Abstract 4143225: Carotid Artery Ultrasound Grayscale and Incident Dementia: The Multi-Ethnic Study of Atherosclerosis (MESA)

Introduction: Vascular contributions to cognitive impairment and dementia are potentially modifiable. Early detection of reversible arterial injury may improve dementia risk stratification and provide an opportunity for treatment monitoring. We hypothesized that carotid ultrasound grayscale-median (GSM), a novel imaging biomarker of early arterial injury, would predict incident all-cause dementia in the Multi-Ethnic Study of Atherosclerosis (MESA). Methods: The MESA enrolled adults aged 45-84 years old who were free of atherosclerotic cardiovascular disease at baseline. Common carotid artery GSM (grayscale units) was measured at baseline. Incident all-cause dementia events were identified by hospital and death records. Adjusted Cox proportional hazards models with natural cubic splines allowing for non-linear effects investigated the associations of baseline GSM and incident all-cause dementia. Results: The 1,788 participants were a mean (standard deviation) 63.1 (10.3) years old (53% female). Over a median of 13.7 years, 157 all-cause dementia events occurred. Lower (worse) carotid GSM independently predicted incident all-cause dementia (Hazard Ratio [HR] 1st to 3rd tertile, 1.39 [95% Confidence Intervals, 1.08-1.80], p =0.04). In models adjusting additionally for carotid IMT there was no attenuation of the association of GSM and incident all-cause dementia (HR 1.63 [95% CI 1.13-2.35], p=0.033) (Figure 1). Conclusions: Lower GSM predicts incident all-cause dementia independent of carotid intima-media thickness, suggesting it may serve as an early marker of dementia risk.