Poor Glycemic Control Is Associated With Increased Extracellular Volume Fraction in Diabetes

Association of diabetes mellitus and glycemic control with left ventricular function and deformation in patients after acute myocardial infarction: a 3 T cardiac magnetic resonance study

BACKGROUND

Diabetes mellitus (DM) is considered a major risk factor for myocardial infarction (MI), and MI patients with DM have a poor prognosis. Accordingly, we aimed to investigate the additive effects of DM on LV deformation in patients after acute MI.

MATERIALS AND METHODS

One hundred thirteen MI patients without DM [MI (DM-)], 95 with DM [MI (DM+)] and 71 control subjects who underwent CMRscanning were included. LV function, infarct size and LV global peak strains in the radial, circumferential and longitudinal directions were measured. MI (DM+) patients were divided into two subgroups based on the HbA1c level (< 7.0% and ≥ 7.0%). The determinants of reduced LV global myocardial strain for all MI patients and MI (DM+) patients were assessed using multivariable linear regression analyses.

RESULTS

Compared with control subjects, both MI (DM-) and MI (DM+) patients presented higher LV end-diastolic and end-systolic volume index and lower LV ejection fraction. LV global peak strains progressively declined from the control group to the MI(DM-) group to the MI(DM+) group (all p < 0.05). Subgroup analysis showed that LV global radial PS and longitudinal PS were worse in MI(MD+) patients with poor glycemic control than in those with good glycemic control (all p < 0.05). DM was an independent determinant of impaired LV global peak strain in radial, circumferential and longitudinal directions in patients after acute MI (β = - 0.166, 0.164 and 0.262, both p < 0.05). The HbA1c level was independently associated with a decreased LV global radial PS (β =  - 0.209, p = 0.025) and longitudinal PS (β = 0.221, p = 0.010) in MI (DM+) patients.

CONCLUSIONS

DM has an additive deleterious effect on LV function and deformation in patients after acute MI, and HbA1c was independently associated with impaired LV myocardial strain.

Low diet quality is associated with adverse levels of metabolic health markers and clustering of risk factors in adults with type 2 diabetes

BACKGROUND

Nutritional recommendations for diabetes management emphasise an overall, healthful diet consistent with the guidelines for the general population. The present study assessed the relationship of diet quality, as measured by Healthy Eating Index-2015 (HEI-2015), with metabolic health markers and risk factor clustering in type 2 diabetes patients using National Health and Nutrition Examination Survey 2011-2016 data.

METHODS

HEI-2015 diet quality scores were calculated using 24-h dietary recalls. Adults with type 2 diabetes (n = 2220) were assessed for: (1) hyperglycaemia; (2) overweight/obesity; (3) dyslipidaemia; and (4) hypertension. Logistic regression examined associations of diet quality quartiles with odds of hyperglycaemia, overweight/obesity, dyslipidaemia and hypertension, as well as odds of clustering of these risk factors.

RESULTS

Odds of overweight/obesity and hyperglycaemia were significantly greater for participants in the lowest HEI-2015 quartile compared to those in the highest quartile. Furthermore, individuals in the bottom two HEI-2015 quartiles had increased odds of dyslipidaemia. Those in the lowest quartile also had significantly higher odds of having ≥ 2, ≥ 3 and 4 risk factors (vs. having ≤ 1 risk factor).

CONCLUSIONS

Low diet quality was related to increased odds of hyperglycaemia, dyslipidaemia, overweight/obesity and risk factor clustering. Findings imply poorer prognosis of diabetes in individuals with low diet quality.

Myocardial Extracellular Volume Expansion in Type 2 Diabetes Is Associated With Ischemic Heart Disease, Autonomic Neuropathy, and Active Smoking

OBJECTIVE

Myocardial interstitial fibrosis expands the extracellular volume (ECV) and in patients with type 2 diabetes is implicated in development of heart failure. ECV can be determined with gadolinium contrast MRI. We investigated which known risk factors for cardiovascular disease were associated with increased ECV in patients with type 2 diabetes.

