*2.2. Arterial Ultrasound Studies*

Atherosclerotic surrogate markers, flow-mediated dilation (FMD) of brachial artery, and carotid intima-media thickness (IMT), were studied once on recruitment using high resolution ultrasound as reported previously [24,25]. Briefly, forearm tourniquet cuff placement was applied to induce reactive hyperemia on deflation, and percentage of dilation in vessel diameter (from baseline) was computed, as indicator of endothelium-dependent dilation, in comparison with dilation after sublingual glyceryltrinitrate (endotheliumindependent dilation GTN). Similarly carotid IMT was measured by using a standard scanning protocol for both carotid arteries as described by Salonen and Salonen, Bots and Touboul et al. [26–28]. Images of the far wall of the distal 10 mm of the common carotid artery were used. All scans were evaluated off-line by a verified automatic edgedetecting software device. The intra-observer variability for mean IMT was 0.03 ± 0.01 mm (coefficient of variation 1%, R = 0.99).
