Nitric oxide bioavailability and adiponectin production in chronic systolic heart failure: relation to severity of cardiac dysfunction

Unraveling the role of resistin, retinol-binding protein 4 and adiponectin produced by epicardial adipose tissue in cardiac structure and function: evidence of a paracrine effect

PURPOSE

Adipokines produced by adipose tissue have been found to be involved in the pathophysiology of metabolic and cardiovascular diseases. We aimed to investigate the relationships of resistin, retinol-binding protein 4 (RBP4) and adiponectin produced by epicardial adipose tissue with coronary artery disease (CAD) and cardiac structure and function.

METHODS

Forty-one non-diabetic males scheduled for cardiothoracic surgery were examined. Anthropometric measurements, echocardiography, coronary angiography, and blood analysis were performed preoperatively. We measured the serum levels of resistin, RBP4, and adiponectin and their mRNA expression in thoracic subcutaneous adipose tissue and two epicardial adipose tissue samples, one close to left anterior descending artery (LAD) (resistin-LAD, RBP4-LAD, adiponectin-LAD), and another close to the right coronary artery (RCA) (resistin-RCA, RBP4-RCA, adiponectin-RCA).

RESULTS

Left ventricular (LV) ejection fraction correlated negatively with adiponectin-LAD (rho =  - 0.390, p = 0.025). The ratio of early to late diastolic transmitral flow velocity, as an index of LV diastolic function, correlated negatively with resistin-LAD (rho =  - 0.529, p = 0.024) and RBP4-LAD (rho =  - 0.458, p = 0.049). There was no difference in epicardial adipose tissue mRNA expression of resistin, RBP4, and adiponectin between individuals with CAD and those without CAD. When we compared the individuals with CAD in the LAD with those without CAD in the LAD, there was no difference in resistin-LAD, RBP4-LAD, and adiponectin-LAD. There was no difference in resistin-RCA, RBP4-RCA, and adiponectin-RCA between the individuals with CAD in the RCA and those without CAD in the RCA.

CONCLUSION

Elevation of epicardial adipose tissue mRNA expression of adiponectin was associated with LV systolic dysfunction, while that of both resistin and RBP4 was linked to LV diastolic dysfunction.

Molecular Mechanisms and Therapeutic Implications of Endothelial Dysfunction in Patients with Heart Failure

Heart failure is a complex medical syndrome that is attributed to a number of risk factors; nevertheless, its clinical presentation is quite similar among the different etiologies. Heart failure displays a rapidly increasing prevalence due to the aging of the population and the success of medical treatment and devices. The pathophysiology of heart failure comprises several mechanisms, such as activation of neurohormonal systems, oxidative stress, dysfunctional calcium handling, impaired energy utilization, mitochondrial dysfunction, and inflammation, which are also implicated in the development of endothelial dysfunction. Heart failure with reduced ejection fraction is usually the result of myocardial loss, which progressively ends in myocardial remodeling. On the other hand, heart failure with preserved ejection fraction is common in patients with comorbidities such as diabetes mellitus, obesity, and hypertension, which trigger the creation of a micro-environment of chronic, ongoing inflammation. Interestingly, endothelial dysfunction of both peripheral vessels and coronary epicardial vessels and microcirculation is a common characteristic of both categories of heart failure and has been associated with worse cardiovascular outcomes. Indeed, exercise training and several heart failure drug categories display favorable effects against endothelial dysfunction apart from their established direct myocardial benefit.

DDAH1/ADMA Regulates Adiponectin Resistance in Cerebral Ischemia via the ROS/FOXO1/APR1 Pathway

Dimethylarginine dimethylaminohydrolase 1 (DDAH1) protects against cerebral ischemia injury via regulating the level of asymmetric dimethylarginine (ADMA). This study is aimed at exploring the effect of adiponectin resistance on ADMA-induced neuronal loss in ischemic stroke (IS) and the underlying mechanism. DDAH1 knockout (DDAH1^−/−) and wild-type (DDAH1^+/+) rats underwent middle cerebral artery occlusion/reperfusion (MCAO/R). Plasma and brain adiponectin levels and the expressions of adiponectin receptor 1 (APR1), adaptor protein, phosphotyrosine interacting with PH domain and leucine zipper 1 (APPL1), adenosine monophosphate-activated protein kinase (AMPK), and phosphorylated AMPK were determined after 24 h, 3 days, and 7 days. Neurological behavior, infarct volume, and adiponectin signaling were evaluated using adiponectin peptide or AdipoRon. The levels of reactive oxygen species (ROS) and Forkhead box O1 (FOXO1) (a transcription factor for APR1) were also assessed. An oxygen-glucose deprivation/reoxygenation (OGD/R) model was established in primary neurons. DDAH1 was overexpressed in neurons, after which FOXO1 expression, ROS production, adiponectin resistance, and cell viability were detected. DDAH1^−/− rats showed no significant difference in adiponectin level in either plasma or brain after MCAO/R in DDAH1^+/+ rats, but downregulated APR1 expression and suppressed adiponectin signaling were observed. AdipoRon, but not adiponectin peptide, attenuated the neurological deficits and adiponectin resistance in DDAH1^−/− rats. ROS accumulation and phosphorylated FOXO1 expression also increased with DDAH1 depletion. Following DDAH1 overexpression, decreased cell viability and inhibited adiponectin signaling induced by OGD/R were alleviated in primary neurons, accompanied by reduced ROS production and phosphorylated FOXO1 expression. Our study elucidated that in IS, DDAH1 protected against adiponectin resistance in IS via the ROS/FOXO1/APR1 pathway.

