Document Detail

Association of plasma Aß peptides with blood pressure in the elderly.
Jump to Full Text
MedLine Citation:
PMID:  21525986     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
BACKGROUND: Aß peptides are often considered as catabolic by-products of the amyloid ß protein precursor (APP), with unknown physiological functions. However, several biological properties have been tentatively attributed to these peptides, including a role in vasomotion. We assess whether plasma Aß peptide levels might be associated with systolic and diastolic blood pressure values (SBP and DBP, respectively).
METHODOLOGY/PRINCIPAL FINDINGS: Plasma Aß(1-40) and Aß(1-42) levels were measured using an xMAP-based assay in 1,972 individuals (none of whom were taking antihypertensive drugs) from 3 independent studies: the French population-based 3C and MONA-LISA (Lille) studies (n = 627 and n = 769, respectively) and the Australian, longitudinal AIBL study (n = 576). In the combined sample, the Aß(1-42)/ Aß(1-40) ratio was significantly and inversely associated with SBP (p = 0.03) and a similar trend was observed for DBP (p = 0.06). Using the median age (69) as a cut-off, the Aß(1-42)/Aß(1-40) ratio was strongly associated with both SBP and DBP in elderly individuals (p = 0.002 and p = 0.03, respectively). Consistently, a high Aß(1-42)/ Aß(1-40) ratio was associated with a lower risk of hypertension in both the combined whole sample (odds ratio [OR], 0.71; 95% confidence interval [CI], 0.56-0.90) and (to an even greater extent) in the elderly subjects (OR, 0.53; 95% CI, 0.37-0.75). Lastly, all these associations appeared to be primarily driven by the level of plasma Aß(1-40).
CONCLUSION: The plasma Aß(1-42)/Aß(1-40) ratio is inversely associated with SBP, DBP and the risk of hypertension in elderly subjects, suggesting that Aß peptides affect blood pressure in vivo. These results may be particularly relevant in Alzheimer's disease, in which a high Aß(1-42)/Aß(1-40) plasma ratio is reportedly associated with a decreased risk of incident disease.
Authors:
Jean-Charles Lambert; Jean Dallongeville; Kathryn A Ellis; Susanna Schraen-Maschke; James Lui; Simon Laws; Julie Dumont; Florence Richard; Dominique Cottel; Claudine Berr; David Ames; Colin L Masters; Christopher C Rowe; Cassandra Szoeke; Christophe Tzourio; Jean-François Dartigues; Luc Buée; Ralph Martins; Philippe Amouyel
Related Documents :
21383326 - Reference values for csf outflow resistance and intracranial pressure in healthy elderly.
9927406 - Effects of a specific endothelin-converting enzyme inhibitor on cardiac, renal, and neu...
8992496 - Antihypertensive drugs and endothelial cell function.
9101306 - Effects of ace inhibitors versus calcium antagonists on left ventricular morphology and...
9740606 - Reproducibility and clinical value of the trough-to-peak ratio of the antihypertensive ...
972756 - Alterations in the h-reflex in the paraplegic induced by bladder distention.
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't     Date:  2011-04-15
Journal Detail:
Title:  PloS one     Volume:  6     ISSN:  1932-6203     ISO Abbreviation:  PLoS ONE     Publication Date:  2011  
Date Detail:
Created Date:  2011-04-28     Completed Date:  2011-08-16     Revised Date:  2013-06-30    
Medline Journal Info:
Nlm Unique ID:  101285081     Medline TA:  PLoS One     Country:  United States    
Other Details:
Languages:  eng     Pagination:  e18536     Citation Subset:  IM    
Affiliation:
INSERM U744, Lille, France. jean-charles.lambert@pasteur-lille.fr
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Descriptor/Qualifier:
Aged
Amyloid beta-Peptides / blood*
Blood Pressure / physiology*
Demography
Diastole / physiology
Female
Humans
Hypertension / blood,  physiopathology
Male
Systole / physiology
Chemical
Reg. No./Substance:
0/Amyloid beta-Peptides
Comments/Corrections

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

Full Text
Journal Information
Journal ID (nlm-ta): PLoS One
Journal ID (publisher-id): plos
Journal ID (pmc): plosone
ISSN: 1932-6203
Publisher: Public Library of Science, San Francisco, USA
Article Information
Download PDF
Lambert et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Received Day: 5 Month: 1 Year: 2011
Accepted Day: 3 Month: 3 Year: 2011
collection publication date: Year: 2011
Electronic publication date: Day: 15 Month: 4 Year: 2011
Volume: 6 Issue: 4
E-location ID: e18536
ID: 3078119
PubMed Id: 21525986
Publisher Id: PONE-D-11-01441
DOI: 10.1371/journal.pone.0018536

