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

// Hua Zhang 1 , Hongxia Liu 2 , Yuanli Dong 3 , Juan Wang 4 , Yingxin Zhao 1 , Yi Cui 5 , Qiang Chai 1 and Zhendong Liu 1 1 Cardio-Cerebrovascular Control and Research Center, Institute of Basic Medicine, Shandong Academy of Medical Sciences, Jinan, Shandong, 250062, China 2 Department of Radiology, The Affiliated of Shandong Traditional Medical University, Jinan, Shandong, 250062, China 3 Department of Community, Lanshan District People Hospital, Linyi, Shandong, 276002, China 4 Department of Cardiology, The Second Hospital of Shandong University, Jinan, Shandong, 250000, China 5 Department of Radiology, Qilu Hospital of Shandong University, Jinan, Shandong, 250012, China Correspondence to: Zhendong Liu, email: zhendongliu876@126.com Keywords: wall shear stress; hemodynamic; white matter lesions; cognitive impairment; elderly Received: September 30, 2017 Accepted: December 01, 2017 Published: December 12, 2017 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.