How Diabetes and Heart Failure Modulate Each Other and Condition Management

Txnip promotes autophagic apoptosis in diabetic cardiomyopathy by upregulating FoxO1 and its acetylation

Autophagy dysfunction and apoptosis exacerbate the risk of heart failure in patients with diabetic cardiomyopathy (DCM). However, the interactions between autophagy and apoptosis in DCM and their underlying mechanisms remain poorly understood. This study induced type 1 DCM in C57BL/6 mice via streptozotocin injection and exposed H9C2 cells to high glucose to investigate these mechanisms. The study revealed a significant elevation in autophagic vesicles and compromised autophagic flux, accompanied by pronounced myocardial cell apoptosis in the myocardium of diabetic mice. Long-term exposure to high glucose in H9C2 cells led to enhanced autophagosome formation and impaired autophagic flux, while inhibition of autophagy with 3-MA reduced cell apoptosis. Additionally, we observed an increase in Txnip expression in the myocardium of diabetic mice and in high glucose-treated H9C2 cells, which regulates autophagic apoptosis in high glucose-treated H9C2 cells. Furthermore, Txnip regulates autophagic apoptosis through the modulation of forkhead box-1 (FoxO1) expression and acetylation. Prolonged high glucose exposure resulted in increased levels of phosphorylated sirtuin 1 (SIRT1) and reduced SIRT1/FoxO1 interaction, changes that were ameliorated by Txnip knockdown. Txnip overexpression elevated FoxO1 levels, which could be suppressed by NAC and GSH. These findings revealed that Txnip mediates autophagic apoptosis in DCM by upregulating FoxO1 via ROS and enhancing FoxO1 acetylation through the suppression of SIRT1 activity. The discovery of this new mechanism provides new perspectives and potential therapeutic targets for understanding and treating DCM.

Prescribing trends of SGLT2 inhibitors among HFrEF and HFpEF patients with and without T2DM, 2013-2021

BACKGROUND

Sodium-glucose cotransporter-2 inhibitors (SGLT2i) are recommended for treatment of heart failure (HF), regardless of type 2 diabetes (T2DM) status. However, limited data exist on SGLT2i prescribing in HF patients without T2DM or across HF subtypes.

METHODS

This was a serial, cross-sectional study of US MarketScan commercial and Medicare claims (2013-2021). Prevalence of SGLT2i was calculated by calendar year among HFrEF and HFpEF patients and stratified by T2DM status.

RESULTS

Among 218,066 HFrEF patients [mean (SD): 54.9 (8.92) years; 66.4% male], the prevalence of SGLT2i use increased from 0.3 to 18.6%, while among 150,437 HFpEF patients [56.5 (7.77) years; 47.6% male], it rose from 0.5 to 9.9%. These increases were driven by the subgroup with comorbid T2DM. SGLT2i prevalence use ratios among patients with T2DM compared to those without decreased from > 100 in 2018 to 3.8 in 2021 among HFrEF patients, and from 83.1 in 2018 to 17.5 in 2021, coinciding with the publication of landmark trials and corresponding changes in clinical guidelines.

CONCLUSIONS

SGLT2i use rose rapidly following changes in guidelines but remained low among those without T2DM. By the end of the study, approximately 1 in 3 HFrEF and 1 in 5 HFpEF patients with T2DM were using an SGLT2i, compared to only 1 in 11 HFrEF and 1 in 85 HFpEF patients without T2DM. Future work identifying barriers with the uptake of GDMT, including SGLT2i, among HF patients is needed.

An Overview of Diabetic Cardiomyopathy

Diabetic cardiomyopathy (DCM) is a myocardial disorder that is characterised by structural and functional abnormalities of the heart muscle in the absence of hypertension, valvular heart disease, congenital heart defects, or coronary artery disease (CAD). After witnessing a particular form of cardiomyopathy in diabetic individuals, Rubler et al. came up with the moniker diabetic cardiomyopathy in 1972. Four stages of DCM are documented, and the American College of Cardiology/American Heart Association Stage and New York Heart Association Class for HF have some overlap. Diabetes is linked to several distinct forms of heart failure. Around 40% of people with heart failure with preserved ejection fraction (HFpEF) have diabetes, which is thought to be closely associated with the pathophysiology of HFpEF. Diabetes and HF are uniquely associated in a bidirectional manner. When compared to the general population without diabetes, those with diabetes have a risk of heart failure that is up to four times higher. A biomarker is a trait that is reliably measured and assessed as a predictor of healthy biological activities, pathological processes, or pharmacologic responses to a clinical treatment. Several biomarker values have been discovered to be greater in patients with diabetes than in control subjects among those who have recently developed heart failure. Myocardial fibrosis and hypertrophy are the primary characteristics of DCM, and structural alterations in the diabetic myocardium are often examined by non-invasive, reliable, and reproducible procedures. An invasive method called endomyocardial biopsy (EMB) is most often used to diagnose many cardiac illnesses.

