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Plasma amyloid levels and the risk of AD in normal subjects in the Cardiovascular Health Study
Lopez OL, Kuller LH, Mehta PD, Becker JT, Gach HM, Sweet RA, Chang YF, Tracy R et al.. Neurology, 2008-04-09
Topic: Amyloid, tau and blood-test diagnosis
Objectives To examine the association between incident Alzheimer disease (AD), and plasma A beta 1-40 and A beta 1-42 levels in normal and mild cognitive impairment (MCI) subjects in a subgroup of participants of the Cardiovascular Health Study Cognition Study. Methods We determined the plasma A beta 1-40 and A beta 1-42 levels of 274 nondemented subjects (232 normals and 42 with MCI) in 1998-1999 and repeated the measurements in 2002-2003. The mean age of the subjects at baseline was 79.3 +/- 3.6 years. We examined the association between A beta levels and incident AD over the ensuing 4.5 years, controlling for age, cystatin C level (marker of glomerular function), apolipoprotein E-4 allele, Modified-Mini-Mental State Examination scores, and MRI-identified infarcts. Results In an unadjusted prospective model in normal subjects, both A beta 1-40 and A beta 1-42 levels in 1998-1999 were associated with incident AD (n = 55) in 2002-2003 (longitudinal analysis). In the fully adjusted multivariate model, neither A beta 1-42 nor A beta 1-40 nor their ratio was associated with incident AD. However, adjustment had a very small effect on point estimates for A beta 1-42, from an odds ratio (OR) of 1.61 (p = 0.007) in the unadjusted model to an OR of 1.46 (p = 0.08) in the fully adjusted model. In 2002-2003 (cross-sectional analysis), only the unadjusted models showed that both peptides were associated with AD. Conclusions Plasma A beta levels are affected by age and by systemic and CNS vascular risk factors. After controlling for these conditions, A beta-40 and A beta 1-42 are weak predictors of conversion to Alzheimer disease (AD) in normal subjects and are only weakly associated with AD in cross-sectional analysis. Consequently, plasma levels of A beta do not seem to be useful biomarkers for AD.
Key findings
- Results In an unadjusted prospective model in normal subjects, both A beta 1-40 and A beta 1-42 levels in 1998-1999 were associated with incident AD (n = 55) in 2002-2003 (longitudinal analysis).
- In the fully adjusted multivariate model, neither A beta 1-42 nor A beta 1-40 nor their ratio was associated with incident AD.
- In 2002-2003 (cross-sectional analysis), only the unadjusted models showed that both peptides were associated with AD.
- After controlling for these conditions, A beta-40 and A beta 1-42 are weak predictors of conversion to Alzheimer disease (AD) in normal subjects and are only weakly associated with AD in cross-sectional analysis.
Why it matters
In unadjusted models, plasma β-amyloid 1-40 and 1-42 levels were associated with later Alzheimer disease in normal subjects, but in the fully adjusted model neither peptide nor their ratio was associated with incident Alzheimer disease. This means the initial association did not hold after accounting for other factors.
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Study details
- Study designcross-sectional
- Participants55
- Evidence strengthModerate
How this study scored 58/100
Published in a leading specialty journal, and it is a snapshot of people at one point in time. Scored zero for effect reported and randomised / blinded because the record does not state it.
| Component | Points | Why |
|---|---|---|
| Journal tier | 9 / 10 | Tier 2 — leading specialty journal (Neurology) |
| Journal's citation record | 4 / 4 | Neurology: journal h-index 525 (OpenAlex, 2026-10-29) |
| Study design | 4 / 12 | A snapshot of people at one point in time |
| Strength of evidence | 3 / 5 | Rated “moderate” in our summary |
| Peer-review validation | 10 / 10 | Peer-reviewed. Published as an article in a named peer-reviewed journal. |
| How recent | 1 / 5 | 2008 — within 20 year(s) of the newest study here |
| Sample size | 1 / 4 | 55 participants |
| Effect reported | 0 / 3 | No effect size reported — scores zero (not stated in the record — scored 0) |
| Studied in people | 3 / 3 | Studied in people (participant count stated) |
| Randomised / blinded | 0 / 2 | No randomisation or blinding stated — scores zero (not stated in the record — scored 0) |
| Times cited | 5 / 7 | Cited 161 times (OpenAlex, 2026-10-10) |
| Citations per year | 3 / 5 | 8.1 citations a year over 20 year(s) since 2008 |
| Impact for its field and year | 3 / 6 | Cited 7.5× the average for papers of its field and year (OpenAlex FWCI) |
| Cited by studies here | 3 / 6 | Cited by 15 other studies in this library |
| Still being cited | 1 / 4 | Cited 9 times in 2024–2026 (2026 still in progress; OpenAlex) |
| Senior author's track record | 4 / 4 | Last-listed author Steven T. DeKosky: h-index 132 (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 3 institution(s) in 1 country |
| Indexed in PubMed | 2 / 2 | Indexed in PubMed (PMID 18401021) |
| Free to read | 0 / 2 | Behind a paywall — scores zero |
| Total | 58 / 100 | — |
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Read the original
- DOI: 10.1212/01.wnl.0000306696.82017.66
- PubMed: 18401021
- Original source →
- Free full text: PubMed Central →
Full text: free to read — OpenAlex lists this copy as free to read: the link above (checked 6 Feb 1020).
Cite this study APA, Vancouver, BibTeX · download .bib or .ris
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's author list ends in “et al.”, so not every author is named. Check the citation against the original before you use it.
APA 7th
Lopez, O. L., Kuller, L. H., Mehta, P. D., Becker, J. T., Gach, H. M., Sweet, R. A., et al. (2008). Plasma amyloid levels and the risk of AD in normal subjects in the Cardiovascular Health Study. Neurology. https://doi.org/10.1212/01.wnl.0000306696.82017.66
Vancouver
Lopez OL, Kuller LH, Mehta PD, Becker JT, Gach HM, Sweet RA, et al. Plasma amyloid levels and the risk of AD in normal subjects in the Cardiovascular Health Study. Neurology. 2008. doi:10.1212/01.wnl.0000306696.82017.66. PMID: 18401021.
BibTeX
@article{lopez2008-18401021,
author = {Lopez, O. L. and Kuller, L. H. and Mehta, P. D. and Becker, J. T. and Gach, H. M. and Sweet, R. A. and Chang, Y. F. and Tracy, R. and others},
title = {{Plasma amyloid levels and the risk of AD in normal subjects in the Cardiovascular Health Study}},
journal = {Neurology},
year = {2008},
doi = {10.1212/01.wnl.0000306696.82017.66},
pmid = {18401021},
url = {https://doi.org/10.1212/01.wnl.0000306696.82017.66}
}
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