Decreased regional left ventricular myocardial strain in type 1 diabetic children: a first sign of diabetic cardiomyopathy?

Diabetic cardiomyopathy: an educational review

This educational review provides information about the epidemiology of diabetes and heart failure (diabetic cardiomyopathy) and the challenges in diagnosis and screening. Details on how to investigate patients with imaging and other modalities are discussed, as well as an update regarding the efficacy and safety of novel agents for treatment of diabetic cardiomyopathy.

Quality of glycemic control has significant impact on myocardial mechanics in type 1 diabetes mellitus

The potential associations between disease duration, glycemic control, and the echocardiographic markers of the myocardial mechanics were investigated in asymptomatic T1DM patients. Seventy T1DM patients (38.2 ± 11.7 years, 46 female) and 30 healthy volunteers were investigated. Besides the conventional and tissue Doppler measurements, left ventricular global longitudinal (GLS) and circumferential (GCS) strain as well as left and right atrial strain parameters were measured with 2D speckle tracking technique. Median HbA_1c level was 7.4 (1.8)%. Even when added age and hypertension to the model, current HbA1c level remained independent predictor of left ventricular GLS (p = 0.002), GCS (p < 0.001), mitral e' (p = 0.018), tricuspid e' (p = 0.018) and left (p = 0.039) and right atrial conduit strain (p = 0.047) in multiple linear regression models. Correlations between disease duration and the echocardiographic variables lost their significance in multiple models. In patients with a combination of HbA_1c ≤ 7.4% and no hypertension, echocardiographic findings did not differ from those in healthy volunteers. Patients with HbA_1c > 7.4% and no hypertension and especially patients with coexisting hypertension and HbA_1c > 7.4%, exhibited significantly impaired myocardial mechanics. Quality of glycemic control has a significant impact on myocardial mechanics in T1DM patients. Regarding disease duration this relationship was not proved.

Diabetic cardiomyopathy: Clinical phenotype and practice

Diabetic cardiomyopathy (DCM) is a pathophysiological condition of cardiac structure and function changes in diabetic patients without coronary artery disease, hypertension, and other types of heart diseases. DCM is not uncommon in people with diabetes, which increases the risk of heart failure. However, the treatment is scarce, and the prognosis is poor. Since 1972, one clinical study after another on DCM has been conducted. However, the complex phenotype of DCM still has not been fully revealed. This dilemma hinders the pace of understanding the essence of DCM and makes it difficult to carry out penetrating clinical or basic research. This review summarizes the literature on DCM over the last 40 years and discusses the overall perspective of DCM, phase of progression, potential clinical indicators, diagnostic and screening criteria, and related randomized controlled trials to understand DCM better.

Heart Failure in Type 1 Diabetes: A Complication of Concern? A Narrative Review

Heart failure (HF) has been a hot topic in diabetology in the last few years, mainly due to the central role of sodium-glucose cotransporter 2 inhibitors (iSGLT2) in the prevention and treatment of cardiovascular disease and heart failure. It is well known that HF is a common complication in diabetes. However, most of the knowledge about it and the evidence of cardiovascular safety trials with antidiabetic drugs refer to type 2 diabetes (T2D). The epidemiology, etiology, and pathophysiology of HF in type 1 diabetes (T1D) is still not well studied, though there are emerging data about it since life expectancy for T1D has increased in the last decades and there are more elderly patients with T1D. The association of T1D and HF confers a worse prognosis than in T2D, thus it is important to investigate the characteristics, risk factors, and pathophysiology of this disease in order to effectively design prevention strategies and therapeutic tools.

Assessment of subclinical diabetic cardiomyopathy by speckle-tracking imaging

BACKGROUND

Diastolic dysfunction is traditionally believed to be the first subclinical manifestation of diabetic cardiomyopathy (DCM), leading to systolic dysfunction and then overt heart failure. However, in the last few years, several studies suggested that systolic subclinical dysfunction measured by speckle-tracking echocardiography (STE) may appear ahead of diastolic dysfunction. In this review, the main endpoint is to show whether subclinical myocardial systolic dysfunction appears ahead of diastolic dysfunction and the implication this may have on the evolution and management of DCM.

MATERIALS AND METHODS

We performed a search in PubMed for all relevant publications on the assessment of DCM by STE from 1 June 2015 to 1 June 2020.