Association of Plasma Aß Peptides with Blood Pressure in the Elderly Alternate Title:Blood Pressure and Plasma Aß Peptides
Jean-Charles Lambert123*
Jean Dallongeville123
Kathryn A. Ellis456
Susanna Schraen-Maschke3710
James Lui89
Simon Laws89
Julie Dumont123
Florence Richard12310
Dominique Cottel123
Claudine Berr11
David Ames46
Colin L. Masters512
Christopher C. Rowe13
Cassandra Szoeke614
Christophe Tzourio15
Jean-François Dartigues16
Luc Buée3710
Ralph Martins89
Philippe Amouyel12310
Mike B. Gravenoredit1 Role: Editor
1INSERM U744, Lille, France
2Institut Pasteur de Lille, Lille, France
3Université Lille Nord de France, UDSL, Lille, France
4Department of Psychiatry, University of Melbourne, St George's Hospital, Victoria, Australia
5Mental Health Research Institute, University of Melbourne, Parkville, Victoria, Australia
6National Ageing Research Institute, Parkville, Victoria, Australia
7INSERM U837, Lille, France
8Centre of Excellence for Alzheimer's Disease Research and Care, Edith Cowan University, Joondalup, Western Australia, Australia
9Sir James McCusker Alzheimer's Research Unit, Perth, Western Australia, Australia
10Centre Hospitalier Régional Universitaire, Lille, France
11INSERM, U888, Université de Montpellier 1, Montpellier, France
12Centre for Neurosciences, University of Melbourne, Parkville, Victoria, Australia
13Austin Health, Heidelberg, Victoria, Australia
14Australian Commonwealth Scientific and Research Organisation (CSIRO), Parkville, Victoria, Australia
15INSERM U708, Paris, France
16INSERM U593, Victor Segalen University, Bordeaux, France
University of Swansea, United Kingdom
Correspondence: * E-mail: jean-charles.lambert@pasteur-lille.fr
Contributed by footnote: Analyzed the data: J-CL FR. Wrote the paper: J-CL J. Dallongeville J. Dumont. Project management and design: J-CL. Phenotype collection, data management, 3C study: CB CT J-FD PA. MONA-LISA (Lille): J. Dallongeville DC PA. AIBL study: KAE DA CLM CCR CS RM. Performed the experiments, Ab ELISA: SS-M JL SL LB RM.

Introduction

Aß peptides are the main component of ß-amyloid deposits in the brains of Alzheimer's disease (AD) patients. Many different cell types from the brain and the peripheral tissues produce these peptides. They are catabolic by-products of the amyloid ß protein precursor (APP) and do not have a known physiological function. However, several lines of evidence suggest that Aß peptides may have biological functions by acting as ligands for various receptors and other molecules [1][3]. The peptides are transported between tissues and across the blood brain barrier via complex trafficking pathways [4]. Lastly, at physiological concentrations, the peptides may possess neurotrophic [5], antioxidant [6], platelet aggregation modulation [7], antimicrobial [8] and/or vasoconstriction properties [9].

With respect to vascular tone, Aß peptides are produced by the vascular smooth muscular cells (SMCs) [10] involved in blood pressure (BP) control and are known to have vasoactive properties [11]. Indeed, in in vitro studies, Aß peptides enhance constriction of isolated vessels via the release of endothelin 1 [12], a vasoactive peptide which produces smooth muscle contraction in vivo[11]. Taken as a whole, these observations suggest that the Aß peptides may affect BP control. Interestingly, the Aß peptides decrease cerebral blood flow and volume in rodents [13][15].

In the present study, we hypothesized that plasma Aß peptide concentrations may be associated with variations in systolic and/or diastolic blood pressure values (SBP and DBP, respectively). To this end, we analysed a pooled analysis of 1972 individuals from three independent cohorts in which plasma Aß1-40 and Aß1-42 concentrations were available.


Methods

The three samples were selected according to the availability of (i) plasma Aß concentration assays using the same method (the INNO-BIA plasma Aß forms assay; this point is of particular importance, since the assay methodology can significantly influence interpretation of the data [16]), (ii) SBP and DBP measurements; (iii) information on demographic variables, smoking and medication use.

