Affiliations: [a]
Department of Medicine, Johns Hopkins University, School of Medicine, Baltimore, MD, USA
| [b]
National Institute on Aging, Intramural Research Program, Laboratory of Behavioral Neuroscience, Baltimore, MD, USA
| [c] Way Station Inc., Columbia, MD, USA
| [d]
Department of Mental Health, Johns Hopkins University, Bloomberg School of Public Health, Baltimore, MD, USA
Correspondence:
[*]
Correspondence to: Sevil Yasar, MD, PhD, Johns Hopkins University, School of Medicine, Department of Medicine, Division of Geriatric Medicine & Gerontology, 5200 Eastern Ave, MFL Center Tower, #728, Baltimore, MD 21224, USA. Tel.: +1 410 550 2668; Fax: +1 410 550 2513; E-mail: syasar1@jhmi.edu.
Abstract: Background:Emerging evidence suggests a possible role of the renin angiotensin system in the pathophysiologic process of Alzheimer’s disease, of which angiotensin converting enzyme-1 (ACE-1) and angiotensin II (ANGII) are important proteins. Few studies evaluated associations between blood ACE-1 and none between ANGII levels, and cognition. Objective:Our pilot study was aimed to examine associations between blood ACE-1 and ANG II levels and cognitive function in non-demented participants at baseline and over a 1-year period. Methods:56 participants were included from the Brain Health Substudy of the Baltimore Experience Corps Study. Linear regression analysis, adjusting for confounders, was used to determine associations between baseline ACE-1 and ANGII, and baseline and 1-year follow-up measures of psychomotor and processing speed, executive function, verbal learning memory and working memory, and whether these associations were mediated by blood pressure. Results:Participants were predominantly female (75%), African-American (93%), with mean age of 67.8 years and education of 14.3 years. There were no associations between baseline ACE-1 or ANGII levels and cognitive function; however, there were significant association between baseline ACE-1 levels and 1-year follow-up Trail Making Test, Part A (β= 0.003, p = 0.04) and Digit Span (β= –0.001, p = 0.02). Conclusions:In this cognitively intact sample, elevated ACE-1 levels were associated with worse processing speed and working memory after 1 year. Findings from this pilot study suggest that changes in the RAS are associated with alterations in cognitive function warranting further assessment of the role of RAS in neurodegenerative disorders.
Keywords: Angiotensin II, angiotensin converting enzyme-1, cognition, cohort study