High plasma adiponectin is associated with increased pulmonary blood flow and reduced right ventricular function in patients with pulmonary hypertension

BACKGROUND

Adiponectin is a biomarker closely related to heart failure. However, its role in pulmonary hypertension remains unclear. In this study, we investigated the association between adiponectin and hemodynamic abnormalities, right ventricular function in patients with congenital heart disease associated pulmonary hypertension (CHD-PH).

METHODS

Patients with CHD-PH were enrolled in this cross-sectional study. Linear regression analysis was performed to assess the association between adiponectin, N-terminal pro-Brain Natriuretic Peptide (NT-proBNP) and different clinical parameters. Results were depicted as beta-estimates(ß) with 95%-confidence intervals (95% CI). In addition, mediation and receiver operating characteristic curve analyses were used to analyze the relationships among adiponectin, NT-proBNP and right ventricular function.

RESULTS

A total of 86 CHD-PH patients were included. The overall mean adiponectin concentration was 7.9 ± 5.8 μg/ml. Log adiponectin was positively correlated with pulmonary circulation index (ß = 2.2, 95% CI 0.5, 4.0), log NT-proBNP (ß = 0.22, 95% CI 0.04, 0.41) and inversely with the tricuspid annular plane systolic excursion (TAPSE, ß = -4.7, 95% CI -8.6, - 0.8). The mediation analysis revealed the association between NT-proBNP and TAPSE was fully mediated by adiponectin (total effect c = - 5.4, 95% CI -9.4, - 1.5, p = 0.013; direct effect c' = - 3.7, 95% CI -7.5, 0.1, p = 0.067). Additionally, the efficiency of adiponectin for detecting right ventricular dysfunction was not inferior to NT-proBNP (AUC = 0.84, 95% CI 0.67-1.00 vs AUC = 0.74, 95% CI 0.51-0.97, p = 0.23).

CONCLUSIONS

Adiponectin is closely correlated with pulmonary blood flow and right ventricular function and may be a valuable biomarker for disease assessment in patients with pulmonary hypertension.

Prognostic Value of Asymmetric Dimethylarginine in Patients with Heart Failure: A Systematic Review and Meta-analysis

Objective

Asymmetric dimethylarginine (ADMA), an endogenous inhibitor of nitric oxide (NO) synthesis, is reported to be a risk factor for cardiovascular disease. The purpose of the present study is to investigate whether ADMA is an independent predictor for future mortality and adverse clinical events among patients with heart failure (HF).

Methods

Electronic literature databases (Central, MEDLINE, and Embase) were searched for relevant observational studies on the prognostic value of ADMA in HF patients published before January 2019. Pooled hazard ratios (HRs) or odds ratio and the corresponding 95% confidence interval (CI) were calculated for risk evaluation.

Results

10 studies with 2195 participants were identified and analyzed. The pooled HR of composite clinical events for the highest vs. lowest quartiles from categorical variable results was 1.34 (95% CI: 1.15-1.57, P < 0.001, I² = 0%), which is 1.31 (95% CI: 1.10-1.55, P < 0.005, I² = 0%) in the subgroup of acute decompensated HF. The pooled HR of composite clinical events from continuous variable results was 1.41 (95% CI: 1.21-1.63, P < 0.001, I² = 21.9%), with 0.1 μM increment accounting for the increasing 25% risk for composite adverse clinical events. The pooled HR for all-cause mortality was 2.38 (95% CI: 1.48-3.82, P < 0.001, I² = 0%) after sensitivity analysis. Two studies reporting the HR of inhospital mortality in HF patients regarded it as a prognostic indicator, with categorical variable HR as 1.26 (95% CI: 1.07-1.84, P < 0.05) and continuous variable OR as 2.15 (95% CI: 1.17–4.29, P < 0.05).

Conclusions

ADMA is an independent predictor for composite clinical outcomes among HF patients with both short-term and long-term prognostic value.

