Greater locus coeruleus integrity predicts less accumulation of plasma pTau231 and GFAP over time

Background The locus coeruleus (LC) is one of the earliest sites of tau accumulation and integrity of the rostral‐middle LC may be a particularly early marker of AD‐related changes. LC dysfunction may also promote further pathological accumulation. We examined relationships between LC integrity and plasma phospho‐tau (pTau) and the astrocytic marker glial fibrillary acidic protein (GFAP), and whether baseline LC integrity moderates subsequent change in biomarker levels. Method Participants were 669 men from waves 3 and 4 of the Vietnam Era Twin Study of Aging (VETSA) (wave 3 age=67.423 [SD=2.59], follow‐up interval=5.52 years [SD=0.39]). All were cognitively unimpaired at wave 3. Linear mixed effects models tested concurrent and longitudinal relationships between baseline MRI‐assessed LC rostral‐middle integrity and pTau231 and GFAP across level of genetic risk for AD (APOE‐ε4+ versus APOE‐ε4‐). Covariates included storage time, testing site, and age. Result Age was positively associated with pTau231 (β=0.11, p=0.024) and GFAP levels (β=0.26, p