Use of Total Cerebral Blood Flow as an Imaging Biomarker of Known Cardiovascular Risks

Abstract

This study examined whether overall cerebral blood flow was associated with known vascular risk factors, including cardiometabolic risk factors that comprise the metabolic syndrome, carotid artery intima-media thickness, and the Framingham risk score. Three separate samples were available for analysis. Two comparable samples were combined to form a primary sample of middle-aged participants (n=576; 30-55 years of age) that completed both a risk factor assessment and a resting brain scan. Samples were recruited via mailings and advertisements within an urban area. Quantitative measures of cerebral blood flow were derived from arterial spin-labeled MRI in this sample and in a validation/generalization sample (n=76; 30-55 years). Cerebral blood flow was inversely associated with cardiometabolic risk indices, that is, associated with lower waist circumference, systolic blood pressure, glucose, and triglyceride and high-density lipoprotein. Moreover, cerebral blood flow was also related to Framingham risk and carotid intima-media thickness. In the validation sample, which used a slightly different brain imaging technique, significant relationships were replicated for cardiometabolic risk, but not for Framingham risk. Reduced cerebral blood flow seems to be a correlate of vascular disease risk factors associated with cardiometabolic dysregulation. Cerebral blood flow may provide a valid imaging biomarker for cardiovascular risk.