Association of Hyperadiponectinemia With Severity of Ventricular Dysfunction in Congestive Heart Failure

Targeting Adiponectin Receptor 1 Phosphorylation Against Ischemic Heart Failure

BACKGROUND

Despite significantly reduced acute myocardial infarction (MI) mortality in recent years, ischemic heart failure continues to escalate. Therapeutic interventions effectively reversing pathological remodeling are an urgent unmet medical need. We recently demonstrated that AdipoR1 (APN [adiponectin] receptor 1) phosphorylation by GRK2 (G-protein-coupled receptor kinase 2) contributes to maladaptive remodeling in the ischemic heart. The current study clarified the underlying mechanisms leading to AdipoR1 phosphorylative desensitization and investigated whether blocking AdipoR1 phosphorylation may restore its protective signaling, reversing post-MI remodeling.

METHODS

Specific sites and underlying molecular mechanisms responsible for AdipoR1 phosphorylative desensitization were investigated in vitro (neonatal and adult cardiomyocytes). The effects of AdipoR1 phosphorylation inhibition upon APN post-MI remodeling and heart failure progression were investigated in vivo.

RESULTS

Among 4 previously identified sites sensitive to GRK2 phosphorylation, alanine substitution of Ser²⁰⁵ (AdipoR1^S205A), but not other 3 sites, rescued GRK2-suppressed AdipoR1 functions, restoring APN-induced cell salvage kinase activation and reducing oxidative cell death. The molecular investigation followed by functional determination demonstrated that AdipoR1 phosphorylation promoted clathrin-dependent (not caveolae) endocytosis and lysosomal-mediated (not proteasome) degradation, reducing AdipoR1 protein level and suppressing AdipoR1-mediated cytoprotective action. GRK2-induced AdipoR1 endocytosis and degradation were blocked by AdipoR1^S205A overexpression. Moreover, AdipoR1^S205E (pseudophosphorylation) phenocopied GRK2 effects, promoted AdipoR1 endocytosis and degradation, and inhibited AdipoR1 biological function. Most importantly, AdipoR1 function was preserved during heart failure development in AdipoR1-KO (AdipoR1 knockout) mice reexpressing hAdipoR1^S205A. APN administration in the failing heart reversed post-MI remodeling and improved cardiac function. However, reexpressing hAdipoR1^WT in AdipoR1-KO mice failed to restore APN cardioprotection.

CONCLUSIONS

Ser²⁰⁵ is responsible for AdipoR1 phosphorylative desensitization in the failing heart. Blockade of AdipoR1 phosphorylation followed by pharmacological APN administration is a novel therapy effective in reversing post-MI remodeling and mitigating heart failure progression.

Fenofibrate attenuates doxorubicin-induced cardiac dysfunction in mice via activating the eNOS/EPC pathway

Endothelial progenitor cells (EPCs) improve endothelial impairment, which in turn restores endothelial function in patients with heart failure (HF). In the present study, we tested whether fenofibrate, with its anti-inflammatory and vasoprotective effects, could improve myocardial function by activating EPCs through the eNOS pathway in a doxorubicin (DOX)-induced cardiomyopathy mouse model. Wild-type mice were divided into 4 groups and treated with vehicle, DOX + saline, DOX + fenofibrate, and DOX + fenofibrate + L-NAME (N(ω)-nitro-L-arginine methyl ester). DOX-induced cardiac atrophy, myocardial dysfunction, the number of circulating EPCs and tissue inflammation were analyzed. Mice in the DOX + fenofibrate group had more circulating EPCs than those in the DOX + saline group (2% versus 0.5% of total events, respectively) after 4 weeks of treatment with fenofibrate. In addition, the inhibition of eNOS by L-NAME in vivo further abolished the fenofibrate-induced suppression of DOX-induced cardiotoxic effects. Protein assays revealed that, after DOX treatment, the differential expression of MMP-2 (matrix metalloproteinase-2), MMP-9 (matrix metalloproteinase-9), TNF-α (tumor necrosis factor-α), and NT-pro-BNP (N-terminal pro-B-type natriuretic peptide) between saline- and DOX-treated mice was involved in the progression of HF. Mechanistically, fenofibrate promotes Akt/eNOS and VEGF (vascular endothelial growth factor), which results in the activation of EPC pathways, thereby ameliorating DOX-induced cardiac toxicity.

Association of plasma adiponectin with pulmonary hypertension, mortality and heart failure in African Americans: Jackson Heart Study

Background

Adiponectin is a polypeptide hormone related to obesity, and a known modulator of pulmonary vascular remodeling. Association between plasma adiponectin levels and pulmonary hypertension (PH) has not been studied in African Americans (AAs) who are disproportionately affected by obesity. The relationship between adiponectin and heart failure (HF) and mortality, outcomes associated with PH, is unclear.

Methods

We performed cross-sectional and longitudinal analysis to examine if there is an association between plasma adiponectin and PH and associated clinical outcomes, in participants of Jackson Heart Study (JHS). JHS is a prospective observational cohort study of heart disease in AAs from Jackson, Mississippi.

Results

Of the 3161 participants included in the study, mean age (SD) was 56.38 (12.61) years, 1028 were men (32.5%), and mean (SD) BMI was 31.42 (7.05) kg/m². Median (IQR) adiponectin was 4516.82 (2799.32–7065.85) ng/mL. After adjusting for potential confounders including BMI, higher adiponectin levels were associated with increased odds of PH (adjusted odds ratio per log increment in adiponectin, (1.81; 95% CI, 1.41–2.32). High adiponectin levels were also associated with associated HF admissions (adjusted hazard ratio [HR] per log increment in adiponectin, 1.63, 95% CI, 1.24–2.14) and mortality (adjusted HR per log increment in adiponectin, 1.20; 95% CI 1.02–1.41).

Conclusions

Elevated plasma adiponectin levels are associated with PH, HF admissions and mortality risk in AAs. High adiponectin levels may help identify an at-risk population that could be evaluated for targeted prevention and management strategies in future studies

Insights Into the Controversial Aspects of Adiponectin in Cardiometabolic Disorders

In 2016, the World Health Organization estimated that more than 1.9 billion adults were overweight or obese. This impressive number shows that weight excess is pandemic. Overweight and obesity are closely associated with a high risk of comorbidities, such as insulin resistance and its most important outcomes, including metabolic syndrome, type 2 diabetes mellitus, and cardiovascular disease. Adiponectin has emerged as a salutary adipocytokine, with insulin-sensitizing, anti-inflammatory, and cardiovascular protective properties. However, under metabolically unfavorable conditions, visceral adipose tissue-derived inflammatory cytokines might reduce the transcription of the adiponectin gene and consequently its circulating levels. Low circulating levels of adiponectin are negatively associated with various conditions, such as insulin resistance, type 2 diabetes mellitus, metabolic syndrome, and cardiovascular disease. In contrast, several recent clinical trials and meta-analyses have reported high circulating adiponectin levels positively associated with cardiovascular mortality and all-cause mortality. These results are biologically intriguing and counterintuitive, and came to be termed "the adiponectin paradox". Adiponectin paradox is frequently associated with adiponectin resistance, a concept related with the downregulation of adiponectin receptors in insulin-resistant states. We review this contradiction between the apparent role of adiponectin as a health promoter and the recent evidence from Mendelian randomization studies indicating that circulating adiponectin levels are an unexpected predictor of increased morbidity and mortality rates in several clinical conditions. We also critically review the therapeutic perspective of synthetic peptide adiponectin receptors agonist that has been postulated as a promising alternative for the treatment of metabolic syndrome and type 2 diabetes mellitus.

