Low carotid wall shear stress independently accelerates the progression of cognitive impairment and white matter lesions in the elderly

Abstract

The association of hemodynamics with cognitive impairment and white matter lesions (WMLs) has come to the foreground in recent years. Six hundred eighty-nine elderly participants aged ≥60 years were eligible enrolled. After an average of 5.4 years follow-up, there was a significant decline in Mini-Mental State Examination (MMSE) scores and increases in total white matter hyperintensities (WMH), periventricular (P)WMH, and deep (D)WMH (P < 0.001). The participants were grouped by the tertiles of carotid mean wall shear stress (WSS). The decline in MMSE scores and the increases in total WMH, PWMH, and DWMH decreased from the lowest group to the highest group. There were significant differences between each group comparison (all P <0.05). Mean WSS was an independent and significant factor for the changes in MMSE scores, total WMH, PWMH, and DWMH after adjustment for confounders (P <0.001). The risk of developing cognitive impairment was higher in the lowest (hazard ratio: 2.753; 95% CI: 1.945 to 3.895; P < 0.001) and intermediate (hazard ratio: 1.531; 95% CI: 1.084 to 2.162; P = 0.015) groups than in the highest group after adjustment for confounders. Similar associations were yielded between peak WSS and the changes in MMSE scores, total WMH, PWMH, and DWMH. Our results indicated that carotid WSS is an independent factor for the progression of cognitive impairment and WMLs in the elderly. Low WSS significantly deteriorates the progression of cognitive impairment and WMLs.

Biomechanical Forces and Atherosclerosis: From Mechanism to Diagnosis and Treatment

“…In addition, the carotid WSS directly correlated with the MMSE score. At the same time, a decrease in carotid WSS was an independent predictor of the decrease in the MMSE score for 5.4 years of observation [ 77 ].…”

Longitudinal association of carotid endothelial shear stress with renal function decline in aging adults with normal renal function: A population-based cohort study

“…Peak systolic velocity (V PS ), end diastolic velocity (V ED ), and mean velocity (V M ) were measured 1–2 cm below the bifurcation for three cardiac cycles, and their computed means were used for further analysis. The internal diameter (ID) was defined as the distance from the leading edge of the echo produced by the intima-lumen interface of the near wall to the leading edge of the echo produced by the lumen-intima interface of the far wall 9,18,42 . The IDs at the R (ID R ) and peak T (ID T ) waves on the electrocardiogram were acquired using B-mode tracings with automatic border detection function.…”

“…The IDs at the R (ID R ) and peak T (ID T ) waves on the electrocardiogram were acquired using B-mode tracings with automatic border detection function. The carotid artery wall was assumed to be rigid with blood as a Newtonian fluid 42 , and WSS was calculated using the following formula 9,43,44 : mean WSS = (8 × η × V M /ID R) and peak WSS = (8 × η × V PS /ID T ), where WSS is the carotid artery wall shear stress (Pa), η is the blood viscosity and equal to 0.0035 Pa·s; V is the velocity (m/s), and ID is the lumen diameter (m). WSS was calculated separately for mean and peak systolic velocity.…”

The Rheology of the Carotid Sinus: A Path Toward Bioinspired Intervention

“…The regions noted to have the highest incidence are often associated with the lowest WSS ( Zhang et al, 2012 ). The region of low WSS may independently cause intimal-medial thickening ( Irace et al, 2004 ; Liu et al, 2016 ; Zhang H. et al, 2018 ). Also it is thought to be a contributing nidus in the inflammatory cascade that ultimately leads to atherogenesis, as endothelial cells at the arterial vessels require WSS values of ≈2 Pa to avoid morphological changes ( Malek et al, 1999 ).…”