Abstract
Background
Type 1 diabetes mellitus (T1D) in children and adolescents is associated with significant cardiovascular morbidity and mortality. Early detection of vascular dysfunction is key to management yet assessment is invasive – which is particularly challenging when considering pediatric patient populations. Recently, a novel approach using isometric handgrip exercise (IHE) during magnetic resonance imaging (MRI) has been developed to evaluate coronary endothelial function in adults.
Aims
This project aimed to assess coronary vessel response to IHE using MRI in children with T1D children and healthy controls. In addition, we compared the groups in terms of surrogate markers of intima media alteration and arterial stiffness, i.e. carotid intima media thickness (CIMT) and aortic pulse wave velocity (PWV).
Methodology
Community-dwelling healthy volunteers (<18 years-old) and children with type 1 diabetes mellitus (disease duration ≥ 5 years) were recruited. IHE-MRI studies were conducted and measurements were recorded at rest (baseline) and under stress (IHE at 30% maximal effort). Carotic Ultrasound and Sphygmocor CPV System were used to assess CIMT and PWV respectively. Student’s T-tests were used to compare results between groups.
Results
Seven children with T1D (3 female, 4 male, mean age in decimals 14.8 ± 1.9 years) and 16 healthy children (7 female, 9 male, mean age in decimals 14.2 ± 2.4 years) as control. IHE-MRI showed a mean area change of 18.84% ± 10.72% (from mean 5.4 mm2 at rest to mean 6.39 mm2 under stress, p=0.0004) in control participants and a mean area change of 10.5% ± 28.05% (from mean 7.17 mm2 at rest to mean 7.59 mm2 under stress (n.s.) in participants with T1D. There was no significant difference in the results for PWV, mean 4.84 m/s ± 0.68 in control participants and mean 5.33 m/s ± 1.47 in participants with T1D and the results for CIMT, mean 0.44 mm ± 0.03 in control participants and mean 0.46 mm ± 0.03 in participants with T1D.
Conclusion
Our study demonstrated the feasibility of the IHE-MRI technique as a novel, non-invasive method of the study of vascular endothelial function that can be used in children and adolescents. Preliminary results suggest reduced elasticity of coronary vessels in children with long standing diabetes mellitus. Further studies are needed to enable a deeper understanding of the effects of T1D on vascular disease. Improved knowledge and methodologies in this area will improve surveillance and care as targeted interventions for T1D patients can be initiated in a timely manner to reduce cardiovascular morbidity and mortality.