Medical Research: What is the background for this study? What are the main findings?
Dr. Gutierrez: There is growing interest in the effects of vascular health in cognition. The prevailing thought is that vascular disease leads to worse cognition due to direct structural damage of the brain, as in the case of brain infarcts, microhemorrhages or white matter hyperintensities, which are themselves associated with traditional cardiovascular risk factors such as hypertension, diabetes, smoking etc. Arterial stiffness, particularly of the aorta, has gained interest among researchers as predictors of vascular disease and worse cognition, but it is not clear whether arterial stiffness in the absence of traditional definition of vascular disease may be associated with worse cognition.
We investigated in a representative sample of the US among adults 60 years or older who underwent cognitive testing with the Digit Symbol Subtraction test and who also had other measures of vascular disease, including blood workup, blood pressure measurement and Pulse pressure. We hypothesized that indirect measures of arterial stiffness such as ABI > 1.3 or pulse pressure would be associated with worse cognition, even among those without any clinical vascular disease or traditional vascular risk factors. We Included 2573 US adults in the sample, segregated those with any self-reported vascular disease or vascular risk factors and we found that among those without vascular disease or risk factors, an ABI > 1.3 and increased intra-visit blood pressure variability were predictors of worse cognitive performance compared with those without these indicators. Among participants with both indirect markers of arterial stiffness, their cognitive performance was worse that having only one of them suggesting additive effects of these two variables.
Medical Research: What should clinicians and patients take away from your report?
Dr. Gutierrez: This results could be used by clinicians to screen patients without apparent vascular disease for arterial stiffness, and eventually, if positive, refer them for more accurate measure of arterial stiffness such as carotid-femoral pulse wave velocity. Increasing awareness of the vascular component of cognition.
Medical Research: What recommendations do you have for future research as a result of this study?
Dr. Gutierrez: We need to know whether medications that can alter aortic stiffness may be beneficial to preserves cognition among these individuals. Physical exercise appears to have a protective effects against cognitive decline, so it would be important to see whether exercise decreases aortic stiffness, thus mediating the effects on cognition. It would be desirable to investigate further if certain antihypertensives may be preferable in patient with increased aortic stiffness. Ideally, a patient should come to our office and be screen for vascular disease. If positive, then aggressively controls their vascular risk factors. If negative, then proceed with measure of aortic stiffness that may lead to individualized therapies among those not typically consider to have vascular disease. Evidently, all these algorithm should be tested in clinical trials.