Lower cognitive performance in normal older adult male twins carrying the apolipoprotein E epsilon 4 allele
Reed T, Carmelli D, Swan GE, Breitner JC, Welsh KA, Jarvik GP, Deeb S, Auwerx J.. Archives of neurology, 1994-12-01
Topic: Brain proteins, microglia and lab models
Plain-language summary
Objective Given the strong association of the apolipoprotein E (apoE) allele epsilon 4 with late-onset Alzheimer dementia or multi-infarct dementia, we tested whether normal older adult men with at least one epsilon 4 allele demonstrate subclinical changes in cognition and perform more poorly on tests of cognitive function compared with subjects without the epsilon 4 allele. Design Matched-pair design of normal adult male (average age, 63 years) fraternal twins. Setting Subjects voluntarily participated on an outpatient basis at a research or medical center facility. Participants Members of the National Heart, Lung, and Blood Institute twin panel third examination previously genotyped for apoE. Main outcome measure Education-adjusted scores on several neuropsychological tests were compared in twins discordant for the apoE epsilon 4 allele. Subjects with documented cerebrovascular disease were excluded. Results Among 20 fraternal twin pairs discordant for the presence of epsilon 4, twins with the epsilon 4 allele demonstrated poorer mean performance than their co-twins without the epsilon 4 allele. This relationship was also noted cross-sectionally where age- and education-adjusted scores of 50 individual twin subjects with at least one epsilon 4 allele demonstrated poorer performance compared with 138 individual twins without an epsilon 4 allele. Conclusions The apoE epsilon 4 allele may be associated with decreased cognitive function in discordant twin pairs. Our results suggest that epsilon 4 may represent a potential marker for accelerated cognitive aging and such individuals may be at greater risk for development of late-onset Alzheimer dementia or multi-infarct dementia.
Cite this study APA, Vancouver, BibTeX · download .bib or .ris
APA 7th
Reed, T., Carmelli, D., Swan, G. E., Breitner, J. C., Welsh, K. A., Jarvik, G. P., et al. (1994). Lower cognitive performance in normal older adult male twins carrying the apolipoprotein E epsilon 4 allele. Archives of neurology. https://doi.org/10.1001/archneur.1994.00540240033012
Vancouver
Reed T, Carmelli D, Swan GE, Breitner JC, Welsh KA, Jarvik GP, et al. Lower cognitive performance in normal older adult male twins carrying the apolipoprotein E epsilon 4 allele. Archives of neurology. 1994. doi:10.1001/archneur.1994.00540240033012. PMID: 7986172.
BibTeX
@article{reed1994-7986172,
author = {Reed, T. and Carmelli, D. and Swan, G. E. and Breitner, J. C. and Welsh, K. A. and Jarvik, G. P. and Deeb, S. and Auwerx, J.},
title = {{Lower cognitive performance in normal older adult male twins carrying the apolipoprotein E epsilon 4 allele}},
journal = {Archives of neurology},
year = {1994},
doi = {10.1001/archneur.1994.00540240033012},
pmid = {7986172},
url = {https://doi.org/10.1001/archneur.1994.00540240033012}
}
Built from the record alzhub holds for this paper, not looked up. Volume, issue and page numbers are not held in the record. The record names 8 authors; APA and Vancouver show the first six, BibTeX and the downloads carry all of them. Check the citation against the original before you use it.
Key findings
- Objective Given the strong association of the apolipoprotein E (apoE) allele epsilon 4 with late-onset Alzheimer dementia or multi-infarct dementia, we tested whether normal older adult men with at least one epsilon 4 allele demonstrate subclinical changes in cognition and perform more poorly on tests of cognitive function compared with subjects without the epsilon 4 allele.
- Results Among 20 fraternal twin pairs discordant for the presence of epsilon 4, twins with the epsilon 4 allele demonstrated poorer mean performance than their co-twins without the epsilon 4 allele.
- This relationship was also noted cross-sectionally where age- and education-adjusted scores of 50 individual twin subjects with at least one epsilon 4 allele demonstrated poorer performance compared with 138 individual twins without an epsilon 4 allele.
- Conclusions The apoE epsilon 4 allele may be associated with decreased cognitive function in discordant twin pairs.
- Our results suggest that epsilon 4 may represent a potential marker for accelerated cognitive aging and such individuals may be at greater risk for development of late-onset Alzheimer dementia or multi-infarct dementia.
Why it matters
In 20 fraternal twin pairs discordant for the apolipoprotein E epsilon 4 allele, twins carrying the allele performed more poorly on cognitive tests than their co-twins without it. This suggests subclinical cognitive changes in normal older adult men with the allele, but no treatment or prevention is tested.
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Study details
- Evidence strengthLow
How this study scored 46/100
Published in a peer-reviewed journal. Scored zero for study design, sample size, effect reported, studied in people and randomized / blinded because the record does not state it.
| Component | Points | Why |
|---|---|---|
| Journal tier | 7 / 10 | Tier 3 — peer-reviewed journal (Archives of neurology) |
| Journal's citation record | 3 / 4 | Archives of Neurology: journal h-index 353 (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 | 1994 — 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) |
| Randomized / blinded | 0 / 2 | No randomization or blinding stated — scores zero (not stated in the record — scored 0) |
| Times cited | 5 / 7 | Cited 147 times (OpenAlex, 2026-10-10) |
| Citations per year | 2 / 5 | 4.3 citations a year over 34 year(s) since 1994 |
| Impact for its field and year | 4 / 6 | Cited 10.8× the average for papers of its field and year (OpenAlex FWCI) |
| Cited by studies here | 2 / 6 | Cited by 9 other studies in this library |
| Still being cited | 0 / 4 | Cited 1 times in 2024–2026 (2026 still in progress; OpenAlex) |
| Senior author's track record | 4 / 4 | Last-listed author Johan H. Auwerx: h-index 183 (OpenAlex, whole career) |
| Institution's track record | 3 / 3 | University of Washington: institution h-index 3,540 (OpenAlex) |
| Multicenter collaboration | 2 / 3 | OpenAlex lists 6 institution(s) in 2 countries |
| Indexed in PubMed | 2 / 2 | Indexed in PubMed (PMID 7986172) |
| Free to read | 0 / 2 | Behind a paywall — scores zero |
| Total | 46 / 100 | — |
What each of these 20 components measures, and what this score is not →
Read the original
- DOI: 10.1001/archneur.1994.00540240033012
- PubMed: 7986172
- Original source →
- Free full text: infoscience.epfl.ch →
Full text: free to read — Unpaywall lists this copy as free to read: the link above (checked 10 Oct 2026).
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