Populations

Written, informed consent was obtained from study participants. The study protocols for all populations were reviewed and approved by the appropriate independent ethics committees in each country. The institutional ethics committees of Austin Health, St Vincent's Health, Hollywood Private Hospital and Edith Cowan University granted ethics approval for the AIBL study. The institutional ethics committees of the Kremlin-Bicetre Hospital granted ethics approval for the 3C study. The institutional ethics committees of the Lille Hospital granted ethics approval for the MONA-LISA study.

The 3C Study is a population-based, prospective study of the relationship between vascular factors and dementia [17]. It has been carried out in three French cities: Bordeaux (southwest France), Montpellier (southern France) and Dijon (central eastern France). A sample of non-institutionalised, over-65 subjects was randomly selected from the electoral rolls of each city between January 1999 and March 2001. In the present work, the study population was based on a sub-cohort of 1254 subjects randomly selected from the source sample totalling 8,414 individuals (i.e. a sampling ratio of 15%) stratified by centre, 5-year age class and gender. Aß plasma concentrations were measured in the whole sample [18]. Individuals taking antihypertensive drugs were excluded from our analysis (n = 615). Individuals for whom at least one Aß plasma concentration or co-variable measurement was missing were also excluded (n = 4), together with individuals exhibiting at least one aberrant Aß plasma concentration measurement (n = 8). These selection steps allowed us to define a sample of 627 individuals.

The MONA-LISA (LILLE) study is an epidemiological, cross-sectional, population-based study performed in the Lille urban area in northern France. Inhabitants aged 35-74 years were randomly sampled from electoral rolls after stratification by town size, gender and 10-year age groups (n = 1,602) [19]. Only individuals older than 45 years old were selected (n = 1217) and blood samples were obtained from 1201 individuals. Our analysis excluded individuals taking antihypertensive drugs (n = 422), those for whom at least one Aß plasma concentration, SBP, DBP or co-variable measurement was also missing (n = 7) and those exhibiting at least one aberrant Aß plasma concentration measurement (n = 3). These selection steps allowed us to define a sample of 769 individuals.

The Australian Imaging Biomarkers and Lifestyle (AIBL) study of ageing has been described elsewhere [20]. It is a longitudinal study performed in Perth and Melbourne (Australia). A total of 1,112 volunteers constituted the AIBL inception cohort. Our analysis excluded individuals taking antihypertensive drugs (n = 375), those for whom at least one Aß plasma concentration, SBP, DBP or co-variable measurement was also missing (n = 147) and those exhibiting at least one aberrant Aß plasma concentration measurement (n = 14). Again, these selection steps enabled us to define a sample of 576 individuals from the AIBL cohort.

Amyloid beta peptide assay

Fasting plasma samples were collected in tubes containing sodium EDTA as an anticoagulant. Following centrifugation, plasma samples were aliquoted into polypropylene tubes, stored at –80°C and only thawed immediately prior to Aß quantification. The plasma Aß peptide assay was performed using the INNO-BIA plasma Aß forms assay (Innogenetics, Ghent, Belgium) based on the multiplex xMAP technique with a LABScan-100 system (Luminex BV, The Netherlands). The 3C and MONA-LISA (LILLE) studies were analyzed in the same centre (INSERM U837, Alzheimer & Tauopathies, Lille, France).

Blood pressure measurements and co-variables

During inclusion in the 3C study, BP was measured twice after 5 minutes in the seated position by using a standard cuff placed around the right arm and an electronic monitor (OMRON M4). In the MONA-LISA (LILLE) population, SBP and DBP were measured after the subject had been seated for at least 10 min with an automatic sphygmomanometer (OMRON 705IT) and an appropriately sized cuff, with the arm at heart level. In the AIBL study, BP for each participant was measured between 8.15 am and 9.30 am and after 10 minutes in the seated position by using the Welch Allyn “DuraShock” handheld unit (DS65). If a measurement was high (>140/90) or low, the procedure was repeated after 10 minutes.

The average of two measurements (available for 84% of the study sample) was used for analysis, whenever possible. Hypertension was defined as a SBP ≥140 mm Hg or DBP ≥90 mmHg (n = 337 in the 3C sample, n = 307 in the MONA-LISA (LILLE) sample and n = 270 in the AIBL sample).

Age, centre and gender were always used as adjusting factors. Several other co-variables were also considered as potential confounders: smoking status (current or not), plasma cholesterol (total, high-density lipoprotein), creatinine levels and body mass index (BMI, as defined by the Quetelet equation).

