Heart Failure: The Most Important, Preventable, and Treatable Cardiovascular Complication of Type 2 Diabetes

Modeling recurrent heart failure risk in type 2 diabetes: impact of flexible HbA1c trajectories using nonhomogeneous Poisson processes

Background

Many clinical trials yielded inconsistent results regarding the effect of intensive glycated hemoglobin control on cardiovascular diseases in type 2 diabetes. We identified distinct HbA1c trajectories and their association with the recurrent hospitalization of heart failures (HHF) for patients with type 2 diabetes starting from the date of diabetes diagnosis.

Methods

In this study, we included 194,258 patients who entered the SingHealth Diabetes Registry from 2013 to 2020. Their diagnoses of type 2 diabetes spanned the years 1960-2020, encompassing HbA1c measurements, records of HHF, and other cardiovascular complications. Latent class growth models (LCGM) with splines were used to extract the subgroups with distinct HbA1c trajectories. The association between HbA1c trajectories and the recurrent risk of HHF was investigated by nonhomogeneous Poisson processes (NHPP).

Results

Eight distinct HbA1c trajectories were identified as follows: low stable (LowS, 22.2%), moderate low ascending (ModLowA, 12.7%), moderate high ascending (ModHighA, 11.5%), moderate low descending (ModLowD, 17.2%), moderate high descending (ModHighD, 10.1%), moderate high volatility (ModHighV, 10.1%), high with a sharp decline (HighSD, 8.0%), and high volatility (HighV, 10.2%). Using the Class LowS as a reference, the hazard ratios for recurrent HHF for the other classes are as follows: 0.79 for ModLowA, 1.30 for ModHighA, 1.17 for ModLowD, 1.89 for ModHighD, 1.94 for ModHighV, 1.25 for HighSD, and 2.88 for HighV. Considering recurrent HHFs, our NHPP model demonstrated predictive capability for type 2 diabetes patients' future HHF events.

Conclusions

Low baseline HbA1c levels are associated with a lower risk of recurrent HHF, while poor glycemic control significantly increases this risk. Our application of LCGM with splines effectively captures flexible, long-term HbA1c trajectories, while the innovative use of the NHPP model allows for precise modeling of HHF recurrence risk. This approach provides a foundation for personalized risk predictions and future HF management by incorporating dynamically updated risk factors.

The Role of Resistin in Macrovascular and Microvascular Complications of Type 2 Diabetes

Resistin is an adipokine produced in adipose tissue with pro-inflammatory properties, whose elevation has been associated with insulin resistance and diabetes. Over the past years, significant research has explored the pathophysiological mechanisms involving resistin, utilizing various in vitro and in vivo models. Additionally, numerous clinical studies have aimed to establish a correlation between resistin and the development and progression of macrovascular and microvascular complications in type 2 diabetes. This narrative review summarizes in vitro, in vivo, and human studies published in English since the discovery of resistin in 2001 to the present, examining the role of this adipokine in the pathophysiology of macrovascular and microvascular complications in in vivo and in vitro T2D models, as well as the clinical evidence supporting its use as a biochemical marker in patients with these conditions. The results exhibit considerable heterogeneity and appear to be dependent on the experimental model or population studied. While experimental evidence supports resistin's involvement at the cellular and molecular levels in the pathogenesis of these complications, current clinical evidence remains insufficient to justify its use as a biochemical marker for either diagnosis or prognosis. Therefore, further well-designed studies are required to elucidate resistin's potential role in the clinical setting.

Comparative Outcomes of Glucagon-Like Peptide-1 Receptor Agonists to Dipeptidyl Peptidase 4 Inhibitors in Patients With Heart Failure and Type 2 Diabetes

BACKGROUND

Clinical trials showed that glucagon-like peptide-1 receptor agonist (GLP1-RA) significantly improved the control of diabetes and reduced body weight compared with dipeptidyl peptidase 4 inhibitor (DPP-4i). However, it is unclear whether GLP1-RA is effective compared with DPP-4i in patients with heart failure (HF) with type 2 diabetes (T2D). The purpose of this study was to evaluate the risk of GLP1-RA compared with DPP-4i in all-cause death and hospitalization in patients with HF and T2D.

METHODS

This multicenter retrospective observational study using TriNetX, a global health care data and analytics platform, included patients with HF and T2D who had received GLP1-RA or DPP-4i from January 1, 2018, to December 31, 2022. Primary outcome was 12-month incidence of all-cause death. Secondary outcome was hospitalization. We used odds ratios (ORs) and 95% CIs to evaluate outcome measures.

RESULTS

Among 1 005 097 patients with HF and T2D, 57 965 initiated GLP1-RA and 77 098 initiated DPP-4i. After propensity score matching, the number of participants in both the GLP1-RA group and the DPP-4i group was 36 557. The proportion of 12-month incidence of all-cause death was lower in the GLP1-RA group than in the DPP-4i group (5.9% [2140/36 557] versus 8.5% [3103/36 557]; OR, 0.67 [95% CI, 0.63-0.71]).The proportion of 12-month incidence of hospitalization was also lower in the GLP1-RA group than in the DPP-4i group (42.3% [15 455/36 557] versus 48.5% [17 733/36 557]; OR, 0.78 [95% CI, 0.76-0.80]).

CONCLUSIONS

Use of GLP1-RA for patients with HF and T2D was associated with reduced 12-month incidence of all-cause death and hospitalization compared with DPP-4i.

Management of a Dual Low Sodium and Diabetic Diet by Patient-Caregiver Dyads: A Qualitative Descriptive Study

PURPOSE

The purpose of the study was to explore factors surrounding management of simultaneous dietary recommendations for heart failure and type 2 diabetes among patient-caregiver dyads.

METHODS

Qualitative description was used to explore dyad experiences managing a dual diet. Semi-structured interviews were conducted with patients with a concurrent diagnosis of type 2 diabetes and heart failure and their family caregiver. Each 60-minute interview was conducted virtually. Interviews were audio recorded and transcribed verbatim. Thematic analysis was conducted with coding used for themes at dyadic-and individual levels.

RESULTS

Twelve patient-caregiver dyads (N = 24) were interviewed. The mean age was 57 years (±15 years). Most participants were white (75%); patients were predominantly male, and caregivers were predominantly female (83.3% for both). Dyadic-level themes that emerged included factors that influence simultaneous management of dual diet recommendations. Themes included shared barriers, facilitators, motivators, and strategies for dual diet management. Individual-level themes discussed by patients were barriers and motivators to dual diet management, and caregivers discussed barriers to supporting dual diet management.

CONCLUSIONS

Findings from the study highlight that patients and caregivers often work together and share similar barriers, facilitators, motivators, and strategies for adhering to a dual diet. The results provide insight into chronic disease management at the family level and can guide health care providers' efforts to promote family involvement with dietary recommendations for patients with multiple comorbidities.

Endogenous adenine is a potential driver of the cardiovascular-kidney-metabolic syndrome

Mechanisms underlying the cardiovascular-kidney-metabolic (CKM) syndrome are unknown, although key small molecule metabolites may be involved. Bulk and spatial metabolomics identified adenine to be upregulated and specifically enriched in coronary blood vessels in hearts from patients with diabetes and left ventricular hypertrophy. Single nucleus gene expression studies revealed that endothelial methylthioadenosine phosphorylase (MTAP) was increased in human hearts with hypertrophic cardiomyopathy. The urine adenine/creatinine ratio in patients was predictive of incident heart failure with preserved ejection fraction. Heart adenine and MTAP gene expression was increased in a 2-hit mouse model of hypertrophic heart disease and in a model of diastolic dysfunction with diabetes. Inhibition of MTAP blocked adenine accumulation in the heart, restored heart dysfunction in mice with type 2 diabetes and prevented ischemic heart damage in a rat model of myocardial infarction. Mechanistically, adenine-induced impaired mitophagy was reversed by reduction of mTOR. These studies indicate that endogenous adenine is in a causal pathway for heart failure and ischemic heart disease in the context of CKM syndrome.

Application of neutrophil-lymphocyte ratio and red blood cell distribution width in diabetes mellitus complicated with heart failure

BACKGROUND

Accumulating clinical evidence has shown that diabetes mellitus (DM) is a serious risk factor for cardiovascular disorders and an important factor for adverse cardiovascular events.

AIM

To explore the value of the combined determination of the neutrophil-lymphocyte ratio (NLR) and red blood cell distribution width (RDW) in the early diagnosis and prognosis evaluation of DM complicated with heart failure (HF).

