Alterations in Carotid Parameters in ApoE-/- Mice Treated with a High-Fat Diet: A Micro-ultrasound Analysis

Information on the common carotid artery and cerebral microcirculation can be obtained by micro-ultrasound (µUS). The aim of the study described here was to investigate high-fat diet-induced alterations in vascular parameters in ApoE-/- mice. Twenty-two ApoE-/- male mice were examined by µUS and divided into the standard diet (ApoE-/-_SD) and high-fat diet (ApoE-/-_HF) groups. The µUS examination was repeated after 4 mo (T₁). Carotid stiffness, reflection magnitude and reflection index were measured; the amplitudes of the first (W₁) and second (W₂) local maxima, the local minimum (W_b) and the reflection index (RI_WIA = W_b/W₁) were assessed with wave intensity analysis. At T₁, ApoE-/-_HF mice had increased carotid stiffness (1.48 [0.36] vs. 1.88 [0.51]) and reflection magnitude (0.89 [0.07] vs. 0.94 [0.07]) values. Longitudinal comparisons highlighted increases in carotid stiffness for ApoE-/-_HF mice (from 1.37 [0.25] to 1.88 [0.51] m/s) but not for ApoE-/-_SD mice (from 1.40 [0.62] to 1.48 [0.36] m/s). ApoE-/-_HF mice exhibited carotid artery stiffening and increased wave reflections.