Adiponectin in heart failure

The adipose tissue, apart from storing energy, plays a role of an endocrine organ. One of the most important adipokines secreted by adipose tissue is adiponectin, which is also produced by cardiomyocytes and connective tissue cells within the heart. Adiponectin is known for its beneficial effect on the metabolism and cardiovascular system and its low level is a factor of development of many cardiovascular diseases. Paradoxically, in the course of heart failure, adiponectin level gradually increases with the severity of the disease and higher adiponectin level is a factor of poor prognosis. As a result, there is a growing interest in adiponectin as a marker of heart failure progression and a predictor of prognosis in the course of this disease.

Synergistic anti-atherosclerotic role of combined treatment of omega-3 and co-enzyme Q10 in hypercholesterolemia-induced obese rats

Hypercholesterolemia is a metabolic disorder associated with atherosclerosis. This study aimed to investigate the effects of omega-3 and/or coenzyme Q10 (CoQ10) on hypercholesterolemia-induced atherosclerosis. Rats were divided into five groups; (1): served as the negative control, (2): served as hypercholesterolemic (HC) control, (3): HC-rats administrated omega-3 orally, (4): HC-rats administrated CoQ10 orally, and (5): HC-rats administered the combination treatment of both omega-3 and CoQ10. Lipid profile was assayed and cardiovascular risk indices were calculated. Serum levels of Adiponectin (APN) and creatine kinase (CK-MB) were determined using ELISA. Besides, oxidative stress markers, malondialdehyde (MDA), nitric oxide (NO) and glutathione (GSH) were assayed in the heart homogenate. Histopathological investigation of the aortae and heart tissues were investigated. The results revealed that atherogenic HC-rats demonstrated a significant elevation in lipid profiles, except for HDL-C, along with decreased levels of APN, but increased CK-MB activities. Hypercholesterolemia increased lipid peroxidation, reduced NO production, and decreased GSH content in the cardiac tissue. Treatment of atherogenic HC-rats with omega-3 and/or CoQ10 improved dyslipidemia and ameliorated most of the HC-induced biochemical and histopathological changes. The histological observations of aortae and cardiac tissues validated our biochemical results. We concluded that the combined treatment of nutraceuticals such as omega-3 and CoQ10 demonstrated the best outcome, demonstrating their anti-hyperlipidemic, cardioprotective, and atheroprotective potentials. Together, this study supports a beneficial role of dietary co-administration of omega-3 and CoQ10 in obese patients who are prone to develop cardiovascular disorders.

The Role of Cardiac T-Cadherin in the Indicating Heart Failure Severity of Patients with Non-Ischemic Dilated Cardiomyopathy

Background and objectives: T-cadherin (T-cad) is one of the adiponectin receptors abundantly expressed in the heart and blood vessels. Experimental studies show that T-cad sequesters adiponectin in cardiovascular tissues and is critical for adiponectin-mediated cardio-protection. However, there are no data connecting cardiac T-cad levels with human chronic heart failure (HF). The aim of this study was to assess whether myocardial T-cad concentration is associated with chronic HF severity and whether the T-cad levels in human heart tissue might predict outcomes in patients with non-ischemic dilated cardiomyopathy (NI-DCM). Materials and Methods: 29 patients with chronic NI-DCM and advanced HF were enrolled. Patients underwent regular laboratory investigations, echocardiography, coronary angiography, and right heart catheterization. TNF-α and IL6 in serum were detected by enzyme-linked immunosorbent assay (ELISA). Additionally, endomyocardial biopsies were obtained, and the levels of T-cad were assessed by ELISA and CD3, CD45Ro, CD68, and CD4- immunohistochemically. Mean pulmonary capillary wedge pressure (PCWP) was used as a marker of HF severity, subdividing patients into two groups: mean PCWP > 19 mmHg vs. mean PCWP < 19 mmHg. Patients were followed-up for 5 years. The study outcome was composite: left ventricular assist device implantation, heart transplantation, or death from cardiovascular causes. Results: T-cad shows an inverse correlation with the mean PCWP (rho = −0.397, p = 0.037). There is a tendency towards a lower T-cad concentration in patients with more severe HF, as indicated by the mean PCWP > 19 mmHg compared to those with mean PCWP ≤ 19 mmHg (p = 0.058). Cardiac T-cad levels correlate negatively with myocardial CD3 cell count (rho = −0.423, p = 0.028). Conclusions: Univariate Cox regression analysis did not prove T-cad to be an outcome predictor (HR = 1, p = 0.349). However, decreased T-cad levels in human myocardium can be an additional indicator of HF severity. T-cad in human myocardium has an anti-inflammatory role. More studies are needed to extend the role of T-cad in the outcome prediction of patients with NI-DCM.

Association between elevated adiponectin level and adverse outcomes in patients with heart failure: a systematic review and meta-analysis

Studies regarding the prognostic value of circulating adiponectin level in patients with heart failure are conflicting. The aim of this meta-analysis was to evaluate the association between elevated circulating adiponectin level and adverse outcomes in patients with heart failure. We searched PubMed and Embase databases from their inception to June 2018. Original observational studies that investigated the prognostic value of adiponectin in heart failure patients and reported all-cause mortality or combined endpoints of death/readmission as outcome measure were included. Pooled risk ratio (RR) with 95% confidence intervals (CI) were estimated by higher versus lower circulating adiponectin level. A total of 7 studies involving 862 heart failure patients were identified. Meta-analysis showed that heart failure patients with higher adiponectin level had significantly increased risk of all-cause mortality (RR 2.05; 95%CI 1.22–3.43) after adjustment for potential confounders. In addition, higher adiponectin level was associated with an increased risk of the combined endpoints of death/readmission (RR 2.22; 95%CI 1.38–3.57). Elevated baseline circulating adiponectin level is possibly associated with an increased risk of all-cause mortality and the combined endpoints of death/readmission in patients with heart failure. Determination of circulating adiponectin level has potential to improve risk stratification in heart failure patients.

The evolving role of adiponectin as an additive biomarker in HFrEF

Heart failure (HF) is a growing health problem. Despite improved management and outcome, the number of patients with HF is expected to keep rising in the following years. In recent research, adiponectin was shown to exert beneficial effects in the cardiovascular system, but the protein was also implicated in the development and progression of HF. The objective of this review is to provide an overview of current knowledge on the role of adiponectin in HF with reduced ejection fraction. We discuss the cardioprotective and (anti-) inflammatory actions of adiponectin and its potential use in clinical diagnosis and prognosis.

Nutrients restriction upregulates adiponectin in epicardial or subcutaneous adipose tissue: impact in de novo heart failure patients

Background: Hyperadiponectinemia is an indicator of worse outcomes in advanced heart failure (HF), its role in de novo HF is less clear. Objective: Because this protein is a hormone with starvation properties, we wanted to know its association with nutritional state and its regulator factors in de novo HF. Methods: Adiponectin circulating levels were determined by ELISA at discharge in patients admitted for de novo HF (n=74). Nutritional status was determined by CONUT score. Univariate and multivariate Cox regression analyses were employed to calculate the estimated hazard ratio (HR) with 95% confidence interval (CI) for death or all-cause readmission. Stromal vascular cells (SVC) of EAT and subcutaneous adipose tissue (SAT) from patients (n=5) underwent heart surgery were induced to adipogenesis for 18 days. Then, cells were cultured with complete or starved medium for 8 hours. At the end, adiponectin expression levels were analysed by real time polymerase chain reaction. Results: Patients were grouped regarding nutritional status. There was a strong association between high adiponectin levels and failing nutritional status. Those patients with worse nutritional state had the highest adiponectin and proBNP levels at discharge (p<0.01). Both proteins were slightly correlated (p<0.05). However, only high adiponectin levels were independently associated with death or all-cause readmission. Nutrients starvation upregulated adiponectin expression levels in adipogenesis-induced SVC from EAT or SAT. Conclusions: Worse nutritional state in de novo HF patients is associated with higher adiponectin plasma levels. Their levels were upregulated in adipose cells after being nutrients-starved. These results may help us to understand the adiponectin paradox in HF.