METHODS

We retrospectively analyzed clinical data on 65 patients with type 2 DM (T2DM) complicated with HF (research group, Res) and 60 concurrent patients with uncomplicated T2DM (control group, Con) diagnosed at Zhejiang Provincial People's Hospital between January 2019 and December 2021. The NLR and RDW values were determined and comparatively analyzed, and their levels in T2DM + HF patients with different cardiac function grades were recorded. The receiver operating characteristic (ROC) curves were plotted to determine the NLR and RDW values (alone and in combination) for the early diagnosis of HF. The correlation between NLR and RDW with the presence or absence of cardiac events was also investigated.

RESULTS

Higher NLR and RDW levels were identified in the Res vs the Con groups (P < 0.05). The NLR and RDW increased gradually and synchronously with the deterioration of cardiac function in the Res group, with marked differences in their levels among patients with grade II, III, and IV HF (P < 0.05). ROC curve analysis revealed that NLR combined with RDW detection had an area under the curve of 0.915, a sensitivity of 76.9%, and a specificity of 100% for the early diagnosis of HF. Furthermore, HF patients with cardiac events showed higher NLR and RDW values compared with HF patients without cardiac events.

CONCLUSION

NLR and RDW were useful laboratory indicators for the early diagnosis of DM complicated with HF, and their joint detection was beneficial for improving diagnostic efficiency. Additionally, NLR and RDW values were directly proportional to patient outcomes.

Glucagon-like peptide-1 receptor agonists and sodium-glucose cotransporter 2 inhibitors, anti-diabetic drugs in heart failure and cognitive impairment: potential mechanisms of the protective effects

Heart failure and cognitive impairment emerge as public health problems that need to be addressed due to the aging global population. The conditions that often coexist are strongly related to advancing age and multimorbidity. Epidemiological evidence indicates that cardiovascular disease and neurodegenerative processes shares similar aspects, in term of prevalence, age distribution, and mortality. Type 2 diabetes increasingly represents a risk factor associated not only to cardiometabolic pathologies but also to neurological conditions. The pathophysiological features of type 2 diabetes and its metabolic complications (hyperglycemia, hyperinsulinemia, and insulin resistance) play a crucial role in the development and progression of both heart failure and cognitive dysfunction. This connection has opened to a potential new strategy, in which new classes of anti-diabetic medications, such as glucagon-like peptide-1 receptor (GLP-1R) agonists and sodium-glucose cotransporter 2 (SGLT2) inhibitors, are able to reduce the overall risk of cardiovascular events and neuronal damage, showing additional protective effects beyond glycemic control. The pleiotropic effects of GLP-1R agonists and SGLT2 inhibitors have been extensively investigated. They exert direct and indirect cardioprotective and neuroprotective actions, by reducing inflammation, oxidative stress, ions overload, and restoring insulin signaling. Nonetheless, the specificity of pathways and their contribution has not been fully elucidated, and this underlines the urgency for more comprehensive research.

A self-reinforcing cycle hypothesis in heart failure pathogenesis

Heart failure is a progressive syndrome with high morbidity and mortality rates. Here, we suggest that chronic exposure of the heart to risk factors for heart failure damages heart mitochondria, thereby impairing energy production to levels that can suppress the heart's ability to pump blood and repair mitochondria (both energy-consuming processes). As damaged mitochondria accumulate, the heart becomes deprived of energy in a 'self-reinforcing cycle', which can persist after the heart is no longer chronically exposed to (or after antagonism of) the risk factors that initiated the cycle. Together with other previously described pathological mechanisms, this proposed cycle can help explain (1) why heart failure progresses, (2) why it can recur after cessation of treatment, and (3) why heart failure is often accompanied by dysfunction of multiple organs. Ideally, therapy of heart failure syndrome would be best attempted before the self-reinforcing cycle is triggered or designed to break the self-reinforcing cycle.

The double burden: type 1 diabetes and heart failure-a comprehensive review

Heart failure (HF) is increasing at an alarming rate, primary due to the rising in aging, obesity and diabetes. Notably, individuals with type 1 diabetes (T1D) face a significantly elevated risk of HF, leading to more hospitalizations and increased case fatality rates. Several risk factors contribute to HF in T1D, including poor glycemic control, female gender, smoking, hypertension, elevated BMI, and albuminuria. However, early and intensive glycemic control can mitigate the long-term risk of HF in individuals with T1D. The pathophysiology of diabetes-associated HF is complex and multifactorial, and the underlying mechanisms in T1D remain incompletely elucidated. In terms of treatment, much of the evidence comes from type 2 diabetes (T2D) populations, so applying it to T1D requires caution. Sodium-glucose cotransporter 2 inhibitors have shown benefits in HF outcomes, even in non-diabetic populations. However, most of the information about HF and the evidence from cardiovascular safety trials related to glucose lowering medications refer to T2D. Glycemic control is key, but the link between hypoglycemia and HF hospitalization risk requires further study. Glycemic variability, common in T1D, is an independent HF risk factor. Technological advances offer the potential to improve glycemic control, including glycemic variability, and may play a role in preventing HF. In summary, HF in T1D is a complex challenge with unique dimensions. This review focuses on HF in individuals with T1D, exploring its epidemiology, risk factors, pathophysiology, diagnosis and treatment, which is crucial for developing tailored prevention and management strategies for this population.

Inhibiting Rev-erbα-mediated ferroptosis alleviates susceptibility to myocardial ischemia-reperfusion injury in type 2 diabetes

The complex progression of type-2 diabetes (T2DM) may result in increased susceptibility to myocardial ischemia-reperfusion (IR) injury. IR injuries in multiple organs involves ferroptosis. Recently, the clock gene Rev-erbα has aroused considerable interest as a novel therapeutic target for metabolic and ischemic heart diseases. Herein, we investigated the roles of Rev-erbα and ferroptosis in myocardial IR injury during T2DM and its potential mechanisms. A T2DM model, myocardial IR and a tissue-specific Rev-erbα-/- mouse in vivo were established, and a high-fat high glucose environment with hypoxia-reoxygenation (HFHG/HR) in H9c2 were also performed. After myocardial IR, glycolipid profiles, creatine kinase-MB, AI, and the expression of Rev-erbα and ferroptosis-related proteins were increased in diabetic rats with impaired cardiac function compared to non-diabetic rats, regardless of the time at which IR was induced. The ferroptosis inhibitor ferrostatin-1 decreased AI in diabetic rats given IR and LPO levels in cells treated with HFHG/HR, as well as the expression of Rev-erbα and ACSL4. The ferroptosis inducer erastin increased AI and LPO levels and ACSL4 expression. Treatment with the circadian regulator nobiletin and genetically targeting Rev-erbα via siRNA or CRISPR/Cas9 technology both protected against severe myocardial injury and decreased Rev-erbα and ACSL4 expression, compared to the respective controls. Taken together, these data suggest that ferroptosis is involved in the susceptibility to myocardial IR injury during T2DM, and that targeting Rev-erbα could alleviate myocardial IR injury by inhibiting ferroptosis.

Heart failure and diabetes: Understanding the bidirectional relationship

Heart failure and diabetes mellitus are 2 common and closely intertwined chronic conditions that often coexist in individuals. The relationship between heart failure and diabetes is bidirectional, meaning that each condition can influence the development and progression of the other. Understanding this complex interplay is crucial for optimizing the management and outcomes of patients with these comorbidities. This review comprehensively analyzed the literature to examine the bidirectional relationship between heart failure and diabetes. We searched various electronic databases and included studies that explored the pathophysiological mechanisms, epidemiology, clinical implications, and therapeutic considerations associated with this relationship. The bidirectional relationship between heart failure and diabetes is multifactorial and involves several interconnected mechanisms. Diabetes is a recognized risk factor for heart failure, increasing the risk of its development and accelerating its progression. On the other hand, heart failure can contribute to the development of insulin resistance and worsen glycemic control in patients with diabetes. Shared risk factors, such as obesity, hypertension, and dyslipidemia, contribute to development of both conditions. Additionally, hyperglycemia, insulin resistance, chronic inflammation, oxidative stress, and mitochondrial dysfunction play significant roles in the pathogenesis of heart failure in individuals with diabetes. The bidirectional relationship between heart failure and diabetes has important clinical implications. Patients with heart failure and diabetes have worse outcomes, including higher hospitalization rates, morbidity, and mortality, than those without diabetes. Optimal management strategies should target both conditions simultaneously, focusing on lifestyle modifications, pharmacotherapy, glycemic control, and cardiovascular risk reduction.