Diabetes leading to heart failure and heart failure leading to diabetes: epidemiological and clinical evidence

Type 2 diabetes mellitus (T2DM) is a risk factor that plays a major role in the onset of heart failure (HF) both directly, by impairing cardiac function, and indirectly, through associated diseases such as hypertension, coronary disease, renal dysfunction, obesity, and other metabolic disorders. In a population of HF patients, the presence of T2DM ranged from 20 to 40%, according to the population studied, risk factor characteristics, geographic area, and age, and it is associated with a worse prognosis. Finally, patients with HF, when compared with those without HF, show an increased risk for the onset of T2DM due to several mechanisms that predispose the HF patient to insulin resistance. Despite the epidemiological data confirmed the relationship between T2DM and HF, the exact prevalence of HF in T2DM comes from interventional trials rather than from observational registries aimed to prospectively evaluate the risk of HF occurrence in T2DM population. This review is focused on the vicious cycle linking HF and T2DM, from epidemiological data to prognostic implications.

Nitrative Modification of Caveolin-3: A Novel Mechanism of Cardiac Insulin Resistance and a Potential Therapeutic Target Against Ischemic Heart Failure in Prediabetic Animals

BACKGROUND

Myocardial insulin resistance is a hallmark of diabetic cardiac injury. However, the underlying molecular mechanisms remain unclear. Recent studies demonstrate that the diabetic heart is resistant to other cardioprotective interventions, including adiponectin and preconditioning. The "universal" resistance to multiple therapeutic interventions suggests impairment of the requisite molecule(s) involved in broad prosurvival signaling cascades. Cav (Caveolin) is a scaffolding protein coordinating transmembrane signaling transduction. However, the role of Cav3 in diabetic impairment of cardiac protective signaling and diabetic ischemic heart failure is unknown.

METHODS

Wild-type and gene-manipulated mice were fed a normal diet or high-fat diet for 2 to 12 weeks and subjected to myocardial ischemia and reperfusion. Insulin cardioprotection was determined.

RESULTS

Compared with the normal diet group, the cardioprotective effect of insulin was significantly blunted as early as 4 weeks of high-fat diet feeding (prediabetes), a time point where expression levels of insulin-signaling molecules remained unchanged. However, Cav3/insulin receptor-β complex formation was significantly reduced. Among multiple posttranslational modifications altering protein/protein interaction, Cav3 (not insulin receptor-β) tyrosine nitration is prominent in the prediabetic heart. Treatment of cardiomyocytes with 5-amino-3-(4-morpholinyl)-1,2,3-oxadiazolium chloride reduced the signalsome complex and blocked insulin transmembrane signaling. Mass spectrometry identified Tyr73 as the Cav3 nitration site. Phenylalanine substitution of Tyr73 (Cav3Y73F) abolished 5-amino-3-(4-morpholinyl)-1,2,3-oxadiazolium chloride-induced Cav3 nitration, restored Cav3/insulin receptor-β complex, and rescued insulin transmembrane signaling. It is most important that adeno-associated virus 9-mediated cardiomyocyte-specific Cav3Y73F reexpression blocked high-fat diet-induced Cav3 nitration, preserved Cav3 signalsome integrity, restored transmembrane signaling, and rescued insulin-protective action against ischemic heart failure. Last, diabetic nitrative modification of Cav3 at Tyr73 also reduced Cav3/AdipoR1 complex formation and blocked adiponectin cardioprotective signaling.

CONCLUSIONS

Nitration of Cav3 at Tyr73 and resultant signal complex dissociation results in cardiac insulin/adiponectin resistance in the prediabetic heart, contributing to ischemic heart failure progression. Early interventions preserving Cav3-centered signalsome integrity is an effective novel strategy against diabetic exacerbation of ischemic heart failure.

Lower Circulating Cell-Free Mitochondrial DNA Is Associated with Heart Failure in Type 2 Diabetes Mellitus Patients

