Retinol-Binding Protein-4—A Predictor of Insulin Resistance and the Severity of Coronary Artery Disease in Type 2 Diabetes Patients with Coronary Artery Disease

Abstract

(1) Background: Insulin resistance (IR) is the fundamental cause of type 2 diabetes (T2D), which leads to endothelial dysfunction and alters systemic lipid metabolism. The changes in the endothelium and lipid metabolism result in atherosclerotic coronary artery disease (CAD). In insulin-resistant and atherosclerotic CAD states, serum cytokine retinol-binding protein-4 (RBP-4) levels are elevated. The adipocyte-specific deletion of glucose transporter 4 (GLUT4) results in higher RBP-4 expression and IR and atherosclerotic CAD progression. (2) Aim: This study aimed to investigate the association of RBP-4 and clinical factors with IR and the severity of CAD. (3) Methods: Patients were recruited from diabetes and cardiology clinics and divided into three subgroups, namely (i) T2D patients with CAD, (ii) T2D-only patients, and (iii) CAD-only patients. The severity of CAD was classified as either single-vessel disease (SVD), double-vessel disease (DVD), or triple-vessel disease (TVD). An enzyme-linked immunosorbent assay was conducted to assess the concentration of serum RBP-4. Univariate (preliminary analysis) and multivariate (secondary analysis) logistic regressions were applied to assess the associations of RBP-4 and clinical factors with IR and the severity of CAD. (4) Results: Serum RBP-4 levels were associated with IR and the severity of CAD in all the three groups (all p-values are less than 0.05). Specifically, serum RBP-4 levels were associated with IR (p = 0.030) and the severity of CAD (SVD vs. DVD, p = 0.044; SVD vs. TVD, p = 0.036) in T2D patients with CAD. The clinical factors fasting plasma glucose (FPG) and angiotensin-converting-enzyme inhibitor (ACEI) were also associated with both IR and the severity of CAD in T2D patients with CAD. (5) Conclusion: RBP-4, FPG, and ACEI are predictors of IR and severity of CAD in T2D patients with CAD.

Impaired Organokine Regulation in Non-Diabetic Obese Subjects: Halfway to the Cardiometabolic Danger Zone

“…A U-shaped association has been described between RBP4 level and the incidence of T2DM [ 41 , 42 ]; however, Schiborn et al mentioned that this association was detected only in women [ 42 ]. A Thai study showed that high circulating RBP4 was a predictor of insulin resistance and the severity of coronary artery disease (CAD) in T2DM with CAD [ 43 ]. However, it must be noted that Asian race, lower BMI (~25 kg/m 2 ), severe comorbidities, i.e., CAD, and intensive insulin therapy can shade these results and make it difficult to compare them with our data.…”

The Search for Associations of Serum Proteins with the Presence of Unstable Atherosclerotic Plaque in Coronary Atherosclerosis

“…It showed that there is a correlation between the concentration of free RBP and the thickness of intima media, a diagnostic indicator of carotid artery atherosclerosis [ 25 ]. In addition, the concentration of RBP4 in the blood is associated with cardiovascular risk factors associated with insulin resistance and CHD, circulating RBP4 can be a marker of metabolic complications and atherosclerosis and used to assess CHD [ 26 , 27 ]. In early studies, we found an increase in the levels of transthyretin transport proteins and RBP4 in the blood of patients with coronary atherosclerosis compared with controls [ 28 ].…”

Epicardial Adipose Tissue and Diabetic Cardiomyopathy

“…30 Meanwhile, extensive epidemiological studies have demonstrated that RBP4 is a circulating biomarker of insulin resistance and the risk of cardiovascular disease and metabolic syndrome. [31][32][33] In 2021, Chauhan et al further proved that RBP4 could be used as an early evaluation indicator of type 2 diabetes and was linearly correlated with HOMA-IR. With increased serum RBP4 level of 1 mg/L, HOMA-IR increased significantly by 0.007 units.…”