Impact of Acute Insulin Resistance on Myocardial Blush in Non-Diabetic Patients Undergoing Primary Percutaneous Coronary Intervention

IGFBP5 mediates the therapeutic effect of isoliquiritigenin in myocardial ischemia-reperfusion injury via AKT/GLUT4 regulated insulin resistance

Background

Myocardial ischemia/reperfusion injury (MIRI) is a critical problem in cardiovascular medicine, often occurring after coronary revascularization procedures or cardiopulmonary bypass. The characters of MIRI are both energy metabolism disturbances and severe myocardium insulin resistance (IR), which exacerbated myocardial damage and cell death. Isoliquiritigenin (ISL), a flavonoid derived from licorice roots (Glycyrrhiza spp.), has demonstrated protective effects on MIRI. However, the potential cardio-protective effects and mechanism of ISL in MIRI remain unclear.

Propose

In this study, we aimed to investigate ISL's therapeutic effects on MIRI. Moreover, we elucidate the underlying mechanisms of ISL regulated myocardium insulin resistance in vivo and in vitro.

Methods

In vivo, SD rats underwent left anterior descending coronary artery ligation/reperfusion to induce MIRI. Chest echocardiography was performed to monitor cardiac function post-reperfusion, followed by measurement of myocardial injury and IR markers. In vitro, H9C2 cardiomyocytes subjected to oxygen-glucose deprivation/reperfusion (OGD/R). Markers associated with myocardial injury and IR were assessed. Then, we identified potential therapeutic targets IGFBP5 for MIRI by network pharmacology and molecular docking analysis. Finally, lentivirus were used to silence or over-express IGFBP5 to elucidate the role of IGFBP5 in regulating the therapeutic effects of ISL on IR in MIRI.

Results

In the present study, In vivo experiments demonstrated that ISL attenuated myocardial infarct size, decreased serum markers of myocardial injury, improved left ventricular systolic function, and enhanced insulin sensitivity. In vitro data revealed that ISL ameliorated glucose uptake and cell survival rate. Furthermore, ISL increased AKT phosphorylation and upregulated membrane-bound GLUT4 (M-GLUT4) protein expression levels. These effects of ISL are mediated by the induction of IGFBP5, as demonstrated using gene-specific shRNA or overexpression for IGFBP5.

Conclusion

Our results reveal that ISL protects against myocardial damage caused by MIRI through the regulation of IR via the IGFBP5/AKT/GLUT4 pathway.

Stress, Hyperglycemia, and Insulin Resistance Correlate With Neutrophil Activity and Impact Acute Myocardial Infarction Outcomes

Introduction Acute insulin resistance (IR) and hyperglycemia are frequently observed during acute myocardial infarction (AMI), significantly influencing both immediate and long-term patient outcomes, irrespective of diabetic status. Neutrophilia and increased neutrophil activity, which are common in these scenarios, have been associated with poorer prognoses, as demonstrated in our recent findings. While it is well established that neutrophils and stress-induced hyperglycemia exacerbate inflammation and hinder recovery, the complex interplay between these factors and their combined impact on AMI prognosis remains inadequately understood. This study aims to investigate the effects of stress hyperglycemia and IR on AMI patients at the onset of the event and to elucidate the relationship between these metabolic disturbances and inflammatory markers, particularly neutrophils. Methods We conducted a longitudinal prospective study on 219 AMI patients at Elias Emergency Hospital in Bucharest, Romania, from April 2021 to September 2022. Patients were included within 24 hours of AMI with ST-segment elevation and excluded if they had acute infections or chronic inflammatory diseases. Blood samples were collected to study inflammatory biomarkers, including neutrophil extracellular traps (NETs), S100A8/A9, interleukin (IL)-1β, IL-18, and IL-6. Diabetic and pre-diabetic statuses were defined using glycated hemoglobin (HbA1c) and medical history (ADA 2019 criteria). To assess glycemic parameters, we employed the glycemia ratio (GR) and the homeostatic model assessment of insulin resistance (HOMA-IR) index, enabling a precise evaluation of stress hyperglycemia, acute IR, and their prognostic implications. Patients were stratified into groups based on GR calculations, categorized as under-average glycemia, normal glycemia, and stress hyperglycemia. Results The majority of patients in the stress hyperglycemia group exhibited an unfavorable prognosis. This group also demonstrated significantly elevated neutrophil counts and neutrophil-to-lymphocyte ratios (NLR). The GR was significantly and positively correlated with inflammation markers, including neutrophil count (Pearson's R = 0.181, P = 0.008) and NLR (Pearson's R = 0.318, P < 0.001), but showed no significant correlation with other evaluated inflammatory markers. Conclusions Our findings suggest that poor outcomes in AMI patients may be associated with stress hyperglycemia, as indicated by GR. AcuteIR, quantified by GR and HOMA-IR, exhibits a strong correlation with neutrophil count and NLR within the first 24 hours of AMI onset. However, no significant correlation was observed with other inflammatory markers, such as IL-1β, IL-18, and IL-6, underscoring the specific interplay between IR and neutrophil activity in this setting.

SGLT2 inhibitor improves the prognosis of patients with coronary heart disease and prevents in-stent restenosis

Coronary heart disease is a narrowing or obstruction of the vascular cavity caused by atherosclerosis of the coronary arteries, which leads to myocardial ischemia and hypoxia. At present, percutaneous coronary intervention (PCI) is an effective treatment for coronary atherosclerotic heart disease. Restenosis is the main limiting factor of the long-term success of PCI, and it is also a difficult problem in the field of intervention. Sodium-glucose cotransporter 2 (SGLT2) inhibitor is a new oral glucose-lowering agent used in the treatment of diabetes in recent years. Recent studies have shown that SGLT2 inhibitors can effectively improve the prognosis of patients after PCI and reduce the occurrence of restenosis. This review provides an overview of the clinical studies and mechanisms of SGLT2 inhibitors in the prevention of restenosis, providing a new option for improving the clinical prognosis of patients after PCI.