Frequency of Reduced Left Ventricular Contractile Efficiency and Discoordinated Myocardial Relaxation in Patients Aged 16 to 21 Years With Type 1 Diabetes Mellitus (from the Emerald Study)

Role of Physical Activity and Sedentary Behaviors on Vascular and Myocardial Structure and Function in Type 1 Diabetes

OBJECTIVE

To estimate associations between physical activity and sedentary behaviors and early markers of cardiovascular diseases (CVD) in adolescents with and without type 1 diabetes.

STUDY DESIGN

Cross-sectional data stem from CARDEA, a study investigating early CVD development in 100 adolescents with type 1 diabetes recruited at Sainte-Justine University Hospital Diabetes Clinic and 97 healthy adolescents without diabetes (14-18 years), in Montréal, Canada. Outcomes included arterial stiffness by pulse-wave velocity, endothelial function (VTI) by flow-mediated dilation test, and cardiac magnetic resonance imaging markers. Moderate-to-vigorous physical activity (MVPA) and sedentary time were estimated by accelerometry and leisure screen time by questionnaire. We estimated multivariable linear regression models stratified by group.

RESULTS

In adolescents with type 1 diabetes, 10-minutes daily increase in MVPA was associated with 3.69 g/m (95% CI: -1.16; 8.54) higher left ventricular (LV) mass/height and 1-h increase in device-measured sedentary time with 0.68 mm (0.20; 1.16) higher wall thickness but only in those with glycated hemoglobin ≤7.5%. In healthy adolescents, a 10-minute increase in MVPA was associated with 1.32 g/m (-0.03; 2.66) higher LV mass/height. Every 1-hour increase in sedentary time was associated with -1.82 cm (-3.25; -0.39) lower VTI, -2.99 g/m (-5.03; -0.95) lower LV mass/height, and -0.47 mm (-0.82; -0.12) lower wall thickness.

CONCLUSIONS

Being active and limiting sedentary time appears beneficial for cardiac structure and endothelial function in healthy adolescents; however adequate glycemic control combined with higher levels of MVPA may be required for adolescents with type 1 diabetes to overcome the impact of diabetes.

Harnessing the Synergy of SGLT2 Inhibitors and Continuous Ketone Monitoring (CKM) in Managing Heart Failure among Patients with Type 1 Diabetes

Heart failure (HF) management in type 1 diabetes (T1D) is particularly challenging due to its increased prevalence and the associated risks of hospitalization and mortality, driven by diabetic cardiomyopathy. Sodium-glucose cotransporter-2 inhibitors (SGLT2-is) offer a promising avenue for treating HF, specifically the preserved ejection fraction variant most common in T1D, but their utility is hampered by the risk of euglycemic diabetic ketoacidosis (DKA). This review investigates the potential of SGLT2-is in T1D HF management alongside emergent Continuous Ketone Monitoring (CKM) technology as a means to mitigate DKA risk through a comprehensive analysis of clinical trials, observational studies, and reviews. The evidence suggests that SGLT2-is significantly reduce HF hospitalization and enhance cardiovascular outcomes. However, their application in T1D patients remains limited due to DKA concerns. CKM technology emerges as a crucial tool in this context, offering real-time monitoring of ketone levels, which enables the safe incorporation of SGLT2-is into treatment regimes by allowing for early detection and intervention in the development of ketosis. The synergy between SGLT2-is and CKM has the potential to revolutionize HF treatment in T1D, promising improved patient safety, quality of life, and reduced HF-related morbidity and mortality. Future research should aim to employ clinical trials directly assessing this integrated approach, potentially guiding new management protocols for HF in T1D.

Myocardial deformation imaging by 2D speckle tracking echocardiography for assessment of diastolic dysfunction in murine cardiopathology

