Avaliação da Relação entre Níveis de Adropina e Circulação Colateral Coronária em Pacientes com Síndrome Coronariana Crônica

[Correlation between insulin resistance and coronary collateral circulation in patients with chronic total coronary occlusion]

OBJECTIVE

To explore the impact of diabetes on collateral circulation (CC) development in patients with chronic total coronary occlusion (CTO) and the underlying regulatory mechanism.

METHODS

This study was conducted among 87 patients with coronary heart disease (CHD), who had CTO in at least one vessel as confirmed by coronary angiography. Among them 42 patients were found to have a low CC level (Cohen-Rentrop grades 0-1) and 45 had a high CC level (grades 2-3). In the 39 patients with comorbid diabetes mellitus and 48 non-diabetic patients, insulin resistance (IR) levels were compared between the subgroups with different CC levels. The steady-state mode evaluation method was employed for calculating the homeostatic model assessment for insulin resistance index (HOMA-IR) using a mathematical model. During the interventional procedures, collateral and peripheral blood samples were collected from 22 patients for comparison of the metabolites using non-targeted metabolomics analysis.

RESULTS

NT-proBNP levels and LVEF differed significantly between the patients with different CC levels (P<0.05). In non-diabetic patients, HOMA-IR was higher in low CC level group than in high CC level groups. Compared with the non-diabetic patients, the diabetic patients showed 63 upregulated and 48 downregulated metabolites in the collateral blood and 23 upregulated and 14 downregulated metabolites in the peripheral blood. The differential metabolites in the collateral blood were involved in aromatic compound degradation, fatty acid biosynthesis, and steroid degradation pathways; those in the peripheral blood were related with pentose phosphate metabolism, bacterial chemotaxis, hexanoyl-CoA degradation, glycerophospholipid metabolism, and lysine degradation pathways.

CONCLUSION

The non-diabetic patients with a low level of CC had significant insulin resistance. The degradation pathways of aromatic compounds, fatty acid biosynthesis, and steroid degradation are closely correlated with the development of CC.

Emerging Evidence Linking the Liver to the Cardiovascular System: Liver-derived Secretory Factors

Cardiovascular diseases (CVDs) remain the leading cause of morbidity and mortality worldwide. Recently, accumulating evidence has revealed hepatic mediators, termed as liver-derived secretory factors (LDSFs), play an important role in regulating CVDs such as atherosclerosis, coronary artery disease, thrombosis, myocardial infarction, heart failure, metabolic cardiomyopathy, arterial hypertension, and pulmonary hypertension. LDSFs presented here consisted of microbial metabolite, extracellular vesicles, proteins, and microRNA, they are primarily or exclusively synthesized and released by the liver, and have been shown to exert pleiotropic actions on cardiovascular system. LDSFs mainly target vascular endothelial cell, vascular smooth muscle cells, cardiomyocytes, fibroblasts, macrophages and platelets, and further modulate endothelial nitric oxide synthase/nitric oxide, endothelial function, energy metabolism, inflammation, oxidative stress, and dystrophic calcification. Although some LDSFs are known to be detrimental/beneficial, controversial findings were also reported for many. Therefore, more studies are required to further explore the causal relationships between LDSFs and CVDs and uncover the exact mechanisms, which is expected to extend our understanding of the crosstalk between the liver and cardiovascular system and identify potential therapeutic targets. Furthermore, in the case of patients with liver disease, awareness should be given to the implications of these abnormalities in the cardiovascular system. These studies also underline the importance of early recognition and intervention of liver abnormalities in the practice of cardiovascular care, and a multidisciplinary approach combining hepatologists and cardiologists would be more preferable for such patients.

The Relationship Between Coronary Collateral Circulation and Serum Adropin Levels

Objective Coronary collateral circulation (CCC) are vascular structures that limit the infarct area, protect left ventricular function, and reduce the frequency of arrhythmia and mortality during myocardial ischemia and infarction. In this study, we examined the relationship between the development of CCC and serum adropin levels, which has been shown in previous studies to regulate endothelial functions and increase endothelial nitric oxide synthesis, in patients with acute myocardial infarction. Methods This study included 41 patients with insufficient CCC and 43 patients with well-developed CCC who were hospitalized for acute myocardial infarction and underwent coronary angiography. The Cohen-Rentrop classification was used to grade the CCC. The patients were divided into two groups according to Rentrop grades: those with a 0-1 stage were considered as insufficient and those with grades of 2-3 were considered as well-developed CCC. We took blood samples to measure the adropin levels within the first 24 hours of hospitalization. Results The mean age was 59.1±11.9 years and 62 (73.8%) were male. The right coronary artery was the most frequently target vessel (n: 51, 60.7%), and the majority of the patients presented with ST-segment elevation myocardial infarction (STEMI) (n:58, 69%). The median interval between the severe chest pain and the intervention was significantly higher in patients with well-developed CCC (p=0.042). The serum adropin levels in patients with insufficient CCC were significantly lower than in those with well-developed CCC (196.3 [131.5 - 837.0] pg/mL vs. 235.5 [171.9 - 1124.2] pg/mL, p<0.001). Logistic regression analysis revealed that the circumflex artery as the target vessel, NSTEMI (non-STEMI) as the type of myocardial infarction, and serum adropin level were the independent risk factors for the prediction of poor coronary collateral vessel formation (p<0.05). Conclusions In this study, we found that in patients with acute myocardial infarction, those with well-developed CCC had higher adropin levels.

Adropin’s Role in Energy Homeostasis and Metabolic Disorders

Adropin is a novel 76-amino acid-peptide that is expressed in different tissues and cells including the liver, pancreas, heart and vascular tissues, kidney, milk, serum, plasma and many parts of the brain. Adropin, encoded by the Enho gene, plays a crucial role in energy homeostasis. The literature review indicates that adropin alleviates the degree of insulin resistance by reducing endogenous hepatic glucose production. Adropin improves glucose metabolism by enhancing glucose utilization in mice, including the sensitization of insulin signaling pathways such as Akt phosphorylation and the activation of the glucose transporter 4 receptor. Several studies have also demonstrated that adropin improves cardiac function, cardiac efficiency and coronary blood flow in mice. Adropin can also reduce the levels of serum triglycerides, total cholesterol and low-density lipoprotein cholesterol. In contrast, it increases the level of high-density lipoprotein cholesterol, often referred to as the beneficial cholesterol. Adropin inhibits inflammation by reducing the tissue level of pro-inflammatory cytokines such as tumor necrosis factor alpha and interleukin-6. The protective effect of adropin on the vascular endothelium is through an increase in the expression of endothelial nitric oxide synthase. This article provides an overview of the existing literature about the role of adropin in different pathological conditions.