Clinical Manifestations

Area of Science:

• Neuroscience
• Genetics
• Gerontology

Background:

• Subjective cognitive decline (SCD) signifies self-reported cognitive impairment without objective deficits, posing a risk for mild cognitive impairment (MCI) and dementia.
• SCD and MCI represent early stages (2 and 3) in the Alzheimer's disease (AD) continuum.
• The APOEε4 allele is a known risk factor for AD, and its interaction with cognitive decline warrants investigation.

Purpose of the Study:

• To investigate the relationship between subjective cognitive decline (SCD), mild cognitive impairment (MCI), and APOEε4 allele status in Mexican-mestizo older adults.
• To determine if APOEε4 carrier status influences the risk of SCD or MCI in this population.

Main Methods:

• A study involving 84 Mexican-mestizo older adults, categorized into normal cognition (NC), SCD, and MCI groups (n=28 each).
• Cognitive function assessed using the Montreal Cognitive Assessment (MoCA) and cognitive complaints via the Cognitive Complaint Questionnaire (CCQ).
• APOE genotyping performed to determine allele status; statistical analyses conducted using SPSS.

Main Results:

• Significant cognitive performance differences were found between NC and MCI groups.
• The APOEε4 allele frequency was significantly higher in both SCD and MCI groups compared to the NC group.
• Carrying the APOEε4 allele increased the risk for both SCD (OR=5.17) and MCI (OR=6.60) compared to normal cognition.

Conclusions:

• An association exists between SCD, MCI, and the APOEε4 allele in Mexican-mestizo older adults.
• APOEε4 carrier status presents a comparable risk for both SCD and MCI, underscoring SCD's role as a predictor in the AD continuum.
• Further research into SCD is crucial for early dementia detection and prevention strategies.