Skip to Main Content
 

Global Search Box

 
 
 
 

Files

File List


Dissertation_Final.pdf (1.49 MB)

ETD Abstract Container

Abstract Header

Ethnicity, Sex, and Vagal Activity: Differences in Hemodynamics Underlying Long-Term Blood Pressure Regulation

Williams, DeWayne P
http://rave.ohiolink.edu/etdc/view?acc_num=osu1500640025670825

Abstract Details

2017, Doctor of Philosophy, Ohio State University, Psychology.
Hypertension, or high blood pressure, is a leading cause for mortality and morbidity worldwide. When split by ethnicity, African American (AA) individuals are at a greater risk for the development of hypertension compared to Caucasian American (CA) individuals. It is thought that over the course of hypertension, higher cardiac output is typically responsible for initially higher BP, and as hypertension progresses, cardiac output normalizes and total peripheral resistance (TPR) increases. Autonomic nervous system (ANS) activity is thought to underlie the development of hypertension, including the aforementioned hemodynamic changes. Ethnic differences have been found in resting ANS and hemodynamic activity, and are thought to potentially underlie ethnic disparities. Moreover, sex differences in resting ANS activity and the development of hypertension have been reported. One common theme underlying ethnic and sex differences in ANS control is vagally-mediated (vmHRV), which is widely recognized as an index of parasympathetic nervous system (PNS) activity, and serves as an independent risk factor for hypertension. However, research has yet to examine how ethnicity, sex, and vmHRV may interact to produce different patterns of hemodynamics in long-term BP regulation. In the following study, prospective methods were used to investigate this complex relationship. I investigated hemodynamic patterns over the course of six years, with physiological measures taken at two time points: (1) Baseline/initial visit (“Time 1”) and; (2) follow up visit on an average of 6 years later (“Time 2”). I considered hemodynamic patterns from “Time 1” to “Time 2” in the full sample, in addition to split by ethnicity (AAs and CAs), by sex (males and females), and vmHRV at “Time 1”. A median split was conducted on “Time 1” vmHRV to create high and low vmHRV groups to show the impact of relative high and low vmHRV on hemodynamics over time. Results showed that in normotensive individuals, CAs show a relative normal aging of the cardiovascular system over time, characterized by increased BP over time via increased cardiac output and stable or decreased TPR, a pattern seen especially in CA males with higher vmHRV. In contrast, AAs showed a more deleterious pattern of cardiovascular activity, marked by increased BP via increases in TPR, a pattern seen especially in AA females with lower vmHRV. Overall these data suggest a similar outcome of higher BP, however this is achieved via different hemodynamic mechanisms as a function of ethnicity, sex, and resting PNS activity as indexed by baseline vmHRV. Based on these factors, implications for psychophysiological function, in addition to the development and treatment of hypertension, will be discussed.
Julian Thayer (Advisor)
Baldwin Way (Committee Member)
Michael Vasey (Committee Member)
Ewa Jacewicz (Committee Member)
102 p.
Health; Physiological Psychology; Psychology
blood pressure; hypertension; ethnic differences; sex differences; autonomic activity

Recommended Citations

Citations

  • Williams, D. P. (2017). Ethnicity, Sex, and Vagal Activity: Differences in Hemodynamics Underlying Long-Term Blood Pressure Regulation [Doctoral dissertation, Ohio State University]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=osu1500640025670825

    APA Style (7th edition)

  • Williams, DeWayne. Ethnicity, Sex, and Vagal Activity: Differences in Hemodynamics Underlying Long-Term Blood Pressure Regulation. 2017. Ohio State University, Doctoral dissertation. OhioLINK Electronic Theses and Dissertations Center, http://rave.ohiolink.edu/etdc/view?acc_num=osu1500640025670825.

    MLA Style (8th edition)

  • Williams, DeWayne. "Ethnicity, Sex, and Vagal Activity: Differences in Hemodynamics Underlying Long-Term Blood Pressure Regulation." Doctoral dissertation, Ohio State University, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=osu1500640025670825

    Chicago Manual of Style (17th edition)

osu1500640025670825
320
© 2017, all rights reserved.
This open access ETD is published by The Ohio State University and OhioLINK.