title: The Association of Neighborhood Gene-Environment Susceptibility with Cortisol and Blood Pressure in African-American Adults.
abstract: BACKGROUND
  African-American adults are disproportionately affected by stress-related chronic conditions like high blood pressure (BP), and both environmental stress and genetic risk may play a role in its development.
  
  
  OBJECTIVE
  This study tested whether the dual risk of low neighborhood socioeconomic status (SES) and glucocorticoid genetic sensitivity interacted to predict waking cortisol and BP.
  
  
  METHODS
  Cross-sectional waking cortisol and BP were collected from 208 African-American adults who were participating in a follow-up visit as part of the Positive Action for Today's Health trial. Three single-nucleotide polymorphisms were genotyped, salivary cortisol samples were collected, and neighborhood SES was calculated using 2010 Census data.
  
  
  RESULTS
  The sample was mostly female (65 %), with weight classified as overweight or obese (M BMI = 32.74, SD = 8.88) and a mean age of 55.64 (SD = 15.21). The gene-by-neighborhood SES interaction predicted cortisol (B = 0.235, p = .001, r (2) = .036), but not BP. For adults with high genetic sensitivity, waking cortisol was lower with lower SES but higher with higher SES (B = 0.87). Lower neighborhood SES was also related to higher systolic BP (B = -0.794, p = .028).
  
  
  CONCLUSIONS
  Findings demonstrated an interaction whereby African-American adults with high genetic sensitivity had high levels of waking cortisol with higher neighborhood SES, and low levels with lower neighborhood SES. This moderation effect is consistent with a differential susceptibility gene-environment pattern, rather than a dual-risk pattern. These findings contribute to a growing body of evidence that demonstrates the importance of investigating complex gene-environment relations in order to better understand stress-related health disparities.
authors.affiliation: Department of Psychology, University of South Carolina, Barnwell College, Columbia, SC, 29201, USA. coulon@mailbox.sc.edu.
authors.forename: Sandra M
authors.initials: SM
authors.lastname: Coulon
authors.affiliation: Department of Psychology, University of South Carolina, Barnwell College, Columbia, SC, 29201, USA.
authors.forename: Dawn K
authors.initials: DK
authors.lastname: Wilson
authors.affiliation: Educational Psychology, University of New Mexico, Albuquerque, NM, 87131, USA.
authors.forename: M L
authors.initials: ML
authors.lastname: Van Horn
authors.affiliation: School of Public Health, West Virginia University, Morgantown, WV, 26506, USA.
authors.forename: Gregory A
authors.initials: GA
authors.lastname: Hand
authors.affiliation: Genetics and Biochemistry, Clemson University, Clemson, SC, 29634, USA.
authors.forename: Stephen
authors.initials: S
authors.lastname: Kresovich
mesh_terms: D001741:Black or African American / Q000235:genetics*; D001794:Blood Pressure / Q000502:physiology*; D003430:Cross-Sectional Studies; D019938:Cyclin D1 / Q000235:genetics; D005260:Female; D059647:Gene-Environment Interaction; D020022:Genetic Predisposition to Disease / Q000235:genetics; D005838:Genotype; D006801:Humans; D006854:Hydrocortisone / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D020641:Polymorphism, Single Nucleotide / Q000235:genetics; D011965:Receptors, Glucocorticoid / Q000235:genetics; D012111:Residence Characteristics; D012463:Saliva / Q000378:metabolism; D012923:Social Class; D022021:Tacrolimus Binding Proteins / Q000235:genetics; D000099159:Tacrolimus Binding Protein 5
chemical_list: D019938:Cyclin D1; D006854:Hydrocortisone; D011965:Receptors, Glucocorticoid; D022021:Tacrolimus Binding Proteins; D000099159:Tacrolimus Binding Protein 5
keywords: African American; Blood pressure; Cortisol; Genetic; Neighborhood; Socioeconomic status