The Role of Serum Adiponectin for Outcome Prediction in Patients with Dilated Cardiomyopathy and Advanced Heart Failure

Clinical interpretation of patients' plasma adiponectin (APN) remains challenging; its value as biomarker in dilated cardiomyopathy (DCM) is equivocal. We evaluated whether circulating APN level is an independent predictor of composite outcome: death, left ventricle assist device (LVAD) implantation, and heart transplantation (HT) in patients with nonischemic DCM. 57 patients with nonischemic DCM (average LV diastolic diameter 6.85 cm, LV ejection fraction 26.63%, and pulmonary capillary wedge pressure 22.06  mmHg) were enrolled. Patients underwent echocardiography, right heart catheterization, and endomyocardial biopsy. During a mean follow-up of 33.42 months, 15 (26%) patients died, 12 (21%) patients underwent HT, and 8 (14%) patients were implanted with LVAD. APN level was significantly higher in patients who experienced study endpoints (23.4 versus 10.9 ug/ml, p = 0.01). APN was associated with worse outcome in univariate Cox proportional hazards model (HR 1.04, CI 1.02-1.07, p = 0.001) but lost significance adjusting for other covariates. Average global strain (AGS) is an independent outcome predictor (HR 1.42, CI 1.081-1.866, p = 0.012). Increased circulating APN level was associated with higher mortality and may be an additive prognostic marker in DCM with advanced HF. Combination of serum (APN, BNP, TNF-α) and echocardiographic (AGS) markers may increase the HF predicting power for the nonischemic DCM patients.

Health Benefits of Fasting and Caloric Restriction

PURPOSE OF REVIEW

Obesity and obesity-related diseases, largely resulting from urbanization and behavioral changes, are now of global importance. Energy restriction, though, is associated with health improvements and increased longevity. We review some important mechanisms related to calorie limitation aimed at controlling of metabolic diseases, particularly diabetes.

RECENT FINDINGS

Calorie restriction triggers a complex series of intricate events, including activation of cellular stress response elements, improved autophagy, modification of apoptosis, and alteration in hormonal balance. Intermittent fasting is not only more acceptable to patients, but it also prevents some of the adverse effects of chronic calorie restriction, especially malnutrition. There are many somatic and potentially psychologic benefits of fasting or intermittent calorie restriction. However, some behavioral modifications related to abstinence of binge eating following a fasting period are crucial in maintaining the desired favorable outcomes.

Potential novel biomarkers of cardiovascular dysfunction and disease: cardiotrophin-1, adipokines and galectin-3

Cardiovascular disease is one of the main burdens of healthcare systems worldwide. Nevertheless, assessing cardiovascular risk in both apparently healthy individuals and low/high-risk patients remains a difficult issue. Already established biomarkers (e.g. brain natriuretic peptide, troponin) have significantly improved the assessment of major cardiovascular events and diseases but cannot be applied to all patients and in some cases do not provide sufficiently accurate information. In this context, new potential biomarkers that reflect various underlying pathophysiological cardiac and vascular modifications are needed. Also, a multiple biomarker evaluation that shows changes in the cardiovascular state is of interest. This review describes the role of selected markers of vascular inflammation, atherosclerosis, atherothrombosis, endothelial dysfunction and cardiovascular fibrosis in the pathogenesis and prognosis of cardiovascular disease: the potential use of cardiotrophin-1, leptin, adiponectin, resistin and galectin-3 as biomarkers for various cardiovascular conditions is discussed.

Adiponectin improves endothelial function in mesenteric arteries of rats fed a high-fat diet: role of perivascular adipose tissue

BACKGROUND AND PURPOSE

Adiponectin, the most abundant peptide secreted by adipocytes, is involved in the regulation of energy metabolism and vascular physiology. Here, we have investigated the effects of exogenous administration of adiponectin on metabolism, vascular reactivity and perivascular adipose tissue (PVAT) of mesenteric arteries in Wistar rats fed a high-fat diet.

EXPERIMENTAL APPROACH

The effects of adiponectin on NO-dependent and independent vasorelaxation were investigated in isolated mesenteric arteries from 12-month-old male Wistar rats (W12m) fed a high-fat diet (HFD) for 4 months and compared with those from age-matched rats given a control diet. Adiponectin ((96 μg·day^-1 ) was administered by continuous infusion with a minipump, implanted subcutaneously, for 28 days.

KEY RESULTS

Chronic adiponectin treatment reduced body weight, total cholesterol, free fatty acids, fasting glucose and area under the curve of intraperitoneal glucose tolerance test, compared with HFD rats. It also normalized NO-dependent vasorelaxation increasing endothelial NO synthase (eNOS) phosphorylation in mesenteric arteries of HFD rats. In PVAT from aged (W12m) and HFD rats there was increased expression of chemokines and pro-inflammatory adipokines, the latter being important contributors to endothelial dysfunction. Infusion of adiponectin reduced these changes.

CONCLUSIONS AND IMPLICATIONS

Adiponectin normalized endothelial cell function by a mechanism that involved increased eNOS phoshorylation and decreased PVAT inflammation. Detailed characterization of the adiponectin signalling pathway in the vasculature and perivascular fat is likely to provide novel approaches to the management of atherosclerosis and metabolic disease.

LINKED ARTICLES

This article is part of a themed section on Molecular Mechanisms Regulating Perivascular Adipose Tissue - Potential Pharmacological Targets? To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v174.20/issuetoc.

Pleiotropic effects of niacin: Current possibilities for its clinical use

Niacin was the first hypolipidemic drug to significantly reduce both major cardiovascular events and mortality in patients with cardiovascular disease. Niacin favorably influences all lipoprotein classes, including lipoprotein[a],and belongs to the most potent hypolipidemic drugs for increasing HDL-C. Moreover, niacin causes favorable changes to the qualitative composition of lipoprotein HDL. In addition to its pronounced hypolipidemic action, niacin exerts many other, non-hypolipidemic effects (e.g., antioxidative, anti-inflammatory, antithrombotic), which favorably influence the development and progression of atherosclerosis. These effects are dependent on activation of the specific receptor HCA2. Recent results published by the two large clinical studies, AIM-HIGH and HPS2-THRIVE, have led to the impugnation of niacin's role in future clinical practice. However, due to several methodological flaws in the AIM-HIGH and HPS2-THRIVE studies, the pleiotropic effects of niacin now deserve thorough evaluation. This review summarizes the present and possible future use of niacin in clinical practice in light of its newly recognized pleiotropic effects.

Prognostic value of adiponectin in coronary artery disease: Role of diabetes and left ventricular systolic dysfunction

OBJECTIVES

Adiponectin (AD) promotes insulin sensitivity and has anti-atherogenic properties. However, the role of AD on clinical outcomes in coronary artery disease (CAD) is controversial. We analyzed whether AD was an independent predictor of all-cause mortality and hospitalization in patients with CAD.

METHOD

We prospectively enrolled 138 patients with stable CAD, with or without type 2 diabetes and with or without left ventricular dysfunction. A telephone follow-up was conducted to register long term outcomes. Sensitivity/specificity ratio for AD was investigated with ROC analysis and the independent role of AD on outcome was evaluated with Cox regression model of analysis. The survival rate was represented by Kaplan Meyer curves.