Diastolic dysfunction is increasingly identified as a key, early onset subclinical condition characterizing cardiopathologies of rising prevalence, including diabetic heart disease and heart failure with preserved ejection fraction (HFpEF). Diastolic dysfunction characterization has important prognostic value in management of disease outcomes. Validated tools for in vivo monitoring of diastolic function in rodent models of diabetes are required for progress in pre-clinical cardiology studies. 2D speckle tracking echocardiography has emerged as a powerful tool for evaluating cardiac wall deformation throughout the cardiac cycle. The aim of this study was to examine the applicability of 2D speckle tracking echocardiography for comprehensive global and regional assessment of diastolic function in a pre-clinical murine model of cardio-metabolic disease. Type 2 diabetes (T2D) was induced in C57Bl/6 male mice using a high fat high sugar dietary intervention for 20 weeks. Significant impairment in left ventricle peak diastolic strain rate was evident in longitudinal, radial and circumferential planes in T2D mice. Peak diastolic velocity was similarly impaired in the longitudinal and radial planes. Regional analysis of longitudinal peak diastolic strain rate revealed that the anterior free left ventricular wall is particularly susceptible to T2D-induced diastolic dysfunction. These findings provide a significant advance on characterization of diastolic dysfunction in a pre-clinical mouse model of cardiopathology and offer a comprehensive suite of benchmark values for future pre-clinical cardiology studies.

Bromocriptine quick-release as adjunct therapy in youth and adults with type 1 diabetes: A randomized, placebo-controlled crossover study

AIM

To evaluate the potential for glycaemic, renal and vascular benefits of bromocriptine quick release (BCQR) in adolescents and adults with type 1 diabetes.

MATERIALS AND METHODS

Forty adolescents and 40 adults with type 1 diabetes aged 12-60 years old were enrolled in a double-blind, placebo-controlled, random order crossover study of 4 weeks of treatment in the morning with BCQR (titrated weekly from 0.8 mg to 1.6 mg to 3.2 mg, minimum dose 1.6 mg). Study assessments after each phase included blood pressure (BP), lipids, peripheral arterial stiffness and autonomic function, mixed meal tolerance test, continuous glucose monitoring (CGM), creatinine, estimated glomerular filtration rate, estimated insulin sensitivity, insulin dose and indirect calorimetry.

RESULTS

Adolescents displayed baseline hyperglycaemia, insulin resistance, metabolic dysfunction and increased renal filtration compared with adults. In both age groups, continuous glucose monitoring measures, estimated insulin sensitivity and insulin dose did not differ with BCQR treatment. In adolescents, BCQR decreased systolic BP, diastolic BP and triangular index and increased serum creatinine. In adults, systolic BP, mean arterial pressure, systemic vascular resistance, and mixed meal tolerance test glucose and glucagon-like peptide 1 areas under the curve were lower, and the orthostatic drop in systolic BP was greater with BCQR.

CONCLUSIONS

Greater hyperglycaemia, insulin resistance, metabolic dysfunction and renal hyperfiltration in adolescents argues for increased attention during this high-risk age period. Although BCQR had little impact on glycaemia or insulin sensitivity, initial vascular and renal responses suggest potential benefits of BCQR in adolescents and adults with type 1 diabetes requiring further study.

Repolarization Dispersion Is Associated With Diastolic Electromechanical Discoordination in Children With Pulmonary Arterial Hypertension

Background

Electromechanical dyssynchrony is a well described comorbidity in pulmonary arterial hypertension (PAH). ECG‐derived measurements reflective of diastolic dysfunction and electromechanical imaging markers are yet to be investigated. In this study we investigated the ECG‐ derived marker of repolarization dispersion, interval between the peak and end of T wave (TpTe), in pediatric patients with PAH and left ventricular (LV) diastolic dysfunction.

Methods and Results

We measured TpTe from a standard 12‐lead ECG and in 30 children with PAH and matched control subjects. All participants underwent same‐day echocardiography and myocardial strain analysis to calculate the diastolic electromechanical discoordination marker diastolic relaxation fraction. When compared with control subjects, patients with PAH had increased TpTe (93±15 versus 81±12 ms, P=0.001) and elevated diastolic relaxation fraction (0.33±0.10 versus 0.27±0.03, P=0.001). Patients with PAH with LV diastolic dysfunction had significantly increased TpTe when compared with patients with PAH without diastolic dysfunction (P=0.012) and when compared with control group (P<0.001). Similarly, patients with PAH with LV diastolic dysfunction had increased diastolic relaxation fraction when compared with PAH patients without diastolic dysfunction (P=0.007) and when compared with control group (P<0.001). A 10‐ms increase in TpTe was significantly associated with 0.023 increase in diastolic relaxation fraction (P=0.008) adjusting for body surface area, heart rate, right ventricular volumes, and function.

