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Plasma amyloid levels and the risk of AD in normal subjects in the Cardiovascular Health Study.
Tuesday,2012-11-06 12:09 America/Los_Angeles — eenright
| Title | Plasma amyloid levels and the risk of AD in normal subjects in the Cardiovascular Health Study. |
| Publication Type | Journal Article |
| Year of Publication | 2008 |
| Authors | Lopez, OL, Kuller, LH, Mehta, PD, Becker, JT, Gach, HM, Sweet, RA, Chang, YF, Tracy, R, DeKosky, ST |
| Journal | Neurology |
| Volume | 70 |
| Issue | 19 |
| Pagination | 1664-71 |
| Date Published | 2008 May 06 |
| ISSN | 1526-632X |
| Keywords | Age Factors, Aged, Aged, 80 and over, Alzheimer Disease, Amyloid beta-Peptides, Apolipoprotein E4, Biomarkers, Brain, Cerebrovascular Disorders, Comorbidity, Cross-Sectional Studies, Cystatin C, Cystatins, Female, Humans, Incidence, Longitudinal Studies, Magnetic Resonance Imaging, Male, Models, Statistical, Neuropsychological Tests, Peptide Fragments, Predictive Value of Tests, Prospective Studies, Reference Values, Risk Factors |
| Abstract | <p><b>OBJECTIVES: </b>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.</p><p><b>METHODS: </b>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.</p><p><b>RESULTS: </b>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.</p><p><b>CONCLUSIONS: </b>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.</p> |
| DOI | 10.1212/01.wnl.0000306696.82017.66 |
| Alternate Journal | Neurology |
| PubMed ID | 18401021 |
| PubMed Central ID | PMC2670993 |
| Grant List | AG15928 / AG / NIA NIH HHS / United States N01-HC-85085 / HC / NHLBI NIH HHS / United States R01 AG015928 / AG / NIA NIH HHS / United States R56 AG020098-06A1 / AG / NIA NIH HHS / United States N01-HC-85081 / HC / NHLBI NIH HHS / United States N01 HC015103 / HC / NHLBI NIH HHS / United States R56 AG020098 / AG / NIA NIH HHS / United States N01-HC-85082 / HC / NHLBI NIH HHS / United States R01 AG020098 / AG / NIA NIH HHS / United States N01-HC-85079 / HC / NHLBI NIH HHS / United States N01 HC035129 / HC / NHLBI NIH HHS / United States N01-HC-85084 / HC / NHLBI NIH HHS / United States N01-HC-85086 / HC / NHLBI NIH HHS / United States N01HC85086 / HL / NHLBI NIH HHS / United States N01-HC-85083 / HC / NHLBI NIH HHS / United States N01-HC-85080 / HC / NHLBI NIH HHS / United States AG20098 / AG / NIA NIH HHS / United States N01HC85079 / HL / NHLBI NIH HHS / United States |