title: Black-white blood pressure disparities: depressive symptoms and differential vulnerability to blood lead.
abstract: BACKGROUND
  Blacks have higher hypertension rates than whites, but the reasons for these disparities are unknown. Differential vulnerability, through which stress alters vulnerability to the effects of environmental hazards, is an emergent notion in environmental health that may contribute to these disparities.
  
  
  OBJECTIVE
  We examined whether blacks and whites exhibit different associations between blood lead (BPb) and blood pressure (BP) and whether depressive symptoms may play a role.
  
  
  METHODS
  Using the National Health and Nutrition Examination Survey 2005-2008, we regressed BP on the three-way interaction among race/ethnicity, BPb, and depressive symptoms in blacks and whites ≥ 20 years of age.
  
  
  RESULTS
  Blacks but not whites showed a positive association between BPb and systolic blood pressure (SBP). The disparity in this association between blacks and whites appeared to be specific to the high depressive symptoms group. In the low depressive symptoms group, there was no significant black-white disparity (βinteraction = 0.9 mmHg; 95% CI: -0.9, 2.7). However, of those with high depressive symptoms, blacks and whites had 5.6 mmHg (95% CI: 2.0, 9.2) and 1.2 mmHg (95% CI: -0.5, 2.9) increases in SBP, respectively, in association with each doubling of BPb (βinteraction = 4.4 mmHg; 95% CI: 0.5, 8.3). The pattern of results was similar for diastolic blood pressure.
  
  
  CONCLUSIONS
  Our results suggest that depressive symptoms may contribute to the black-white disparity in the association between BPb and BP. Depressive symptoms may result, in part, from psychosocial stress. Our results support the notion that stress increases vulnerability to the health effects of environmental hazards and suggest that stress-related vulnerability may be an important determinant of racial/ethnic health disparities.
authors.affiliation: Department of Epidemiology, University of Michigan, Ann Arbor, Michigan 48109-2029, USA. mhicken@umich.edu
authors.forename: Margaret T
authors.initials: MT
authors.lastname: Hicken
authors.forename: Gilbert C
authors.initials: GC
authors.lastname: Gee
authors.forename: Cathleen
authors.initials: C
authors.lastname: Connell
authors.forename: Rachel C
authors.initials: RC
authors.lastname: Snow
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Morenoff
authors.forename: Howard
authors.initials: H
authors.lastname: Hu
mesh_terms: D044383:Black People; D001794:Blood Pressure; D003863:Depression / Q000097:blood*; D004785:Environmental Pollutants / Q000097:blood*; D006801:Humans; D007854:Lead / Q000097:blood*; D009749:Nutrition Surveys; D044465:White People
chemical_list: D004785:Environmental Pollutants; D007854:Lead