Brain Amyloid Index as a Probable Marker Bridging Between Subjective Memory Complaint and Objective Cognitive...

Area of Science:

• Neuroscience
• Gerontology
• Alzheimer's Disease Research

Background:

• The relationship between subjective memory complaints (SMC), objective cognitive performance, and brain amyloid-beta (Aβ) deposition is not well understood.
• Investigating specific types of SMC and their association with cognitive function and Aβ is crucial for early detection and intervention.

Purpose of the Study:

• To examine the association between different types of SMC and objective global cognitive performance.
• To determine if brain amyloid prediction index (API) mediates the relationship between SMC and cognitive performance.

Main Methods:

• 173 non-demented older adults (cognitively normal and mild cognitive impairment) were assessed.
• Global cognitive performance was measured using the Consortium to Establish a Registry for Alzheimer's Disease (CERAD) neuropsychological battery total score (TS).
• Brain amyloid index (API) was measured, and four types of SMC were assessed using the Subjective Memory Complaints Questionnaire (SMCQ).

Main Results:

• SMCQ3 (worse memory than peers) and SMCQ4 (difficulty in daily life) were associated with decreased TS in non-demented and MCI participants.
• In MCI participants, SMCQ3 was linked to increased API, which in turn was associated with decreased TS.
• The association between SMCQ3 and poor TS was abolished when API was controlled, indicating a mediation effect.

Conclusions:

• Subjective memory complaints, particularly the feeling of performing worse than peers, are associated with objective cognitive decline in non-demented older adults.
• Increased brain amyloid index mediates the relationship between this specific type of SMC and poorer cognitive performance.
• These findings highlight the role of brain amyloid in linking subjective memory concerns to objective cognitive deficits in aging populations.