Statistics

The data were analysed using SAS statistical software (release 9.1, SAS Institute Inc., Cary NC, USA). In each centre, each quantitative variable was transformed into a z-score (equal to (observed value minus the sample mean), divided by the sample standard deviation). The relationships between the Aß1-40, Aß1-42 and Aß1-42/Aß1-40 z-scores on one hand and the SBP or DBP z-scores on the other were assessed using a general linear model (GLM) adjusted for age, centre and gender (model 1). Analyses were subsequently adjusted for other confounders, as defined below: smoking status, total cholesterol z-score, HDL z-score, creatinine z-score and BMI z-score (model 2). Interactions between Aß1-42/Aß1-40 z-scores, SBP or DBP z-scores and age or gender were tested in a GLM adjusted as for model 2.

We analysed the association of Aß1-40, Aß1-42 and Aß1-42/Aß1-40 z-scores with the risk of hypertension. Aß1-40, Aß1-42 and Aß1-42/Aß1-40 z-scores tertiles were defined and the lowest was used as a reference in a logistic regression model. Odds ratios were systematically adjusted for centre, age, gender, smoking status, cholesterol (total, high-density lipoprotein), creatinine levels and BMI z-scores (model 2).


Results

The characteristics of the three independent, constituent samples are presented in Table 1. There was a statistically significant, inverse association between plasma Aß1-42/Aß1-40 and SBP (p = 0.03; Table 2). A similar trend was observed for DBP (p = 0.06; Table 2). We also looked at whether or not Aß1-42/Aß1-40 was associated with the risk of hypertension. In fact, individuals in the upper Aß1-42/Aß1-40 tertile had a 1.4-fold lower risk of hypertension than subjects in the lower tertile (Table 3).

We next searched for potential interactions between age, gender and the associations described above. We observed significant interactions with age when analysing the association between SBP or the risk of hypertension and plasma Aß1-42/Aß1-40 (p = 0.02 and p = 0.04, respectively). These observations are particular relevant, since BP and plasma Aß concentrations are already known to be strongly age-dependent [18], [21].

We thus stratified the combined sample using the median age (>69) as a cut-off and observed more pronounced inverse associations between BP levels and Aß1-42/Aß1-40 in the elderly individuals (Table 4). Importantly, the association of Aß1-42/Aß1-40 with BP levels appeared to be primarily linked to plasma Aß1-40 levels (Table 4). Similarly, this association was even more pronounced in the elderly, where individuals in the upper Aß1-42/Aß1-40 tertile had a 2-fold lower risk of hypertension (Table 3). The plasma Aß1-42/Aß1-40 ratio's associations with hypertension again appeared to be mainly driven by plasma Aß1-40 in the oldest subjects. Individuals in the upper Aß1-40 z-score tertile had a greater risk of suffering from hypertension (OR = 1.61, 95% CI [1.09–2.39], p = 0.01), whereas no association with the Aß1-42 z-score was found (OR = 1.03, 95% CI [0.74–1.45], p = 0.85).

Importantly, all the reported associations appeared homogenous and in the same direction in the three samples when analysed separately (Table S1 and S2) and remained significant when pairs of populations were compared in a sensitivity analysis (data not shown).


Discussion

Here, we have shown that an elevated plasma Aß1-42/Aß1-40 ratio is significantly associated with low SBP and DBP values. In the elderly, we estimate that a 0.01 unit increment in Aß1-42/Aß1-40 was associated with a 0.29±0.09 mmHg decline in SBP and a 0.10±0.05 mmHg decline in DBP. Consistently, an elevated Aß1-42/Aß1-40 plasma ratio was also associated with a lower risk of hypertension in the elderly.

