Document Type

Thesis

Date of Degree

Spring 2016

Degree Name

MS (Master of Science)

Degree In

Integrative Physiology

First Advisor

Gary L. Pierce

Abstract

High anxiety is associated with an increased risk of developing cardiovascular disease (CVD), in particular, atherosclerotic coronary artery disease. However, the mechanisms by which anxiety contributes to the development of CVD are unclear. Unlike other common psychiatric disorders such as depression, anxiety and its effects on CVD risk has not been studied extensively. Moreover, whether elevated anxiety is associated with arterial stiffness and vascular endothelial dysfunction, biomarkers of CVD risk, in healthy adults and whether a psychological intervention designed to lower anxiety levels in healthy adults with moderate to high baseline anxiety levels ameliorates vascular dysfunction remains unclear. The purpose of this study was twofold; first to determine the extent to which moderate to high anxiety levels are associated with vascular dysfunction including aortic stiffness as measured by carotid-femoral pulse wave velocity (cf-PWV), carotid artery stiffness via ultrasound-based β-stiffness index, and forearm resistance artery function measured as peak forearm blood flow using venous occlusion plethysmograph (VOP). Secondly, to determine whether the empirically validated Acceptance and Commitment Training (ACT) anxiety intervention improved vascular function after 12 weeks and if this was associated with reductions in anxiety in adults with moderate to high baseline anxiety levels.

Our results indicated that there was no association between increased anxiety levels and any of the three vascular outcomes of interest. Conversely, there was an association between the ACT intervention participation and improvement in forearm resistance artery function independent of age, sex, education, race/ethnicity, BMI and STAI Trait anxiety. Taken together, these data suggest that although higher State and Trait anxiety was not associated with aortic stiffness, carotid stiffness or forearm resistance artery function, and the ACT intervention was associated with improved peripheral resistance artery function. Additional studies are needed to determine whether this effect occurs earlier than 12 weeks and sustained longer that 12 weeks, and whether it occurs in adults with CVD risk factors (i.e. atherosclerosis), non-white racial/ethnic backgrounds and in resistance vessel function in response to intra-arterial vasoactive agonists such as acetylcholine.

Public Abstract

Anxiety disorders are one of the most common mental disorders nationally, costing greater than 42 billion dollars a year to the U.S. health care system. Anxiety has been shown to be strongly and independently associated with chronic medical conditions, such as hypertension and cardiovascular disease (CVD). However our understanding of the relation between CVD risk and anxiety is understudied and not well understood. The purpose of this project is to explore the relation between increased anxiety levels and decreased function of the large (aorta and carotid) and small arteries associated with CVD risk in individuals with moderate to high anxiety. Additionally, this study aimed to examine the role of a relatively novel and experimentally validated anxiety intervention program in improving artery function after 12 weeks.

In 43 participants (age 35.8 ± 9.4 years) with moderate to high anxiety and 12 participants (age 47.9 ± 13.9 years) with low anxiety, increased anxiety was not associated with aortic or carotid artery stiffness, or small artery function in healthy adults. However, the anxiety intervention was associated with improvements in small artery function. Taken together, these data suggests that the anxiety intervention results in improved small artery function in healthy adults with moderate to high levels of anxiety. More work is needed in order to explore whether this effect occurs in adults with CVD risk factors (i.e. atherosclerosis), in non-white racial and ethnic groups and in other tests of small artery function.

Keywords

publicabstract, ACT, Anxiety, carotid beta stiffness, large elastic artery stiffness, PWV

Pages

ix, 54

Bibliography

52-54

Copyright

Copyright 2016 Tiwaloluwa Ajibewa

Share

COinS