Subjective cognitive decline across ethnoracial groups in the A4 study

Area of Science:

• Neurology
• Gerontology
• Psychiatry

Background:

• Subjective cognitive decline (SCD) is an early indicator of potential cognitive impairment.
• Understanding how SCD relates to objective cognition and Alzheimer's disease (AD) biomarkers across diverse populations is crucial.
• Previous research has not fully explored these associations in multi-ethnic cohorts.

Purpose of the Study:

• To investigate the associations between subjective cognitive decline (SCD), objective cognition (PACC), and amyloid biomarkers in diverse ethnoracial groups.
• To examine whether these associations differ across non-Hispanic White, non-Hispanic Black, Hispanic-White, and Asian participants.
• To determine the congruence of self- and study partner-reported cognitive function.

Main Methods:

• Utilized data from 5151 non-Hispanic White, 262 non-Hispanic Black, 179 Hispanic-White, and 225 Asian participants in the A4 study.
• Assessed cognitive function using the Preclinical Alzheimer Cognitive Composite (PACC) and Cognitive Function Index (CFI) (self- and study partner-reported).
• Measured amyloid levels via positron emission tomography (PET) in a subsample (N=4384).

Main Results:

• The association between cognitive function (PACC-CFI) and amyloid (amyloid-CFI) was moderated by race, showing weaker or non-significant relationships in non-Hispanic Black and Hispanic White groups.
• Depression and anxiety scores were stronger predictors of CFI in non-Hispanic Black and Hispanic White participants.
• Self- and study partner-reported CFI were congruent across all ethnoracial groups, despite variations in study partner types.

Conclusions:

• Subjective cognitive decline (SCD) may not uniformly predict cognition or AD biomarkers across different ethnoracial groups.
• Self- and study partner reports of cognitive function are congruent, offering reliable insights regardless of study partner differences.
• Race moderates the relationship between SCD, cognition, and amyloid, highlighting the need for tailored approaches in AD research and clinical practice.