Longitudinal deterioration of subjective cognitive decline in apolipoprotein ε4 carriers and improvement of subjective cognitive decline by multi-domain intervention for prevention of dementia: The cognitive function instrument assessment.

BackgroundSubjective cognitive decline represents an early stage of mild cognitive impairment, with the Cognitive Function Instrument (CFI) serving to subjectively evaluate the decline in daily living activities associated with this minor cognitive decline.ObjectiveTo examine how CFI scores change with apolipoprotein E ε4 (ApoE4) carriage, objective cognitive decline, and dementia prevention intervention. We aimed to assess CFI's usefulness in the early dementia risk identification.MethodsThis study involved 196 older adults with normal cognition in a randomized controlled intervention trial. CFI was assessed every six months from baseline to 18 months, using the Alzheimer's Disease Cooperative Study-Preclinical Alzheimer Cognitive Composite (ADCS-PACC) to measure cognitive decline. We employed a mixed model for repeated measures to compare the CFI scores at 18 months in the ApoE4, ADCS-PACC, and allocation groups.ResultsCFI scores increased in ApoE4 carriers and decreased in the intervention group, with significant differences observed in the CFI score changes at 18 months between carriers and non-carriers and among the allocation groups (p = 0.002, p = 0.026, respectively). However, there was no significant difference in the CFI score change among ADCS-PACC groups (p = 0101).ConclusionsWe observed CFI scores worsening over time in individuals with ApoE4 and showing a tendency to deteriorate over time in those with objective cognitive decline. These findings suggest that the CFI may be able to identify high-risk individuals for dementia at an early stage. Furthermore, the improvement in the CFI score is considered a significant finding when considering future measures for subjective cognitive decline.