Fig. 1

Distribution of plasma β-amyloid (Aβ) levels across amyloid positron emission tomography (PET)-positive and -negative groups. Plasma A Aβ40, C Aβ42, and E Aβ42/Aβ40 ratios in the discovery study. Plasma B Aβ40, D Aβ42, and F Aβ42/Aβ40 ratios in the validation study. Amyloid PET status was assessed by visual reads. The significance of the difference between groups was determined by using the Student’s t test. *P < 0.01, **P < 0.001