RESULTS

Of 138 patients, 61 had type 2 diabetes and 71 left ventricular systolic dysfunction (EF<40%). Median time of follow-up was 1384days; mortality rate was 18.8% (26 deaths) and hospitalization rate was 47.1% (65 events). Mean concentration of AD was 9.87±7.53ng/ml; the analysis of the ROC curve identified an AD cut-off level of 13.2ng/ml (AUC 0.779; p<0.0001). Patients with AD >13.2ng/ml had a significantly higher risk of death (HR=6.50; 95% CI: 2.40-17.70), but not of cardiovascular hospitalization (HR=0.87; 95% CI: 0.31-2.44). AD predictivity remained significant also in patients with type 2 diabetes and with left ventricular systolic dysfunction.

CONCLUSION

In stable CAD, an AD value of >13.2ng/ml independently predicts a 6-fold increased risk of all-cause mortality.

Adiponectin resistance in skeletal muscle: pathophysiological implications in chronic heart failure

Skeletal muscle wasting is a common complication of chronic heart failure (CHF) and linked to poor patient prognosis. In recent years, adiponectin was postulated to be centrally involved in CHF-associated metabolic failure and muscle wasting. This review discusses current knowledge on the role of adiponectin in CHF. Particular emphasis will be given to the complex interaction mechanisms and the intracellular pathways underlying adiponectin resistance in skeletal muscle of CHF patients. In this review, we propose that the resistance process is multifactorial, integrating abnormalities emanating from insulin signalling, mitochondrial biogenesis, and ceramide metabolism.

Tumor necrosis factor-α impairs adiponectin signalling, mitochondrial biogenesis, and myogenesis in primary human myotubes cultures

Skeletal muscle metabolic changes are common in patients with chronic heart failure (HF). Previously, we demonstrated a functional skeletal muscle adiponectin resistance in HF patients with reduced left ventricular ejection fraction (HFrEF). We aimed to examine the impact of adiponectin receptor 1 (AdipoR1) deficiency and TNF-α treatment on adiponectin signaling, proliferative capacity, myogenic differentiation, and mitochondrial biogenesis in primary human skeletal muscle cells. Primary cultures of myoblasts and myotubes were initiated from the musculus vastus lateralis of 10 HFrEF patients (left ventricular ejection fraction; 31.30 ± 2.89%) and 10 age- and gender-matched healthy controls. Healthy control cultures were transfected with siAdipoR1 and/or exposed to TNF-α (10 ng/ml; 72 h). Primary cultures from HFrEF patients preserved the features of adiponectin resistance in vivo. AdipoR1 mRNA was negatively correlated with time to reach maximal cell index (r = -0.7319, P = 0.003). SiRNA-mediated AdipoR1 silencing reduced pAMPK (P < 0.01), AMPK activation (P = 0.046), and myoblast proliferation rate (xCELLigence Real-Time Cellular Analysis; P < 0.0001). Moreover, TNF-α decreased the mRNA expression of genes involved in glucose (APPL1, P = 0.0002; AMPK, P = 0.021), lipid (PPARα, P = 0.025; ACADM, P = 0.003), and mitochondrial (FOXO3, P = 0.018) metabolism, impaired myogenesis (MyoD1, P = 0.053; myogenin, P = 0.048) and polarized cytokine secretion toward a growth-promoting phenotype (IL-10, IL-1β, IFN-γ, P < 0.05 for all; Meso Scale Discovery Technology). Major features of adiponectin resistance are retained in primary cultures from the skeletal muscle of HFrEF patients. In addition, our results suggest that an increased inflammatory constitution contributes to adiponectin resistance and confers alterations in skeletal muscle differentiation, growth, and function.

G-protein-coupled receptor kinase 2-mediated desensitization of adiponectin receptor 1 in failing heart

BACKGROUND

Phosphorylative desensitization of G-protein-coupled receptors contributes significantly to post-myocardial infarction (MI) remodeling and heart failure (HF). Here, we determined whether adiponectin receptors (AdipoRs) 1 and 2 (the 7-transmembrane domain-containing receptors mediating adiponectin functions) are phosphorylatively modified and functionally impaired after MI.

METHODS AND RESULTS

Post-MI HF was induced by coronary artery occlusion. Receptor phosphorylation, kinase expression, and adiponectin function were determined via in vivo, ex vivo, and in vitro models. AdipoR1 and AdipoR2 are not phosphorylated in the normal heart. However, AdipoR1 was significantly phosphorylated after MI, peaking at 7 days and remaining significantly phosphorylated thereafter. The extent of post-MI AdipoR1 phosphorylation positively correlated with the expression level of GPCR kinase (GRK) 2, the predominant GRK isoform upregulated in the failing heart. Cardiac-specific GRK2 knockout virtually abolished post-MI AdipoR1 phosphorylation, whereas virus-mediated GRK2 overexpression significantly phosphorylated AdipoR1 and blocked adiponectin metabolic-regulatory/anti-inflammatory signaling. Mass spectrometry identified serine-7, threonine-24, and threonine-53 (residues located in the n-terminal intracellular AdipoR1 region) as the GRK2 phosphorylation sites. Ex vivo experiments demonstrated that adenosine monophosphate-activated protein kinase activation and the anti-tumor necrosis factor-α effect of adiponectin were significantly inhibited in cardiomyocytes isolated from nonischemic area 7 days after MI. In vivo experiments demonstrated that acute adiponectin administration-induced cardiac GLUT4 translocation and endothelial nitric oxide synthase phosphorylation were blunted 7 days after MI. Continuous adiponectin administration beginning 7 days after MI failed to protect the heart from adverse remodeling and HF progression. Finally, cardiac-specific GRK2 knockdown restored the cardioprotective effect of adiponectin.

CONCLUSION

AdipoR1 is phosphorylatively modified and desensitized by GRK2 in failing cardiomyocytes, contributing to post-MI remodeling and HF progression.

Relationship between adiponectin, obesity and insulin resistance

Objectives: the conditions of obesity and overweight pose a major risk for a number of comorbidities, including clinical syndromes resulting from atherosclerotic disease. Recent studies strongly indicate that adipose tissue is an active endocrine organ that secretes bioactive factors such as adipokines. Adiponectin appears to have a regulatory role in the mechanism of insulin resistance and in the development of atherosclerosis. This systematic review aims to evaluate the anti-atherogenic effects of adiponectin and its properties to improve and mimic metabolic and vascular actions of insulin and its influence on endothelial function. Methods: a qualitative, exploratory and literature review was performed in the PubMed, Portal Capes and Scielo databases using as key-words "adiponectin", "obesity", "insulin resistance", "anti-inflammatory", "therapeutic strategies" and "future prospects". Results: evidence suggests that adiponectin has anti-atherogenic properties with anti-inflammatory effects on the vascular wall. Moreover, it modifies the vascular intracellular signaling and has indirect antioxidant effects on the human myocardium. On the other hand, there are studies suggesting that increased levels of adiponectin are paradoxically associated with a worse prognosis in heart failure syndrome, although the mechanisms are not clear. Conclusion: it is not clear whether adiponectin levels have any clinical significance for risk stratification in cardiovascular disease or if they simply reflect the activation of complex underlying mechanisms. Changes in lifestyle and some drug treatments for hypertension and coronary heart disease have shown significant effect to increase adiponectin levels, and simultaneously decrease in insulin resistance and endothelial dysfunction.

