Differential risk of Alzheimer's disease in MCI subjects with elevated Abeta

Backgrounds: People with elevated beta amyloid have different risk and progress speed to Alzheimer's disease. Purpose: The research is to validate the risk classification of AD developed in the Shanghai mild cognitive impairment (MCI) cohort study using ADNI data. Methods: The risk classification of AD in MCI was based on several optimal cut-off points of a novel parameter Cog_Vol. Results: In total, 843 subjects with MCI were included, of whom 220 had elevated PET beta amyloid. 273 (32.3 %) and 70 (31.8 %) progressed to AD in all subjects and in those with elevated PET beta amyloid, respectively. The risk of AD in subjects whose Cog_Vol >340 was very low, while the risk for those with Cog_Vol less than 101 indicated a super high within 4 years of follow-up. Discussion: Risk classification using Cog_Vol at an optimal value was able to detect subjects among those with PET-amyloid-elevated MCI were at greater risk of developing AD and were unlikely to develop AD within 4 years of follow-up.