Nobiletin alleviates myocardial ischemia-reperfusion injury via ferroptosis in rats with type-2 diabetes mellitus

Susceptibility to myocardial ischemia-reperfusion (IR) injury in type-2 diabetes (T2DM) remains disputed, although studies have reported that ferroptosis is associated with myocardial IR injury. Nobiletin, a flavonoid isolated from citrus peels, is an antioxidant that possesses anti-inflammatory and anti-diabetic activities. However, it remains unknown whether nobiletin has any protective effects on susceptibility to myocardial IR injury during T2DM in rats via ferroptosis. To investigate the effects and underlying mechanisms of nobiletin on myocardial IR injury during T2DM, we induced myocardial IR model in rats at T2DM onset vs mature disease. We also established a high-fat high-glucose (HFHG) and hypoxia-reoxygenation (H/R) model in H9c2 cells to imitate abnormal glycolipid metabolism during T2DM. Myocardial injury, oxidative stress and ferroptosis towards myocardial IR in rats with mature T2DM but not at T2DM onset were increased. These changes were restored under treatment with ferrostain-1 or nobiletin. Both ferrostain-1 and nobiletin decreased the expression of ferroptosis-related proteins including Acyl-CoA synthetase long chain family member 4 (ACSL4) and nuclear receptor coactivator 4 (NCOA4) but not glutathione peroxidase 4 (GPX4) in rats with mature T2DM and cells with HFHG and H/R injury. Nobiletin strengthened the effect of si-ACSL4 on inhibiting ACSL4 expression, and also inhibited the effect of Erastin or oe-ACSL4 on increasing ACSL4 expression. Taken together, our data indicates that ferroptosis involves in susceptibility to myocardial IR injury in rats during T2DM. Nobiletin has therapeutic potential for alleviating myocardial IR injury associated with ACSL4- and NCOA4-related ferroptosis.

Diabetes and heart failure associations in women and men: Results from the MORGAM consortium

Background

Diabetes and its cardiovascular complications are a growing concern worldwide. Recently, some studies have demonstrated that relative risk of heart failure (HF) is higher in women with type 1 diabetes (T1DM) than in men. This study aims to validate these findings in cohorts representing five countries across Europe.

Methods

This study includes 88,559 (51.8% women) participants, 3,281 (46.3% women) of whom had diabetes at baseline. Survival analysis was performed with the outcomes of interest being death and HF with a follow-up time of 12 years. Sub-group analysis according to sex and type of diabetes was also performed for the HF outcome.

Results

6,460 deaths were recorded, of which 567 were amongst those with diabetes. Additionally, HF was diagnosed in 2,772 individuals (446 with diabetes). A multivariable Cox proportional hazard analysis showed that there was an increased risk of death and HF (hazard ratio (HR) of 1.73 [1.58-1.89] and 2.12 [1.91-2.36], respectively) when comparing those with diabetes and those without. The HR for HF was 6.72 [2.75-16.41] for women with T1DM vs. 5.80 [2.72-12.37] for men with T1DM, but the interaction term for sex differences was insignificant (p for interaction 0.45). There was no significant difference in the relative risk of HF between men and women when both types of diabetes were combined (HR 2.22 [1.93-2.54] vs. 1.99 [1.67-2.38] respectively, p for interaction 0.80).

Conclusion

Diabetes is associated with increased risks of death and heart failure, and there was no difference in relative risk according to sex.

Recommendations for Early and Comprehensive Management of Type 2 Diabetes and Its Related Cardio-Renal Complications

Type 2 diabetes (T2D) is a global health problem accompanied by an elevated risk of complications, the most common being cardiac and renal diseases. In Lebanon, the prevalence of T2D is estimated at 8-13%. Local medical practice generally suffers from clinical inertia, with gaps in the yearly assessment of clinical manifestations and suboptimal screening for major complications. The joint statement presented here, endorsed by five Lebanese scientific medical societies, aims at providing physicians in Lebanon with a tool for early, effective, and comprehensive care of patients with T2D. Findings from major randomized clinical trials of antidiabetic medications with cardio-renal benefits are presented, together with recommendations from international medical societies. Optimal care should be multidisciplinary and should include a multifactorial risk assessment, lifestyle modifications, and a regular evaluation of risks, including the risks for cardiovascular (CV) and renal complications. With international guidelines supporting a shift in T2D management from glucose-lowering agents to disease-modifying drugs, the present statement recommends treatment initiation with metformin, followed by the addition of sodium-glucose cotransporter 2 inhibitors or glucagon-like peptide-1 receptor agonists due to their CV and renal protection properties, whenever possible. In addition to the selection of the most appropriate pharmacological therapy, efforts should be made to provide continuous education to patients about their disease, with the aim to achieve a patient-centered approach and to foster self-management and adherence to the medical plan. Increasing the level of patient engagement is expected to be associated with favorable health outcomes. Finally, this statement recommends setting an achievable individualized management plan and conducting regular follow-ups to monitor the patients' glycemic status and assess their risks every 3-6 months.

Parasympathetic tonus in type 2 diabetes and pre-diabetes and its clinical implications

Autonomic imbalance reflected by higher resting heart rate and reduced parasympathetic tone may be driven by low-grade inflammation (LGI) and impaired glycemic control in type 2 diabetes mellitus (T2DM) and pre-diabetes. We examined the interaction of parasympathetic components of heart rate variability (HRV), variables of LGI, and glucose metabolism in people with T2DM, pre-diabetes, and normal glucose metabolism (NGM). We recorded HRV by Holter (48 h) in 633 community-dwelling people of whom T2DM n = 131, pre-diabetes n = 372, and NGM n = 130 and mean HbA1c of 7.2, 6.0 and 5.3%, respectively. Age was 55-75 years and all were without known cardiovascular disease except from hypertension. Fasting plasma glucose, fasting insulin, HOMA-IR, HbA1c and LGI (CRP, Interleukin-18 (IL-18), and white blood cells) were measured. Root-mean-square-of-normal-to-normal-beats (RMSSD), and proportion of normal-to-normal complexes differing by more than 50 ms (pNN50) are accepted measures of parasympathetic activity. In univariate analyses, RMSSD and pNN50 were significantly inversely correlated with level of HbA1c and CRP among people with T2DM and pre-diabetes, but not among NGM. RMSSD and pNN50 remained significantly inversely associated with level of HbA1c after adjusting for age, sex, smoking, and BMI among people with T2DM (β = - 0.22) and pre-diabetes (β = - 0.11); adjustment for LGI, HOMA-IR, and FPG did not attenuate these associations. In backward elimination models, age and level of HbA1c remained associated with RMSSD and pNN50. In people with well controlled diabetes and pre-diabetes, a lower parasympathetic activity was more related to age and HbA1c than to markers of LGI. Thus, this study shows that the driver of parasympathetic tonus may be more the level of glycemic control than inflammation in people with prediabetes and well controlled diabetes.

Cardiovascular protection by SGLT2 inhibitors - Do anti-inflammatory mechanisms play a role?

BACKGROUND

Metabolic syndrome and related metabolic disturbances represent a state of low-grade inflammation, which accelerates insulin resistance, type 2 diabetes (T2D) and cardiovascular disease (CVD) progression. Among antidiabetic medications, sodium glucose co-transporter (SGLT) 2 inhibitors are the only agents which showed remarkable reductions in heart failure (HF) hospitalizations and major cardiovascular endpoints (MACE) as well as renal endpoints regardless of diabetes status in large randomized clinical outcome trials (RCTs). Although the exact mechanisms underlying these benefits are yet to be established, growing evidence suggests that modulating inflammation by SGLT2 inhibitors may play a key role.

SCOPE OF REVIEW

In this manuscript, we summarize the current knowledge on anti-inflammatory effects of SGLT2 inhibitors as one of the mechanisms potentially mediating their cardiovascular (CV) benefits. We introduce the different metabolic and systemic actions mediated by these agents which could mitigate inflammation, and further present the signalling pathways potentially responsible for their proposed direct anti-inflammatory effects. We also discuss controversies surrounding some of these mechanisms.

MAJOR CONCLUSIONS

SGLT2 inhibitors are promising anti-inflammatory agents by acting either indirectly via improving metabolism and reducing stress conditions or via direct modulation of inflammatory signalling pathways. These effects were achieved, to a great extent, in a glucose-independent manner which established their clinical use in HF patients with and without diabetes.

Cardiovascular complications of diabetes

INTRODUCTION

Type 2 diabetes mellitus (T2DM) is the ninth leading cause of mortality globally, and the prevalence continues to rise. Among individuals with T2DM, over two-thirds of deaths are caused by the cardiovascular complications of diabetes. These complications include atherosclerosis, coronary artery disease, nephropathy, stroke, thromboembolism, peripheral vascular disease. They have been long studied, and there are several theories as to the pathophysiology of how diabetes leads to these complications. The least understood mechanism is the pathophysiology linking diabetes to heart failure.

