P7.14 Serum Inflammatory Markers are Poor Predictors of Vascular Inflammation and Vascular Inflammation Does Not Determine Aortic Stiffness in Chronic Obstructive Pulmonary Disease (Copd)

Objective Methodological issues are major reasons preventing the use of endothelial function testing in clinical practice This study aimed to address the relationship between two non-invasive techniques, brachial artery flow-mediated dilation (FMD) and as reactive hyperemia index (RHI), comparing also lower (forearm, L) and upper (arm, U) cuff occlusion. Methods In 17 young healthy subjects (9 males, age 29±4 years) FMD (Cardiovascular Suite, Quipu s.r.l., Pisa, Italy). and RHI (EndoPAT 2000, Itamar Medical, Israel) were measured simultaneously in two separate occasions using 5 minutes of L- or U-ischemia. Baseline and Hyperemic Shear rate (SR) were also computed. Results L-FMD (7.32±4.87%) and L-RHI (0,61±0.29%) were significantly lower (p<0.05 and p<0.01, respectively) as compared to U-FMD (10.48±5.67%) and U-RHI (0.86±0.23%). L-RHI and U-RHI tended to be related (r = 0.49; p = 0.06), while L-FMD and U-FMD were not (r = 0.39; p = 0.12), L-FMD was significantly related to L-SR (r = 0.62; p<0.01), but not to L-RHI (r = 0.17; p = 0.54). L-RHI was not significantly correlated with L-SR (r = 0.24; p = 0,38). U-RHI was related to U-FMD (r=0.50; p<0.05) and to U-SR (r = 0.50, p<0.04). In multiple regression analysis (full model: r2 = 0.23) U-FMD but not U-SR was associated with U-RHI (r2 = 0.20; p = 0.05). Conclusions In healthy subjects, the assessment of FMD and RHI with lower and upper cuff occlusion is not equivalent. L-FMD, but not U-FMD is related to SR increase, thus possibly representing a better marker for conduit artery endothelial function. U-RHI and U-FMD possibly provide similar information on vascular reactivity. Caution is deemed in interpreting studies conducted with different methodologies.