Cell-free nuclear (cf-nDNA) and mitochondrial (cf-mDNA) DNA are released from damaged cells in type 2 diabetes mellitus (T2DM) patients, contributing to adverse cardiac remodeling, vascular dysfunction, and inflammation. The purpose of this study was to correlate the presence and type of cf-DNAs with HF in T2DM patients. A total of 612 T2DM patients were prescreened by using a local database, and 240 patients (120 non-HF and 120 HF individuals) were ultimately selected. The collection of medical information, including both echocardiography and Doppler imagery, as well as the assessment of biochemistry parameters and the circulating biomarkers, were performed at baseline. The N-terminal brain natriuretic pro-peptide (NT-proBNP) and cf-nDNA/cf-mtDNA levels were measured via an ELISA kit and real-time quantitative PCR tests, respectively. We found that HF patients possessed significantly higher levels of cf-nDNA (9.9 ± 2.5 μmol/L vs. 5.4 ± 2.7 μmol/L; p = 0.04) and lower cf-mtDNA (15.7 ± 3.3 μmol/L vs. 30.4 ± 4.8 μmol/L; p = 0.001) than those without HF. The multivariate log regression showed that the discriminative potency of cf-nDNA >7.6 μmol/L (OR = 1.07; 95% CI = 1.03–1.12; p = 0.01) was higher that the NT-proBNP (odds ratio [OR] = 1.10; 95% confidence interval [CI] = 1.04–1.19; p = 0.001) for HF. In conclusion, we independently established that elevated levels of cf-nDNA, originating from NT-proBNP, were associated with HF in T2DM patients.

Predictive value of serum irisin for chronic heart failure in patients with type 2 diabetes mellitus

We hypothesize that serum irisin can have additional discriminative potency for heart failure (HF) in individuals with type 2 diabetes mellitus (T2DM). The study group comprised 226 consecutive T2DM patients (153 patients with any HF phenotypes and 30 patients without HF) aged 41 to 65 years. The plasma levels N-terminal brain natriuretic pro-peptide (NT-proBNP) and irisin were detected by ELISA at the baseline of the study. We found that the most appropriate cut-off value of irisin (HF versus non-HF) were 10.4 ng/mL (area under curve [AUC] = 0.96, sensitivity = 81.0%, specificity = 88.0%; P = 0.0001). Cutoff point of NT-proBNP that distinguished patients with HF and without it was 750 pmol/L (AUC = 0.78; sensitivity = 72.7%, specificity 76.5%, p = 0.0001). Using multivariate comparative analysis we established that concentrations of irisin < 10.4 ng/mL (odds ration [OR] = 1.30; P = 0.001) and NT-proBNP > 750 pmol/mL (OR = 1.17; P = 0.042), left atrial volume index (LAVI) > 34 mL/m² (OR = 1.06; P = 0.042) independently predicted HF. Irisin being added to NT-proBNP improved predictive modality for HF, whereas combination of NT-proBNP and LAVI > 34 mL/m² did not. In conclusion, we established that irisin had independent predicted potency for HF in patients with established T2DM.

Diabetes Mellitus and Heart Failure

The coexistence of diabetes mellitus (DM) and heart failure (HF) is frequent and is associated with a higher risk of hospitalization for HF and all-cause and cardiovascular mortality. It has been estimated that millions of people are affected by HF and DM, and the prevalence of both conditions has increased over time. Concomitant HF and diabetes confer a worse prognosis than each alone; therefore, managing DM care is critical for preventing HF. This article reviews the prevalence of HF and diabetes and the correlated prognosis as well as provides a basic understanding of diabetic cardiomyopathy, including its pathophysiology, focusing on the relationship between DM and HF with a preserved ejection fraction and summarizes the potential aldosterone and the mineralocorticoid receptor antagonists approaches for managing heart failure and DM. Sodium–glucose cotransporter 2 inhibitors (SGLT2Is) are an emerging class of glucose-lowering drugs, and the role of SGLT2Is in DM patients with HF was reviewed to establish updated and comprehensive concepts for improving optimal medical care in clinical practice.

Use of Digital Health Technology in Heart Failure and Diabetes: a Scoping Review

Use of digital health technologies (DHT) in chronic disease management is rising. We aim to evaluate the impact of DHT on clinical outcomes from randomized controlled trials (RCTs) of patients with heart failure (HF) and diabetes mellitus (DM). Electronic databases were searched for DHT RCTs in patients with HF and DM until February 2021. Patient characteristics and outcomes were analyzed. One published (N = 519) and 6 registered (N = 3423) eligible studies were identified, with one study exclusively including HF and DM patients. Median DHT monitoring was 12 months, with six studies using mobile platforms as their key exposure. Clinical outcomes included quality-of-life or self-care surveys (n = 1 each), physical activity metrics, changes in biomarkers, and other clinical endpoints (n = 3). Limited data exist on RCTs evaluating DHT in patients with concomitant HF and DM. Further work should define standardized clinical endpoints and platforms that can manage patients with multiple comorbidities.

KDM3A Inhibition Ameliorates Hyperglycemia-Mediated Myocardial Injury by Epigenetic Modulation of Nuclear Factor Kappa-B/P65

Objectives

Even after the glucose level returns to normal, hyperglycemia-induced cardiac dysfunction as well as reactive oxygen species (ROS) generation, inflammatory responses, and apoptosis continued deterioration, showing a long-lasting adverse effect on cardiac function and structure. We aimed to unveil the molecular and cellular mechanisms underlying hyperglycemia-induced persistent myocardial injury and cardiac dysfunction.