AREAS COVERED

This review focuses on the mechanisms of how T2DM leads to the aforementioned complications, particularly highlighting the development of heart failure. An extensive literature review of novel therapeutic options targeting the cardiovascular effects of T2DM was completed and summarized in this review.

EXPERT OPINION

This review finds that most studies to date have focused on the atherosclerotic vascular complications of diabetes. The pathophysiology between T2DM and heart failure is even less understood. Currently therapies that aim to decrease the risk of heart failure in diabetes are sparse. More research is required in order to better understand the changes at a cellular level and subsequently help providers to choose therapeutics that better target cardiovascular complications.

Nonalbuminuric Diabetic Kidney Disease and Risk of All-Cause Mortality and Cardiovascular and Kidney Outcomes in Type 2 Diabetes: Findings From the Hong Kong Diabetes Biobank

RATIONALE & OBJECTIVE

Nonalbuminuric diabetic kidney disease (DKD) has become the prevailing DKD phenotype. We compared the risks of adverse outcomes among patients with this phenotype compared with other DKD phenotypes.

STUDY DESIGN

Multicenter prospective cohort study.

SETTINGS & PARTICIPANTS

19,025 Chinese adults with type 2 diabetes enrolled in the Hong Kong Diabetes Biobank.

EXPOSURES

DKD phenotypes defined by baseline estimated glomerular filtration rate (eGFR) and albuminuria: no DKD (no decreased eGFR or albuminuria), albuminuria without decreased eGFR, decreased eGFR without albuminuria, and albuminuria with decreased eGFR.

OUTCOMES

All-cause mortality, cardiovascular disease (CVD) events, hospitalization for heart failure (HF), and chronic kidney disease (CKD) progression (incident kidney failure or sustained eGFR reduction ≥40%).

ANALYTICAL APPROACH

Multivariable Cox proportional or cause-specific hazards models to estimate the relative risks of death, CVD, hospitalization for HF, and CKD progression. Multiple imputation was used for missing covariates.

RESULTS

Mean participant age was 61.1 years, 58.3% were male, and mean diabetes duration was 11.1 years. During 54,260 person-years of follow-up, 438 deaths, 1,076 CVD events, 298 hospitalizations for HF, and 1,161 episodes of CKD progression occurred. Compared with the no-DKD subgroup, the subgroup with decreased eGFR without albuminuria had higher risks of all-cause mortality (hazard ratio [HR], 1.59 [95% CI, 1.04-2.44]), hospitalization for HF (HR, 3.08 [95% CI, 1.82-5.21]), and CKD progression (HR, 2.37 [95% CI, 1.63-3.43]), but the risk of CVD was not significantly greater (HR, 1.14 [95% CI, 0.88-1.48]). The risks of death, CVD, hospitalization for HF, and CKD progression were higher in the setting of albuminuria with or without decreased eGFR. A sensitivity analysis that excluded participants with baseline eGFR <30 mL/min/1.73 m² yielded similar findings.

LIMITATIONS

Potential misclassification because of drug use.

CONCLUSIONS

Nonalbuminuric DKD was associated with higher risks of hospitalization for HF and of CKD progression than no DKD, regardless of baseline eGFR.

The mitochondria-targeted antioxidant MitoQ ameliorates myocardial ischemia-reperfusion injury by enhancing PINK1/Parkin-mediated mitophagy in type 2 diabetic rats

Type 2 diabetic hearts are more vulnerable to myocardial ischemia reperfusion (MIR) injury, which involves decreased mitophagy status with unknown mechanisms. MitoQ, a mitochondria-targeted antioxidant, has been shown to have protection against ischemia reperfusion injury through upregulating mitophagy. The aim of this study was to investigate the effects of MitoQ on myocardium during MIR injury in type 2 diabetes (T2D). Herein, this study discovered that type 2 diabetic hearts with PINK1/Parkin downregulation suffered more MIR injury accompanied by reduced mitophagy. Treatment with MitoQ significantly decreased the levels of CK-MB, LDH, myocardial infarction, myocardial pathological damage, and cardiomyocytes apoptosis, while it improved cardiac function, mitophagy status, and PINK1/Parkin pathway in vivo study. Furthermore, MitoQ significantly reduced high glucose/high fat and hypoxia/reoxygenation induced injury in H9C2 cells as evidenced by reduced cardiomyocytes apoptosis and ROS production, and increased cell viability, the level of mitochondrial membrane potential, PINK1/Parkin expression. However, mitochondrial division inhibitor (mdivi-1), an inhibitor of mitophagy, reversed the improvement and protein expression levels of PINK1/Parkin pathway in vitro models. In conclusion, MIR induced more severe damage in T2D by reduction of mitophagy. MitoQ can confer cardioprotection following MIR in T2D by mitophagy up-regulation via PINK1/Parkin pathway.

Stopping Empagliflozin Unmasks Heart Failure

SGLT2 inhibitors have been shown to have a role in the management of heart failure in patients with type 2 diabetes mellitus, but there is a risk of exacerbation when discontinued.

Risk of Incident Heart Failure in Individuals With Early-Onset Type 2 Diabetes

CONTEXT

Early-onset diabetes has been associated with unfavorable cardiovascular risk but data on heart failure (HF) in this subpopulation are scarce.

OBJECTIVE

We aimed to study the risk of, and risk factors for, incident HF in individuals with early-onset type 2 diabetes.

METHODS

We studied 606 individuals with type 2 diabetes diagnosed before 40 years of age (early-onset) and 1258 counterparts with diabetes diagnosed from 41 to 65 years of age (usual-onset) with no HF history, at a regional hospital, over a median follow-up period of 7.1 years. Incident HF by European Cardiology Society criteria was determined.

RESULTS

A total of 62 and 108 HF events were identified in the early- and usual-onset groups (1.55 and 1.29 per 100 patient-years), respectively. Compared with usual-onset counterparts, individuals with early-onset diabetes had a 1.20-fold unadjusted (95% CI, 0.88-1.63; P = 0.26) and 1.91-fold age-adjusted (95% CI, 1.37-2.66; P < 0.001) hazard ratio (HR) for incident HF. Adjustment for traditional cardiometabolic risk factors only moderately mitigated the hazards (adjusted HR 1.69; 95% CI, 1.19-2.40; P = 0.003). However, additional adjustment for estimated glomerular filtration rate and albuminuria markedly attenuated the association of early-onset age with incident HF (adjusted HR 1.24; 95% CI, 0.87-1.77; P = 0.24). Notably, a long diabetes duration was not significantly associated with HF risk after accounting for kidney measures.

CONCLUSION

Individuals with early-onset diabetes have at least the same absolute risk and a 2-fold age-adjusted relative risk for incident HF. Excess cardiorenal risk factors but not a long diabetes duration are main drivers for HF development in this diabetic population.

Current status on the therapeutic strategies for heart failure and diabetic cardiomyopathy

Heart failure (HF) is a leading cause of disease and death from cardiovascular diseases, with cardiovascular diseases accounting for the highest cases of deaths worldwide. The reality is that the quality-of-life survival for those suffering HF remains poor with 45-60% reported deaths within five years. Furthermore, cardiovascular disease is the foremost cause of mortality and disability in people with type 2 diabetes mellitus (T2DM), with T2DM patients having a two-fold greater risk of developing heart failure. The number of T2DM affected persons only continues to surge as there are more than 400 million adults affected by diabetes and an estimated 64.3 million affected by heart failure globally (1). In order to cater to the demands of modern society, the medical field has continuously improved upon the standards for clinical management and its therapeutic approaches. For this purpose, in this review, we aim to provide an overview of the current updates regarding heart failure, to include both heart failure with reduced ejection fraction (HFrEF) and heart failure with preserved ejection fraction (HFpEF) and their respective treatments, while also diving further into heart failure and its correlation with diabetes and diabetic cardiomyopathy and their respective therapeutic approaches.