RESEARCH DESIGN AND METHODS

A total of 296 patients with type 2 diabetes and 25 sex and age-matched control subjects were included in a cross-sectional MRI study. The influence of risk factors on ECV was investigated with multiple regression analysis.

RESULTS

Control subjects and patients with type 2 diabetes without complications had similar ECV (mean ± SD 27.4 ± 2.1% vs. 27.9 ± 2.6%, P = 0.4). Compared with patients without, ECV was significantly increased in patients with one or more complications (29.0 ± 3.3%, P = 0.02). Both in univariable analysis and after multivariable adjustment, ischemic heart disease, autonomic neuropathy, and active smoking were associated with increased levels of ECV. Active smoking exhibited the largest effect size (β = 2.0 percentage points, 95% CI 0.7-3.3). Former smokers ECV similar to that of never smokers. Albuminuria and systolic blood pressure were inversely associated with ECV in multivariable analysis, but after adjustment for medication suspected to affect ECV, the association with albuminuria was no longer significant (P = 0.1). Sodium-glucose cotransporter 2 inhibitor treatment was not significantly associated with reduced ECV (-0.8%, 95% CI -1.7 to 0.06, P = 0.067).

CONCLUSIONS

Patients with complications of diabetes have increased ECV, not seen in patients without complications. Ischemic heart disease, autonomic neuropathy, and active but not former smoking were highly associated with increased ECV.

LncRNA Airn alleviates diabetic cardiac fibrosis by inhibiting activation of cardiac fibroblasts via a m6A-IMP2-p53 axis

BACKGROUND

Cardiac fibrosis is a leading cause of cardiac dysfunction in patients with diabetes. However, the underlying mechanisms of cardiac fibrosis remain unclear. This study aimed to investigate the role of the long non-coding RNA (LncRNA) Airn in the pathogenesis of cardiac fibrosis in diabetic cardiomyopathy (DCM) and its underlying mechanism.

METHODS

Diabetes mellitus (DM) was induced in mice by streptozotocin injection. An intramyocardial adeno-associated virus (AAV) was used to manipulate Airn expression. The functional significance and underlying mechanisms in DCM fibrosis were investigated both in vitro and in vivo.

RESULTS

Diabetic hearts showed a significant impairment in cardiac function, accompanied by obviously increased cardiac fibrosis. Interestingly, lncRNA Airn expression was significantly decreased in both diabetic hearts and high glucose (HG)-treated cardiac fibroblasts (CFs). AAV-mediated Airn reconstitution prevented cardiac fibrosis and the development of DCM, while Airn knockdown induced cardiac fibrosis phenotyping DCM. As in vitro, Airn reversed HG-induced fibroblast-myofibroblast transition, aberrant CFs proliferation and section of collagen I. In contrast, Airn knockdown mimicked a HG-induced CFs phenotype. Mechanistically, we identified that Airn exerts anti-fibrotic effects by directly binding to insulin-like growth factor 2 mRNA-binding protein 2 (IMP2) and further prevents its ubiquitination-dependent degradation. Moreover, we revealed that Airn/IMP2 protected p53 mRNA from degradation in m6A manner, leading to CF cell cycle arrest and reduced cardiac fibrosis. As a result, ablation of p53 blunted the inhibitory effects of Airn on fibroblast activation and cardiac fibrosis.

CONCLUSIONS

Our study demonstrated for the first time that Airn prevented the development of cardiac fibrosis in diabetic heart via IMP2-p53 axis in an m6A dependent manner. LncRNA Airn could be a promising therapeutic target for cardiac fibrosis in DCM.

Assessing the Effectiveness of Type 2 Diabetes Screening in the Republic of Uzbekistan

BACKGROUND

Type 2 diabetes (T2D) screening should be performed continuously at the primary care level in order to prevent disabling complications. Due to the high prevalence of undiagnosed T2D in the Republic of Uzbekistan, a decision was made to implement a nationwide screening program for T2D.

