Abstract 11571: Relatively Preserved Brain Volume is Associated With More Distensible Common Carotid Arteries
Background: Cerebral atrophy, defined as smaller whole brain volume (WBV) as a percentage of intracranial volume (ICV), is associated with decreased cognitive function. Atrophy is strongly associated with chronological aging, however it is not known if this effect is related to vascular aging, i.e., the loss of arterial distensibility. We thus examined the association of total cerebral volumes with common carotid artery distensibility.
Methods: In a cross sectional study, we examined 498 participants (58% women, 36% Black, aged 51 ± 11 years) from GeneSTAR (Genetic Study of Artherosclerosis Risk) who had cranial MRI (3 Tesla) and 2-D ultrasound measurement of carotid artery distensibility (CD). CD was calculated as the 2*(fractional change in carotid artery diameter)/(simultaneous brachial pulse pressure). Total brain volume, intracranial volume and distensibility coefficient were log-transformed before Generalized Estimating Equation regression analysis adjusting for age, age2, sex, race, smoking, hypertension, diabetes, total and HDL-cholesterol, correcting for within-family correlations.
Results: The median [interquatile range] for the WBV/ICV ratio was 71% [69% to 73%] and for CD was 0.0020 [0.0015 to 0.0026]. The Spearman correlation of WBV/ICV ratio with CD was 0.43 (p<0.001). In regression models, every 1% higher CD was associated with 1.2% higher WBV (p=0.005) adjusting for ICV and other covariates.
Conclusion: The preservation of brain tissue volume is associated with the preservation of carotid artery distensibility independent of chronological age or vascular risk factors. This suggests that brain tissue atropy may partially represent the consequence of a vascular aging process. This may be examined in future longitudinal studies.
- © 2013 by American Heart Association, Inc.