title: Socioeconomic status, race, and diurnal cortisol decline in the Coronary Artery Risk Development in Young Adults (CARDIA) Study.
abstract: OBJECTIVE
  The objectives of this study were to assess whether socioeconomic status (SES) is associated with dysregulation of the cortisol diurnal rhythm and whether this association is independent of race and occurs equally in whites and blacks; and to determine if an association between SES and cortisol can be explained (is mediated) by behavioral, social, and emotional differences across the SES gradient.
  
  
  METHODS
  Seven hundred eighty-one subjects from a multisite sample representing both whites and blacks provided six saliva cortisol samples over the course of the day: at awakening, 45 minutes, 2.5 hours, 8 hours, and 12 hours after awakening, and at bedtime.
  
  
  RESULTS
  Both lower SES (education and income) and being black were associated with higher evening levels of cortisol. These relationships were independent of one another and SES associations with cortisol were similar across racial categories. The evidence was consistent with poorer health practices (primarily smoking), higher levels of depressive symptoms, poorer social networks and supports, and feelings of helplessness (low mastery) mediating the link between SES and cortisol. However, we found no evidence for psychosocial or behavioral mediation of the association between race and cortisol response.
  
  
  CONCLUSIONS
  Lower SES was associated in a graded fashion with flatter diurnal rhythms as a result of less of a decline during the evening. This association occurred independent of race and the data were consistent with mediation by health practices, emotional and social factors. Blacks also showed a flatter rhythm at the end of the day. This association was independent of SES and could not be explained by behavioral, social, or emotional mediators.
authors.affiliation: Department of Psychology, Carnegie Mellon University, Pittsburgh, PA 15213, USA. scohen@cmu.edu
authors.forename: Sheldon
authors.initials: S
authors.lastname: Cohen
authors.forename: Joseph E
authors.initials: JE
authors.lastname: Schwartz
authors.forename: Elissa
authors.initials: E
authors.lastname: Epel
authors.forename: Clemens
authors.initials: C
authors.lastname: Kirschbaum
authors.forename: Steve
authors.initials: S
authors.lastname: Sidney
authors.forename: Teresa
authors.initials: T
authors.lastname: Seeman
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D021081:Chronobiology Disorders / Q000503:physiopathology / Q000523:psychology; D003324:Coronary Artery Disease / Q000150:complications / Q000503:physiopathology* / Q000523:psychology*; D005260:Female; D006801:Humans; D006854:Hydrocortisone / Q000032:analysis*; D008297:Male; D044469:Racial Groups; D012307:Risk Factors; D012923:Social Class; D013315:Stress, Psychological / Q000150:complications / Q000503:physiopathology
chemical_list: D006854:Hydrocortisone