OBJECTIVES

The current study, taking into account the limited resources of Uzbekistan's health care system, aimed to offer the most effective, simple, and economical option required for the actual implementation of regular T2D screening in the country's primary care.

METHODS

The screening was conducted from December 2018 to March 2019. There were four different scenarios, which differed in terms of eligibility criteria and the methodology adopted for detecting dysglycemia.

RESULTS

A total of 2,430 patients were examined in four months. The T2D diagnosis was established by an endocrinologist in 9.3% of the cases with one eligibility criterion and 15.9% of the cases with three eligibility criteria. The diagnosis of T2D was established by an endocrinologist in 11.7% of the cases with HbA1c screening and 13.5% of the cases with glucose screening.

CONCLUSIONS

The screening was feasible in Uzbekistan only in limited conditions. The reasonable strategy was found to be the screening for incidental glycemia in all patients with at least one T2D risk factor. It was recommended that patients with incidental glycemia ≥ 7.8 mmol/L should be tested for fasting glycemia.

Anti-diabetogenic and in vivo antioxidant activity of ethanol extract of Dryopteris dilatata in alloxan-induced male Wistar rats

AIMS

Oxido-inflammatory stress has been implicated as the main targets in alleviating diabetic complications induced by hyperglycaemia. Dryopteris dilatata: a bioactive plant serves great medicinal benefits in ethnopharmacology to ameliorate pathological conditions. This study investigated the protective effects of ethanol extract of Dryopteris dilatata (EEDD) in alloxan-induced diabetic rats through mechanism involving inhibition of oxidative stress and liver and kidney inflammatory markers.

METHODOLOGY

Male Wistar rats were made diabetic via alloxan monohydrate (100 mg/kg) administration intraperitoneally. Diabetic rats were post-treated with EEDD (800 mg/kg) and Metformin (50 mg/kg) orally for two weeks. Fasting blood sugar (FBS), body and organ weight change, markers of oxidative stress, liver and kidney inflammation were evaluated.

RESULTS

Our results revealed that EEDD significantly reduced alloxan-induced hyperglycaemia in the diabetic rats after 5, 10 and 15 days of treatment. Markers of oxidative injury were also significantly ameliorated in the pancreas, liver and kidney of the diabetic rats following treatment with EEDD. However, liver and kidney injury markers were significantly attenuated with marked decreased organ weight in the diabetic rats after treatment with EEDD.

CONCLUSION

Here in, we found that Dryopteris dilatata could be used as nutraceuticals in the prevention and treatment of diabetes and its related complications through positively modulating oxidative stress and liver and kidney inflammatory markers.

Fibrosis of the diabetic heart: Clinical significance, molecular mechanisms, and therapeutic opportunities

In patients with diabetes, myocardial fibrosis may contribute to the pathogenesis of heart failure and arrhythmogenesis, increasing ventricular stiffness and delaying conduction. Diabetic myocardial fibrosis involves effects of hyperglycemia, lipotoxicity and insulin resistance on cardiac fibroblasts, directly resulting in increased matrix secretion, and activation of paracrine signaling in cardiomyocytes, immune and vascular cells, that release fibroblast-activating mediators. Neurohumoral pathways, cytokines, growth factors, oxidative stress, advanced glycation end-products (AGEs), and matricellular proteins have been implicated in diabetic fibrosis; however, the molecular links between the metabolic perturbations and activation of a fibrogenic program remain poorly understood. Although existing therapies using glucose- and lipid-lowering agents and neurohumoral inhibition may act in part by attenuating myocardial collagen deposition, specific therapies targeting the fibrotic response are lacking. This review manuscript discusses the clinical significance, molecular mechanisms and cell biology of diabetic cardiac fibrosis and proposes therapeutic targets that may attenuate the fibrotic response, preventing heart failure progression.

