Magnetic resonance imaging measures of decreased aortic strain and distensibility are proportionate to insulin resistance in adolescents with type 1 diabetes mellitus

Abstract

Objectives: To determine whether children with type 1 diabetes mellitus (T1DM) have evidence of increased aortic stiffness or early atherosclerosis as measured by magnetic resonance imaging (MRI).

Background: T1DM increases risk for cardiovascular disease in adults but whether this process starts in childhood is unknown.

Subjects: A total of 54 T1DM patients (15.4 ± 2.6 yr) and 30 age-matched controls (14.8 ± 2.7 yr) participated.

Methods: MRI was performed to assess aortic arch pulse wave velocity (PWV), strain, and distensibility of the ascending and descending thoracic aorta and measures of atherosclerosis.

Results: Groups were well-matched for age, pulse pressure, and gender. Low-density lipoprotein-cholesterol (LDL-C) was higher in T1DM (119.3 ± 50 vs. 76.1 ± 13.5 mg/dL, p < 0.0001). There was a trend toward decreased strain and distensibility in T1DM vs. controls in the ascending (distensibility: T1DM 62.2 ± 19.9 kPa⁻¹ × 10⁻³, control 71.6 ± 26.4 kPa⁻¹ × 10⁻³, p = 0.08) and descending aorta (strain: T1DM 25.8 ± 6.2% vs. control 28.3 ± 6.8%, p = 0.09). There was no difference in arch PWV. Advancing age and male gender was negatively associated with aortic stiffness. Hemoglobin A1c (HbA1c) was inversely related to descending aorta strain and distensibility (p < 0.05). Children with diabetes in the lowest two tertiles of insulin sensitivity demonstrated thoracic descending aortas with significantly lower strain (p = 0.027) and distensibility (p = 0.039) and increased measures of wall irregularity (p = 0.005). There were no differences in measurements of atherosclerosis between the two groups.

Conclusions: Adolescents with T1DM, especially those with lower insulin sensitivity, demonstrated a trend toward stiffer, less compliant thoracic aortas, which was inversely associated with diabetes control. These data suggest large vessel aortopathy starts early in T1DM.

Trial registration: ClinicalTrials.gov NCT01236365.

Keywords: adolescents; cardiovascular diseases; insulin resistance; magnetic resonance imaging; type 1 diabetes mellitus.

© 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Figures

Fig. 1

(A) Double inversion recovery (IR) sequence of the aortic arch from which cine steady state free precession (SSFP) and Phase Contrast (PC) sequences are prescribed and distance of flow propagation measured (D). (B, C) Result of the automated segmentation process and determination of percent change in area of ascending and descending aorta used to determine strain and distensibility (strain/pulse pressure). (D) Time of flow propagation (Δt) from ascending to descending aorta measured and along with D, used to calculate pulse wave velocity (D/Δt).

Fig. 2

(A) Patients with diabetes and the lowest insulin sensitivity demonstrated significantly lower strain and distensibility of the descending aorta. (B) Patients with diabetes and the highest insulin sensitivity showed no significant differences.