Depressive symptoms, race, and glucose concentrations: the role of cortisol as mediator.
OBJECTIVE
This study examined the associations of depressive symptoms with glucose concentrations and morning cortisol levels in 665 African-American and 4,216 Caucasian Vietnam-era veterans.


METHODS
Glucose level was measured as a three-level variable (diabetes, impaired glucose, and normal). Depressive symptoms were measured by the Obvious Depression Scale (OBD) from the Minnesota Multiphasic Personality Inventory.


RESULTS
Regression models showed significant race x OBD interactions in relation to glucose concentration (P < 0.0001) and cortisol (P < 0.0001). The OBD was positively associated with glucose concentration and cortisol in both racial groups. However, the magnitude of those associations was larger for African Americans. Further analyses suggested that cortisol partially mediated the race difference in the relation of depressive symptoms to glucose concentrations.


CONCLUSIONS
These results suggest that enhanced hypothalamic pituitary adrenal activity plays an important role in the relation of depressive symptoms to dysregulated glucose metabolism and may partially explain the differential effects of depressive symptoms on glucose levels in African-American and Caucasian male subjects.
Boyle
Stephen H
SH
Department of Psychiatry and Behavioral Medicine, Duke University Medical Center, Box 2969, Durham, NC 27745, USA. shboyle@duke.edu
Surwit
Richard S
RS
Georgiades
Anastasia
A
Brummett
Beverly H
BH
Helms
Michael J
MJ
Williams
Redford B
RB
Barefoot
John C
JC
D000328:Adult; D044383:Black People / Q000706:statistics & numerical data*; D001786:Blood Glucose / Q000378:metabolism*; D003430:Cross-Sectional Studies; D003863:Depression / Q000097:blood / Q000453:epidemiology*; D006801:Humans; D006854:Hydrocortisone / Q000097:blood*; D007031:Hypothalamus / Q000503:physiopathology; D011569:Psychiatric Status Rating Scales; D044469:Racial Groups; D012959:Socioeconomic Factors; D013313:Stress Disorders, Post-Traumatic / Q000453:epidemiology; D014481:United States / Q000453:epidemiology; D014728:Veterans; D044465:White People / Q000706:statistics & numerical data*; D001741:Black or African American
D001786:Blood Glucose; D006854:Hydrocortisone