Cardiovascular benefit of SGLT2 inhibitors

Patients with type 2 diabetes mellitus (T2D) are at increased risk of cardiovascular (CV) disease. Sodium glucose cotransporter 2 (SGLT2) inhibitors, also known as gliflozins, are a class of medications used to treat T2D by preventing the reabsorption of glucose filtered through the kidney and thereby facilitating glucose excretion in the urine. Over the past 5 years, many cardiovascular outcome trials (CVOTs) have evaluated the safety and efficacy of SGLT2 inhibitors in preventing CV events. The results of 7 CVOTs have provided solid evidence that the use of SGLT2 in patients with T2D and at high CV risk significantly reduced the risk of death from CV causes. Moreover, in patient with heart failure with reduced ejection fraction, regardless of the presence or absence of T2D, SGLT2 inhibitors use significantly reduced the risk of worsening heart failure and death from CV causes. Although the exact mechanism of the cardiorenal benefit of SGLT2 inhibitors is still unknown, studies have shown that the beneficial effect of these drugs cannot be exclusively explained by their glucose lowering effect, and several possible mechanisms have been proposed. This review will explore the changing role of SGLT2 inhibitors from a diabetes drug to clinical practice guideline-supported therapy for the prevention and treatment of CV diseases, including heart failure.

Association of the KDIGO Risk Classification with the Prevalence of Heart Failure in Patients with Type 2 Diabetes

The objectives of this study were to determine the main characteristics associated with the presence of heart failure (HF) in patients with type 2 diabetes (T2DM), and specifically to assess the association of the risk classification proposed by the Kidney Disease Improving Global Outcomes (KDIGO) guidelines with HF. The DIABET-IC study is a multicentre, observational, prospective and analytical study in T2DM patients recruited in Spanish hospitals. This work, which features a cross-sectional design, has been conducted with the data obtained at the inclusion visit. The main dependent variable analysed was the presence of HF. The predictive variables evaluated were the demography, clinic, laboratory testing (including natriuretic peptides) and echocardiography. Patients were classified according to the number of vascular territories with atherosclerotic involvement and the KDIGO risk category. Multivariate logistic regression models were performed to determine the risk posed by the various baseline variables to present HF at the time of study inclusion. The study included 1517 patients from 58 hospitals, with a mean age of 67.3 (standard deviation (SD): 10) years, out of which 33% were women. The mean DM duration was 14 (SD: 11) years. The prevalence of HF was 37%. In a multivariate analysis, the independent predictors of HF were increased age (odds ratio (OR) per 1 year = 1.02; p = 0.006), decreased systolic blood pressure (OR per 1 mmHg = 0.98; p < 0.001), decreased haemoglobin (OR per 1 g/dL = 0.86; p < 0.001), the presence of obstructive sleep apnoea (OR = 1.61; p = 0.006), the absence of hepatic steatosis (OR = 0.59; p = 0.016), the severity of atherosclerotic involvement (OR 1 territory = 1.38 and OR > 1 territory = 2.39; p = 0.02 and p < 0.001 respectively) and the KDIGO risk classification (high-risk OR = 2.46 and very high-risk OR = 3.39; p < 0.001 for both). The KDIGO risk classification is useful to screen for the presence of HF in T2DM patients. Therefore, we believe that it is necessary to carry out a systematic screening for HF in the high- and very high-risk KDIGO categories.

Interrelationship between micronutrients and cardiovascular structure and function in type 2 diabetes

Micronutrients are important for normal cardiovascular function. They may play a role in the increased risk of cardiovascular disease observed in people with type 2 diabetes (T2D) and T2D-related heart failure. The aims of this study were to (1) examine micronutrient status in people with T2D v. healthy controls; (2) assess any changes following a nutritionally complete meal replacement plan (MRP) compared with routine care; (3) determine if any changes were associated with changes in cardiovascular structure/function. This was a secondary analysis of data from a prospective, randomised, open-label, blinded end-point trial of people with T2D, with a nested case-control [NCT02590822]. Anthropometrics, cardiac resonance imaging and fasting blood samples (to quantify vitamins B1, B6, B12, D and C; and iron and ferritin) were collected at baseline and 12 weeks following the MRP or routine care. Comparative data in healthy controls were collected at baseline. A total of eighty-three people with T2D and thirty-six healthy controls were compared at baseline; all had micronutrient status within reference ranges. Vitamin B1 was higher (148⋅9 v. 131⋅7; P 0⋅01) and B6 lower (37⋅3 v. 52⋅9; P 0⋅01) in T2D v. controls. All thirty participants randomised to routine care and twenty-four to the MRP completed the study. There was an increase in vitamins B1, B6, D and C following the MRP, which were not associated with changes in cardiovascular structure/function. In conclusion, changes in micronutrient status following the MRP were not independently associated with improvements in cardiovascular structure/function in people with T2D.

Skin autofluorescence is associated with higher risk of cardiovascular events in Chinese adults with type 2 diabetes: A prospective cohort study from the Hong Kong Diabetes Biobank

AIMS

To investigate association between skin autofluorescence (SAF) and cardiovascular events (CVE) and assess its predictive value in Chinese adults with type 2 diabetes (T2D).

MATERIALS AND METHODS

SAF was measured non-invasively in 3806 Chinese adults with T2D between 2016 and 2019 with CVE as primary endpoint and individual components as secondary endpoints. Cox proportional hazard models were used to examine associations between SAF and endpoints with adjustment for conventional risk factors. C-statistic, integrated discrimination improvement (IDI), and net reclassification improvement (NRI) were performed to evaluate SAF's predictive value.

RESULTS

During a median 1.8 (interquartile range, 1.2-3.1) years of follow-up, 172 individuals experienced CVE. Multivariate Cox model showed that SAF was independently associated with CVE (HR 1.18 per SD, 95% CI [1.02, 1.37]), coronary heart disease (HR 1.29 per SD, 95% CI [1.02, 1.63]), and congestive heart failure (HR 1.53 per SD, 95% CI [1.14, 2.05]). SAF yielded additional value on CVE risk stratification with enhanced IDI (95% CI) (0.023 [0.001, 0.057]) and continuous NRI (0.377 [0.002, 0.558]) over traditional risk factors.

CONCLUSIONS

Higher SAF was independently associated with CVE in Chinese adults with T2D and yielded incremental predictive information for CVE. SAF has potential as a prognostic maker for CVE.

Revealing the Angiopathy of Lacrimal Gland Lesion in Type 2 Diabetes

For a better understanding of diabetic angiopathy (DA), the potential biomarkers in lacrimal DA and its potential mechanism, we evaluated the morphological and hemodynamic alterations of lacrimal glands (LGs) in patients with type 2 diabetes and healthy counterparts by color Doppler flow imaging (CDFI). We further established a type 2 diabetic mice model and performed hematoxylin-eosin (HE) staining, immunofluorescence staining of CD31, RNA-sequencing analysis, and connectivity map (CMap) analysis. We found atrophy and ischemia in patients with type 2 diabetes and mice models. Furthermore, we identified 846 differentially expressed genes (DEGs) between type 2 diabetes mellitus (T2DM) and vehicle mice by RNA-seq. The gene ontology (GO) analysis indicated significant enrichment of immune system process, regulation of blood circulation, apoptotic, regulation of secretion, regulation of blood vessel diameter, and so on. The molecular complex detection (MCODE) showed 17 genes were involved in the most significant module, and 6/17 genes were involved in vascular disorders. CytoHubba revealed the top 10 hub genes of DEGs, and four hub genes (App, F5, Fgg, and Gas6) related to vascular regulation were identified repeatedly by MCODE and cytoHubba. GeneMANIA analysis demonstrated functions of the four hub genes above and their associated molecules were primarily related to the regulation of circulation and coagulation. CMap analysis found several small molecular compounds to reverse the altered DEGs, including disulfiram, bumetanide, genistein, and so on. Our outputs could empower the novel potential targets to treat lacrimal angiopathy, diabetes dry eye, and other diabetes-related diseases.

Knowledge and attitude toward health and CVD risk factors among firefighters in Cape Town, South Africa

BACKGROUND

Firefighting is a hazardous occupation, and the firefighters' fitness for duty is affected by their knowledge of and attitudes toward their health and their relationship in the development of cardiovascular disease (CVD). The aim of this study was to assess knowledge and attitude toward health and CVD risk factors among firefighters in South Africa.

DESIGN AND METHODS

The study used a cross-sectional research design. A sample of 110 firefighters, males and females, aged 18 to 65 years were conveniently sampled from the City of Cape Town Fire and Rescue Service. A researcher-generated self-administered questionnaire was completed online to obtain data from firefighters. A p-value of less than 0.05 indicated statistical significance.

RESULTS

The results showed that 52.8% of firefighters had a poor knowledge of health, and 47.2% had a good knowledge of health, while 10% reported a negative attitude towards health and 90.0% had a positive attitude towards health. There was a significant difference between firefighters' knowledge of health and their attitudes toward health (p<0.05), particularly related to marital status, age, years of experience and in those with CVD risk factors (p<0.05). Significant correlations were found between knowledge of CVD and knowledge of health-risk behaviors (p<0.05).