Methods and Results

Recently, the accumulated evidence indicated epigenetic regulation act as a determining factor in hyperglycemia-induced continuous cardiovascular dysfunction. As an important histone demethylase, the expression of lysine-specific demethylase 3A (KDM3A) was continually increased, accompanied by a sustained decline of H3K9me2 levels in diabetic myocardium even if received hypoglycemic therapy. Besides, by utilizing gain- and loss-of-functional approaches, we identified KDM3A as a novel regulator that accelerates hyperglycemia-mediated myocardial injury by promoting ROS generation, aggregating inflammatory reaction, and facilitating cell apoptosis in vitro and in vivo. The KDM3A inhibition could significantly ameliorate the adverse effect of hyperglycemia in both diabetes model and diabetic intensive glycemic control model. Mechanically, our data uncovered that KDM3A could promote the expression and transcriptional activity of nuclear factor kappa-B (NF-κB/P65), and the succedent rescue experiments further verified that KDM3A regulates hyperglycemia-induced myocardial injury in an NF-κB/P65 dependent manner.

Conclusion

This study revealed histone-modifying enzymes KDM3A drives persistent oxidative stress, inflammation, apoptosis, and subsequent myocardial injury in the diabetic heart by regulating the transcription of NF-κB/P65.

CIDEC: A Potential Factor in Diabetic Vascular Inflammation

Cell death-inducing DFF45-like effector C (CIDEC) is involved in diet-induced adipose inflammation. Whether CIDEC plays a role in diabetic vascular inflammation remains unclear. A type 2 diabetic rat model was induced by high-fat diet and low-dose streptozotocin. We evaluated its characteristics by metabolic tests, Western blot analysis of CIDEC and C1q/tumor necrosis factor-related protein-3 (CTRP3) expression, and histopathological analysis of aortic tissues. The diabetic group exhibited elevated CIDEC expression, aortic inflammation, and remodeling. To further investigate the role of CIDEC in the pathogenesis of aortic inflammation, gene silencing was used. With CIDEC gene silencing, CTRP3 expression was restored, accompanied with amelioration of insulin resistance, aortic inflammation, and remodeling in diabetic rats. Thus, the silencing of CIDEC is potent in mediating the reversal of aortic inflammation and remodeling, indicating that CIDEC may be a potential therapeutic target for vascular complications in diabetes.

Inhibition of the long non-coding RNA ZFAS1 attenuates ferroptosis by sponging miR-150-5p and activates CCND2 against diabetic cardiomyopathy

Diabetic cardiomyopathy (DbCM) is responsible for increased morbidity and mortality in patients with diabetes and heart failure. However, the pathogenesis of DbCM has not yet been identified. Here, we investigated the important role of lncRNA-ZFAS1 in the pathological process of DbCM, which is associated with ferroptosis. Microarray data analysis of DbCM in patients or mouse models from GEO revealed the significance of ZFAS1 and the significant downregulation of miR-150-5p and CCND2. Briefly, DbCM was established in high glucose (HG)-treated cardiomyocytes and db/db mice to form in vitro and in vivo models. Ad-ZFAS1, Ad-sh-ZFAS1, mimic miR-150-5p, Ad-CCND2 and Ad-sh-CCND2 were intracoronarily administered to the mouse model or transfected into HG-treated cardiomyocytes to determine whether ZFAS1 regulates miR-150-5p and CCND2 in ferroptosis. The effect of ZFAS1 on the left ventricular myocardial tissues of db/db mice and HG-treated cardiomyocytes, ferroptosis and apoptosis was determined by Masson staining, immunohistochemical staining, Western blotting, monobromobimane staining, immunofluorescence staining and JC-1 staining. The relationships among ZFAS1, miR-150-5p and CCND2 were evaluated using dual-luciferase reporter assays and RNA pull-down assays. Inhibition of ZFAS1 led to reduced collagen deposition, decreased cardiomyocyte apoptosis and ferroptosis, and attenuated DbCM progression. ZFAS1 sponges miR-150-5p to downregulate CCND2 expression. Ad-sh-ZFAS1, miR-150-5p mimic, and Ad-CCND2 transfection attenuated ferroptosis and DbCM development both in vitro and in vivo. However, transfection with Ad-ZFAS1 could reverse the positive effects of miR-150-5p mimic and Ad-CCND2 in vitro and in vivo. lncRNA-ZFAS1 acted as a ceRNA to sponge miR-150-5p and downregulate CCND2 to promote cardiomyocyte ferroptosis and DbCM development. Thus, ZFAS1 inhibition could be a promising therapeutic target for the treatment and prevention of DbCM.