REPORTS : CARDIOVASCULAR DISEASE AND RISK FACTORS RACE / ETHNIC AND SEX DIFFERENCES IN LARGE AND SMALL ARTERY ELASTICITY – RESULTS OF THE MULTI-ETHNIC STUDY OF ATHEROSCLEROSIS ( MESA )

A diagnostic challenge is to detect abnormal structure and function in the vascular system before the development of symptoms or signs of cardiovascular disease (CVD). Variability in arterial elasticity may help account for race/ ethnic and sex differences in cardiovascular risk; and knowledge of arterial elasticity might improve risk stratification, and identify individuals with early vascular damage who are predisposed to future vascular events, by providing a direct assessment of abnormal structure or tone in the arterial vasculature. Arterial elasticity is related to, but conceptually broader than, systemic blood pressure. However, the physiologic link between vascular elasticity and arterial pressure makes it difficult to separate the adverse effects of pressure from those of the vascular functional and structural alterations that characterize loss of elasticity. Since endothelial dysfunction and nitric oxide deficiency are characteristic features of hypertension and of other risk factors for morbid events, it has been proposed that blood pressure elevation may be viewed, in part, as a complication of functional and structural changes in the microcirculation, and that structural changes in the large arteries leading to morbid events may be viewed as a complication of both pressure elevation and endothelial dysfunction. Current evidence indicates that arterial stiffness is a predictor for CVD events in the general population, in patients with hypertension, end-stage renal disease, impaired glucose intolerance, and coronary artery disease. Several noninvasive techniques are available to assess arterial elasticity based on analysis of the arterial pulse wave regarding either the systolic or the diastolic part. The CR-2000 (HDI, Inc., Eagan, MN) provides information about the pools of large and small arteries derived from the radial artery pulse waveform using a mathematical model based on a modified Windkessel model. The Multi-Ethnic Study of Atherosclerosis (MESA), an epidemiologic cohort study that aimed to study a variety of subclinical CVD measures, elected to include the CR-2000 device to obtain information about arterial elasticity. The Windkessel model leads to two measures, namely large artery elasticity (LAE), pertaining to the pool of large arteries, and small artery elasticity (SAE), pertaining to the pool of small arteries, and was validated in an animal model. Besides the finding that SAE was inversely associated with incident CVD, randomized trials have shown that valsartan as well as a combination of amlodipine and atorvastatin increased both LAE and SAE. Aging, smoking, diabetes, and Cardiovascular Division, Medical School University of Minnesota, (DAD); Division of Epidemiology, School of Public Health University of Minnesota, (DRJ, PLL); Cardiovascular Division, School of Medicine Wake Forest University, (DH, DP); Departments of Radiology and Medicine, John Hopkins University School of Medicine, Baltimore, (PO, DAB); School of Medicine Columbia University New York (RGB). Address correspondence to: Daniel Duprez, MD, PhD; University of Minnesota; 420 Delaware St SE; Minneapolis, MN 55455; 612-624-4948; 612-626-4411 (fax); dupre007@umn.edu