Stress hormones in patients with posttraumatic stress disorder caused by myocardial infarction and role of comorbid depression

Background: Chronic posttraumatic stress disorder (PTSD) has been associated with perturbed hypothalamic-pituitary-adrenal (HPA) axis function and a hyperadrenergic state. We hypothesized that patients with PTSD attributable to myocardial infarction (MI) would show peripheral hypocortisolemia and increased norepinephrine levels, whereby taking into account that depressive Symptoms Would affect this relationship. Methods: We investigated 15 patients with interviewer-rated PTSD Caused by myocardial infarction (MI) and 29 post-MI patients with no PTSD. Patients also completed the depression subscale of the Hospital Anxiety and Depression Scale and had blood collected to determine plasma cortisol and norepinephrine levels. Results: In bivariate correlation analysis PTSD and depressive symptoms were not significantly associated with cortisol levels. However, patients with PTSD had lower mean +/- SEM cortisol levels than patients with no PTSD when controlling for depressive symptoms (77 +/- 11 vs. 110 +/- 7 ng/ml, p=.035). In turn, depressive symptoms correlated with cortisol levels when taking PTSD into account (r=.36, p=.019). In all patients cortisol levels correlated with total PTSD symptoms (r= -.43, p=.005) and hyperarousal symptoms (r= -.45, p=.002) after controlling for depressive symptoms. Depression correlated with cortisol levels after controlling for total PTSD symptoms (r=.45, p=.002). Posttraumatic stress disorder and depressive symptoms were not significantly associated with norepinephrine levels. Conclusions: In post-MI patients we found peripheral hypocortisolemia related to PTSD, respectively hypercortisolemia related to depressive symptoms, when taking joint effects of PTSD and depression into account. No evidence was found for a hyperadrenergic state. Comorbid depressive symptoms ought to be considered to disentangle the unique associations of PTSD with HPA axis dysfunction in cardiac patients. (C) 2009 Elsevier B.V. All rights reserved.