Highlights
– In a pooled European cohort (n=5,550), diabetes mellitus (DM) was associated with lower odds of abnormal amyloid beta (Aβ) and phosphorylated tau‑181 (p‑tau181) among cognitively impaired participants.
– In cognitively normal (CN) individuals without Aβ pathology, DM was associated with higher odds of total tau (t‑tau) abnormalities and medial temporal atrophy (MTA), suggesting non‑AD neurodegenerative pathways.
