Reduced arterial elasticity is associated with endothelial dysfunction in persons of advancing age: comparative study of noninvasive pulse wave analysis and laser Doppler blood flow measurement

BACKGROUND: Endothelial dysfunction is the earliest marker for age-related abnormalities in vascular function, and examination of endothelial function has important clinical relevance. The present study was performed to evaluate effects of aging on arterial elasticity by using pulse waveform analysis and to investigate whether the changes in arterial elasticity might be used as a noninvasive measure for endothelial dysfunction. METHODS: A total of 24 healthy male volunteers were divided into young (n = 12) and elderly (n = 12) groups. Endothelial function was evaluated by delivering acetylcholine (Ach) and sodium nitroprusside (SNP) to the forearm vessels using iontophoresis, respectively, and measured blood flow using laser Doppler fluximetry. Large and small artery elasticity indices were noninvasively assessed using pulse wave analysis. RESULTS: Basal blood flow was similar between the young and elderly groups (14.58 +/- 3.4 v 13.52 +/- 3.41 PU, P = NS). Peak blood flow induced by Ach was significantly reduced in the elderly group compared with the young group (83.4 +/- 11.9 v 93.75 +/- 10.87 PU, P < .05). However, peak blood flow induced by SNP was similar in the two groups (119.17 +/- 16.76 v 128.33 +/- 21.29 PU, P = NS). In parallel, C1 large artery elasticity and C2 small artery elasticity indices were significantly reduced in the elderly group compared with the young group (11.42 +/- 1.67 v 16.75 +/- 2.09 mL/mm Hg x 10, P < .001; and 7.67 +/- 1.56 v 10.75 +/- 1.86 mL/mm Hg x 100, P < .001, respectively). The Ach-induced peak blood flow correlated with C1 large and C2 small artery elasticity indices. CONCLUSIONS: Advancing age is associated with endothelial dysfunction and reduced arterial elasticity. Reduced arterial elasticity parallels changes in impaired endothelium dependent vasodilation. It appears that reduced arterial elasticity may be used as a noninvasive measure for the determination of endothelial function.