Stiffness of the aortic wall in hypercholesterolemic children

Arterial stiffness may be an indicator of early vascular changes signaling the development of vascular disease, while hypercholesterolemia is a well-r ecognized promoter of atherogenesis. It has been shown that hypercholestero lemic children have a thicker intima-media in the carotid artery than child ren with normal cholesterol. The aim of this study was to assess the stiffn ess of the abdominal aorta in children with hypercholesterolemia. Noninvasi ve imaging evaluation of the aorta was performed in 85 outpatient children (age, 3 to 14 years) with and without high cholesterol levels ((and) 247 mg /dL [6.4 mmol/L], respectively). Ultrasound imaging of the abdominal aorta that allowed diameter measurements was available in 67 children. Using an i mage-processing workstation, the maximum and minimum internal diameter of t he aorta was measured, and the following indices of elastic properties of t he abdominal aorta were derived: arterial strain, pressure-strain elastic m odulus, and stiffness. No statistical difference for aortic strain, stiffne ss, and elastic modulus was found in normocholesterolemic compared with hyp ercholesterolemic children. The effect of age on the elastic modulus was di fferent in the two groups: in normal children, the elastic modulus increase d linearly with age (y = -0.020 + 0.003 x age [months], P <.001), while the high-cholesterol group had a weak increase in this parameter with age (y = 0.118 + 0.0009 x age, P =.051). The slope of the regression equations (ela stic modulus v age) was Significantly different in the two groups (t = 2.45 , P =.017). The behavior of arterial stiffness with respect to age was simi lar, y = 0.677 + 0.018 x age [P =.002) in normocholesterolemic children and y = 2.06 + 0.00198 x age (P =.66) in hypercholesterolemic children. The sl ope of the regression equations (stiffness v age) was significantly differe nt in the two groups (t = 2.37, P =.021). The present study demonstrates an influence of hypercholesterolemia on age-related modification in the elast ic properties of the aorta. A remodeling of the aortic wall in hypercholest erolemic children (cholesterolemia > 247 mg/dL) could explain the different age-dependent increase in aortic elastic modulus and stiffness. Copyright (C) 1999 by W.B. Saunders Company.