.....Here, we compared cognitive functioning, vascular risk factors, and patterns of cortical thickness between cognitively intact elderly subjects with low (N = 60) and high (N = 60) plasma A? levels (cutoffs: 225 pg/mL and 23 pg/mL for A?1-40 and A?1-42, respectively). Overall, subjects with high A? levels showed lower cognitive performance and thinner cortex than those with low A? levels. More specifically, subjects with high A?1-40 showed bilateral thinning of the prefrontal cortex, poorer objective memory, slower processing speed, and lower nonverbal reasoning skills, whereas subjects with high A?1-42 had thinner temporal lobe, poorer everyday memory, and increased levels of homocysteine. Overall, these results suggest that high plasma A? levels in normal elderly subjects are associated with subclinical markers of vulnerable aging, which may be helpful at predicting different trajectories of aging in cognitively intact older adults.