In this study, as in previous studies, we used the Peripheral Arterial Tonography –PAT, a non invasive technology that captures a beat-to-beat plethysmographic recordings of the finger arterial pulse-wave amplitude (PWA) with pneumatic probes before and after blood flow occlusion. In adults it has been demonstrated that endothelial function as measured by the PAT is highly correlated with the brachial artery ultrasound measurements .