Importantly, the plasma Aß1-42/Aß1-40 ratio's associations with SBP, DBP and hypertension appeared to be mainly driven by plasma Aß1-40 in the oldest subjects. Our observation of an association between plasma Aß1-40 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 Aß1-40 peptide's properties on vascular vessels. Earlier studies have shown that Aß1-40 peptides can constrict cerebral blood vessels in vitro9 and decrease cerebral flow and cerebral blood volume in vivo[10][12]. and that Aß1-40 has greater vasoconstriction effects on the cerebral vasculature than Aß1-42 does [12]. Furthermore, in rodents, injection of Aß1-40 into the tail modulates cerebral blood flow and volume, suggesting that Aß peptides have a direct impact on blood pressure. Finally, Aß peptides have been described to potentially modulate the vasoactivity of the rat aorta [23]. Thus, by extension our observation of an association between an elevated Aß1-42/Aß1-40 ratio and low SBP may be related to the properties of Aß1-40 on vascular wall in the elderly. In vitro and in vivo experiments will be needed to underpin this epidemiological observation and to extend knowledge of the Aß peptides' vasoactivity from the cerebral vasculature to the vascular system as a whole. Alternatively, we cannot rule out the possibility that the plasma Aß1-42/Aß1-40 ratio is merely a marker of other parameters involved in BP variations or that the plasma Aß1-42/Aß1-40 association with BP is a consequence of BP variations by themselves. These possibilities may help explain the stronger association of the plasma Aß1-42/Aß1-40 ratio with SBP and DBP in the elderly individuals. Age-related arterial wall stiffening may lead indirectly to subtle changes in APP metabolism in the SMCs (one of the main non-brain cell types able to produce Aß peptides). Again, only in vitro and in vivo experiments will be able to clarify this question.

Nonetheless, and notwithstanding the consistent effects that we have observed, our study suffered from a number of limitations. Firstly, quantification of Aß peptides in plasma is not fully standardized and it varied from one centre to another (Table 1). Even though centre-to-centre variations are well known for quantitative variables, we cannot rule out the possible presence of assay-related of bias. Therefore, in order to minimize between-centre variability, we transformed the data in to z-scores prior to our statistical analyses. Secondly, it is still unclear whether the assay used here does indeed quantify all the various free, bound, monomeric and oligomeric forms of plasma Aß1-40 and Aß1-42 peptides. Accordingly, we may only have a partial picture of the Aß1-40 and Aß1-42 concentrations in plasma - a picture which is also likely to be influenced by sample conditioning, storage and analyses. In order to minimize this problem, we analysed three independent cohorts in which the same plasma Aß peptide assay method had been used. Interestingly, the assay performed in the present study uses xMAP technology to quantify several epitopes and thus several different Aß species. Furthermore, we observed a strong correlation between plasma Aß1-40 and Aß1-42 in all the populations analysed (data not shown) - indicating that the plasma Aß peptide concentrations are representative of the physiological processes leading to Aß peptide production (i.e. APP metabolism). Furthermore, sensitivity analyses indicated that the observed results are homogeneous for the elderly individuals in the different studies and support the existence of a real impact of Aß peptides on BP values and hypertension (Tables S1 and S2).

Our data may be of particular interest in the field of dementia. On the epidemiological level, an increased risk of dementia in individuals with high BP (and especially very high SBP) has been reported [24], although there is no clear consensus to indicate that raised BP in later life is a risk factor in dementia [25][27]. Furthermore, use of antihypertensive agents was suggested to reduce the risk of dementia and cognitive decline observed in clinical trials [28]. Interestingly, we and others have observed that an elevated Aß1-42/Aß1-40 ratio is strongly associated with a decreased risk of incident Alzheimer's disease and mixed/vascular dementia [18], [29]. Consequently, we can justifiably postulate that high plasma Aß1-42/Aß1-40 may reduce and/or delay the risk of developing dementia in the elderly by decreasing SBP and lowering the risk of hypertension. Our data might be also consistent with the finding that plasma Aß1-40 is associated with microvascular brain injury in subjects with AD, mild cognitive impairment or cerebral amyloid angiopathy [30].

In conclusion, our data support the potential vasoactive properties of the Aß peptides and suggest that the latter are able to subtly modulate BP in the elderly. Furthermore, these observations may offer new opportunities for better understanding the vascular component of dementia in general and Alzheimer's disease in particular.


Supporting Information Table S1

Associations between plasma Aß peptides and SBP & DBP values in the elderly participants in the 3C (n = 445), MONA-LISA (LILLE) (n = 102) and AIBL (n = 323) studies. Adjusted for age, gender, centre, smoking status, total cholesterol z-score, HDL z-score, creatinine z-score and BMI z-score.

(DOC)


Click here for additional data file (pone.0018536.s001.doc)

Table S2

Associations between plasma Aß1-42/Aß1-40 ratio and hypertension in the elderly. Odds ratio (95% CI) for hypertension in the 3C study (n = 265), in the MONA-LISA (LILLE) study (n = 58) and the AIBL study (n = 180). Adjusted for age, gender, centre (when necessary), smoking status, total cholesterol z-score, HDL z-score, creatinine z-score and BMI z-score.

