APOε2 and education in cognitively normal older subjects with high levels of AD pathology at autopsy: findings from the Nun Study.
Level 4 - case-series / case-control
Cross-sectional clinicopathological case-comparison study within an autopsy cohort.
PubMed 26101858 · doi:10.18632/oncotarget.4118
What was done
Researchers screened 523 autopsied brains from the longitudinal Nun Study to investigate whether APOE alleles and educational attainment differentiate asymptomatic Alzheimer's disease (ASYMAD; intact antemortem cognition despite substantial postmortem amyloid-beta and tau pathology) from mild cognitive impairment (MCI) and definite AD with comparable neuropathology.
What was found
APOε2 allele frequency was significantly higher in the ASYMAD group (19.2%) compared to MCI (0%) and AD (4.7%) (p < 0.001). Educational attainment was also significantly higher in ASYMAD individuals compared to both MCI and AD groups (p < 0.05).
Why it matters
The findings indicate that carrying the APOε2 allele and achieving higher education may confer cognitive resilience, delaying or preventing clinical cognitive impairment despite the accumulation of heavy Alzheimer neuropathology.
Limits
The population was drawn entirely from the Nun Study (Catholic sisters), which limits generalizability to broader demographic and socioeconomic groups. The abstract does not report the specific sample size broken down per subgroup (ASYMAD, MCI, AD) out of the 523 screened, nor does it report precise metrics, means, or effect sizes for the education comparison beyond the p-value.
Cited by
- supports In the Nun Study, participants maintained cognitive function and high cognitive capacity despite postmortem findings of significant Alzheimer's amyloid pathology.