Assessing the risk factors for myocardial infarction in diet-induced prediabetes: myocardial tissue changes

Abstract

Background Hyperglycaemia is known to result in oxidative stress tissue injury and dysfunction. Interestingly, studies have reported hepatic and renal oxidative stress injury during prediabetes; however, any injury to the myocardium during prediabetes has not been investigated. Hence this study aims to assess changes in the myocardial tissue in an HFHC diet-induced model of prediabetes. Methods Male Sprague Dawley rats were randomly grouped into non-prediabetes and prediabetes (n = 6 in each group) and consumed a standard rat chow or fed a high-fat-high-carbohydrate diet respectively for a 20-week prediabetes induction period. Post induction, prediabetes was confirmed using the ADA criteria. Aldose reductase, NADH oxidase 1, superoxide dismutase, glutathione peroxide, cardiac troponins were analysed in cardiac tissue homogenate using specific ELISA kits. Lipid peroxidation was estimated by determining the concentration of malondialdehyde in the heart tissue homogenate according to the previously described protocol. Myocardial tissue sections were stained with H&E stain and analysed using Leica microsystem. All data were expressed as means ± SEM. Statistical comparisons were performed with Graph Pad instat Software using the Student's two-sided t-test. Pearson correlation coefficient was calculated to assess the association. Value of p < 0.05 was considered statistically significant. Results The prediabetes group showed a markedly high oxidative stress as indicated by significantly increased NADH oxidase 1 and malondialdehyde while superoxide dismutase and glutathione peroxide were decreased compared to non-prediabetes group. There was no statistical difference between cardiac troponin I and T in the non-prediabetes and prediabetes groups. Cardiac troponins had a weak positive association with glycated haemoglobin. Conclusion The findings of this study demonstrate that prediabetes is associated with myocardial injury through oxidative stress. Future studies are to investigate cardiac contractile function and include more cardiac biomarkers.

The Impact of Resveratrol-Enriched Bread on Cardiac Remodeling in a Preclinical Model of Diabetes

“…However, there were no significant differences in the SIRT3 content among the experimental groups, and there were no signs of increased ROS production given by protein carbonylation and nitration. These findings are in contrast with other studies that observed an increase in oxidative stress biomarkers and a decrease in antioxidant enzymes in high-fat high-carbohydrates diet prediabetic-induced Sprague Dawley rats [80]. Overall, our data highlight a higher reliance of fructose/STZ rats on FAO to support the energetic needs of the heart, despite no apparent alterations in glycolysis and mitochondrial dynamics and increased ROS generation.…”

The Role of Pro-Opiomelanocortin Derivatives in the Development of Type 2 Diabetes-Associated Myocardial Infarction: Possible Links with Prediabetes

“…Impaired glucose homeostasis plays a role in CVD through inflammation, atherosclerosis, endothelial dysfunction, and hypertension [133]. Studies have demonstrated that during prediabetes, there is an increase in heart rate, blood pressure, CRP, and ET-1 and a decrease in eNOS; therefore, there is an increased risk of MI [134]. Impaired fasting glucose (IFG) is associated with unrecognized myocardial infarctions in a multi-ethnic population free of baseline cardiovascular disease [135].…”

Evaluating the impact of type 2 diabetes mellitus on pulmonary vascular function and the development of pulmonary fibrosis

“…There is growing evidence that respiratory disorders may also be associated with prediabetes ( 11 – 13 ). While the primary focus has traditionally been on the risk of cardiovascular disease and microvascular complications in prediabetes, attention should also be increased to the potential impact on pulmonary health ( 85 ). See in Figure 2 below.…”

“…Prediabetes is a metabolic condition that serves as an intermediate stage in the progression from normal glucose metabolism to overt diabetes and is associated with an increased risk of developing T2DM and cardiovascular disease ( 85 , 86 ). This intermediate hyperglycemic state is characterized by impaired glucose tolerance and elevated blood sugar levels below the threshold for diabetes diagnosis ( 86 ).…”