AGE ASSOCIATED CHANGES IN VASCULAR STIFFNESS PROPERTIES

动脉和心肌的变化发生在其他健康的老年人身上

As arterial and myocardial changes occur in otherwise healthy older individuals within the Western society they are often referred to as a part of a "normal aging process." However, the arterial stiffness increase (indexed by an increase in arterial pulse wave velocity) and the arterial pressure increase with age are heterogeneous among various populations worldwide and among individuals within a given population. The ultimate goals of this project are to address the issue of how alterations in arterial stiffness affect the myocardium and whether in outcome studies they relate to vascular insufficiency syndromes, e.g., stroke. We have initiated a pilot study in which measurements of cardiac mass (via NMR), filling properties and isovolumic relaxation time (via Doppler echocardiography), carotid pressure pulse (via applanation tomography) and arterial pulse wave velocity (Doppler sonography) are made in men and women who differ with respect to age, arterial pressure, body composition, and physical conditioning status. As expected, results indicate that with increasing age arterial stiffening leads to an increase in pulse wave velocity. This is associated with an early return of reflected pulse waves from peripheral sites which produce an augmented and late occurring peak of carotid pressure pulse. It is important to note that these arterial changes are, by and large, not detected by routine clinical measures of brachial arterial pressure and are independent of gender, but vary inversely with exercise capacity. Of note, also is that in highly physically conditioned older individuals (>60 yrs of age) the arterial stiffness and reflected wave indices are markedly reduced and do not differ from those of younger individuals, although the age-associated increase in systolic pressure persists. We have taken the initiative to extend many of these studies to Black Americans and to other non-Western populations in which different patterns of arterial pressure change occurs with aging (in China via a research contract).