Differentiating the impact of episodic and chronic stressors on hypothalamic-pituitary-adrenocortical axis regulation in young women.
OBJECTIVE
The goal of this study was to examine the impact of episodic stress and chronic interpersonal stress on indices of HPA regulation. To explore the potential downstream consequences of altered HPA dynamics, the authors also assessed indicators of metabolic control and systemic inflammation.


METHODS
One hundred four medically healthy women between the ages of 15 and 19 participated. Following an in-depth interview of life stress, a sample of blood was drawn through antecubital venipuncture. Over the course of the next 2 days, participants gathered salivary cortisol samples.


METHODS
Cortisol morning response, cortisol daily output, glucocorticoid receptor (GR) mRNA, C-reactive protein (CRP), insulin, and glucose.


RESULTS
The simple presence of episodic stress or chronic interpersonal stress was not reliably associated with cortisol output, GR mRNA, insulin, or glucose. When women were exposed to an episodic stressor in the midst of chronic stress they showed increased cortisol output and reduced expression of GR mRNA. By contrast, when women had low levels of chronic stress, episodic events were associated with decreased cortisol output and increased GR mRNA. Episodic and chronic stress also interacted to predict CRP, but not insulin or glucose.


CONCLUSIONS
The impact of episodic stress is accentuated in the midst of chronic interpersonal stress and diminished in its absence. Simultaneous exposure to episodic and chronic stress may create wear and tear on the body, whereas exposure to episodic stress in the context of a supportive environment may toughen the body, protecting it against subsequent stressors.
Marin
Teresa J
TJ
Department of Psychology, University of British Columbia, Vancouver, BC, Canada.
Martin
Tara M
TM
Blackwell
Ekin
E
Stetler
Cinnamon
C
Miller
Gregory E
GE
D000293:Adolescent; D000328:Adult; D001786:Blood Glucose / Q000032:analysis; D002097:C-Reactive Protein / Q000032:analysis; D002908:Chronic Disease; D002940:Circadian Rhythm; D005260:Female; D006801:Humans; D006854:Hydrocortisone / Q000097:blood; D007030:Hypothalamo-Hypophyseal System / Q000502:physiology; D007328:Insulin / Q000097:blood; D007398:Interpersonal Relations; D008016:Life Change Events; D010913:Pituitary-Adrenal System / Q000502:physiology; D011569:Psychiatric Status Rating Scales / Q000706:statistics & numerical data; D011965:Receptors, Glucocorticoid / Q000502:physiology; D012463:Saliva / Q000737:chemistry; D012737:Sex Factors; D012944:Social Support; D013315:Stress, Psychological / Q000097:blood / Q000175:diagnosis*
D001786:Blood Glucose; D007328:Insulin; D011965:Receptors, Glucocorticoid; D002097:C-Reactive Protein; D006854:Hydrocortisone