RESULTS AND CONCLUSIONS

The results illustrate that subclinical systolic dysfunction assessed by STE is present in early DCM stages, with or without the association of diastolic dysfunction. This could be a promising perspective for the early management of patients with DCM leading to the prevention of the overt form of disease.

Use of strain, strain rate, tissue velocity imaging, and endothelial function for early detection of cardiovascular involvement in young diabetics

Background:

Subtle structural and functional changes may precede the onset of overt global left ventricular (LV) dysfunction. Data pertaining to tissue velocity imaging (TVI)and strain imaging to assess regional myocardial function and flow mediated vasodilatation are limited in young patients with diabetes.

Materials:

Conventional echocardiography, TVI parameters along with strain (S), and strain rate (SR) were measured in 50 young diabetics (15.16 ± 2.95 years, mean HBA1c 8.15 ± 1.37 g %) and 25 controls (15.60 ± 2.51 years). Flow-mediated dilation (FMD), nitrate--mediated dilatation (NMD), and carotid intima–media thickness were also assessed.

Results:

Conventional echocardiography parameters were similar in patients and controls; however, deceleration time of the mitral inflow velocity (early deceleration time) was significantly shorter in patients when compared with controls (149.06 ± 31.66 vs. 184.56 ± 19.27 ms, P =0.001). Patients had lower strain values at the basal lateral LV (21.39 ± 4.12 vs. 23.78 ± 2.02; P =0.001), mid-lateral LV (21.43 ± 4.27 vs. 23.17 ± 1.92 P =0.02), basal septum (20.59 ± 5.28 vs. 22.91 ± 2.00; P = 0.01), and midseptum (22.06 ± 4.75 vs. 24.10 ± 1.99; P = 0.01) as compared to controls. SR at the basal and midsegments of the lateral LV wall and at the basal septum was also significantly lower in diabetic patients. Diabetic children also had endothelial dysfunction with significantly lower FMD (8.36 ± 4.27 vs. 10.57 ± 4.12, P = 0.04).

Conclusions:

LV strain indices and flow--mediated dilatation are impaired in asymptomatic children and adolescents with type 1 diabetes mellitus despite absence of overt heart failure and normal ejection fraction. Early detection of subclinical regional myocardial dysfunction by deformation analysis including strain and strain rate may be useful in the asymptomatic diabetic population.

Cardiovascular disease in young People with Type 1 Diabetes: Search for Cardiovascular Biomarkers

Premature onset of cardiovascular disease is common in people with type 1 diabetes and is relatively understudied in youth. Several reports in adolescents and young adults with diabetes demonstrate evidence of arterial stiffness and cardiac dysfunction, yet critical gaps exist in our current understanding of the temporal progression of cardiac and vascular dysfunction in these youth, and mechanistic investigations with robust pathophysiologic assessment are lacking. This review attempts to summarize relevant cardiovascular studies concerning children, adolescents, and young adults with type 1 diabetes. We focus on imaging-based biomarkers routinely applied to youth and adults that are well-established in their ability to predict adjudicated cardiovascular outcomes, and their relevant physiologic interpretation. Particularly, we focus the attention to 1) cardiac ventricular strain imaging techniques which are known to be predictive of clinical outcomes in patients with heterogenous causes of heart failure, and 2) stiffness in large arteries, a well-established prognostic marker of cardiovascular events. We conclude that there remains an urgent need for sensitive and quantitative biomarkers to define the natural history of cardiac and vascular disease origination and progression in type 1 diabetes, and set the stage for interpreting interventional studies focused on preventing, reversing or slowing disease progression.

Left ventricular functions in pediatric patients with ten years or more type 1 diabetes mellitus: Conventional echocardiography, tissue Doppler, and two-dimensional speckle tracking study

BACKGROUND

Cardiac dysfunction is a complication of type 1 diabetes mellitus (T1DM) with primary concern in adults. However, studies have evaluated left ventricle (LV) myocardial changes in pediatrics but not the long-term effect of T1DM in such vulnerable age. Therefore, we assessed LV functions in pediatric patients with long-duration T1DM using different echocardiographic modalities.

