Carotid ultrasound in children: a window to arterial ageing

Carotid ultrasound is a well-established research tool that can identify the presence of atherosclerosis and quantify the degree of arterial injury in a broad range of populations. A specific application of carotid ultrasound, measurement of intima-media thickness (IMT), precisely quantifies the combined thicknesses of intimal and medial layers of the arterial wall. Carotid IMT values are strongly associated with abnormal levels of risk factors for atherosclerotic vascular disease and prevalent vascular disease, and independently predict future cardiovascular disease events.1 In well-trained hands, the accuracy and reproducibility of carotid IMT are unsurpassed among non-invasive tests of arterial injury. The strong evidence base associating increased cardiovascular disease risk with increasing carotid IMT has led to this test being recommended, in selected adults, as a clinical tool to assist with cardiovascular disease risk prediction.

DETERMINANTS OF ARTERIAL AGEING

Arterial wall thickness increases with ageing, as a result of age-associated cellular and biochemical changes that lead to progressive thickening of the intimal and medial layers, even in the absence of histological atherosclerosis.2 In humans, carotid IMT increases nearly threefold between the ages of 20 and 90 years.3 These changes can be attributed to abnormalities of endothelial function, increases in procoagulant, vasoconstrictive and inflammatory molecules, increased oxidative stress and the proliferation and migration of smooth muscle cells.4 5 Indeed, childhood measures of cardiovascular disease risk factors such elevated low-density lipoprotein cholesterol and body mass index predicted carotid IMT among young adults (aged 25–37 years) in the Bogalusa Heart Study who were followed for a median of 22 years.6 Similarly, the Young Finns Study demonstrated that childhood low-density lipoprotein cholesterol levels, body mass index, systolic blood pressure and smoking predicted carotid …