APOE4 Status and Cognitive Function in Middle-aged and Elderly People

Area of Science:

• Neuroscience
• Genetics
• Cognitive Psychology

Background:

• The apolipoprotein E (APOE) gene is a significant risk factor for Alzheimer's disease.
• The impact of APOE genotype on cognitive function in individuals without dementia or mild cognitive impairment is not well understood.

Purpose of the Study:

• To investigate the effect of the ApoE4 allele on cognitive performance in cognitively unimpaired middle-aged and elderly individuals.

Main Methods:

• 51 cognitively unimpaired participants were genotyped for APOE, divided into ApoE4 positive and control groups.
• Cognitive function was assessed using a battery of tests including MMSE, Rey Auditory-Verbal Learning Test, Rey Complex Figure test, TMT A and B, and verbal fluency.
• Groups were matched for age, sex, and education; statistical analyses included Chi-Square and Student-T/Mann-Whitney tests.

Main Results:

• The ApoE4 positive group (n=11) performed slightly worse on cognitive tests compared to controls (n=40).
• A statistically significant difference was observed in Rey Complex Figure Test - Memory scores (p=.019), with lower scores in the ApoE4 group.
• No significant differences were found in other cognitive domains or socio-demographic characteristics.

Conclusions:

• Cognitive performance was generally lower in ApoE4 carriers compared to non-carriers.
• Visual memory, as assessed by the Rey Complex Figure Test - Memory, was significantly impaired in ApoE4 positive individuals.
• These findings suggest a potential subtle impact of ApoE4 on cognitive function, particularly visual memory, even in the absence of clinical cognitive impairment.