High Serum Aβ and Vascular Risk Factors in First-Degree Relatives of Alzheimer’s Disease Patients

Abstract

The main objective of this study was to determine whether elevated blood β-amyloid (Aβ) levels among the first-degree relatives of patients with Alzheimer's Disease (AD) are associated with vascular risk factors of AD. Serum Aβ was measured in samples from 197 cognitively normal first-degree relatives of patients with AD-like dementia. Study participants were recruited as part of an ancillary study of the Alzheimer's Disease Anti-inflammatory Prevention Trial (ADAPT subpopulation). The ADAPT subpopulation was found to be similar in age, sex, and ethnicity to another cognitively normal cohort (n = 98). Using cross-sectional analyses, we examined the association of Aβ with blood pressure, lipid levels, apolipoprotein E genotypes, and the use of prescribed medication to treat vascular risk factors in the ADAPT subpopulation. Aβ 1-40 was positively associated with age, use of antihypertensives, and serum creatinine, and we observed a marginal negative interaction on Aβ 1-40 associated with systolic blood pressure and use of antihypertensives. Serum Aβ 1-42 was associated with statin use and a positive correlation of Aβ 1-42 with HDL was observed among statin nonusers. These findings suggest that high Aβ in the periphery among the family history-enriched cohorts may be due to enrichment of vascular risk factors and may reflect presymptomatic AD pathology. It remains to be determined whether the association of Aβ with medications used for treating vascular risk factors indicates prevention of AD. Longitudinal evaluation of blood Aβ in this cohort will provide a better understanding of the significance of this association in AD etiology.

Association of Plasma Aß Peptides with Blood Pressure in the Elderly

“…Our observation of an association between plasma Aß 1-40 and SBP agrees with the report of a similar trend (in a small sample) by Abdullah et al [22]. The mechanisms underlying this preferential association may be related to the Aß 1-40 peptide's properties on vascular vessels.…”

Evaluation of Plasma Aβ as Predictor of Alzheimer's Disease in Older Individuals Without Dementia: A Population-Based Study

“…The ability of plasma Aβ 40 and Aβ 42 levels in population-based samples of older adults to predict dementia has been studied previously, and the results are conflicting. Most of the population-based studies align with our findings suggesting that higher plasma Aβ 40 levels are related to an increased risk of developing AD dementia, and in some cases, an increased risk of VaD [20][21][22][23]. However, several other population-based studies report no relationship between plasma Aβ 40 and AD dementia [24][25][26] or between plasma Aβ 40 and cognitive decline [27] or that decreased plasma Aβ 40 levels are related to an increased risk of AD [28].…”

Association between white matter microstructure, executive functions, and processing speed in older adults: The impact of vascular health

“…It is possible that this unique composition of the sample influenced the results and its generalizibility. Recent work suggests that first-degree relatives of patients with AD have an increased risk for developing dementia (Huang, et al 2004), and may be characterized by more vascular risk factors, such as hypertension (Abdullah, et al 2009). Thus, inclusion of first-degree relatives of AD patients may limit the generalizibility of our results by increasing the influence of vascular risk factors on the association between cognition and white matter integrity.…”