CONCLUSION

Significant differences in health knowledge and attitudes toward health were present in married, aged and hypertensive firefighters. Overall health knowledge and health-risk behaviours were significant predictors of attitudes toward health.

Differential Pathophysiological Mechanisms in Heart Failure With a Reduced or Preserved Ejection Fraction in Diabetes

Diabetes promotes the development of both heart failure with a reduced ejection fraction and heart failure with a preserved ejection fraction through diverse mechanisms, which are likely mediated through hyperinsulinemia rather than hyperglycemia. Diabetes promotes nutrient surplus signaling (through Akt and mammalian target of rapamycin complex 1) and inhibits nutrient deprivation signaling (through sirtuin-1 and its downstream effectors); this suppresses autophagy and promotes endoplasmic reticulum and oxidative stress and mitochondrial dysfunction, thereby undermining the health of diabetic cardiomyocytes. The hyperinsulinemia of diabetes may also activate sodium-hydrogen exchangers in cardiomyocytes (leading to injury and loss) and in the proximal renal tubules (leading to sodium retention). Diabetes may cause epicardial adipose tissue expansion, and the resulting secretion of proinflammatory adipocytokines onto the adjoining myocardium can lead to coronary microcirculatory dysfunction and myocardial inflammation and fibrosis. Interestingly, sodium-glucose cotransporter 2 (SGLT2) inhibitors-the only class of antidiabetic medication that reduces serious heart failure events-may act to mitigate each of these mechanisms. SGLT2 inhibitors up-regulate sirtuin-1 and its downstream effectors and autophagic flux, thus explaining the actions of these drugs to reduce oxidative stress, normalize mitochondrial structure and function, and mute proinflammatory pathways in the stressed myocardium. Inhibition of SGLT2 may also lead to a reduction in the activity of sodium-hydrogen exchangers in the kidney (leading to diuresis) and in the heart (attenuating the development of cardiac hypertrophy and systolic dysfunction). Finally, SGLT2 inhibitors reduce the mass and mute the adverse biology of epicardial adipose tissue (and reduce the secretion of leptin), thus explaining the capacity of these drugs to mitigate myocardial inflammation, microcirculatory dysfunction, and fibrosis, and improve ventricular filling dynamics. The pathophysiological mechanisms by which SGLT2 inhibitors may benefit heart failure likely differ depending on ejection fraction, but each represents interference with distinct pathways by which hyperinsulinemia may adversely affect cardiac structure and function.

Usefulness of Sodium-Glucose Cotransporter 2 Inhibitors for Primary Prevention of Heart Failure in Patients With Type 2 Diabetes Mellitus

The sodium-glucose cotransporter 2 inhibitors (SGLT2i) empagliflozin, canagliflozin, and dapagliflozin reduce the risk of heart failure (HF) events in patients with diabetes mellitus (DM) at high risk for HF. Differences in HF outcomes between SGLT2i were demonstrated in a recent-published meta-analysis. Nevertheless, comparative cost-effectiveness analyses of SGLT2i provided for this indication have not been published yet. Therefore, we aimed to provide a preceding economic comparison of the costs required for improving HF outcomes by these three SGLT2i. The primary outcome was the cost needed to treat (CNT) to prevent one event of hospitalization for HF or cardiovascular mortality. CNT is calculated by multiplying the annualized number needed to treat to prevent one event by the annual cost of therapy. Clinical outcome data were extracted from pre-specified cohorts of HF-naïve patients in the pivotal randomized controlled trials (RCTs). Costs of interventions were estimated as 75% of the US National Average Drug Acquisition Cost listing. Sensitivity analysis was performed to mitigate differences between the RCT's populations. We figured the CNT for the primary prevention of HF events in DM patients to be $542,328 ($409,044-$905,412) for empagliflozin, $2,347,488 ($1,066,208-∞) for canagliflozin and $2,128,374 ($1,204,740-$48,140,518) for dapagliflozin. Sensitivity analysis confirmed the cost benefit of empagliflozin. Our findings suggest that between the available SGLT2i, the cost of primary prevention of HF in patients with DM at high risk for HF is lowest with empagliflozin. These findings may help choose an SGLT2i until head-to-head RCTs, and comprehensive cost-effective analyses for this indication are available.

A Review of the Role of Type 2 Diabetes and SGLT2 Inhibitors in Heart Failure with Preserved Ejection Fraction

Previous research has demonstrated that patients with Type 2 Diabetes (T2DM) are at an increased risk for cardiovascular events, including heart failure. Moreover, there's a higher risk of mortality in individuals who have both T2DM and heart failure with preserved ejection fraction (HFpEF). Although there are antidiabetic agents that have shown both cardiovascular safety and improved cardiovascular outcomes, only certain agents have been associated with heart failure benefits, such as sodium-glucose cotransporter-2 (SGLT2) inhibitors. This study aims to review the pathophysiology of HFpEF in the setting of T2DM, and more specifically the role of SGLT2 inhibitors in HFpEF outcomes.

Sodium-glucose co-transporter 2 inhibitor therapy: mechanisms of action in heart failure

Patients with type 2 diabetes mellitus are at a higher risk of developing heart failure compared with the healthy population. In recent landmark clinical trials, sodium-glucose co-transporter 2 (SGLT2) inhibitor therapies improve blood glucose control and also reduce cardiovascular events and heart failure hospitalisations in patients with type 2 diabetes. Intriguingly, such clinical benefits have also been seen in patients with heart failure in the absence of type 2 diabetes although the underlying mechanisms are not clearly understood. Potential pathways include improved glycaemic control, diuresis, weight reduction and reduction in blood pressure, but none fully explain the observed improvements in clinical outcomes. More recently, novel mechanisms have been proposed to explain these benefits that include improved cardiomyocyte calcium handling, enhanced myocardial energetics, induced autophagy and reduced epicardial fat. We provide an up-to-date review of cardiac-specific SGLT2 inhibitor-mediated mechanisms and highlight studies currently underway investigating some of the proposed mechanisms of action in cardiovascular health and disease.

Women With Diabetes Are at Increased Relative Risk of Heart Failure Compared to Men: Insights From UK Biobank

Aims: To investigate the effect of diabetes on mortality and incident heart failure (HF) according to sex, in the low risk population of UK Biobank. To evaluate potential contributing factors for any differences seen in HF end-point. Methods: The entire UK Biobank study population were included. Participants that withdrew consent or were diagnosed with diabetes after enrolment were excluded from the study. Univariate and multivariate cox regression models were used to assess endpoints of mortality and incident HF, with median follow-up periods of 9 years and 8 years respectively. Results: A total of 493,167 participants were included, hereof 22,685 with diabetes (4.6%). Two thousand four hundred fifty four died and 1,223 were diagnosed or admitted with HF during the follow up periods of 9 and 8 years respectively. Overall, the mortality and HF risk were almost doubled in those with diabetes compared to those without diabetes (hazard ratio (HR) of 1.9 for both mortality and heart failure) in the UK Biobank population. Women with diabetes (both types) experience a 22% increased risk of HF compared to men (HR of 2.2 (95% CI: 1.9-2.5) vs. 1.8 (1.7-2.0) respectively). Women with type 1 diabetes (T1DM) were associated with 88% increased risk of HF compared to men (HR 4.7 (3.6-6.2) vs. 2.5 (2.0-3.0) respectively), while the risk of HF for type 2 diabetes (T2DM) was 17% higher in women compared to men (2.0 (1.7-2.3) vs. 1.7 (1.6-1.9) respectively). The increased risk of HF in women was independent of confounding factors. The findings were similar in a model with all-cause mortality as a competing risk. This interaction between sex, diabetes and outcome of HF is much more prominent for T1DM (p = 0.0001) than T2DM (p = 0.1). Conclusion: Women with diabetes, particularly those with T1DM, experience a greater increase in risk of heart failure compared to men with diabetes, which cannot be explained by the increased prevalence of cardiac risk factors in this cohort.

Association of Plasma Leucine-Rich α-2 Glycoprotein 1, a Modulator of Transforming Growth Factor-β Signaling Pathway, With Incident Heart Failure in Individuals With Type 2 Diabetes

OBJECTIVE

Leucine-rich α-2 glycoprotein 1 (LRG1) is a circulating protein potentially involved in several pathways related to pathogenesis of heart failure (HF). We aimed to study whether plasma LRG1 is associated with risks of incident HF and hospitalization attributable to HF (HHF) in individuals with type 2 diabetes.