Chrysophyllum albidum fruit ethanol extract ameliorates hyperglycaemia and elevated blood pressure in streptozotocin-induced diabetic rats through modulation of oxidative stress, NF-κB and PPAR-γ

Oxidative stress and inflammation arising from hyperglycaemia have been identified as important targets in mitigating hyperglycaemia-induced organ dysfunction in diabetics. Chrysophyllum albidum fruit is commonly consumed as fruit snacks because of its beneficial effects in diabetes management. This study aim to evaluate the protective mechanisms of Chrysophyllum albidum fruit extract (CAFE) in streptozotocin-induced rats involving attenuation of oxidative stress, nuclear factor-kappa B (NF-κB) and peroxisome proliferator-activated receptor-gamma (PPAR-γ). CAFE was investigated for in vitro antioxidant and alpha amylase inhibitory activity. Male Wistar rats were made diabetic by single intraperitoneal injection of streptozotocin (60 mg/kg). The rats were then treated with CAFE (100 and 200 mg/kg) and pioglitazone (10 mg/kg) for two weeks. Fasting blood sugar (FBS), blood pressure parameters, lipid profile, oxidative stress parameters, NF-κB and PPAR-γ were determined. The extract showed antioxidant and alpha amylase inhibitory activities. CAFE significantly reduced STZ-induced hyperglycaemia after 7 and 14 days of treatment. CAFE also reduced STZ-induced elevation of diastolic blood pressure and mean arterial pressure and as well reduced atherogenic index in diabetic rats. It significantly decreased lipid peroxidation but increased the enzymatic and non-enzymatic antioxidant markers in the plasma, liver, kidney and pancreas. The immunohistochemical analysis revealed that CAFE significantly decreased hepatic and renal tissues NF-κB while increasing PPAR-γ gene expressions. The results of this study collectively showed the protective effect of Chrysophyllum albidum fruit extract in streptozotocin-induced diabetic rats via modulation of oxidative stress and NF-κB/ PPAR-γ expressions.

Impact of Chronic Obstructive Pulmonary Disease in Heart Failure With Preserved Ejection Fraction

COPD often coexists with HFpEF, but its impact on cardiovascular structure and function in HFpEF is incompletely understood. We aimed to compare cardiovascular phenotypes in patients with Chronic Obstructive Pulmonary Disease (COPD), Heart Failure with Preserved Ejection Fraction (HFpEF), or both. We studied 159 subjects with COPD alone (n = 48), HFpEF alone (n = 79) and HFpEF + COPD (n = 32). We used MRI and arterial tonometry to assess cardiac structure and function, thoracic aortic stiffness, and measures of body composition. Relative to participants with COPD only, those with HFpEF with or without COPD exhibited a greater prevalence of female sex and obesity, whereas those with HFpEF + COPD were more often African-American. Compared to the other groups, participants with HFpEF and COPD demonstrated a more concentric LV geometry (LV wall-cavity ratio 1.2, 95%CI: 1.1-1.3; p = 0.003), a greater LV mass (67.4, 95%CI: 60.7-74.2; p = 0.03, and LV extracellular volume (49.4, 95%CI: 40.9-57.9; p = 0.002). Patients with comorbid HFpEF + COPD also exhibited greater thoracic aortic stiffness assessed by pulse-wave velocity (11.3, 95% CI: 8.7-14.0 m/s; p = 0.004) and pulsatile load imposed by the ascending aorta as measured by aortic characteristic impedance (139 dsc; 95%CI=111-166; p = 0.005). Participants with HFpEF, with or without COPD, exhibited greater abdominal and pericardial fat, without difference in thoracic skeletal muscle size. In conclusion, individuals with co-morbid HFpEF and COPD have a greater degree of systemic large artery stiffening, LV remodeling, and LV fibrosis than those with either condition alone.