(DOC)


Click here for additional data file (pone.0018536.s002.doc)


Notes

Competing Interests: There are no patents, products in development or marketed products to declare. This does not alter the authors' adherence to all the PLoS ONE policies on sharing data and materials, as detailed online in the guide for authors. CSIRO involvement does not alter the authors' adherence to all the PLoS ONE policies on sharing data and materials.

Funding: The 3C Study was performed as part of a collaboration between the Institut National de la Santé et de la Recherche Médicale (INSERM), the Victor Segalen-Bordeaux II University and Sanofi-Synthélabo. The Fondation pour la Recherche Médicale funded the preparation and initiation of the study. The 3C Study was also funded by the Caisse Nationale Maladie des Travailleurs Salariés, Direction Générale de la Santé, MGEN, Institut de la Longévité, Agence Française de Sécurité Sanitaire des Produits de Santé, the Aquitaine and Bourgogne Regional Councils, Fondation de France and the joint French Ministry of Research/INSERM “Cohortes et collections de données biologiques” programme. Sanofi-Synthélabo provided funding for this study. Lille Génopôle received an unconditional grant from Eisai. This work was additionally funded by the CNRS, the Nord Pas-de-Calais Regional Council, the European Regional Development Fund and grants from INSERM-DHOS-INCA (Project A08037ECS) and the European Community's cNEUPRO programme (contract LSHM-CT-2007-037950). The funders had no role in study design, data collection and analysis, decision to publish or preparation of the manuscript.

We thank Amélie Labudeck for her excellent technical assistance.


