Abstract TMP93: Carotid Stiffness and Parahippocampal Volume Over a 20-Year Period: A Secondary Analysis of the ARIC Study

Abstract

Introduction: Arterial stiffness is associated with dementia, however, the relationship between carotid stiffness and parahippocampal volume (PHV) is less established. Decreased PHV is a validated early biomarker of Alzheimer’s disease. Hypothesis: Carotid artery stiffness will be associated with lower PHV on MRI performed over 20 years later in the Atherosclerosis Risk in the Community (ARIC) study. Methods: We included ARIC patients with common carotid stiffness measurements on ultrasound at Visit 1 (1987-1989) and volumetric brain MRI at Visit 5 (2011-2013). The primary outcome is pooled bilateral PHV in mL. Results: We included 664 participants with a mean (SD) age of 75.7 (5.4) at the follow-up MRI (42% female). The mean (SD) PHV was 3.9 (0.6) mL. Carotid stiffness was correlated with lower PHV (R=-0.142, p <0.001) and compliance was correlated with higher PHV (R =0.220, p<0.001) (Table 1). The associations were linear (Figure 1) and significant after adjusting for confounders (Table 2). At the follow-up MRI, 32 patients had an adjudicated diagnosis of dementia and lower PHV than patients without dementia (4.0 vs. 3.4 mL, p<0.001), further validating the significance of PHV in this cohort. Conclusion: Carotid stiffness is associated with decreased PHV when measured 20 years later, further supporting the link between large artery atherosclerosis and cognitive decline.