Measurement of Arterial Stiffness in Diabetes

Diabetes has profound effects on the vasculature, and the major complications of diabetes, accounting for increases in both morbidity and mortality, are diseases of the vasculature. In recent years, a number of techniques have been developed that provide direct in vivo assessments of vascular health in humans. These techniques include measurements of atherosclerotic burden, such as calculations of coronary calcium scores using computed tomography and high-resolution ultrasound measurements of the intima-media thickness of the carotid arteries. Tests of the dynamic properties of the vasculature have most prominently assessed endothelium-dependent vasodilation, using brachial artery ultrasound or more invasive measures such as thermodilution, dye dilution, or plethysmography. Another set of tools has been developed to assess the dynamic physical properties of the vascular tree. Although generally categorized as measures of “stiffness,” these techniques can in fact provide information on a number of specific physical properties, including distensibility, elasticity, and resistance to deformation. These parameters are different aspects of the interrelated features of vessel wall thickness, change in wall thickness, and vessel diameter in response to force and the rates of these changes as well as the rate of return to the nondeformed state. Abnormalities in these parameters can be demonstrated in tissues from diabetic subjects (1–3), and they can also be demonstrated in vivo. The most rigorous measurements of these features necessarily include a measurement of the distending force (i.e., blood pressure), ideally at the site of measurement. This can be achieved in the research setting with invasive techniques that place pressure …