Imaging Targets in Diabetic Cardiomyopathy: Current Status and Perspective

CARDEA study protocol: investigating early markers of cardiovascular disease and their association with lifestyle habits, inflammation and oxidative stress in adolescence using a cross-sectional comparison of adolescents with type 1 diabetes and healthy controls

INTRODUCTION

Little is known regarding associations between potentially modifiable lifestyle habits and early markers of cardiovascular disease (CVD) in pediatric type 1 diabetes (T1D), hindering early prevention efforts. Specific objectives are: (1) compare established risk factors (dyslipidemia, hypertension) with novel early markers for CVD (cardiac phenotype, aortic distensibility, endothelial function) in adolescents with T1D and healthy age-matched and sex-matched controls; (2) examine associations between these novel early markers with: (i) lifestyle habits; (ii) adipokines and measures of inflammation; and (iii) markers of oxidative stress among adolescents with T1D and controls, and determine group differences in these associations; (3) explore, across both groups, associations between CVD markers and residential neighbourhood features.

METHODS AND ANALYSES

Using a cross-sectional design, we will compare 100 participants aged 14-18 years with T1D to 100 healthy controls. Measures include: anthropometrics; stage of sexual maturity (Tanner stages); physical activity (7-day accelerometry); sleep and sedentary behaviour (self-report and accelerometry); fitness (peak oxygen consumption); and dietary intake (three non-consecutive 24- hour dietary recalls). Repeated measures of blood pressure will be obtained. Lipid profiles will be determined after a 12- hour fast. Cardiac structure/function: non-contrast cardiac magnetic resonance imaging (CMR) images will evaluate volume, mass, systolic and diastolic function and myocardial fibrosis. Aortic distensibility will be determined by pulse wave velocity with elasticity and resistance studies at the central aorta. Endothelial function will be determined by flow-mediated dilation. Inflammatory markers include plasma leptin, adiponectin, tumour necrosis factor alpha (TNF-α), type I and type II TNF-α soluble receptors and interleukin-6 concentrations. Measures of endogenous antioxidants include manganese superoxide dismutase, glutathione peroxidase and glutathione in blood. Neighbourhood features include built and social environment indicators and air quality.

ETHICS AND DISSEMINATION

This study was approved by the Sainte-Justine Hospital Research Ethics Board. Written informed assent and consent will be obtained from participants and their parents.

TRIAL REGISTRATION NUMBER

NCT04304729.

Subclinical diastolic dysfunction in young adults with Type 2 diabetes mellitus: a multiparametric contrast-enhanced cardiovascular magnetic resonance pilot study assessing potential mechanisms

AIMS

To assess the cardiac, vascular, anthropometric, and biochemical determinants of subclinical diastolic dysfunction in younger adults with Type 2 diabetes mellitus (T2DM) using multiparametric contrast-enhanced cardiovascular magnetic resonance (CMR) imaging.

METHODS AND RESULTS

Twenty adults <40 years with T2DM [mean age 31.8(6.6) years, T2DM duration 4.7(4.0) years] and 20 age and sex-matched controls [10 obese non-diabetic controls and 10 lean controls (LC)] were studied. Cardiac volumes and function, circumferential strain and peak early diastolic strain rate (PEDSR), myocardial perfusion reserve, aortic stiffness (distensibility, pulse-wave velocity), focal fibrosis on late gadolinium enhancement, and pre- and post-contrast T1 mapping for contrast agent partition coefficient (subset, n = 26) were determined by CMR. In the T2DM cohort, mean aortic distensibility correlated with PEDSR (r = 0.564, P = 0.023) and diabetes duration correlated inversely with PEDSR (r = -0.534, P = 0.015) on univariate analysis. There was a close association between PEDSR and peak systolic strain (r = -0.580, P = 0.007).

CONCLUSION

In young adults with T2DM, diabetes duration and aortic distensibility were associated with diastolic dysfunction. Interventional studies are required to assess whether cardiac dysfunction can be reversed in this phenotype of patients.

Diabetic cardiomyopathy and diastolic heart failure -- difficulties with relaxation

Diabetic patients carry a four- to five-fold increased risk of heart failure. Hyperglycaemia plays a central role in the pathogenesis of diabetic cardiomyopathy. Diabetic cardiomyopathy represents a distinct structural and functional disorder of the myocardium characterized by cardiac hypertrophy and an increased myocardial stiffness. At an early stage, diabetic cardiomyopathy is manifested by diastolic heart failure with preserved ejection fraction. In some patients, diastolic dysfunction may progress to heart failure with reduced ejection fraction and result in overt systolic heart failure. Diastolic dysfunction can accurately be diagnosed by echocardiography and BNP measurement in daily clinical practice. Early treatment is prognostically important. Optimal control of blood glucose levels and blood pressure is beneficial. So far metformin is the only antidiabetic agent not associated with harm in diabetic patients with heart failure. Incretin-based therapies potentially provide cardiovascular benefits. ACE inhibitors, angiotensin-1 receptor antagonists and beta-blockers should be preferred in heart failure therapy.