Significance of plasma adiponectin for diagnosis, neurological severity and functional outcome in ischemic stroke - Research for Biomarkers in Ischemic Stroke (REBIOS)

OBJECTIVE

Although adiponectin is a major adipocytokine that affects the pathogenesis of various cardiovascular diseases, its clinical significance in stroke remains controversial. We investigated the clinical significance of plasma adiponectin for the diagnosis, neurological severity and functional outcomes of patients with ischemic stroke.

METHODS

We prospectively enrolled 171 patients with ischemic stroke and 171 age- and sex-matched healthy controls. Blood samples and clinical information were obtained at day 0, 3, 7, 14 and 90 after stroke onset.

RESULTS

Average adiponectin values at day 0 did not significantly differ between the controls and the patients, but were significantly lower and higher in patients with atherothrombotic brain (ATBI) (p=0.047) and cardioembolic (CE) (p=0.008) infarction, respectively, than in the controls. Multivariate logistic regression analyses showed that the adiponectin value at day 0 could predict ATBI (odds ratio, 0.75; 95% confidence interval, 0.58 to 0.91, p=0.009, per 1-μg/mL increase). Adiponectin values at day 0 were positively associated with neurological severity as evaluated by the National Institute of Health Stroke Scale upon admission (r=0.420, p=0.003) and were higher in the groups with poor outcomes (modified Rankin Scale (mRS) ≥ 3 on day 90) than in those with good ones (mRS ≤ 2) in all stroke subtypes, with statistical significance in ATBI (p=0.015).

CONCLUSIONS

Plasma adiponectin values may help to classify stroke subtypes and predict neurological severity and functional outcome in ischemic stroke patients.

Direct effects of adipokines on the heart: focus on adiponectin

Cardiovascular disease, including heart failure, is a principal cause of death in individuals with obesity and diabetes. However, the mechanisms of obesity- and diabetes-induced heart disease are multifaceted and remain to be clearly defined. Of relevance to this review, there is currently great research and clinical interest in the endocrine effects of adipokines on the myocardium and their role in heart failure. We will discuss the potential significance of adipokines in the pathogenesis of heart failure via their ability to regulate remodeling events including metabolism, hypertrophy, fibrosis, and cell death. As an excellent example, we will first focus on adiponectin which is best known to confer numerous cardioprotective effects. However, we comprehensively discuss the existing literature that highlights it would be naive to assume that this was always the case. We also focus on lipocalin-2 which mediates pro-inflammatory and pro-apoptotic effects. It is important when studying actions of adipokines to integrate cellular and mechanistic analyses and translate these to physiologically relevant in vivo models and clinical studies. However, assimilating studies on numerous cardiac remodeling events which ultimately dictate cardiac dysfunction into a unifying conclusion is challenging. Nevertheless, there is undoubted potential for the use of adipokines as robust biomarkers and appropriate therapeutic targets in heart failure.

Should we target obesity in advanced heart failure?

OPINION STATEMENT

Obesity is a risk factor for the development of heart failure (HF), but has been associated with improved survival in patients with established HF. Weight loss should clearly be recommended and supported for obese individuals without cardiac pathology to prevent cardiomyopathy development. Clinical recommendations at the other end of the obesity heart failure spectrum are also relatively clear. Morbidly obese individuals (BMI ≥ 40 kg/m(2)) aged <50 years with severely depressed systolic function and NYHA class III-IV symptoms should be considered for malabsorptive bariatric surgery at an experienced center. The goal is either improved systolic function and symptoms, or sufficient weight loss for heart transplant eligibility. Recommendations for patients falling between these extremes are more challenging. Overweight and mildly obese HF patients (25-35 kg/m(2)) may be somewhat protected from cardiac cachexia and weight loss is not expected to enhance survival, but may offer symptomatic benefits.

Adiponectin as a routine clinical biomarker

Adiponectin is a protein synthesized and secreted predominantly by adipocytes into the peripheral blood. However, circulating adiponectin level is inversely related with body weight, especially visceral fat accumulation. The mechanism of this paradoxical relation remains obscure. Low circulating adiponectin concentrations (hypoadiponectinemia; <4 μg/mL) are associated with a variety of diseases, including dysmetabolism (type 2 diabetes, insulin resistance, hypertension, dyslipidemia, metabolic syndrome, hyperuricemia), atherosclerosis (coronary artery disease, stroke, peripheral artery disease), sleep apnea, non-alcoholic fatty liver disease, gastritis and gastro-esophageal reflux disease, inflammatory bowel diseases, pancreatitis, osteoporosis, and cancer (endometrial cancer, postmenopausal breast cancer, leukemia, colon cancer, gastric cancer, prostate cancer). On the other hand, hyperadiponectinemia is associated with cardiac, renal and pulmonary diseases. This review article focuses on the significance of adiponectin as a clinical biomarker of obesity-related diseases. Routine measurement of adiponectin in patients with lifestyle-related diseases is highly recommended.

Plasma adiponectin in heart failure with and without cachexia: catabolic signal linking catabolism, symptomatic status, and prognosis

BACKGROUND AND AIMS

Adiponectin (ADPN) as an adipose tissue hormone contributes to regulation of energy metabolism and body composition and is associated with cardiovascular risk profile parameters. Cardiac cachexia may develop as a result of severe catabolic derangement in chronic heart failure (CHF). We aimed to determinate an abnormal ADPN regulation as a link between catabolic signalling, symptomatic deterioration and poor prognosis.

METHODS AND RESULTS

We measured plasma ADPN in 111 CHF patients (age 65 ± 11, 90% male, left ventricular ejection fraction (LVEF) 36 ± 11%, peak oxygen consumption (peakVO2) 18.1 ± 5.7 l/kg*min, body mass index (BMI) 27 ± 4 kg/m(2), all mean ± standard deviation) and 36 healthy controls of similar age and BMI. Body composition was assessed by dual energy X-ray absorptiometry, insulin sensitivity was evaluated by homoeostasis model assessment, exercise capacity by spiroergometry. Plasma ADPN did not differ between CHF vs. controls (13.5 ± 11.0 vs. 10.5 ± 5.3 mg/l, p > 0.4), but increased stepwise with NYHA functional class (I/II/III: 5.7 ± 1.4/10.7 ± 8.3/19.2 ± 14.0 mg/l, ANOVA p < 0.01). Furthermore, ADPN correlated with VO2 at anaerobic threshold (r = -0.34, p < 0.05). ADPN was highest in cachectic patients (cCHF, 16%) vs. non-cachectic (ncCHF) (18.7 ± 15.0 vs. 12.5 ± 9.9 mg/l; p < 0.05). ADPN indicated mortality risk independently of established prognosticators (HR: 1.04 95% CI: 1.02-1.07; p < 0.0001). ADPN above the mean (13.5 mg/l) was associated with a 3.4 times higher mortality risk in CHF vs. patients with ADPN levels below the mean.

CONCLUSION

Circulating ADPN is abnormally regulated in CHF. ADPN may be involved in impaired metabolic signalling linking disease progression, tissue wasting, and poor outcome in CHF.

Medication adherence, depressive symptoms, and cardiac event-free survival in patients with heart failure

BACKGROUND

Medication nonadherence and depressive symptoms predict hospitalization and death in patients with heart failure (HF). Depressed patients have lower medication adherence than nondepressed patients. However, the predictive power of the combination of medication adherence and depressive symptoms for hospitalization and death has not been investigated in patients with HF.

OBJECTIVE

The aim of this study was to explore the combined influence of medication adherence and depressive symptoms for prediction of cardiac event-free survival in patients with HF.

