined and includes pro-inflammatory as well as cardioprotective elements. The herein identified candidate genes and pathways may provide promising prognostic biomarker and therapeutic targets.

Resistin decreases expression of endothelial nitric oxide synthase through oxidative stress in human coronary artery endothelial cells

Resistin is a newly discovered adipocyte-derived cytokine that may play an important role in insulin resistance, diabetes, adipogenesis, inflammation, and cardiovascular disease. However, it is largely unknown whether resistin impairs endothelial functions by affecting the endothelial nitric oxide synthase (eNOS) system. In this study, we determined the effect of human recombinant resistin protein on eNOS expression and regulation in human coronary artery endothelial cells (HCAECs). When cells were treated with clinically relevant concentrations of resistin (40 or 80 ng/ml) for 24 h, the levels of eNOS mRNA, protein, and activity and eNOS mRNA stability were significantly reduced. Cellular nitric oxide levels were also decreased. In addition, the cellular levels of reactive oxygen species (ROS), including superoxide anion, were significantly increased in resistin-treated HCAECs. Mitochondrial membrane potential and the activities of catalase and superoxide dismutase were reduced. Three antioxidants, seleno-L-methionine, ginsenoside Rb1, and MnTBAP (superoxide dismutase mimetic), effectively blocked resistin-induced eNOS downregulation. Meanwhile, resistin activated the mitogen-activated protein kinases p38 and c-Jun NH(2)-terminal kinase (JNK), and the specific p38 inhibitor SB-239063 effectively blocked resistin-induced ROS production and eNOS downregulation. Furthermore, immunoreactivity of resistin was increased in atherosclerotic regions of human aorta and carotid arteries. Thus resistin directly induces eNOS downregulation through overproduction of ROS and activation of p38 and JNK in HCAECs. Resistin-induced mitochondrial dysfunction and imbalance in cellular redox enzymes may be the underlying mechanisms of oxidative stress.

Increased expression and secretion of resistin in epicardial adipose tissue of patients with acute coronary syndrome

The purpose of this study was to test the hypothesis that specific epicardial adipose tissue (EAT) proinflammatory adipokines might be implicated in acute coronary syndrome (ACS). We compared expression and protein secretion of several EAT adipokines of male ACS with those of matched stable coronary artery disease (CAD) patients and controls with angiographically normal coronary arteries. The effect of supernatant of cultured EAT on endothelial cell permeability in vitro was also evaluated in the three study groups. EAT of ACS patients showed significantly higher gene expression and protein secretion of resistin than patients with stable CAD. Interleukin-6, plasminogen activator inhibitor-1, and monocyte chemoattractant protein-1 genes were also significantly overexpressed in ACS compared with the control group but not when compared with stable CAD. Immunofluorescence of EAT sections revealed a significantly greater number of CD68(+) cells in ACS patients than stable CAD and control groups. The permeability of endothelial cells in vitro was significantly increased after exposure to supernatant of cultured EAT from ACS, but not control or stable CAD groups, and this effect was normalized by anti-resistin antiserum. We found that EAT of patients with ACS is characterized by increased expression and secretion of resistin and associated with increased in vitro endothelial cell permeability.

Circulating adiponectin level is associated with major adverse cardiovascular events in type 2 diabetic patients with coronary artery disease

Elevated levels of circulating adiponectin (ADPN), an anti- inflammatory and anti-oxidative peptide, are associated with unfavorable cardiovascular outcomes in patients with cardiovascular diseases. The aim of this study was to investigate whether plasma ADPN levels could help predict major adverse cardiovascular events (MACE) in patients with documented coronary artery disease (CAD). We prospectively enrolled 193 CAD patients, who underwent percutaneous coronary intervention (PCI), and/or stenting and coronary artery bypass graft (CABG) surgery. ELISA was used to measure plasma ADPN concentrations. MACE--myocardial infarction, PCI, CABG, stroke, carotid revascularization, and death--was evaluated during a follow-up period of median 15.3 months (range 5-21 months). Cox regression analysis revealed that diabetes status, waist circumference, and plasma ADPN levels were significantly associated with MACE occurrence. On stratification according to diabetes status, plasma ADPN levels helped predict MACE only in patients with type 2 diabetes mellitus (T2DM). Kaplan-Meier analysis revealed higher MACE rates in diabetic patients with high-plasma ADPN levels than in those with low-plasma ADPN levels. High ADPN plasma concentrations can independently be associated with MACE in CAD with T2DM but not in those without diabetes. This indicates that plasma ADPN may have potential roles in high risk T2DM patients with ischemic heart disease.

Elevated serum PTH is independently associated with poor outcomes in older patients with hip fracture and vitamin D inadequacy

To determine whether serum 25(OH)D and/or PTH levels in older patients with hip fracture (HF) could predict short-term clinical outcomes, we conducted a prospective observational study of 287 consecutive HF patients (mean age 81.9 + or - 7.5 [SD] years, 72% females). The prevalence of vitamin D inadequacy (25[OH]D < 80 nmol/l) was 97.1%, that of vitamin D deficiency (25[OH]D < 50 nmol/l) was 79.8%, and that of elevated PTH level (>6.8 pmol/l) was 35.5%. After adjustment for age and sex, PTH was significantly associated with in-hospital mortality (OR = 1.12, 95% CI 10.5-1.20, P < 0.001), myocardial injury (OR = 1.05, 95% CI 1.03-1.15, P = 0.002), prolonged length of stay (LOS > or = 20 days; OR = 1.05, 95% CI 1.01-1.06, P = 0.044), and being discharged to institutional care (OR = 1.07, 95% CI 1.01-1.18, P = 0.48). Secondary hyperparathyroidism (SHPT), but not vitamin D deficiency, was associated with older age, a higher prevalence of trochanteric fracture, coronary artery disease, hypertension, previous stroke, renal impairment, increased levels of serum osteocalcin, bone-specific alkaline phosphatase, and adiponectin as well as a significantly higher in-hospital mortality (11.8 vs. 0.54%, P = 0.001), perioperative myocardial injury (32.7 vs. 22.5%, P = 0.043), LOS > or = 20 days (40.2 vs. 26.9%, P = 0.017), and being discharged to institutional care (29.5 vs. 14.6%, P = 0.019). In multivariate regression analyses, SHPT was strongly associated with in-hospital mortality and LOS > or = 20 days. We conclude that elevated PTH (but not vitamin D deficiency per se) is a strong independent predictor of poor outcomes in older patients.