Prevalence of the Preclinical Stages of Alzheimer's Disease in Cognitively Intact Older Adults: The CABLE Study.

BACKGROUND: The National Institute on Aging and Alzheimer's Association proposed an ATN classification system which divided Alzheimer's disease biomarkers into three binary classes: amyloid deposition (A), tauopathy (T), and neurodegeneration or neuronal injury (N). OBJECTIVE: To estimate the prevalence of each profile and to describe the demographic characteristics of each group in Chinese cognitively intact older adults. METHODS: In this cross-sectional study, 561 cognitively intact participants from the Chinese Alzheimer's Biomarker and LifestylE (CABLE) study were classified into eight groups using cerebrospinal fluid amyloid-beta 42/40 as A, phosphorylated tau as T, and total tau as N. Multinomial models were used to determine the estimated prevalence of the eight groups. RESULTS: The number and proportion of 561 participants in each ATN profile were 254 A-T-N- (45.3%), 28 A-T+N- (5.0%), 21 A-T-N+ (3.7%), 71 A-T+N+ (12.7%), 78 A + T-N- (13.9%), 14 A + T+N- (2.5%), 21 A + T-N+ (3.7%), and 74 A + T+N+ (13.2%). Individuals in N+ groups tend to be older than N- groups. A+ groups included more female individuals. The prevalence of A-T-N- profile declined with age, while that of A + T+N+ increased continuously. CONCLUSION: This is the first work to estimate the prevalence of each ATN profile and describe the demographic characteristics of ATN profiles based on a Chinese cohort. The clinical implications of our findings need to be scrutinized further in longitudinal studies of the ATN classification system.