METHODS AND RESULTS

We monitored medication adherence in 216 HF patients who completed the Patient Health Questionnaire-9 (PHQ-9) at baseline. Medication adherence was measured objectively with the use of the Medication Event Monitoring System (MEMS). Patients were followed for up to 3.5 years to collect data on cardiac events. Survival analyses were used to compare cardiac event-free survival among groups. The risk of experiencing a cardiac event for patients with medication nonadherence and depressive symptoms was 5 times higher than those who were medication adherent without depressive symptoms. The risk of experiencing a cardiac event for patients with only 1 risk factor was 1.2-1.3 times that of those with neither risk factor.

CONCLUSIONS

Medication nonadherence and depressive symptoms had a negative synergistic effect on cardiac event-free survival in patients with HF.

Impact of adiponectin and leptin on long-term adverse events in Japanese patients with acute myocardial infarction. Results from the Nagoya Acute Myocardial Infarction Study (NAMIS)

BACKGROUND

Low adiponectin levels and high leptin levels are associated with a high incidence of developing cardiovascular disease. However, the relationship between the levels of these adipokines and the development of adverse events after acute myocardial infarction (AMI) remains unclear.

METHODS AND RESULTS

This study enrolled 724 Japanese subjects with AMI who underwent successful emergency percutaneous coronary intervention (PCI). Their serum adiponectin and leptin levels were measured 7 days after AMI onset. There were 63 adverse events during the 3-year follow-up. The levels of adiponectin and leptin and the leptin to adiponectin ratio, were significantly associated with adverse events [hazard ratio 2.08 (95% confidence interval (CI) 1.33-3.24), P=0.001; hazard ratio 0.62 (95% CI 0.43-0.90), P=0.012; hazard ratio 0.59 (95% CI 0.45-0.76), P<0.001, respectively]. The leptin to adiponectin ratio remained a significant independent predictor of adverse events during long-term follow-up in a multivariable analysis [adjusted hazard ratio 0.60 (95% CI 0.43-0.83), P=0.002].

CONCLUSIONS

Higher adiponectin and lower leptin levels are associated with a high incidence of adverse events in Japanese patients after AMI, and the leptin to adiponectin ratio independently predicts prognosis after AMI.

Adiponectin, diabetes and ischemic heart failure: a challenging relationship

BACKGROUND

Several peptides, named adipokines, are produced by the adipose tissue. Among those, adiponectin (AD) is the most abundant. AD promotes peripheral insulin sensitivity, inhibits liver gluconeogenesis and displays anti-atherogenic and anti-inflammatory properties. Lower levels of AD are related to a higher risk of myocardial infarction and a worse prognosis in patients with coronary artery disease. However, despite a favorable clinical profile, AD increases in relation to worsening heart failure (HF); in this context, higher adiponectinemia is reliably related to poor prognosis. There is still little knowledge about how certain metabolic conditions, such as diabetes mellitus, modulate the relationship between AD and HF.We evaluated the level of adiponectin in patients with ischemic HF, with and without type 2 diabetes, to elucidate whether the metabolic syndrome was able to influence the relationship between AD and HF.

RESULTS

We demonstrated that AD rises in patients with advanced HF, but to a lesser extent in diabetics than in non-diabetics. Diabetic patients with reduced systolic performance orchestrated a slower rise of AD which began only in face of overt HF. The different behavior of AD in the presence of diabetes was not entirely explained by differences in body mass index. In addition, NT-proBNP, the second strongest predictor of AD, did not differ significantly between diabetic and non-diabetic patients. These data indicate that some other mechanisms are involved in the regulation of AD in patients with type 2 diabetes and coronary artery disease.

CONCLUSIONS

AD rises across chronic heart failure stages but this phenomenon is less evident in type 2 diabetic patients. In the presence of diabetes, the progressive increase of AD in relation to the severity of LV dysfunction is hampered and becomes evident only in overt HF.

Potential interaction of brain natriuretic peptide with hyperadiponectinemia in preeclampsia

Adiponectin was reported recently to have roles in the pathophysiology of preeclampsia. Moreover, elevation of adiponectin and brain natriuretic peptide (BNP) has been observed in preeclampsia. We examined the possible links between adiponectin and BNP in the pathophysiology of preeclampsia. We performed a cross-sectional study in 56 preeclampsia patients and 56 controls matched for gestational age and body mass index. The BNP, leptin, and adiponectin levels were measured by ELISA, and their mRNA expressions were evaluated in omental adipose tissue by real-time PCR. The effects of BNP on adiponectin and leptin mRNA expression and secretion were investigated in primary cultures of adipocytes from obese and normal-weight women. The BNP, adiponectin, and leptin levels were significantly higher in preeclampsia patients compared with controls. The adiponectin level was increased significantly in normal-weight preeclampsia patients compared with overweight preeclampsia patients. Adiponectin mRNA expression was increased significantly in adipose tissues of preeclampsia patients compared with controls and was also increased significantly in normal-weight preeclampsia patients compared with overweight preeclampsia patients, whereas leptin was not. BNP and adiponectin showed significant positive correlations in both normal-weight and overweight preeclampsia patients. BNP had a significantly weaker effect on adiponectin in overweight compared with normal-weight preeclampsia patients. Moreover, BNP had a weaker effect on adiponectin production in adipocytes from overweight women compared with adipocytes from normal-weight women using primary culture of human adipocytes. These data suggested that BNP may play a role in hyperadiponectinemia of preeclampsia patients. The weaker effect of BNP on adiponectin production may participate in the pathophysiology of overweight preeclampsia patients.

Adiponectin in outpatients with coronary artery disease: independent predictors and relationship with heart failure

BACKGROUND AND AIMS

Chronic heart failure (HF) is characterised by a neurohormonal dysfunction associated with chronic inflammation. A role of metabolic derangement in the pathophysiology of HF has been recently reported. Adiponectin, an adipose-tissue-derived cytokine, seems to play an important role in cardiac dysfunction. We investigated the variation of circulating adiponectin in patients with coronary artery disease (CAD), with or without HF, in order to identify its independent predictors.

METHODS AND RESULTS

A total of 107 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 HF symptoms (group 2) and CAD with overt HF (group 3). Plasma adiponectin was determined by enzyme-linked immunosorbent assay. Adiponectin concentrations increased progressively from group 1 (7.6 ± 3.6 ng ml⁻¹) to group 2 (9.1 ± 6.7 ng ml⁻¹) and group 3 (13.7 ± 7.6 ng ml⁻¹), with the difference reaching statistical significance in group 3 versus 1 and 2 (p < 0.001). A multivariable model of analysis demonstrated that the best predictors of plasma adiponectin were body mass index, N-terminal pro-brain natriuretic peptide and high-density lipoprotein cholesterol. However, even after adjusting for all three independent predictors, the increase of adiponectin in group 3 still remained statistically significant (p = 0.015).

CONCLUSION

Our data confirm the rise of adiponectin in overt HF. The levels of circulating adipokine seem to be mainly predicted by the metabolic profile of patients and by biohumoral indicators, rather than by clinical and echocardiographic indexes of HF severity.

Adiponectin is associated with favorable lipoprotein profile, independent of BMI and insulin resistance, in adolescents

CONTEXT

Children with obesity and insulin resistance (IR) have decreased adiponectin and have increased cardiovascular risk. Adiponectin has antiatherogenic effects, but its mechanism is unclear.

