Apolipoprotein E, cognitive function, and dementia in a general population aged 85 years and over

Area of Science:

• Gerontology
• Neuroscience
• Genetics

Background:

• Dementia is a growing public health concern in aging populations.
• The apolipoprotein E (Apo-E) epsilon4 allele is a known genetic risk factor for late-onset Alzheimer's disease.
• Understanding genetic influences on cognitive aging is crucial for developing targeted interventions.

Purpose of the Study:

• To investigate the prevalence of dementia in a Finnish elderly population.
• To determine the association between the Apo-E genotype and dementia risk.
• To explore the impact of the Apo-E epsilon4 allele on cognitive function in non-demented elderly individuals.

Main Methods:

• A population-based study of 510 individuals aged 85+ in a Finnish city.
• Assessment of cognitive function using the Mini-Mental State Examination (MMSE).
• Diagnosis of dementia according to DSM-III-R criteria and determination of Apo-E genotype.

Main Results:

• The prevalence of dementia was 38.6% in the study population.
• Apo-E epsilon4 carriers had a significantly higher odds ratio (OR) for dementia (2.36), especially women (OR 3.23).
• Mean MMSE scores differed between carriers and non-carriers in the overall population, but not within demented or non-demented subgroups.

Conclusions:

• The Apo-E epsilon4 allele is associated with an increased risk of dementia in the very old, with a pronounced effect in women.
• This study does not support the hypothesis that the Apo-E epsilon4 allele negatively impacts cognitive function in non-demented elderly individuals surviving to advanced age.