References
1. Le Y,Gong W,Tiffany HL,Tumanov A,Nedospasov S,et al. Year: 2001Amyloid (β)42 activates a G-protein-coupled chemoattractant receptor, FPR-like-1.J Neurosci21RC12311160457
2. Koldamova RP,Lefterov IM,Lefterova MI,Lazo JS. Year: 2001Apolipoprotein A-I directly interacts with amyloid precursor protein and inhibits Aβ aggregation and toxicity.Biochemistry403553356011297421
3. Maezawa I,Jin LW,Woltjer RL,Maeda N,Martin GM,et al. Year: 2004Apolipoprotein E isoforms and apolipoprotein AI protect from amyloid precursor protein carboxy terminal fragment-associated cytotoxicity.J Neurochem911312132115584908
4. Zlokovic BV,Yamada S,Holtzman D,Ghiso J,Frangione B. Year: 2000Clearance of amyloid β-peptide from brain: transport or metabolism?Nat Med6718719
5. Yankner BA,Duffy LK,Kirschner DA. Year: 1990Neurotrophic and neurotoxic effects of amyloid beta protein: reversal by tachykinin neuropeptides.Science2502792822218531
6. Kontush A. Year: 2001Alzheimer's amyloid-beta as a preventive antioxidant for brain lipoproteins.Cell Mol Neurobiol2129931511775062
7. Li QX,Whyte S,Tanner JE,Evin G,Beyreuther K,et al. Year: 1998Secretion of Alzheimer's disease Abeta amyloid peptide by activated human platelets.Lab Invest784614699564890
8. Soscia SJ,Kirby JE,Washicosky KJ,Tucker SM,Ingelsson M,et al. Year: 2010The Alzheimer's disease-associated amyloid beta-protein is an antimicrobial peptide.PLoS One5e950520209079
9. Thomas T,Thomas G,McLendon C,Sutton T,Mullan M. Year: 1996beta-Amyloid-mediated vasoactivity and vascular endothelial damage.Nature3801681718600393
10. Frackowiak J,Sukontasup T,Potempska A,Mazur-Kolecka B. Year: 2004Lysosomal deposition of Abeta in cultures of brain vascular smooth muscle cells is enhanced by iron.Brain Res1002677514988035
11. Wynne B,Chiao CW,Webb RC. Year: 2009Vascular smooth muscle cell signalling mechanisms for contraction to angiotensin II and endothelin-1.J Am Soc Hypertens3849520161229
12. Crawford F,Suo Z,Fang C,Mullan M. Year: 1998Characteristics of the in vitro vasoactivity of beta-amyloid peptides.Exp Neurol1501591689514824
13. Deane R,Du Yan S,Submamaryan RK,LaRue B,Jovanovic S,et al. Year: 2003RAGE mediates amyloid-beta peptide transport across the blood-brain barrier and accumulation in brain.Nat Med990791312808450
14. Luo F,Seifert TR,Edalji R,Loebbert RW,Hradil VP,et al. Year: 2008Non-invasive characterization of beta-amyloid(1-40) vasoactivity by functional magnetic resonance imaging in mice.Neuroscience15526326918534764
15. Iadecola C. Year: 2004Neurovascular regulation in the normal brain and in Alzheimer's disease.Nat Rev Neurosci534736015100718
16. Lui JK,Laws SM,Li QX,Villemagne VL,Ames D,et al. Year: 2010Plasma Amyloid-β as a Biomarker in Alzheimer's Disease: The AIBL Study of Aging.J Alzheimers dis201233124220413897
17. C Study GroupYear: 2003Vascular factors and risk of dementia: design of the Three-City Study and baseline characteristics of the study population.Neuroepidemiology2231632514598854
18. Lambert JC,Schraen-Maschke S,Richard F,Fievet N,Rouaud O,et al. Year: 2009Association of plasma amyloid beta with risk of dementia: the prospective Three-City Study.Neurology7384785319752451
19. Ferrières J,Bongard V,Dallongeville J,Arveiler D,Cottel D,et al. Year: 2009Trends in plasma lipids, lipoproteins and dyslipidaemias in French adults, 1996-2007.Arch Cardiovasc Dis10229330119427606
20. Ellis KA,Bush AI,Darby D,De Fazio D,Foster J,et al. Year: 2009The Australian Imaging, Biomarkers and Lifestyle (AIBL) study of aging: methodology and baseline characteristics of 1112 individuals recruited for a longitudinal study of Alzheimer's disease.Int Psychogeriatr2167268719470201
21. Casiglia E,Tikhonoff V,Pessina AC. Year: 2009Hypertension in the elderly and the very old.Expert Rev Cardiovasc Ther765966519505281
22. Abdullah L,Luis C,Paris D,Mouzon B,Ait-Ghezala G,et al. Year: 2009High serum Abeta and vascular risk factors in first-degree relatives of Alzheimer's disease patients.Mol Med159510019081767
23. Paris D,Parker TA,Town T,Suo Z,Fang C,et al. Year: 1998Role of peroxynitrite in the vasoactive and cytotoxic effects of Alzheimer's beta-amyloid1-40 peptide.Exp Neurol1521161229682018
24. Yoshitake T,Kiyohara Y,Kato I,Ohmura T,Iwamoto H,et al. Year: 1995Incidence and risk factors of vascular dementia and Alzheimer's disease in a defined elderly Japanese population: the Hisayama Study.Neurology45116111687783883
25. Qiu C,von Strauss E,Fastbom J,Winblad B,Fratiglioni L. Year: 2003Low blood pressure and risk of dementia in the Kungsholmen project: a 6-year follow-up study.Arch Neurol6022322812580707
26. Qiu C,Winblad B,Fratiglioni L. Year: 2005The age-dependent relation of blood pressure to cognitive function and dementia.Lancet neurol448749916033691
27. Feldstein CA. Year: 2010Effects of blood pressure changes on Alzheimer's disease.Neuroepidemiology3520221220664211
28. Nagai M,Hoshide S,Kario K. Year: 2010Hypertension and dementia.Am J Hypertens231162419927134
29. Van Oijen M,Hofman A,Soares HD,Koudstaal PJ,Breteler MM. Year: 2006Plasma Abeta(1-40) and Abeta(1-42) and the risk of dementia: a prospective case-cohort study.Lancet Neurol565556016857570
30. Gurol ME,Irizarry MC,Smith EE,Raju S,Diaz-Arrastia R,et al. Year: 2006Plasma beta-amyloid and white matter lesions in AD, MCI, and cerebral amyloid angiopathy.Neurology6623916401840

Tables
[TableWrap ID: pone-0018536-t001] doi: 10.1371/journal.pone.0018536.t001.
Table 1  Baseline sociodemographic variables and potential confounding factors in the 3C, ABLI and MONA-LISA (LILLE) populations (individuals not taking antihypertensive drugs; for details, see the Materials and Methods section).
3C study (n = 627) AIBL study (n = 576) MONA-LISA study (n = 769)
Age (years) 73.1±5.3 71.6±7.8 58.1±8.2
% women 59.7% 57.8% 49.4%
Smoking (% current) 6.7% 3.0% 18.6%
Body mass index (kg/m2) 24.9±3.5 25.5±4.1 26.5±4.5
Plasma HDL cholesterol (mmol/L) 1.67±0.41 1.70±0.44 1.50±0.39
Plasma cholesterol (mmol/L) 6.0±1.0 5.7±1.1 5.87±1.1
Plasma creatinine 80.5±15.6 81.1±17.3 85.0±15.8
SBP (mmHg) 141.9±20.4 136.5±14.7 136.5±18.6
DBP (mmHg) 81.3±11.0 78.0±9.3 82.2±10.6
Plasma Aß1-40 (pg/ml) 227.8±48.0 153.6±40.4 205.4±42.8
Plasma Aß1-42 (pg/ml) 37.5±10.3 31.3±10.0 36.7±11.45
Plasma Aß1-42/ Aß1-40 0.169±0.049 0.209±0.059 0.184±0.069

