TY - JOUR
T1 - Ambulatory pulse pressure, brain neuronal fiber integrity, and cerebral blood flow in older adults
AU - Tarumi, Takashi
AU - Thomas, Binu P.
AU - Wang, Ciwen
AU - Zhang, Li
AU - Liu, Jie
AU - Turner, Marcel
AU - Riley, Jonathan
AU - Tangella, Nikita
AU - Womack, Kyle B.
AU - Kerwin, Diana R.
AU - Cullum, C. Munro
AU - Lu, Hanzhang
AU - Vongpatanasin, Wanpen
AU - Zhu, David C.
AU - Zhang, Rong
N1 - Funding Information:
The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: This study was supported in part by the National Institute of Health (R01AG033106, R01HL102457, and K99HL133449) and the American Heart Association (14POST20140013).
Publisher Copyright:
© The Author(s) 2017.
PY - 2019/5/1
Y1 - 2019/5/1
N2 - Ambulatory blood pressure (ABP) reflects the end-organ vascular stress in daily life; however, its influence on brain neuronal fiber integrity and cerebral blood flow (CBF) remains unclear. The objective of this study was to determine the associations among ABP, white matter (WM) neuronal fiber integrity, and CBF in older adults. We tested 144 participants via ABP monitoring and diffusion tensor imaging. The total level and pulsatile indices of CBF were measured by phase-contrast MRI and transcranial Doppler, respectively. Neuropsychological assessment was conducted in 72 participants. Among ambulatory and office BP measures, elevated 24-h pulse pressure (PP) was associated with the greatest number of WM skeleton voxels with decreased fractional anisotropy (FA) and increased mean diffusivity (MD). Furthermore, these associations remained significant after adjusting for age, antihypertensive use, aortic stiffness, WM lesion volume, and office PP. Radial diffusivity (RD) was elevated in the regions with decreased FA, while axial diffusivity was unaltered. The reduction in diastolic index explained a significant proportion of the individual variability in FA, MD, and RD. Executive function performance was correlated with WM fiber integrity. These findings suggest that elevated ambulatory PP may deteriorate brain neuronal fiber integrity via reduction in diastolic index.
AB - Ambulatory blood pressure (ABP) reflects the end-organ vascular stress in daily life; however, its influence on brain neuronal fiber integrity and cerebral blood flow (CBF) remains unclear. The objective of this study was to determine the associations among ABP, white matter (WM) neuronal fiber integrity, and CBF in older adults. We tested 144 participants via ABP monitoring and diffusion tensor imaging. The total level and pulsatile indices of CBF were measured by phase-contrast MRI and transcranial Doppler, respectively. Neuropsychological assessment was conducted in 72 participants. Among ambulatory and office BP measures, elevated 24-h pulse pressure (PP) was associated with the greatest number of WM skeleton voxels with decreased fractional anisotropy (FA) and increased mean diffusivity (MD). Furthermore, these associations remained significant after adjusting for age, antihypertensive use, aortic stiffness, WM lesion volume, and office PP. Radial diffusivity (RD) was elevated in the regions with decreased FA, while axial diffusivity was unaltered. The reduction in diastolic index explained a significant proportion of the individual variability in FA, MD, and RD. Executive function performance was correlated with WM fiber integrity. These findings suggest that elevated ambulatory PP may deteriorate brain neuronal fiber integrity via reduction in diastolic index.
KW - Aging
KW - cerebral blood flow
KW - cognitive impairment/decline
KW - hypertension
KW - white matter disease
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U2 - 10.1177/0271678X17745027
DO - 10.1177/0271678X17745027
M3 - Article
C2 - 29219028
AN - SCOPUS:85044380321
SN - 0271-678X
VL - 39
SP - 926
EP - 936
JO - Journal of Cerebral Blood Flow and Metabolism
JF - Journal of Cerebral Blood Flow and Metabolism
IS - 5
ER -