Elevated Plasma Adiponectin Levels Are Associated with Abnormal Corrected QT Interval in Patients with Stable Angina

Low-circulating levels of adiponectin (ADPN) are associated with obesity, diabetes mellitus, and coronary artery disease. On the contrary, some studies have demonstrated a link between relatively high levels of plasma ADPN and heart failure, atrial fibrillation, and adverse outcome. However, little is known about the relationship between ADPN level and prolonged QT interval. The aim of this study was to investigate the association between plasma ADPN levels and prolonged QT interval in patients with stable angina.In this retrospective study, because the diverse disease severity and condition of the study population may have affected the results, we chose individuals with stable angina. Plasma ADPN concentrations were measured using enzyme-linked immunosorbent assays. A 12-lead ECG recording was obtained from each patient.We enrolled 479 stable-angina patients. Patients with an abnormal corrected QT (QTc) interval had higher median plasma ADPN levels than those with normal QTc intervals. Age- and sex-adjusted ADPN levels were positively associated with heart rate, QTc interval, left ventricular mass index, and creatinine but negatively associated with left ventricular ejection fraction, waist circumference, current smoking, total cholesterol, triglycerides, low-density lipoprotein cholesterol, albumin, and estimated glomerular filtration rate. A multiple logistic regression analysis revealed ADPN as an independent association factor for abnormal QTc interval. Increasing concentrations of sex-specific ADPN were independently and significantly associated with abnormal QTc interval, even after full adjustment of known biomarkers.Our results indicate that ADPN may play a role in the pathogenesis of abnormal QTc interval in patients with stable angina.

Cardio-adipose tissue cross-talk: relationship between adiponectin, plasma pro brain natriuretic peptide and incident heart failure

AIMS

There is increasing evidence of cross-talk between the heart, body metabolism, and adipose tissue, but the precise mechanisms are poorly understood. Natriuretic peptides (NPs) have recently emerged as the prime candidate for a mediator. In patients with heart failure (HF), infusion of NPs increases adiponectin secretion, indicating that NPs may improve adipose tissue function and in this way function as a cardio-protective agent in HF. Accordingly we investigated the interplay between plasma adiponectin, plasma proBNP, and development of HF.

METHODS AND RESULTS

We prospectively followed 5574 randomly selected men and women from the community without ischaemic heart disease or HF. Plasma adiponectin and proBNP were measured at study entry. Median follow-up time was 8.5 years (interquartile range 8.0-9.1 years). During follow-up 271 participants developed symptomatic HF. Plasma adiponectin and proBNP were strongly associated (P < 0.001). Participants with increasing adiponectin had increased risk of incident HF (P < 0.001). After adjustment for confounding risk factors (including age, gender, smoking status, body mass ratio, waist-hip ratio, glucose, glycated haemoglobin, systolic and diastolic blood pressure, lipid profile, high sensitivity C-reactive protein, estimated glomerular filtration rate, and physical activity) by Cox regression analysis, adiponectin remained an independent predictor of HF: the hazard ratio (HR) per 1 standard deviation (SD) increase in adiponectin was 1.20 [95% confidence interval (CI) 1.06-1.30; P = 0.003]. However, the association vanished when plasma proBNP was included in the analysis, HR 1.08 (95% CI 0.95-1.23; P = 0.26).

CONCLUSIONS

In conclusion, plasma adiponectin and proBNP are strongly associated. Increasing plasma adiponectin is associated with increased risk of HF. However, concomitantly elevated proBNP levels appear to explain the positive association between adiponectin and risk of HF.

The NO/ONOO-cycle as the central cause of heart failure

The NO/ONOO-cycle is a primarily local, biochemical vicious cycle mechanism, centered on elevated peroxynitrite and oxidative stress, but also involving 10 additional elements: NF-κB, inflammatory cytokines, iNOS, nitric oxide (NO), superoxide, mitochondrial dysfunction (lowered energy charge, ATP), NMDA activity, intracellular Ca(2+), TRP receptors and tetrahydrobiopterin depletion. All 12 of these elements have causal roles in heart failure (HF) and each is linked through a total of 87 studies to specific correlates of HF. Two apparent causal factors of HF, RhoA and endothelin-1, each act as tissue-limited cycle elements. Nineteen stressors that initiate cases of HF, each act to raise multiple cycle elements, potentially initiating the cycle in this way. Different types of HF, left vs. right ventricular HF, with or without arrhythmia, etc., may differ from one another in the regions of the myocardium most impacted by the cycle. None of the elements of the cycle or the mechanisms linking them are original, but they collectively produce the robust nature of the NO/ONOO-cycle which creates a major challenge for treatment of HF or other proposed NO/ONOO-cycle diseases. Elevated peroxynitrite/NO ratio and consequent oxidative stress are essential to both HF and the NO/ONOO-cycle.