Objective: African-Americans have been found to experience increased rates of post-traumatic stress disorder (PTSD), obesity, and flatter diurnal cortisol slopes compared to other demographic groups. Further exploration, however, is needed to understand how PTSD impacts diurnal cortisol activity in obese African-American women. The purpose of the current study is to examine the relationship between salivary cortisol levels and PTSD in a sample of obese young adult African-American women and to examine how depression and insomnia influence the relationship.
Methods: Thirty-four young adult African-American women (mean age = 24.0 years; mean BMI = 37.4 kg/m(2), 6/34 of the sample had a score of 40 or above on the PTSD Checklist (PCL) representing clinically significant PTSD) filled out questionnaires assessing PTSD, lifetime exposure to traumatic events, insomnia severity, and depression. A home-based assessment of salivary cortisol was provided upon awakening at 30 min and 1, 3, 6, and 12 h.
Results: There was a significant interaction between PTSD status and diurnal cortisol activity (p < 0.04). There were trends for higher cortisol levels at awakening (p < 0.051) and 30 min post-awakening (p < 0.059) with PTSD. The significance of the interaction between PTSD and cortisol was attenuated by co-varying for depression and insomnia (p > 0.05).
Conclusion: PTSD, influenced by depression and insomnia symptoms, has an impact on diurnal cortisol activity in obese young adult African-American women.
Keywords: African-Americans; Cortisol; Obesity; Post-traumatic stress disorder.