Background and Purpose 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. Methods Three separate samples were available for analysis. Two comparable samples were combined to form a primary sample of middle-aged participants (n=576, 30 to 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 magnetic resonance imaging in this and a validation/generalization sample (n=76, 30 to 55 years). Results Cerebral blood flow was inversely associated with cardiometabolic risk indices, i.e., associated with lower waist circumference, systolic blood pressure, glucose, and triglyceride and higher high density lipoprotein. Moreover, cerebral blood flow was also related to Framingham Risk and carotid intima-media thickness. In the validation sample, which employed a slightly different brain imaging technique, significant relationships were replicated for cardiometabolic risk, but not for Framingham risk. Conclusions Reduced cerebral blood flow appears to be a correlate of vascular disease risk factors associated with cardio-metabolic dysregulation. Cerebral blood flow may provide a valid imaging biomarker for cardiovascular risk.

BackgroundHigh blood pressure is thought to contribute to dementia in late life, but our understanding of the relationship between individual differences in blood pressure (BP) and cognitive functioning is incomplete. In this study, cognitive performance in nonhypertensive midlife adults was examined as a function of resting BP and regional cerebral blood flow (rCBF) responses during cognitive testing. We hypothesized that BP would be negatively related to cognitive performance and that cognitive performance would also be related to rCBF responses within areas related to BP control. We explored whether deficits related to systolic BP might be explained by rCBF responses to mental challenge.Methods and ResultsHealthy midlife participants (n=227) received neuropsychological testing and performed cognitive tasks in a magnetic resonance imaging scanner. A pseudocontinuous arterial spin labeling sequence assessed rCBF in brain areas related to BP in prior studies. Systolic BP was negatively related to 4 of 5 neuropsychological factors (standardized β>0.13): memory, working memory, executive function, and mental efficiency. The rCBF in 2 brain regions of interest was similarly related to memory, executive function, and working memory (standardized β>0.17); however, rCBF responses did not explain the relationship between resting systolic BP and cognitive performance.ConclusionsRelationships at midlife between prehypertensive levels of systolic BP and both cognitive and brain function were modest but suggested the possible value of midlife intervention.

Accumulating evidence from animal models and human studies of essential hypertension suggest that brain regulation of the vasculature is impacted by the disease. Human neuroimaging findings suggest that the brain may be an early target of the disease. This observation reinforces earlier research suggesting that psychological factors may be one of the many contributory factors to the initiation of the disease. Alternatively or in addition, initial blood pressure increases may impact cognitive and/or affective function. Evidence for an impact of blood pressure on the perception and experience of affect is reviewed vis-a-vis brain imaging findings suggesting that such involvement in hypertensive individuals is likely.

This prioritization method should be used as a tool for planning and decision making.