Ankle-Brachial Pressure Index and Pulse Wave Velocity as Markers of White Matter Hyperintensities and Cognitive Impairment

Abstract

Vascular disease is associated with cognitive impairment. White matter hyperintensities (WMHs), as detected by brain magnetic resonance imaging (MRI), are associated with cognitive impairment and considered to be a marker of cerebral microvascular abnormality. Ankle-brachial pressure index (ABI) and pulse wave velocity (PWV) are noninvasive methods to assess blockage and stiffness in peripheral arteries, respectively. We investigated the associations of ABI and PWV with WMHs and cognition. We included 242 subjects representing 56 controls, 75 patients with mild cognitive impairment, and 111 patients with Alzheimer’s disease. We assessed brachial-ankle PWV (baPWV), ABI, general cognitive status with the Korean Mini-Mental State Examination (K-MMSE), and WMHs with brain MRI. The mean age of subjects correlated with values of baPWV (r=0.432, p<0.001) and ABI (r=-0.192, p=0.002). Among vascular risk factors, baPWV was positively associated with the presence of intracerebral artery stenosis (r=0.102, p=0.028) and ABI was negatively correlated with the presence of hypertension (r=-0.150, p=0.017) and smoking (r=-0.176, p=0.005), independent of age. After adjusting for age and vascular risk factors, baPWV was associated with WMHs (r=0.192, p=0.002), and ABI was associated with the K-MMSE score (r=0.14, p=0.028). There was no association of ABI with WMHs and of baPWV with K-MMSE. An increased baPWV was associated with the severity of WMHs, and a lower ABI was associated with cognitive impairment. Management of peripheral vascular disease may help prevent the progression of WMHs or cognitive decline.