OBJECTIVES

Our objectives were 1) to compare lipoprotein subclass particles among obese and lean adolescents and delineate their relationships with IR and 2) to measure relationships between adiponectin and lipoproteins and their dependence on body mass index (BMI) and/or IR. DESIGN, SETTING, PATIENTS, AND MAIN OUTCOME MEASURES: This was a cross-sectional study of 57 obese and 38 lean pubertal adolescents, measuring lipoprotein subclass particles (nuclear magnetic resonance spectroscopy), lipids, adiponectin, and homeostasis model assessment of IR (HOMA-IR).

RESULTS

Obese had higher low-density lipoprotein (LDL) cholesterol (P = 0.018), higher small LDL particles (LDL-P) (P < 0.0005), smaller LDL-P size (P < 0.0005), smaller high-density lipoprotein particle (HDL-P) size (P < 0.0005), lower HDL cholesterol (HDL-C) (P < 0.0005), and higher small HDL-P (P = 0.009) compared with lean. HOMA-IR was higher in obese than lean (P < 0.0005) and positively associated with triglycerides, large very LDL-P, and small HDL-P and negatively with HDL-P size in obese. Adiponectin was lower in obese than lean (P < 0.0005) and was positively associated with LDL-P size, HDL-P size, and HDL-C and negatively with triglycerides, small LDL-P, large very LDL-P, and small HDL-P in obese. Using linear regression adjusting for demographics, Tanner stage, BMI, and HOMA-IR in all adolescents, adiponectin was positively associated with LDL-P size (P = 0.028), HDL-P size (P < 0.0005), and HDL-C (P = 0.042) and negatively with small LDL-P (P = 0.009) and small HDL-P (P = 0.004).

CONCLUSIONS

Obese adolescents have lower adiponectin levels than lean, and a more atherogenic lipoprotein profile, associated with increased IR. Adiponectin was inversely associated with atherogenic lipoproteins in adolescents, even after adjusting for obesity and IR. This is the first such report in children, and suggests a relationship between adiponectin and lipoproteins in adolescents independent of BMI and IR.

Adiponectin is associated with abnormal lipid profile and coronary microvascular dysfunction in patients with dilated cardiomyopathy without overt heart failure

Reduced plasma adiponectin has been associated with abnormal lipid profile, reduced left ventricle (LV) function, and the extent of coronary atherosclerosis in coronary artery disease. The aim of this study was to assess these relationships in patients with dilated cardiomyopathy (DCM) without overt heart failure. Plasma adiponectin was measured in 55 DCM patients (age, 59 ± 12 years; male, 36; body mass index [BMI], 26.9 ± 0.49 kg/m²; LV ejection fraction, 39.8% ± 1.3%; New York Heart Association class I-II) and in 40 age- and BMI-matched healthy controls. In a subset of 25 patients, myocardial blood flow (MBF) was measured at rest and during intravenous dipyridamole (0.56 mg/kg in 4 minutes) by positron emission tomography and ¹³N-ammonia as a flow tracer. Adiponectin was 6.6 ± 0.34 μg/mL in controls and 10.9 ± 0.85 μg/mL in DCM patients (P < .001), where it was related inversely with BMI (P = .009) and directly with brain natriuretic peptide (P = .017), high-density lipoprotein (HDL) cholesterol (P = .002), and MBF dipyridamole (P = .020). Adiponectin lesser than median value in patients was associated with higher total to HDL cholesterol ratio (4.8 ± 0.24 vs 3.9 ± 0.18, P = .009) and lower MBF reserve (1.76 ± 0.16 vs 2.43 ± 0.19, P = .01). These results could suggest that down-regulation of the adiponectin levels and reduced HDL cholesterol have a key role in causing impaired coronary function and myocardial perfusion in DCM.

Adiponectin provides cardiovascular protection in metabolic syndrome

Adipose tissue plays a central role in the pathogenesis of metabolic syndrome. Adiponectin (APN) is a bioactive adipocytokine secreted from adipocytes. Low plasma APN levels (hypoadiponectinemia) are observed among obese individuals and in those with related disorders such as diabetes, hypertension, and dyslipidemia. APN ameliorates such disorders. Hypoadiponectinemia is also associated with major cardiovascular diseases including atherosclerosis and cardiac hypertrophy. Accumulating evidence indicates that APN directly interacts with cardiovascular tissue and prevents cardiovascular pathology. Increasing plasma APN or enhancing APN signal transduction may be an ideal strategy to prevent and treat the cardiovascular diseases associated with metabolic syndrome. However, further studies are required to uncover the precise biological actions of APN.

Determinants of adiponectin levels in patients with chronic systolic heart failure

Adiponectin, an adipocytokine, is secreted by adipocytes and mediates antihypertrophic and anti-inflammatory effects in the heart. Plasma concentrations of adiponectin are decreased in the presence of obesity, insulin resistance, and obesity-associated conditions such as hypertension and coronary heart disease. However, a paradoxical increase in adiponectin levels is observed in human systolic heart failure (HF). We sought to investigate the determinants of adiponectin levels in patients with chronic systolic HF. Total adiponectin levels were measured in 99 patients with stable HF and a left ventricular (LV) ejection fraction of <40%. The determinants of adiponectin levels on univariate analysis were included in a multivariate linear regression model. At baseline, 62% of the patients were black, 63% were men, the mean age was 60 + or - 13 years, the LV ejection fraction was 21 + or - 9%, and the body mass index was 30.6 + or - 6.7 kg/m(2). The mean adiponectin level was 15.8 + or - 15 microg/ml. Beta-Blocker use, body mass index, and blood urea nitrogen were significant determinants of adiponectin level on multivariate analysis. The LV mass, structure, and LV ejection fraction were not related to adiponectin levels on multivariate analysis. The effect of beta-blocker therapy was most marked in nonobese patients with a body mass index <30 kg/m(2). In conclusion, in patients with chronic systolic HF, beta-blocker therapy correlated with lower adiponectin levels, especially in nonobese patients. This relation should be taken into account when studying the complex role of adiponectin in patients with chronic systolic HF.

Elevation of plasma retinol-binding protein 4 and reduction of plasma adiponectin in subjects with cerebral infarction

The present study was undertaken to determine plasma retinol-binding protein 4 (RBP4) and adiponectin levels in subjects with cerebral infarction. Fifty-eight subjects with cerebral infarction and 53 age- and sex-matched control subjects were enrolled. Plasma RBP4, adiponectin, and high-molecular-weight adiponectin were measured by the method of enzyme-linked immunosorbent assay. Plasma RBP4 was 16.4 +/- 2.8 microg/mL in the subjects with cerebral infarction, a value significantly greater than that of 10.1 +/- 1.2 microg/mL in the controls (P = .044). Inversely, plasma adiponectin was significantly less in the subjects with cerebral infarction than the control subjects (8.1 +/- 0.8 vs 10.8 +/- 0.7 microg/mL, P = .015). However, there was no difference in plasma high-molecular-weight adiponectin between the 2 groups of subjects. In the control subjects, there were negative correlations between plasma RBP4 and adiponectin and between plasma RBP4 and high-molecular-weight adiponectin levels; and they totally disappeared in the subjects with cerebral infarction. The multiple regression analysis showed that adiponectin and hypertension were independent factors contributing to cerebral infarction (P < .001). These findings indicate that hypoadiponectinemia is concomitantly involved in the pathogenesis of atherosclerosis, and that an elevation of plasma RBP4 may be a useful marker for the development of atherosclerosis, in subjects with cerebral infarction.