Diabetic fibrosis

Diabetes-associated morbidity and mortality is predominantly due to complications of the disease that may cause debilitating conditions, such as heart and renal failure, hepatic insufficiency, retinopathy or peripheral neuropathy. Fibrosis, the excessive and inappropriate deposition of extracellular matrix in various tissues, is commonly found in patients with advanced type 1 or type 2 diabetes, and may contribute to organ dysfunction. Hyperglycemia, lipotoxic injury and insulin resistance activate a fibrotic response, not only through direct stimulation of matrix synthesis by fibroblasts, but also by promoting a fibrogenic phenotype in immune and vascular cells, and possibly also by triggering epithelial and endothelial cell conversion to a fibroblast-like phenotype. High glucose stimulates several fibrogenic pathways, triggering reactive oxygen species generation, stimulating neurohumoral responses, activating growth factor cascades (such as TGF-β/Smad3 and PDGFs), inducing pro-inflammatory cytokines and chemokines, generating advanced glycation end-products (AGEs) and stimulating the AGE-RAGE axis, and upregulating fibrogenic matricellular proteins. Although diabetes-activated fibrogenic signaling has common characteristics in various tissues, some organs, such as the heart, kidney and liver develop more pronounced and clinically significant fibrosis. This review manuscript summarizes current knowledge on the cellular and molecular pathways involved in diabetic fibrosis, discussing the fundamental links between metabolic perturbations and fibrogenic activation, the basis for organ-specific differences, and the promises and challenges of anti-fibrotic therapies for diabetic patients.

Secreted Frizzled-Related Protein 2 and Extracellular Volume Fraction in Patients with Heart Failure

Background

Quantification of extracellular volume (ECV) fraction by cardiovascular magnetic resonance (CMR) has emerged as a noninvasive diagnostic tool to assess myocardial fibrosis. Secreted frizzled-related protein 2 (SFRP2) appears to play an important role in cardiac fibrosis. We aimed to evaluate the association between SFRP2 and myocardial fibrosis and the prognostic value of ECV fraction in patients with heart failure (HF).

Methods

In this prospective cohort study, 72 hospitalized adult patients (age ≥ 18 years) with severe decompensated HF were included. CMR measurements and T1 mapping were performed to calculate ECV fraction. Serum SFRP2 level was detected by an enzyme-linked immunosorbent assay kit. All patients were followed up, and the primary outcomes were composite events including all-cause mortality and HF hospitalization.

Results

During the median follow-up of 12 months, 27 (37.5%) patients experienced primary outcome events and had higher levels of N-terminal pro-B-type natriuretic peptide (NT-proBNP), SFRP2, and ECV fraction compared with those without events. In Pearson correlation analysis, levels of SFRP2 (r = 0.33), high-sensitivity C-reactive protein (r = 0.31), and hemoglobin A1c (r = 0.29) were associated with ECV fraction (all P < 0.05); however, in multivariate linear regression analysis, SFRP2 was the only significant factor determined for ECV fraction (r_partial = 0.33, P = 0.02). In multivariate Cox regression analysis, age (each 10 years, hazard ratio (HR) 1.13, 95% confidence interval (CI) 1.04–1.22), ECV fraction (per doubling, HR 1.68, 95% CI 1.03–2.74), and NT-proBNP (per doubling, HR 2.46, 95% CI 1.05–5.76) were independent risk factors for primary outcomes.

Conclusions

Higher ECV fraction is associated with worsened prognosis in HF. SFRP2 is an independent biomarker for myocardial fibrosis. Further studies are needed to explore the potential therapeutic value of SFRP2 in myocardial fibrosis.

Impact of Diabetes Mellitus on Ventricular Structure, Arterial Stiffness, and Pulsatile Hemodynamics in Heart Failure With Preserved Ejection Fraction

