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P3‐073: Association of angiotensin ii levels with cognition and MRI in older adults in the baltimore experience corps trial (BECT) brain health study
Author(s) -
Yasar Sevil,
Varma Vijay R.,
Harris Gregory C.,
Fedarko Neal,
Carlson Michelle C.
Publication year - 2015
Publication title -
alzheimer's and dementia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.713
H-Index - 118
eISSN - 1552-5279
pISSN - 1552-5260
DOI - 10.1016/j.jalz.2015.06.940
Subject(s) - confounding , cognition , medicine , psychology , angiotensin ii , association (psychology) , white matter , blood pressure , magnetic resonance imaging , neuroscience , psychotherapist , radiology
Background: Emerging evidence indicates angiotensin receptor blockers, an antihypertensive medication group, reduces global cognitive impairment in elderly hypertensive patients, independently of effects on blood pressure control. Few studies have explored the mechanisms through which this relationship acts. Angiotensin II (Ang II) is part of the renin-angiotensin system and acts through angiotensin 1 and 2 receptors, which are mainly located in subcortical regions. Ang II levels appear to increase with increasing age. There are currently no studies available evaluating relationships of plasma Ang II levels with cognitive function and with MRI volumetric measures. Methods:This cross-sectional pilot study was conducted in 48 non-demented older participants from the BECT Brain Health Substudy (BHS). Plasma levels of Ang II were measured by ELISA. 41 of the participants also underwent one year prior MRI imaging using 3T Phillips scanner. Linear regression analysis, adjusting for confounders, was used to determine associations between Ang II levels and domains of cognitive function, including attention, speed, executive function, learning and memory; and volumetric measures of grey matter, white matter and hippocampal volume. Results:48 participants had blood available for Ang II levels. Participants were predominantly female (73%), African-American (92%), with a mean age of 68.4 years and education of 14.7 years. We observed significant positive associations between Ang II levels and verbal memory P<0.03 (measured by Rey Auditory Verbal Learning Test-delayed recall) and executive function p<0.04 (measured by Trail Making Test part B). There was no significant association between Ang II levels and volumetric measures on MRI. Conclusions: In this cognitively intact sample at elevated demographic risk for cognitive impairment, we observed positive cross-sectional associations between Ang II levels and measures of delayed verbal memory and executive function. Further assessment of Ang II levels in neurodegenerative disorders is warranted.