RESEARCH DESIGN AND METHODS

A total of 1,978 individuals with type 2 diabetes were followed for a median of 7.1 years (interquartile range 6.1-7.6). Association of LRG1 with HF was studied using cause-specific Cox regression models.

RESULTS

In follow-up, 191 incident HF and 119 HHF events were identified. As compared with quartile 1, participants with LRG1 in quartiles 3 and 4 had 3.60-fold (95% CI 1.63-7.99) and 5.99-fold (95% CI 2.21-16.20) increased risk of incident HF and 5.88-fold (95% CI 1.83-18.85) and 10.44-fold (95% CI 2.37-45.98) increased risk of HHF, respectively, after adjustment for multiple known cardiorenal risk factors. As a continuous variable, 1 SD increment in natural log-transformed LRG1 was associated with 1.78-fold (95% CI 1.33-2.38) adjusted risk of incident HF and 1.92-fold (95% CI 1.27-2.92) adjusted risk of HHF. Adding LRG1 to the clinical variable-based model improved risk discrimination for incident HF (area under the curve [AUC] 0.79-0.81; P = 0.02) and HHF (AUC 0.81-0.84; P = 0.02).

CONCLUSIONS

Plasma LRG1 is associated with risks of incident HF and HHF, suggesting that it may potentially be involved in pathogenesis of HF in individuals with type 2 diabetes. Additional studies are warranted to determine whether LRG1 is a novel biomarker for HF risk stratification.

Roles of HDAC3-orchestrated circadian clock gene oscillations in diabetic rats following myocardial ischaemia/reperfusion injury

The circadian clock is closely related to the development of diabetes mellitus and cardiovascular disease, and disruption of the circadian clock exacerbates myocardial ischaemia/reperfusion injury (MI/RI). HDAC3 is a key component of the circadian negative feedback loop that controls the expression pattern of the circadian nuclear receptor Rev-erbα to maintain the stability of circadian genes such as BMAL1. However, the mechanism by which the HDAC3-orchestrated Rev-erbα/BMAL1 pathway increases MI/RI in diabetes and its relationship with mitophagy have yet to be elucidated. Here, we observed that the clock genes Rev-erbα, BMAL1, and C/EBPβ oscillations were altered in the hearts of rats with streptozotocin (STZ)-induced diabetes, with upregulated HDAC3 expression. Oscillations of Rev-erbα and BMAL1 were rapidly attenuated in diabetic MI/R hearts versus non-diabetic I/RI hearts, in accordance with impaired and rhythm-disordered circadian-dependent mitophagy that increased injury. Genetic knockdown of HDAC3 significantly attenuated diabetic MI/RI by mediating the Rev-erbα/BMAL1 circadian pathway to recover mitophagy. Primary cardiomyocytes with or without HDAC3 siRNA and Rev-erbα siRNA were exposed to hypoxia/reoxygenation (H/R) in vitro. The expression of HDAC3 and Rev-erbα in cardiomyocytes was increased under high-glucose conditions compared with low-glucose conditions, with decreased BMAL1 expression and mitophagy levels. After H/R stimulation, high glucose aggravated H/R injury, with upregulated HDAC3 and Rev-erbα expression and decreased BMAL1 and mitophagy levels. HDAC3 and Rev-erbα siRNA can alleviate high glucose-induced and H/R-induced injury by upregulating BMAL1 to increase mitophagy. Collectively, these findings suggest that disruption of HDAC3-mediated circadian gene expression oscillations induces mitophagy dysfunction, aggravating diabetic MI/RI. Cardiac-specific HDAC3 knockdown could alleviate diabetic MI/RI by regulating the Rev-erbα/BMAL1 pathway to restore the activation of mitophagy.

Cardiovascular Outcomes with SGLT-2 inhibitors in patients with heart failure with or without type 2 diabetes: A systematic review and meta-analysis of randomized controlled trials

BACKGROUND AND AIMS

We conducted a systematic review and meta-analysis of all the randomized controlled trials (RCTs) with SGLT-2 inhibitors (SGLT-2i) in patients with known heart failure (HF) with or without type 2 diabetes (T2DM), that have studied the outcomes of cardiovascular (CV) death, hospitalization due to HF (HHF), and composite of CV death or HHF.

METHODS

A systematic search in PubMed, Embase and Cochrane Library database were made up till November 20, 2020 using specific keywords. RCTs that qualified underwent a meta-analysis by applying the inverse variance-weighted averages of pooled logarithmic hazard ratio (HR) using both random- and fixed-effects model.

RESULTS

This meta-analysis of 9 RCTs (N = 19,741) have found a significant 26% relative risk reduction in composite of CV death or HHF (HR 0.74; 95% CI, 0.69-0.79; p < 0.001) with SGLT-2i in patients with HF. The meta-analysis of 8 RCTs (N = 16,460) also showed a significant reduction in CV death (HR 0.86; 95% CI, 0.78-0.95; p = 0.003) and HHF (HR 0.68; 95% CI, 0.62-0.74; p < 0.001) outcomes with SGLT-2i in patients with HF. Subgroup analysis stratified on baseline ejection fraction (EF) showed a similar benefit in the composite of CV death or HHF in patients with HF with reduced EF (HFrEF) or preserved EF (HFpEF).

CONCLUSIONS

SGLT-2i significantly reduces the composite of CV death or HHF, CV death, and HHF in patients with HF. Although subgroup analysis suggested an insignificant Pheterogenity for these outcomes irrespective of the types of HF, however, reduction in both CV death and HHF were more pronounced in patients with HFrEF.

Contemporary Management of Heart Failure in Patients With Diabetes

Both heart failure and diabetes are increasing in prevalence in Western communities. The interrelationship between these two conditions is well known, with conventional heart failure therapies including several newer drug classes providing benefit to subjects with diabetes. Furthermore, several of the more recently introduced medications for type 2 diabetes have resulted in significant cardiovascular morbidity and mortality benefits with a marked improvement in heart failure symptoms and hospital presentations as well as deaths. This review outlines current therapies used to treat patients with or at risk for heart failure and their particular role in subjects with diabetes. Newer therapies, including certain glucose-lowering medications and their benefits in treating heart failure patients with and without diabetes, are also discussed. Finally, heart failure is also observed in long-duration, aging patients with type 1 diabetes, but this clinical issue has not been as extensively explored as in patients with type 2 diabetes and warrants further clinical investigation.

SGLT2 Inhibitors: A Novel Player in the Treatment and Prevention of Diabetic Cardiomyopathy

Diabetic cardiomyopathy (DCM) characterized by diastolic and systolic dysfunction independently of hypertension and coronary heart disease, eventually develops into heart failure, which is strongly linked to a high prevalence of mortality in people with diabetes mellitus (DM). Sodium-glucose cotransporter type2 inhibitors (SGLT2Is) are a novel type of hypoglycemic agent in increasing urinary glucose and sodium excretion. Excitingly, the EMPA-REG clinical trial proved that empagliflozin significantly reduced the relative risk of cardiovascular (CV) death and hospitalization for heart failure (HHF) in patients with type 2 DM (T2DM) plus CV disease (CVD). The EMPRISE trial showed that empagliflozin decreased the risk of HHF in T2DM patients with and without a CVD history in routine care. These beneficial effects of SGLT2Is could not be entirely attributed to glucose-lowering or natriuretic action. There could be potential direct mechanisms of SGLT2Is in cardioprotection. Recent studies have shown the effects of SGLT2Is on cardiac iron homeostasis, mitochondrial function, anti-inflammation, anti-fibrosis, antioxidative stress, and renin-angiotensin-aldosterone system activity, as well as GlcNAcylation in the heart. This article reviews the current literature on the effects of SGLT2Is on DCM in preclinical studies. Possible molecular mechanisms regarding potential benefits of SGLT2Is for DCM are highlighted, with the purpose of providing a novel strategy for preventing DCM.

Dapagliflozin Versus Placebo on Left Ventricular Remodeling in Patients With Diabetes and Heart Failure: The REFORM Trial

OBJECTIVE

To determine the effects of dapagliflozin in patients with heart failure (HF) and type 2 diabetes mellitus (T2DM) on left ventricular (LV) remodeling using cardiac MRI.

RESEARCH DESIGN AND METHODS

We randomized 56 patients with T2DM and HF with LV systolic dysfunction to dapagliflozin 10 mg daily or placebo for 1 year, on top of usual therapy. The primary end point was difference in LV end-systolic volume (LVESV) using cardiac MRI. Key secondary end points included other measures of LV remodeling and clinical and biochemical parameters.

