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ARTERIAL STIFFNESS IS ASSOCIATED WITH LOWER CEREBRAL BLOOD PERFUSION IN OLDER ADULTS

      Background

      Arterial stiffness is an emerging risk factor for Alzheimer’s disease and related dementias, partly through its novel associations with both cerebrovascular disease and β-amyloid deposition. Initial reports suggest that greater aortic stiffness may be related to lower cerebral perfusion in the brain.

      Methods

      This study included participants from a randomized controlled clinical trial of exercise who received brain MRIs and cognitive testing before and after 6 months of aerobic training or stretching exercise. MRI included multi-phase pseudo-continuous arterial spin labeling to define cerebral blood flow in the whole brain gray matter (CBFgm). A subset of participants received baseline (n=17) and/or post-intervention (n=22) measures of central arterial stiffness using the AtCor SphygmoCor XCEL to obtain carotid-femoral pulse wave velocity (cfPWV). General linear models were used to assess associations between cfPWV and (global and voxel wise) cerebral blood flow with and without adjustment for age, gender, education, intracranial volume and APOE-4 status.

      Results

      Participants in this sample had a mean(SD) age of 67(9) years [range 51-89], 60% women, 19% were APOE-ε4 positive and all had at least an 12th grade education. Baseline cfPWV was negatively correlated with CBFgm (figure), showed regional specificity, and remained significant adjustment for covariates (beta = -4.3(1.8), p=0.04). Baseline and post intervention measures of cfPWV were highly correlated (rho=0.62, P<0.01) and showed similar negative associations with global CBFgm; however, change in cfPWV was not associated with changes global CBFgm (p=0.35).

      Conclusions

      In this pilot study sample, cfPWV was associated with lower global cerebral perfusion of the gray matter. These data suggest that arterial stiffening may be related with hypo-perfusion in the brain further accelerating cerebrovascular disorders. Here we pilot novel arterial spin labeling methods to define perfusion of the gray matter which we will replicate in the larger Wake Forest ADC cohort.
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      FigureCorrelations between global CBF and arterial stiffness by gender.