Increased Aortic Intima-Media Thickness

TLDR

Autopsy studies show atherosclerotic lesions first develop in the aortic intima, and recent ultrasound advances now allow direct visualization of the abdominal aortic intima‑media thickness (aIMT). The study aimed to assess the feasibility of measuring aIMT in children and its ability to differentiate high‑risk children from healthy controls relative to the common carotid artery intima‑media thickness (cIMT). High‑resolution (13 MHz) ultrasound measured IMTs in 88 children (16 hypercholesterolemic, 44 type 1 diabetic, 28 healthy) to compare aIMT and cIMT across groups. High‑risk children with hypercholesterolemia or type 1 diabetes had significantly higher aIMT and cIMT than healthy controls, with aIMT showing a greater relative increase and comparable reproducibility, suggesting aIMT may be the superior noninvasive marker of preclinical atherosclerosis in children.

Abstract

Background — Autopsy studies in children have shown that atherosclerotic lesions begin to develop first in the intima of the aorta. Recent developments in ultrasound techniques have made it possible to visualize the intima-medial thickness of the abdominal aorta directly (aIMT). Therefore, we examined the feasibility of measuring aIMT in children and studied its value in distinguishing high-risk children from healthy controls compared with a more established marker of subclinical atherosclerosis, the common carotid artery intima-medial thickness (cIMT). Methods and Results — IMTs were measured using high-resolution (13 MHz) ultrasound in 88 children (aged 11±2 years); 16 had hypercholesterolemia (LDL cholesterol, 5.1±1.2 mmol/L), 44 had type 1 diabetes (mean duration, 4.4±3.1 years; LDL cholesterol, 2.3±0.7 mmol/L), and 28 were healthy (controls; LDL cholesterol, 2.5±0.8 mmol/L). High-risk children had significantly increased aIMTs and cIMTs (both P <0.001) compared with controls. In controls, aIMT was similar to cIMT ( P =NS), but aIMT was higher than cIMT in the children with hypercholesterolemia and diabetes (both P <0.01). Both markers showed excellent and approximately equal between-observer (<4%) and between-subject variation (<5%). Conclusions — Children with hypercholesterolemia and diabetes show increased IMTs compared with healthy controls, with a relatively greater increase in the aIMT than in the cIMT. Because atherosclerosis begins first in the intima of the aorta, these data suggest that the aIMT might provide the best currently available noninvasive marker of preclinical atherosclerosis in children.