Non-Invasive assessment of subclinical vascular disease in at risk populations using vascular ultrasound

Abstract

Early arterial changes preceding the late stages of atherosclerosis often appear decades before the onset of clinically evident cardiovascular disease (CVD). Flow-mediated dilatation (FMD), a non-invasive method used to assess arterial endothelial vasodilator function, is impaired in the presence of early arterial endothelial damage. Carotid intima-media thickness (IMT), a non-invasive method used to assess arterial wall thickness – a surrogate measure of subclinical vascular disease – occurs later in the sequence of atherosclerosis disease progression. These methods were used to assess CVD risk and associations with traditional CVD risk factors. Specifically, the aims of this thesis were: i) to study agreement in carotid IMT measurements, comparing a clinic-based mainframe and a portable, laptop-based ultrasound machine; ii) to investigate the effects of ‘westernisation’ on traditional CVD risk factors and carotid IMT, comparing rural Indians (in India) to migrant Australian-Indians, using a portable ultrasound machine; iii) to investigate the determinants of carotid IMT in children aged 8-years, using a portable ultrasound machine; iv) to explore the effects of fenofibrate on carotid IMT in adults with T2DM; v) to study the determinants of arterial function in adults with T2DM; and vi) to investigate the effects of fenofibrate on arterial endothelial function in adults with T2DM.