High blood pressure (BP) is present in up to 78% of older adults in the United States, is more prevalent in African Americans than other ethnic groups, and is a leading cause of cardiovascular disease mortality. Social- environmental stress and social support factors, such as individual socioeconomic status (SES), have been linked to high BP, as have related physiological mechanisms such as hypothalamic-pituitary-adrenal (HPA) secretion of glucocorticoid stress hormones (e.g. cortisol), and genetic factors such as polymorphisms in glucocorticoid receptor (GR) genes. However, few studies have integrated these factors in African Americans, and social-environmental factors have often been measured at the individual- but not at the community-level, giving little insight into community factors (e.g. community SES) relevant to population-level efforts to understand BP regulatory mechanisms and health disparities. Investigating how these factors interact to influence BP outcomes may afford a better understanding of BP etiology and contribute to successful prevention efforts. Additionally, ecological, psychosocial, and biological theories of health may guide such an integrated investigation. Thus, the aim of the proposed study is to examine how community-level social- environmental factors interact with GR polymorphisms to predict cortisol and high BP, and whether cortisol mediates the association of social-environmental factors with BP as an underlying physiologic mechanism, as has been well established in clinical and experimental models. Data for each variable will be collected within an existing sample of older adult African Americans (N=434;Mage=51.2 years) nested within three communities as part of the on-going NIH-funded PATH trial. The PI of the trial, Dr. Dawn Wilson, is the primary sponsor of this application. Participants will attend health screenings during which data for target variables will be collected. Social-environmental variables will include census-derived community-level SES, community crime rates, and community connectedness measured via questionnaire. Saliva samples will allow measurement of morning and afternoon cortisol as a marker of basal HPA functioning and stress. Genomic DNA for three single nucleotide polymorphisms (SNPs) previously linked to social-environmental and physiologic mechanisms of high BP (Bcl1, rs 41423247;FKBP5, rs1360780;92, rs6198) will be extracted from buccal swab samples and assayed via polymerase chain reaction, under the guidance of Dr. Matthew Kostek, a co-sponsor of this application. Structural equation modeling and regression will be applied to test stated study aims and hypotheses, with relevant covariates such as BP medication status, age, and sex included in statistical models. Potential clustering by community will be controlled by examining intra-class correlation coefficients. Thus, through the integrated study of social-environmental, physiologic, and genetic factors, this investigation will contribute to a comprehensive conceptualization of high BP and disparity in underserved African American populations, and has the potential to inform innovative prevention approaches and public policy.

Public Health Relevance

The proposed study will expand our understanding of social-environmental, physiologic, and genetic effects on high blood pressure (BP) in African Americans. This project will ultimately inform prevention programs in reducing high BP, chronic disease, and health disparities experienced by African Americans.

National Institute of Health (NIH)
National Institute on Aging (NIA)
Predoctoral Individual National Research Service Award (F31)
Project #
Application #
Study Section
Special Emphasis Panel (ZRG1-F16-B (20))
Program Officer
Spotts, Erica L
Project Start
Project End
Budget Start
Budget End
Support Year
Fiscal Year
Total Cost
Indirect Cost
University of South Carolina at Columbia
Schools of Arts and Sciences
United States
Zip Code
Coulon, Sandra M; Wilson, Dawn K; Van Horn, M L et al. (2016) The Association of Neighborhood Gene-Environment Susceptibility with Cortisol and Blood Pressure in African-American Adults. Ann Behav Med 50:98-107
Coulon, Sandra M; Wilson, Dawn K; Alia, Kassandra A et al. (2016) Multilevel Associations of Neighborhood Poverty, Crime, and Satisfaction With Blood Pressure in African-American Adults. Am J Hypertens 29:90-5
Coulon, S M; Wilson, D K (2015) Social support buffering of the relation between low income and elevated blood pressure in at-risk African-American adults. J Behav Med 38:830-4
Siceloff, E Rebekah; Coulon, Sandra M; Wilson, Dawn K (2014) Physical activity as a mediator linking neighborhood environmental supports and obesity in African Americans in the path trial. Health Psychol 33:481-9
Wilson, Dawn K; St George, Sara M; Trumpeter, Nevelyn N et al. (2013) Qualitative developmental research among low income African American adults to inform a social marketing campaign for walking. Int J Behav Nutr Phys Act 10:33
Wilson, Dawn K; Ellerbe, Caitlyn; Lawson, Andrew B et al. (2013) Imputational modeling of spatial context and social environmental predictors of walking in an underserved community: the PATH trial. Spat Spatiotemporal Epidemiol 4:15-23
Coulon, Sandra M; Wilson, Dawn K; Egan, Brent M (2013) Associations among environmental supports, physical activity, and blood pressure in African-American adults in the PATH trial. Soc Sci Med 87:108-15
Coulon, Sandra M; Wilson, Dawn K; Griffin, Sarah et al. (2012) Formative process evaluation for implementing a social marketing intervention to increase walking among African Americans in the Positive Action for Today's Health trial. Am J Public Health 102:2315-21