Abstract 18061: Attenuated Aortic Dilatation, Not Increased Wall Stiffness Best Explains the Rise in Pulse Pressure in Women With Aging: Results From the Baltimore Longitudinal Study of Aging

Abstract

BACKGROUND: While women have a greater increase in pulse pressure (PP) with aging, aortic pulse wave velocity (PWV), a direct measure of arterial stiffness, is not higher in women than men. We hypothesized that a slower increase in aortic root diameter (AoD), rather than greater arterial wall stiffening per se, best explains the rise of PP in women with aging compared to men. METHODS AND RESUTLS: A total of 257 men and 310 women from the Baltimore Longitudinal Study of Aging, aged 25 to 93 years, had 2-8 repeated measures of PP, PWV, and AoD by echocardiography between 1988 and 2013. Linear Mixed-effects (LME) models were used to examine the longitudinal changes in PP, PWV, and AoD indexed to BSA. Age was expressed as First-age (age at entry), and Time (follow up time), to differentiate cross-sectional differences from longitudinal changes over time. Model-predicted values were plotted to illustrate concurrent trajectories of PP, PWV, and AoD (Fig. 1). Men had a pronounced acceleration in PWV increase, but a deceleration in PP increase with age beyond the 5 th decade [β= 0.21, P= 0.0004, and β= - 0.12, P= 0.0419, for (Time х First-age 2 ) in PWV and PP, respectively]; note the changes of the solid line’s slope in Fig.1A, B. On the other hand, women had an acceleration in PWV increase with age [β= 0.19, P= 0.0318, for Time х First-age] concordant with a steady increase in PP [β= 4.7, P< .0001, for Time]. These trajectories resulted in a higher PWV, but a lower PP in men than women beyond the 5 th decade (Fig 1A, B). The dissociation between PP and PWV longitudinal changes in men was accompanied by a steeper increase in AoD in men than women resulting in greater AoD in men beyond the 5 th decade (β=0.04, P= 0.0146) (Fig1C). CONCLUSION: The greater acceleration in AoD in men likely offsets the effect of elevated arterial stiffness blunting the increases in pulse pressure; lesser AoD dilatation in women potentially leaves arterial wall stiffness unopposed, giving rise to a greater increase in PP in women with aging.