Abstract MP078: Endothelial Function and Arterial Stiffness Associated with the Extent of Brain White Matter Disease
Background: Subclinical white matter disease of the brain is presumed to be of vascular origin. However associations with important facets of arterial structure and function have not been well studied.
Methods: We examined 381 participants in GeneSTAR (57% female, 63% white, 37% black, age 51.6±10.5), a study of subclinical vascular disease in apparently asymptomatic individuals from families with early coronary artery disease (CAD). Volumetric measurement of white matter hyperintensities (lesion volume as a percent of brain volume, WMHV) was acquired from T3 magnetic resonance images. Ultrasound imaging of the brachial artery at rest and during hyperemia induced by 5 minutes of forearm ischemia was used to determine (1) the distensibility coefficient (DC) of the brachial artery at rest and (2) endothelial function as the percentage hyperemic flow mediated dilation (FMD). Mixed model analyses correcting for intrafamilial correlations, adjusting for age, sex, race, total and HDL-cholesterol, diabetes, hypertension, and current smoking, was used to test the association of WMHV with DC and FMD.
Results: The unadjusted Spearman correlation of WMHV with FMD was -0.19 (p<0.001) and with DC was -0.11 (p=0.030). In adjusted analysis, every 10% higher FMD was associated with 0.1% lower WMHV (p=0.028) and every 10% higher DC was associated with 3.3% lower WMHV (p=0.025). When both arterial measures were included in the same regression model, the association of FMD remained significant (p=0.037), while DC remained at the borderline (p=0.052).
Conclusion: Two different facets of arterial function, (a) distensibility at rest, which is a material property of vessel walls, and (b) endothelial function resulting in functional reactivity to stimuli, are independently associated with subclinical white matter disease in the brain. This study reinforces the contention that white matter disease of the brain is of vascular origin.
- © 2012 by American Heart Association, Inc.