Morning and afternoon serum cortisol level in patients with post-myocardial infarction depression

Background: Post-myocardial depression is a highly prevalent condition which worsens the course and prognosis of coronary artery disease. One possible pathogenetic factor is dysregulation of the hypothalamic-pituitary-adrenal axis, resulting in cortisol profile disturbances. Methods: Thirty seven patients hospitalized due to a first myocardial infarction (MI) were enrolled in this study. The Beck Depression Inventory (BDI) was used to rate the severity of their depressive symptoms. Morning and afternoon serum cortisol samples were taken on the fifth day of the MI. Results: Depression, defined as BDI ≥ 10, was present in 34.4% of the patients. A statistically significant difference was observed between the mean morning and the evening plasma concentrations in patients with depression compared to the no-depression group: F (1.29) = 5.0405, p = 0.0328. Conclusions: Patients with depressive symptoms directly after MI have a flattened diurnal serum cortisol profile. This is particularly expressed in patients with longer lasting symptoms.