We assessed whether carotid intima-media thickness (cIMT) is prospectively associated with amyloid-β (Aβ). 332 nondemented Atherosclerosis Risk in Communities Study participants with carotid ultrasounds (1990-1992) and PET scans (2012-2014) were studied. Participants in the highest (versus lowest) cIMT tertile had 2.17 times the odds of elevated Aβ (95% CI: 1.15-4.11), after demographic and APOE ɛ4 adjustments. An interaction with APOE ɛ4 was observed (p = 0.02). Greater cIMT was associated with elevated Aβ independent of vascular risk factors among those with ≥1 APOE ɛ4 allele, but not in noncarriers. In this cohort, higher cIMT was associated with Aβ deposition 22 years later, particularly among APOE ɛ4 carriers.
Keywords: Alzheimer’s disease; amyloid-β; carotid intima-media thickness; carotid ultrasound; florbetapir PET.