METHODS

Between July 2015 and March 2016, 48 T1DM patients were prospectively compared to 35 healthy controls. Pediatric patients with T1DM for 10 years or more were included in the study. Patients were subjected to history taking, clinical examination, glycated hemoglobin (HbA1c), and microalbuminuria measurements. Moreover, conventional echocardiography, tissue Doppler, and 2D speckle tracking were performed to analyze LV functions.

RESULTS

Mean age of patients was 15.5 ± 2 years, and mean T1DM duration was 11.7 ± 1.8 years. LV dimensions, EF and FS, and mass index did not statistically differ between groups, but E/E' ratio was significantly higher in the diabetic group. Global longitudinal strain (GLS) and global circumferential strain (GCS) were significantly lower in diabetic patients compared with controls (P = 0.038; P = 0.001, respectively). Mean HbA1c was found to be a significant predictor of decreased GLS in the diabetic population (95% CI, 0.096-0.244; P = 0.001) but not predicting GCS. Microalbuminuria had no significance in predicting strain.

CONCLUSIONS

Despite the long-duration of affection with T1DM during childhood in our patients, alterations on LV myocardial function could not be detected either clinically or by conventional echocardiography. Tissue Doppler and speckle tracking could be used in the follow up of myocardial status in pediatric diabetic patients.

Left ventricular systolic dysfunction predicts long-term major microvascular complication outcomes in type 1 diabetes. The Pittsburgh Epidemiology of Diabetes Complications (EDC) study of childhood onset diabetes

OBJECTIVES

We aimed to assess association between abnormal LVEF, in the absence of coronary artery disease (CAD), and 25-year incidence of major outcomes of diabetes (MOD) in a cardiology substudy of the Pittsburgh Epidemiology of Diabetes Complications cohort of childhood-onset type 1 diabetes.

METHODS

115 normotensive type 1 diabetes individuals without known CAD, underwent a baseline exercise radionuclide ventriculography. Abnormal LVEF was defined as a resting ejection fraction <50% or a failure to increase ejection fraction with exercise by >5% (men) or a fall in ejection fraction with exercise (women). Cox proportional hazards models were used to predict the composite endpoint of MOD (first instance of major CAD, stroke, end-stage renal disease, blindness, amputation or diabetes-related death).

RESULTS

Mean baseline age was 28 and diabetes duration 19 years. In a mean follow-up of 19 years, 50 MOD events were identified. Allowing for established risk factors at baseline, abnormal LVEF (n = 22) independently predicted MOD incidence (HR = 2.12, 95% CI: 1.12-4.00, p = 0.022) but not major CAD (HR = 1.33, 95% CI: 0.53-3.33, p = 0.539).

CONCLUSIONS

An abnormal LVEF may identify diabetic cardiomyopathy and predict long term risk of MOD (but not CAD alone) in type 1 diabetes individuals, consistent with it reflecting microvascular disease.

miR-503 Is Involved in the Protective Effect of Phase II Enzyme Inducer (CPDT) in Diabetic Cardiomyopathy via Nrf2/ARE Signaling Pathway

Diabetic cardiomyopathy (DCM) is a common heart disease. The Phase II enzyme inducer (CPDT) is a complex enzyme that promotes the expression of antioxidant enzymes through activating nuclear factor erythroid 2-related factor 2 (Nrf2); these compounds have been shown to protect against oxidative stress. However, whether these compounds have similar protective effects in DCM still remains unclear. The purpose of this study is to investigate the protective effects and potential mechanism of CPDT in diabetic cardiomyopathy. In the results, firstly, compared with control rats, myocardial cell size, left ventricular mass index, and myocardial apoptosis index were increased, miR-503 was increased, and Nrf2, malondialdehyde (MDA), and heme oxygenase 1 (HO-1) were decreased in diabetic cardiomyopathy rats. Furthermore, compared with diabetic cardiomyopathy rats, these above parameters show the opposite change in CPDT treatment rats. In addition, the bioinformatics and luciferase reporter assay demonstrated that Nrf2 is a direct target of miR-503. Finally, the miR-503 could also regulate Nrf2 in the myocardial cells. Therefore, miR-503 is involved in the protective effect of CPDT in diabetic cardiomyopathy via Nrf2/ARE signaling pathway; miR-503 and Nrf2 may be a promising therapeutic target for the management of diabetic cardiomyopathy.