title: The relationship between alcohol consumption, perceived stress, and CRHR1 genotype on the hypothalamic-pituitary-adrenal axis in rural African Americans.
abstract: OBJECTIVE
  Rurally situated African Americans suffer from stress and drug-related health disparities. Unfortunately, research on potential mechanisms that underlie this public health problem have received limited focus in the scientific literature. This study investigated the effects of perceived stress, alcohol consumption, and genotype on the hypothalamic-pituitary-adrenal (HPA) Axis.
  
  
  METHODS
  A rural sample of African American emerging adults (n = 84) completed a battery of assessments and provided six samples of salivary cortisol at wakeup, 30 min post wakeup, 90 min post wakeup, 3:00 PM, 3:30 PM, and 4:30 PM.
  
  
  RESULTS
  Participants with a TT genotype of the CRHR1 (rs4792887) gene tended to produce the most basal cortisol throughout the day while participants with a CC genotype produced the least amount. Increased levels of perceived stress or alcohol consumption were associated with a blunted cortisol awakening response (CAR). Moreover, the CAR was obliterated for participants who reported both higher stress and alcohol consumption.
  
  
  CONCLUSIONS
  Perceived stress and alcohol consumption had a deleterious effect on the HPA-Axis. Furthermore, genotype predicted level of cortisol production throughout the day. These findings support the need to further investigate the relationship between stress dysregulation, drug-use vulnerability, and associated health disparities that affect this community.
authors.affiliation: Hwemudua Addictions and Health Disparities Laboratory, Department of Psychological, Health, and Learning Sciences, University of Houston , Houston, TX, USA.
authors.forename: Ezemenari M
authors.initials: EM
authors.lastname: Obasi
authors.affiliation: Human Development and Family Studies, Iowa State University , Ames, IA, USA.
authors.forename: Elizabeth A
authors.initials: EA
authors.lastname: Shirtcliff
authors.affiliation: Center for Family Research, University of Georgia , Athens, GA, USA.
authors.forename: Gene H
authors.initials: GH
authors.lastname: Brody
authors.affiliation: Psychiatry and Behavioral Neuroscience, McMaster University , Hamilton, ON, Canada.
authors.forename: James
authors.initials: J
authors.lastname: MacKillop
authors.affiliation: Graduate School of Education and Human Development, George Washington University , Washington, DC, USA.
authors.forename: Delishia M
authors.initials: DM
authors.lastname: Pittman
authors.affiliation: Hwemudua Addictions and Health Disparities Laboratory, Department of Psychological, Health, and Learning Sciences, University of Houston , Houston, TX, USA.
authors.forename: Lucia
authors.initials: L
authors.lastname: Cavanagh
authors.affiliation: Department of Psychiatry, University of Iowa , Iowa City, IA, USA.
authors.forename: Robert A
authors.initials: RA
authors.lastname: Philibert
keywords: African Americans; CRHR1; HPA-axis; alcohol; health disparities; stress