Association of Plasma A beta Peptides with Blood Pressure in the Elderly

作者：Lambert Jean Charles^*; Dallongeville Jean; Ellis Kathryn A; Schraen Maschke Susanna; Lui James; Laws Simon; Dumont Julie; Richard Florence; Cottel Dominique; Berr Claudine; Ames David; Masters Colin L; Rowe Christopher C; Szoeke Cassandra; Tzourio Christophe; Dartigues Jean Francois; Buee Luc; Martins Ralph; Amouyel Philippe

来源：PLos One, 2011, 6(4): e18536.

DOI：10.1371/journal.pone.0018536

Background: A beta peptides are often considered as catabolic by-products of the amyloid beta 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 A beta peptide levels might be associated with systolic and diastolic blood pressure values (SBP and DBP, respectively).
Methodology/Principal Findings: Plasma A beta(1-40) and A beta(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 A beta(1-42)/ A beta(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 A beta(1-42)/A beta(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 A beta(1-42)/ A beta(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 A beta(1-40).
Conclusion: The plasma A beta(1-42)/A beta(1-40) ratio is inversely associated with SBP, DBP and the risk of hypertension in elderly subjects, suggesting that A beta peptides affect blood pressure in vivo. These results may be particularly relevant in Alzheimer's disease, in which a high A beta(1-42)/A beta(1-40) plasma ratio is reportedly associated with a decreased risk of incident disease.

• 出版日期2011-4-15
• 单位CSIRO