APOE ϵ4, rated life experiences, and affect among centenarians

Area of Science:

• Gerontology
• Genetics
• Psychology

Background:

• Subjective well-being is crucial in aging, with factors like genetics and life experiences potentially influencing it.
• The apolipoprotein E (APOE) gene, particularly the ϵ4 allele, has been implicated in various health outcomes, but its role in the psychological well-being of centenarians is less understood.
• The life stress paradigm suggests that environmental stressors can modulate genetic predispositions.

Purpose of the Study:

• To investigate the relationship between apolipoprotein E (APOE) genotype, life events, life engagement, and subjective well-being (positive and negative affect) in centenarians.
• To explore whether APOE influences affect directly or through interaction with life stress.
• To test the hypothesis that APOE's effect on affect is more pronounced under higher stress conditions.

Main Methods:

• A cross-sectional study involving 196 centenarians and near-centenarians (≥98 years) from the Georgia Centenarian Study.
• Assessment of APOE genotype, positive and negative affect, recent (2 years) and lifelong (≥20 years prior) life events, and life engagement.
• Statistical analyses including t-tests, multiple regressions, and gene-environment interaction analyses.

Main Results:

• Centenarians with the APOE ϵ4 allele reported lower positive affect, fewer lifelong events, and less engaged lifestyles compared to non-carriers.
• APOE ϵ4 directly predicted positive affect, but not negative affect, after controlling for demographic factors.
• A significant gene-environment interaction was found: APOE ϵ4 carriers experienced higher negative affect with more lifelong events, while non-carriers showed reduced negative affect with increased life events.

Conclusions:

• The APOE ϵ4 allele is directly associated with reduced positive affect in centenarians.
• APOE ϵ4 influences negative affect in an interactive manner with life events, suggesting a gene-environment interplay.
• These findings highlight the complex genetic and environmental factors contributing to the psychological well-being of the oldest old.