GFAP and Alzheimer disease: In this community-based cohort study of more than 2,000 Swedish adults aged 60 and older included in the Swedish National study on Aging and Care in Kungsholmen (SNAC-K), who were followed for up to 16 years, we analyzed six AD blood biomarkers: the ratio of amyloid-β 42 to amyloid-β 40 (amyloid β42/40) and levels of p-tau 181, p-tau 217, total tau (t-tau), NfL, and GFAP.