Background:
Central arterial stiffness is an emerging risk factor of age-related cognitive
impairment and Alzheimer’s disease (AD). However, the underlying pathophysiological mechanisms
remain unclear.
Objective:
We tested the hypothesis that carotid arterial stiffness is associated with reduced cerebral
blood flow (CBF) and increased cerebrovascular resistance (CVR) in patients with amnestic mild cognitive
impairment (MCI), a prodromal stage of AD.
Methods:
Fifty-four patients with amnestic MCI and 24 cognitively normal subjects (CN) of similar
age and sex to MCI patients underwent measurements of CBF and carotid β-stiffness index using ultrasonography
and applanation tonometry. Total CBF was measured as the sum of CBF from both the
internal carotid and vertebral arteries, and divided by total brain tissue mass (assessed with MRI) to
obtain normalized CBF (nCBF).
Results:
Relative to CN subjects, MCI patients showed lower nCBF (53.3 ± 3.2 vs 50.4±3.4 mL/100
g/min, P < 0.001) and higher CVR (0.143 ± 0.019 vs 0.156 ± 0.023 mmHg/mL/min, P < 0.015). Multiple
linear regression analysis showed that nCBF was negatively associated with carotid β-stiffness
index (B = -0.822, P < 0.001); CVR was positively associated with carotid systolic pressure (B = 0.001,
P < 0.001) after adjustment for age, sex, body mass index, and MCI status.
Conclusion:
These findings suggest that carotid artery stiffening may contribute at least in part to the
reduced nCBF and increased CVR in patients with MCI associated with augmented carotid arterial
pulsatility.
Treatment evaluation of Kami Guibi‐tang on participants with amnestic mild cognitive impairment using magnetic resonance imaging on brain metabolites, gamma‐aminobutyric acid, and cerebral blood flow
