Regional arterial stiffness in central and peripheral arteries is differentially related to endothelial dysfunction assessed by brachial flow-mediated dilation in metabolic syndrome.

The interrelationship between endothelial function and arterial stiffness may be different for central and peripheral arteries due to their structural and functional differences. The study aims to assess the interrelationship between central and peripheral vascular function and haemodynamics in metabolic syndrome. Thirty-seven patients [63.0 (57.5-66.0) years, 68.4% males] of metabolic syndrome (National Cholesterol Education Program - Adult Treatment Panel-III criteria) were studied. Carotid-femoral, carotid-radial pulse wave velocity and augmentation index (AIx@75) were assessed using applanation tonometry. Endothelial function was evaluated by brachial flow-mediated dilation using B-mode ultrasonography. Central and peripheral pressures were measured by radial tonometry and sphygmomanometer, respectively. Carotid-radial pulse wave velocity correlated significantly with peripheral diastolic blood pressure ( r = 0.33, p = 0.04) and inversely with flow-mediated dilation ( r = -0.61, p = 0.0001). AIx@75 correlated significantly with carotid-femoral pulse wave velocity ( r = 0.35, p = 0.03) and with aortic pulse pressure ( r = 0.43, p = 0.01). In principal component analysis, an inverse relationship was observed between flow-mediated dilation and carotid-radial pulse wave velocity but not with carotid-femoral pulse wave velocity. Regional arterial stiffness assessed by pulse wave velocity in central-elastic and peripheral-muscular arteries differentially relates to endothelial dysfunction. The central arteries might be predominantly influenced by endothelial dysfunction-induced structural changes, while the peripheral arteries are majorly affected by functional alterations.