Background Heterogeneity in the underlying processes that contribute to heart failure with preserved ejection fraction ( HF p EF ) is increasingly recognized. Diabetes mellitus is a frequent comorbidity in HF p EF , but its impact on left ventricular and arterial structure and function in HF p EF is unknown. Methods and Results We assessed the impact of diabetes mellitus on left ventricular cellular and interstitial hypertrophy (assessed with cardiac magnetic resonance imaging, including T1 mapping pregadolinium and postgadolinium administration), arterial stiffness (assessed with arterial tonometry), and pulsatile arterial hemodynamics (assessed with in-office pressure-flow analyses and 24-hour ambulatory monitoring) among 53 subjects with HF p EF (32 diabetic and 21 nondiabetic subjects). Despite few differences in clinical characteristics, diabetic subjects with HFpEF exhibited a markedly greater left ventricular mass index (78.1 [95% CI , 70.4-85.9] g versus 63.6 [95% CI , 55.8-71.3] g; P=0.0093) and indexed extracellular volume (23.6 [95% CI , 21.2-26.1] mL/m² versus 16.2 [95% CI , 13.1-19.4] mL/m²; P=0.0008). Pronounced aortic stiffening was also observed in the diabetic group (carotid-femoral pulse wave velocity, 11.86 [95% CI , 10.4-13.1] m/s versus 8.8 [95% CI , 7.5-10.1] m/s; P=0.0027), with an adverse pulsatile hemodynamic profile characterized by increased oscillatory power (315 [95% CI , 258-373] mW versus 190 [95% CI , 144-236] mW; P=0.0007), aortic characteristic impedance (0.154 [95% CI , 0.124-0.183] mm Hg/mL per second versus 0.096 [95% CI , 0.072-0.121] mm Hg/mL per second; P=0.0024), and forward (59.5 [95% CI , 52.8-66.1] mm Hg versus 40.1 [95% CI , 31.6-48.6] mm Hg; P=0.0010) and backward (19.6 [95% CI , 16.2-22.9] mm Hg versus 14.1 [95% CI , 10.9-17.3] mm Hg; P=0.0169) wave amplitude. Abnormal pulsatile hemodynamics were also evident in 24-hour ambulatory monitoring, despite the absence of significant differences in 24-hour systolic blood pressure between the groups. Conclusions Diabetes mellitus is a key determinant of left ventricular remodeling, arterial stiffness, adverse pulsatile hemodynamics, and ventricular-arterial interactions in HF p EF . Clinical Trial Registration URL : https://www.clinicaltrials.gov . Unique identifier: NCT 01516346.

The Diabetic Cardiac Fibroblast: Mechanisms Underlying Phenotype and Function

Diabetic cardiomyopathy involves remodeling of the heart in response to diabetes that includes microvascular damage, cardiomyocyte hypertrophy, and cardiac fibrosis. Cardiac fibrosis is a major contributor to diastolic dysfunction that can ultimately result in heart failure with preserved ejection fraction. Cardiac fibroblasts are the final effector cell in the process of cardiac fibrosis. This review article aims to describe the cardiac fibroblast phenotype in response to high-glucose conditions that mimic the diabetic state, as well as to explain the pathways underlying this phenotype. As such, this review focuses on studies conducted on isolated cardiac fibroblasts. We also describe molecules that appear to oppose the pro-fibrotic actions of high glucose on cardiac fibroblasts. This represents a major gap in knowledge in the field that needs to be addressed.

Effect of Irbesartan on AGEs-RAGE and MMPs systems in rat type 2 diabetes myocardial-fibrosis model

IMPACT STATEMENT

There are about 425 million diabetes patients (20-79 years) in the world according to the International Diabetes Federation Diabetes Atlas - 8th Edition. The cardiovascular complication is one of the major causes of death in diabetes patients. Myocardial fibrosis is one of the serious pathological changes, so investigating the pathogenesis of myocardial fibrosis has the significant value. Our study aims to investigate the effect of Irbesartan (the angiotensin II receptor antagonist) on the changes of AGE-RAGE system and MMP family components, and analyzes the potential mechanisms in type 2 diabetes-induced myocardial fibrosis. Our results provide the theoretical base for better understanding the pathogenesis in type 2 diabetes-induced myocardial complication. It is useful for clinicians to select the effective therapeutic measures for treatment of type 2 diabetes-induced organ fibrosis.