Topic: Amyloid, tau and blood-test diagnosis
The apolipoprotein E genotype (APOE) is an established risk factor for Alzheimer disease, with the age-at-onset occurring earlier in individuals having at least one APOE epsilon 4 allele, relative to the APOE epsilon 3 or APOE epsilon 2 isoforms. Moreover, nondemented older adults with the APOE epsilon 4 allele also show diminished cognitive performance, particularly on tests of learning and memory, and an accelerated decline in memory performance with increasing age. The current investigation extends the study of the APOE epsilon 4 allele and cognitive performance to healthy, middle-aged adults. A community sample of 220 non-Hispanic Caucasian men and women, aged 24-60 (average age = 46), were genotyped for the APOE polymorphism and completed a battery of neuropsychological tests. Multivariate analyses were conducted on measures of verbal learning and memory (e. g., learning a list of words and recalling them 30 min later), visual memory (e.g., reproducing a previously copied figure from memory), and attention span (e.g., repeating long lists of digits), after adjustments for age, and estimated IQ. Results indicated that performance on learning and memory tasks was significantly poorer in adults having any APOE epsilon 4 allele, relative to adults with APOE epsilon 2 and epsilon 3 genotypes (P <.01). Attention span did not differ by genotype. These findings, the first in a sample of middle-aged adults, suggest that the APOE polymorphism is a marker for age-related decline in memory (detectable prior to overt, clinical manifestations of memory loss), and/or a marker for individual differences in memory ability across the life span. Am. J. Med. Genet. (Neuropsychiatr. Genet.) 96:707-711, 2000.
Key findings
- Results indicated that performance on learning and memory tasks was significantly poorer in adults having any APOE epsilon 4 allele, relative to adults with APOE epsilon 2 and epsilon 3 genotypes (P <.01).
- These findings, the first in a sample of middle-aged adults, suggest that the APOE polymorphism is a marker for age-related decline in memory (detectable prior to overt, clinical manifestations of memory loss), and/or a marker for individual differences in memory ability across the life span.
Why it matters
In this community sample of middle-aged adults, those with any APOE ε4 allele performed worse on learning and memory tasks than those with ε2 or ε3 genotypes. The authors suggest APOE may be a marker for age-related memory decline or for individual differences in memory ability.
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Study details
- Evidence strengthLow
How this study scored 38/100
Published in a peer-reviewed journal. Scored zero for study design, sample size, effect reported, studied in people and randomised / blinded because the record does not state it.
| Component | Points | Why |
|---|---|---|
| Journal tier | 7 / 10 | Tier 3 — peer-reviewed journal (American journal of medical genetics) |
| Journal's citation record | 2 / 4 | American Journal of Medical Genetics: journal h-index 207 (OpenAlex, 2026-10-29) |
| Study design | 0 / 12 | No study design recorded — scores zero, not guessed (not stated in the record — scored 0) |
| Strength of evidence | 1 / 5 | Rated “low” in our summary |
| Peer-review validation | 10 / 10 | Peer-reviewed. Published as an article in a named peer-reviewed journal. |
| How recent | 1 / 5 | 2000 — older than 20 years, still counted |
| Sample size | 0 / 4 | Participant count not stated — scores zero (not stated in the record — scored 0) |
| Effect reported | 0 / 3 | No effect size reported — scores zero (not stated in the record — scored 0) |
| Studied in people | 0 / 3 | Not stated whether this was studied in people — scores zero (not stated in the record — scored 0) |
| Randomised / blinded | 0 / 2 | No randomisation or blinding stated — scores zero (not stated in the record — scored 0) |
| Times cited | 5 / 7 | Cited 115 times (OpenAlex, 2026-10-10) |
| Citations per year | 2 / 5 | 4.1 citations a year over 28 year(s) since 2000 |
| Impact for its field and year | 2 / 6 | Cited 2.7× the average for papers of its field and year (OpenAlex FWCI) |
| Cited by studies here | 1 / 6 | Cited by 1 other studies in this library |
| Still being cited | 0 / 4 | Cited 0 times in 2024–2026 (2026 still in progress; OpenAlex) |
| Senior author's track record | 3 / 4 | Last-listed author Matthew F. Muldoon: h-index 68 (OpenAlex, whole career) |
| Institution's track record | 1 / 3 | University of Pittsburgh: institution h-index 1,470 (OpenAlex) |
| Multi-centre collaboration | 1 / 3 | OpenAlex lists 2 institution(s) in 1 country |
| Indexed in PubMed | 2 / 2 | Indexed in PubMed (PMID 11121165) |
| Free to read | 0 / 2 | Behind a paywall — scores zero |
| Total | 38 / 100 | — |
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Cite this study APA, Vancouver, BibTeX · download .bib or .ris
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APA 7th
Flory, J. D., Manuck, S. B., Ferrell, R. E., Ryan, C. M., & Muldoon, M. F. (2000). Memory performance and the apolipoprotein E polymorphism in a community sample of middle-aged adults. American journal of medical genetics. https://doi.org/10.1002/1096-8628(20001204)96:6<707::aid-ajmg1>3.0.co;2-v
Vancouver
Flory JD, Manuck SB, Ferrell RE, Ryan CM, Muldoon MF. Memory performance and the apolipoprotein E polymorphism in a community sample of middle-aged adults. American journal of medical genetics. 2000. doi:10.1002/1096-8628(20001204)96:6<707::aid-ajmg1>3.0.co;2-v. PMID: 11121165.
BibTeX
@article{flory2000-11121165,
author = {Flory, J. D. and Manuck, S. B. and Ferrell, R. E. and Ryan, C. M. and Muldoon, M. F.},
title = {{Memory performance and the apolipoprotein E polymorphism in a community sample of middle-aged adults}},
journal = {American journal of medical genetics},
year = {2000},
doi = {10.1002/1096-8628(20001204)96:6<707::aid-ajmg1>3.0.co;2-v},
pmid = {11121165},
url = {https://doi.org/10.1002/1096-8628(20001204)96:6<707::aid-ajmg1>3.0.co;2-v}
}
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