RESULTS

In our cohort, dapagliflozin had no effect on LVESV or any other parameter of LV remodeling. However, it reduced diastolic blood pressure and loop diuretic requirements while increasing hemoglobin, hematocrit, and ketone bodies. There was a trend toward lower weight.

CONCLUSIONS

We were unable to determine with certainty whether dapagliflozin in patients with T2DM and HF had any effect on LV remodeling. Whether the benefits of dapagliflozin in HF are due to remodeling or other mechanisms remains unknown.

Sodium-Glucose Cotransporter 2 Inhibitors for Prevention of Heart Failure Events in Patients with Type 2 Diabetes Mellitus: A Cost Per Outcome Analysis

BACKGROUND AND OBJECTIVE

Sodium-glucose cotransporter 2 inhibitors (SGLT2i) have significant efficacy in reducing the risk of hospitalization for heart failure (hHF) or cardiovascular (CV) mortality in patients with type 2 diabetes mellitus (T2DM). However, there are differences in HF outcomes between the SGLT2i. Therefore, we compared the cost needed to achieve these outcomes between empagliflozin, canagliflozin, and dapagliflozin.

METHODS

We calculated the cost needed to treat (CNT) in order to prevent one event of hHF or CV mortality, by multiplying the annualized number needed to treat (NNT) to prevent one event, by the annual cost of each therapy. Efficacy estimates were extracted from published randomized controlled trial (RCT) data. A sensitivity analysis was performed to mitigate differences between the RCT populations. Drug costs were extracted from the 2020 US National Average Drug Acquisition Cost listing.

RESULTS

We figured empagliflozin's CNT to be $664,464 (95% CI $499,872-$1,097,280), $1,535,387 (95% CI $886,074-$3,210,501) for canagliflozin, and $2,693,145 (95% CI $1,639,563-$11,092,206) for dapagliflozin. The sensitivity analysis confirmed the cost advantage of empagliflozin.

CONCLUSIONS

Our findings suggest that empagliflozin prescribed for preventing CV death or hHF in T2DM patients seems to be cost saving compared to treatment with canagliflozin, and dapagliflozin.

Metabolomics and Proteomics in Type 2 Diabetes

The persistent increase in the worldwide burden of type 2 diabetes mellitus (T2D) and the accompanying rise of its complications, including cardiovascular disease, necessitates our understanding of the metabolic disturbances that cause diabetes mellitus. Metabolomics and proteomics, facilitated by recent advances in high-throughput technologies, have given us unprecedented insight into circulating biomarkers of T2D even over a decade before overt disease. These markers may be effective tools for diabetes mellitus screening, diagnosis, and prognosis. As participants of metabolic pathways, metabolite and protein markers may also highlight pathways involved in T2D development. The integration of metabolomics and proteomics with genomics in multiomics strategies provides an analytical method that can begin to decipher causal associations. These methods are not without their limitations; however, with careful study design and sample handling, these methods represent powerful scientific tools that can be leveraged for the study of T2D. In this article, we aim to give a timely overview of circulating metabolomics and proteomics findings with T2D observed in large human population studies to provide the reader with a snapshot into these emerging fields of research.

Both Prediabetes and Type 2 Diabetes Are Associated With Lower Heart Rate Variability: The Maastricht Study

OBJECTIVE

Low heart rate variability (HRV), a marker for cardiac autonomic dysfunction, is a known feature of type 2 diabetes, but it remains incompletely understood whether this also applies to prediabetes or across the whole glycemic spectrum. Therefore, we investigated the association among prediabetes, type 2 diabetes, and measures of glycemia and HRV.

RESEARCH DESIGN AND METHODS

In the population-based Maastricht Study (n = 2,107; mean ± SD age 59 ± 8 years; 52% men; normal glucose metabolism [n = 1,226], prediabetes [n = 331], and type 2 diabetes [n = 550, oversampled]), we determined 24-h electrocardiogram-derived HRV in time and frequency domains (individual z-scores, based upon seven and six variables, respectively). We used linear regression with adjustments for age, sex, and major cardiovascular risk factors.

RESULTS

After adjustments, both time and frequency domain HRV were lower in prediabetes and type 2 diabetes as compared with normal glucose metabolism (standardized β [95% CI] for time domain: -0.15 [-0.27; -0.03] and -0.34 [-0.46; -0.22], respectively, P for trend <0.001; for frequency domain: -0.14 [-0.26; -0.02] and -0.31 [-0.43; -0.19], respectively, P for trend <0.001). In addition, 1-SD higher glycated hemoglobin, fasting plasma glucose, and 2-h postload glucose were associated with lower HRV in both domains (time domain: -0.16 [-0.21; -0.12], -0.16 [-0.21; -0.12], and -0.15 [-0.20; -0.10], respectively; frequency domain: -0.14 [-0.19; -0.10], -0.14 [-0.18; -0.09], and -0.13 [-0.18; -0.08], respectively).

CONCLUSIONS

Both prediabetes and type 2 diabetes were independently associated with lower HRV. This is further substantiated by independent continuous associations between measures of hyperglycemia and lower HRV. These data strongly suggest that cardiac autonomic dysfunction is already present in prediabetes.

Critical examination of mechanisms underlying the reduction in heart failure events with SGLT2 inhibitors: identification of a molecular link between their actions to stimulate erythrocytosis and to alleviate cellular stress

Sodium-glucose co-transporter 2 (SGLT2) inhibitors reduce the risk of serious heart failure events, even though SGLT2 is not expressed in the myocardium. This cardioprotective benefit is not related to an effect of these drugs to lower blood glucose, promote ketone body utilization or enhance natriuresis, but it is linked statistically with their action to increase haematocrit. SGLT2 inhibitors increase both erythropoietin and erythropoiesis, but the increase in red blood cell mass does not directly prevent heart failure events. Instead, erythrocytosis is a biomarker of a state of hypoxia mimicry, which is induced by SGLT2 inhibitors in manner akin to cobalt chloride. The primary mediators of the cellular response to states of energy depletion are sirtuin-1 and hypoxia-inducible factors (HIF-1α/HIF-2α). These master regulators promote the cellular adaptation to states of nutrient and oxygen deprivation, promoting mitochondrial capacity and minimizing the generation of oxidative stress. Activation of sirtuin-1 and HIF-1α/HIF-2α also stimulates autophagy, a lysosome-mediated degradative pathway that maintains cellular homoeostasis by removing dangerous constituents (particularly unhealthy mitochondria and peroxisomes), which are a major source of oxidative stress and cardiomyocyte dysfunction and demise. SGLT2 inhibitors can activate SIRT-1 and stimulate autophagy in the heart, and thereby, favourably influence the course of cardiomyopathy. Therefore, the linkage between erythrocytosis and the reduction in heart failure events with SGLT2 inhibitors may be related to a shared underlying molecular mechanism that is triggered by the action of these drugs to induce a perceived state of oxygen and nutrient deprivation.

GDF11 ameliorated myocardial ischemia reperfusion injury by antioxidant stress and up-regulating autophagy in STZ-induced type 1 diabetic rats

Purpose:

To investigate whether GDF11 ameliorates myocardial ischemia reperfusion (MIR) injury in diabetic rats and explore the underlying mechanisms.

Methods:

Diabetic and non-diabetic rats subjected to MIR (30 min of coronary artery occlusion followed by 120 min of reperfusion) with/without GDF11 pretreatment. Cardiac function, myocardial infarct size, creatine kinase-MB (CK-MB), lactate dehydrogenase (LDH), superoxide dismutase (SOD) 15-F2tisoprostane, autophagosome, LC3II/I ratio and Belcin-1 level were determined to reflect myocardial injury, oxidative stress and autophagy, respectively. In in vitro study, H9c2 cells cultured in high glucose (HG, 30mM) suffered hypoxia reoxygenation (HR) with/without GDF11, hydrogen peroxide (H₂O₂) and autophagy inhibitor 3-methyladenine (3-MA) treatment, cell injury; oxidative stress and autophagy were assessed.

Results:

Pretreatment with GDF11 significantly improved cardiac morphology and function in diabetes, concomitant with decreased arrhythmia severity, infarct size, CK-MB, LDH and 15-F2tisoprostane release, increased SOD activity and autophagy level. In addition, GDF11 notably reduced HR injury in H9c2 cells with HG exposure, accompanied by oxidative stress reduction and autophagy up-regulation. However, those effects were completely reversed by H₂O₂ and 3-MA.

Conclusion:

GDF11 can provide protection against MIR injury in diabetic rats, and is implicated in antioxidant stress and autophagy up-regulation.