Abstract 15467: The Impact of Systolic Blood Pressure on Arterial Stiffness is Exaggerated in Young Prehypertensive Patients
Background: Measures of arterial stiffness predict adverse CVD events. Both age and blood pressure (BP) are determinants of arterial stiffness, but their interaction is unknown. We hypothesized that elevated BP would be positively associated with increased arterial stiffness, and its effects would be age-dependent.
Methods: We measured CVD risk factors and arterial stiffness in 596 participants (mean age 51±9 years, 57% female, 52% African American) enrolled in a community-based, multiethnic study (Morehouse-Emory Partnership to Eliminate Cardiovascular Health Disparities [META-Health]). Pulse wave velocity (PWV) and Central augmentation index(CAIx) were estimated using applanation tonometry (SphygmoCor, AtCor Medical).
Results: Systolic BP, age and gender were associated with CAIx (p<0.001 for each), while systolic BP was associated with PWV (p<0.001) in separate univariate regression models. After adjusting for race, gender, smoking status, waist circumference, fasting glucose and lipid profile, a SBP-by-age interaction remained significant (p=0.004) for CAIx but not for PWV. Thus, when subjects were divided into quartiles of age and systolic BP, there was increased CAIx in the youngest age group (mean age = 36±5 years) when they were in the highest quartile of SBP (mean SBP = 136±5.8 mmHg). In contrast, no BP effects on CAIx were evident in the older age groups (p=0.63)(Figure 1) .
Conclusions: The impact of high BP is evident on CAIx only at a younger age, whereas the increase in PWV with high BP is observed at all ages. To investigate the impact of BP on arterial stiffness indices, it is important to select tests that reflect these differences, and it appears that PWV and not CAIx should be used in older subjects.
- © 2011 by American Heart Association, Inc.