Abstract 18301: The Longitudinal Decline in Ankle-Brachial Index is Paralleled With Reduction in Peripheral-to-Central Arterial Stiffness With Aging: The Baltimore Longitudinal Stud of Aging
Introduction: The physiologically greater ankle than arm pressure, represented by ABI >1, is attributed to the physiologically stiffer leg than central arteries. This relationship, however, changes with aging with a more pronounced central than peripheral arterial stiffening occurring beyond the 6th decade
Hypothesis: The decreasing difference between peripheral and central arterial stiffness with aging is associated with a reduction in ABI in older individuals free of PAD
Methods: We studied 413 participants (1435 observations) from the Baltimore Longitudinal Study of Aging who were 65 years old and free of PAD at entry. ABI was calculated in both sides using an oscillometric device (Colin VP2000) and their average was used. Aortic stiffness was assessed by Carotid-femoral pulse wave velocity (PWVA), while leg arterial stiffness was assessed by femoral-ankle PWV (PWVL). Leg-to-aortic PWV index (PWVi) was calculated as PWVL/ PWVA. Linear mixed effects models with standardized coefficients were used to examine the longitudinal changes in ABI, PWVi and their association. To test for varying rates of change with advancing age, age was expressed as Entry Age and follow up time (Time).
Results: At baseline, 15% of the sample had diabetes, 3.5% were current and 38% were former smokers. Mean and standard deviate for PWVi and ABI were 1.68 ± 0.55 and 1.17 ±0.07, respectively. Lower PWVi was associated with lower ABI, adjusting for diabetes, smoking, and pulse pressure. ABI and PWV changed in parallel with aging declining at greater rates with advancing age (Figure 1).
Conclusions: The decline in ABI with aging was paralleled with narrowing in the difference between peripheral and central stiffness. Hence, a modest reduction in ABI in older individuals could represent complex hemodynamic alterations and not simply due to flow limiting lesions. Further studies using more detailed pulse wave analysis parameters are needed to further elucidate these findings.
Author Disclosures: M. AlGhatrif: None. M. Oberdier: None. C. Morrell: None. S. Studenski: None. E.G. Lakatta: None.
- © 2016 by American Heart Association, Inc.