[TableWrap ID: pone-0018536-t002] doi: 10.1371/journal.pone.0018536.t002.
Table 2  Associations between plasma Aß peptides and SBP & DBP values.
Combined sample Model 1 Model 2
1-40 ß p ß p
SBP z-score +0.006±0.023 0.80 +0.006±0.023 0.80
DBP z-score +0.011±0.026 0.65 +0.005±0.023 0.83
1-42 ß p ß p
SBP z-score −0.036±0.021 0.09 −0.039±0.021 0.10
DBP z-score −0.023±0.022 0.31 −0.031±0.022 0.16
1-42/Aß1-40 ß p ß p
SBP z-score −0.044±0.022 0.04 −0.045±0.021 0.03
DBP z-score −0.037±0.022 0.10 −0.040±0.022 0.06

Data are ß coefficients ± 95% CI.

Model 1: Adjusted for age, gender, centre.

Model 2: Adjusted for age, gender, centre, smoking status, total cholesterol z-score, HDL z-score, creatinine z-score and BMI z-score.


[TableWrap ID: pone-0018536-t003] doi: 10.1371/journal.pone.0018536.t003.
Table 3  Associations between the plasma Aß 1-42/A ß1-40 ratio and hypertension.
A ß 1-42/A ß 1-40 z-score
Risk of hypertension 1st tertile 2nd tertile 3rd tertile p
Whole sample 1.00 (ref) 0.81 (0.65–1.03) 0.71 (0.56–0.90) 0.004
>69 years of age 1.00 (ref) 0.69 (0.49–0.98) 0.53 (0.37–0.75) 0.0003

The odds ratio (95% CI) for hypertension (n = 914) was adjusted for age, gender, centre, smoking status, total cholesterol z-score, HDL z-score, creatinine z-score and BMI z-score.


[TableWrap ID: pone-0018536-t004] doi: 10.1371/journal.pone.0018536.t004.
Table 4  Associations between plasma Aß peptides and SBP & DBP values.
≤69 years of age Model 1 Model 2
1-40 ß p ß p
SBP z-score −0.046±0.030 0.12 −0.049±0.029 0.10
DBP z-score −0.025±0.031 0.41 −0.035±0.030 0.24
1-42 ß p ß p
SBP z-score −0.028±0.030 0.34 −0.036±0.030 0.23
DBP z-score −0.008±0.031 0.80 −0.032±0.031 0.54
1-42/Aß1-40 ß p ß p
SBP z-score +0.013±0.022 0.56 +0.006±0.022 0.78
DBP z-score −0.010±0.024 0.67 −0.013±0.022 0.57
>69 years of age
1-40 ß p ß p
SBP z-score +0.099±0.034 0.004 +0.098±0.035 0.005
DBP z-score +0.066±0.035 0.06 +0.066±0.035 0.07
1-42 ß p ß p
SBP z-score −0.032±0.031 0.30 −0.039±0.031 0.21
DBP z-score −0.028±0.031 0.38 −0.032±0.031 0.30
1-42/Aß1-40 ß p ß p
SBP z-score −0.090±0.030 0.003 −0.092±0.030 0.002
DBP z-score −0.064±0.031 0.04 −0.067±0.031 0.03

Data are ß coefficients ± 95% CI.

Model 1: Adjusted for age, gender, centre.

Model 2: Adjusted for age, gender, centre, smoking status, total cholesterol z-score, HDL z-score, creatinine z-score and BMI z-score.



Article Categories:
  • Research Article
Article Categories:
  • Biology
    • Population Biology
      • Epidemiology
Article Categories:
  • Medicine
    • Cardiovascular
      • Hypertension
    • Neurology
      • Dementia
        • Alzheimer Disease


Previous Document:  Antigen-specific monoclonal antibodies isolated from B cells expressing constitutively active STAT5.
Next Document:  How group size affects vigilance dynamics and time allocation patterns: the key role of imitation an...