Conclusions

Prolonged myocardial repolarization and abnormal LV diastolic electromechanical discoordination exist in parallel in children with PAH and are associated with worse LV diastolic function and functional class.

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.

Weighted Gene Co-Expression Network Analysis Identifies ANGPTL4 as a Key Regulator in Diabetic Cardiomyopathy via FAK/SIRT3/ROS Pathway in Cardiomyocyte

BACKGROUND

Diabetic cardiomyopathy (DbCM) is characterized by initial impairment of left ventricular relaxation followed by contractile dysfunction. Despite intensive research, the exact mechanism remains so far unsolved.

METHODS

We constructed weighted gene co-expression network analysis (WGCNA) to screen gene modules that were closely related with DbCM based on the GSE5606 dataset, which contained expression data of the cardiac left ventricle in a rodent model of streptozotocin (STZ)-induced DbCM. Then, the most related hub gene, angiopoietin-like 4 (ANGPTL4), was selected for functional ex vivo and in vitro assays. In our experiments, STZ-induced diabetic mice (C57BL/6J) and human cardiomyocytes (AC16) were used to study the functional roles and potential mechanisms of ANGPTL4 in DbCM.

RESULTS

WGCNA analysis revealed the yellow and green modules were most correlated with DbCM, and identified ANGPTL4 as one of the most significantly upregulated hub genes (ANGPTL4, ACOT1, DECR1, HMGCS2, and PDK4). Consistent with the bioinformatic analysis, the amount of ANGPTL4 was significantly upregulated in diabetic mouse heart. DbCM group, compared with the control group, had increased phosphorylation of focal adhesion kinase (FAK), reduced SIRT3 expression, increased SOD2 acetylation, upregulated NADPH oxidase activation, elevated reactive oxygen species (ROS) produciton, and enhanced apoptosis in the diabetic mouse heart. Moreover, ANGPTL4 induced apoptosis via FAK/SIRT3/ROS pathway in human cardiomyocytes (AC16) under high glucose condition in vitro.These effects were abrogated by treatment of two independent siRNA for ANGPTL4, whereas exogenous recombinant ANGPLT4 protein treatment exacerbated those effects in AC16.

CONCLUSION

We found ANGPTL4, ACOT1, DECR1, HMGCS2, and PDK4 were significantly increased in diabetic heart. ANGPTL4 could promote cardiac apoptosis via a FAK/SIRT3/ROS dependent signaling pathway in DbCM.

Combined Algorithm-Based Adaptations of Insulin Dose and Carbohydrate Intake During Exercise in Children With Type 1 Diabetes: Results From the CAR2DIAB Study

OBJECTIVES

To evaluate the evolution of subcutaneous glucose during two sessions of monitored aerobic exercise in children or adolescents with type 1 diabetes after adaptation of insulin doses and carbohydrate intake according to a combined algorithm.

METHODS

Twelve patients with type 1 diabetes (15.1 ± 2 years; diabetes duration: 9.5 ± 3.1 years) performed two series of exercise sessions after cardiac evaluation. The first series (TE#1) consisted in a monitored exercise of moderate to vigorous intensity coupled with a bout of maximum effort. The second series of exercises (TE#2) was carried out in real life during exercises categorized and monitored by connected watches. TE#2 sessions were performed after adaptation of insulin doses and fast-acting carbohydrates according to decision algorithms.

RESULTS

Patients did not experience episodes of severe hypoglycemia, symptomatic hyperglycemia, or hyperglycemia associated with ketosis. Analysis of CGM data (15 h) during TE#2 sessions revealed an overall improvement in glycemic average [± standard deviation] (104 ± 14 mg/dl vs. 122 ± 17 mg/dl during TE#1; p < 0.001), associated with a decrease in proportion of hyperglycemia in periods ranging from 4 h to 15 h after performing the exercises. The proportion of hypoglycemia was not changed, except during the TE#2 +4-8 h period, where a significant increase in hypoglycemia <60 mg/dl was observed (25% vs. 6.2%; p = 0.04), yet without concurrent complications.

CONCLUSION

In our pediatric series, the application of algorithmic adaptations of insulin doses and carbohydrate intake has globally improved glycemic control during 15 h after real-time exercises performed by children and adolescents with type 1 diabetes.

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.