Effects of adiponectin deficiency on structural and metabolic remodeling in mice subjected to pressure overload

Recent data suggest adiponectin, an adipocyte-derived hormone, affects development of heart failure in response to hypertension. Severe short-term pressure overload [1-3 wk of transverse aortic constriction (TAC)] in adiponectin(-/-) mice causes greater left ventricle (LV) hypertrophy than in wild-type (WT) mice, but conflicting results are reported regarding LV remodeling, with either increased or decreased LV end diastolic volume compared with WT mice. Here we assessed the effects of prolonged TAC on LV hypertrophy and remodeling. WT and adiponectin(-/-) mice were subjected to TAC and maintained for 6 wk. Regardless of strain, TAC induced similar LV hypertrophy ( approximately 70%) and upregulation of mRNA for heart failure marker genes. However, LV chamber size was dramatically different, with classic LV dilation in WT TAC mice but concentric LV hypertrophy in adiponectin(-/-) mice. LV end diastolic and systolic volumes were lower and ejection fraction higher in adiponectin(-/-) TAC mice compared with WT, indicating that adiponectin deletion prevented LV remodeling and deterioration in systolic function. The activities of marker enzymes of mitochondrial oxidative capacity were reduced in WT TAC mice by approximately 35%, whereas enzyme activities were maintained at sham levels in adiponectin(-/-) TAC mice. In conclusion, in WT mice, long-term pressure overload caused dilated LV hypertrophy accompanied by decreased activity of mitochondrial oxidative enzymes. Although adiponectin deletion did not affect LV hypertrophy, it prevented LV chamber remodeling and preserved mitochondrial oxidative capacity, suggesting that adiponectin plays a permissive role in mediating changes in cardiac structure and metabolism in response to pressure overload.

Serial changes in adiponectin and BNP in ACS patients: paradoxical associations with each other and with prognosis

Plasma adiponectin is inversely associated with the risk of coronary heart disease in healthy people. However, adiponectin and BNP (B-type natriuretic peptide) are both known to be positively associated with a risk of poor outcome, and with each other, in ACS (acute coronary syndrome) patients. Serial changes in plasma adiponectin and BNP following ACS have not been assessed previously, and may clarify these apparently paradoxical associations. In the present study, adiponectin, BNP, classical risk markers and clinical parameters were measured in plasma from 442 consecutive ACS patients in an urban teaching hospital, with repeat measures at 7 weeks (n=338). Patients were followed-up for 10 months. Poor outcome was defined as mortality or readmission for ACS or congestive heart failure (n=90). In unadjusted analysis, the change in adiponectin (but not baseline or 7-week adiponectin) was significantly associated with the risk of an adverse outcome {odds ratio (OR), 5.42 [95% CI (confidence interval), 2.78-10.55]}. This association persisted after adjusting for classical risk factors and clinical markers, but was fully attenuated by adjusting for the 7-week BNP measurement [OR, 1.13 (95% CI, 0.27-4.92)], which itself remained associated with risk [OR, 5.86 (95% CI, 1.04-32.94)]. Adiponectin and BNP positively correlated at baseline and 7 weeks, and the change in both parameters over 7 weeks also correlated (r=0.39, P<0.001). In conclusion, increases in plasma adiponectin (rather than absolute levels) after ACS are related to the risk of an adverse outcome, but this relationship is not independent of BNP levels. The results of the present study allude to a potential direct or indirect relationship between adiponectin and BNP post-ACS which requires further investigation.

Adiponectin: from obesity to cardiovascular disease

Adiponectin is an adipokine whose biosynthesis is deranged in obesity and diabetes mellitus, predisposing to atherosclerosis. Evidence suggests that adiponectin has anti-atherogenic properties by improving endothelial function and having anti-inflammatory effects in the vascular wall. In addition, adiponectin modifies vascular intracellular redox signalling and exerts indirect antioxidant effects on human myocardium. However, its clinical role in cardiovascular disease is obscure. Adiponectin's positive prognostic value in coronary artery disease had been widely supported over the last years, but this view has been questioned recently. High adiponectin levels are paradoxically associated with poorer prognosis in heart failure syndrome. These controversial findings seem surprising as adiponectin has been viewed overall as an anti-atherogenic molecule. Therefore, any certain conclusion about adiponectin's role in cardiovascular disease seems premature. Despite the rapidly accumulating literature on this adipokine, it is still unclear whether adiponectin is a key mediator or a bystander in cardiovascular disease. It is still uncertain whether adiponectin levels have any clinical significance for risk stratification in cardiovascular disease or they just reflect the activation of complex and opposing underlying mechanisms. Circulating adiponectin levels should be interpreted with caution, as they may have completely different prognostic value, depending on the underlying disease state.

Adiponectin is increased in cardiac cachexia irrespective of body mass index

AIMS

Cardiac cachexia (CC) is a complication of chronic heart failure (CHF). Little is known about the mechanisms leading to CC. Adiponectin, leptin, and ghrelin are important regulators of energy metabolism and body weight. Previous studies of CHF and CC had great differences in body mass index (BMI) between cachectic and non-cachectic patients. To assess serum adiponectin, leptin, and ghrelin concentrations in cachectic and non-cachectic patients.

METHODS AND RESULTS

We conducted a case-control study in CHF patients matched for BMI. Cases (n = 33) were cachectic patients with unintentional weight loss of > or = 7.5% of the previous baseline weight. Controls (n = 33) had no history of weight loss and were individually matched with cases for age, sex, and BMI. Cachectic patients had significantly higher adiponectin levels than controls: 25.0 +/- 12.3 vs. 14.7 +/- 8.8 microg/mL (P = 0.002). Leptin concentration was lower in the cachectic group: 7.5 (IQR 4.0-10.8) vs. 8.0 (IQR 7.1-10.5) ng/mL. Differences in leptin lost significance once adjusted for fat mass. Adiponectin remained higher in cachectics after such adjustment. Ghrelin was not significantly different between groups. Adiponectin correlated positively with weight loss and BNP.

CONCLUSION

Cachexia in CHF was associated with an increase in adiponectin, irrespective of BMI. This suggests a role of adiponectin in the wasting process of cachectic patients.

Resistin, adiponectin, and risk of heart failure the Framingham offspring study

OBJECTIVES

We tested the association of the adipokines resistin and adiponectin with incident heart failure.

BACKGROUND

Abnormal concentrations of adipokines may partially explain the association between obesity and heart failure.

METHODS

We related circulating adipokine concentrations to the incidence of heart failure in 2,739 participants in the Framingham Offspring Study.

RESULTS

During 6 years of follow-up, 58 participants developed new-onset heart failure. In proportional hazards models (adjusting for age, sex, blood pressure, antihypertensive treatment, diabetes, smoking, total/high-density lipoprotein cholesterol ratio, prevalent coronary heart disease, valvular heart disease, left ventricular hypertrophy, and estimated glomerular filtration rate) using the lowest third of the resistin distribution as the referent, the hazard ratios for heart failure in the middle and top thirds were 2.89 (95% confidence interval [CI]: 1.05 to 7.92) and 4.01 (95% CI: 1.52 to 10.57), respectively (p = 0.004 for trend). Additional adjustment for body mass index, insulin resistance (measured with the homeostasis model), C-reactive protein, and B-type natriuretic peptide did not substantively weaken this association (multivariable hazard ratios [HRs]: 2.62 and 3.74, p = 0.007). In the maximally adjusted model, each SD increment in resistin (7.45 ng/ml) was associated with a 26% increase in heart failure risk (95% CI: 1% to 60%). Concentrations of adiponectin were not associated with heart failure (multivariable HRs: 0.87 and 0.97, p = 0.9).

CONCLUSIONS

Increased circulating concentrations of resistin were associated with incident heart failure, even after accounting for prevalent coronary heart disease, obesity, and measures of insulin resistance and inflammation. The findings suggest a role for resistin in human disease and a novel pathway to heart failure.