Background: In patients with coronary heart disease (CHD), depression leads to worse cardiovascular outcomes. Depression has been associated with increased cortisol in medically healthy patients, suggesting that cortisol may act as a mediator in the pathway between depression and cardiovascular events. However, it is not known whether depression is associated with elevated cortisol levels in patients with CHD.
Methods: We examined the association between depression (assessed by the Computerized Diagnostic Interview Schedule) and 24-hour urinary cortisol in 693 medical outpatients with known CHD.
Results: Of 693 participants, 138 (20%) had current depression. Depressed participants had greater mean cortisol levels than those without depression (42 +/- 25 vs. 36 +/- 20 microg/day, p <.01). With each increasing quartile of cortisol concentration the frequency of depression increased (p <.01). Participants in the highest quartile of cortisol had a twofold increased odds of having depression, compared with those in the lowest quartile (odds ratio [OR] 2.1, 95% confidence interval [CR] 1.2-3.6, p =.01). This association remained strong after adjusting for potential confounding variables (OR 2.4, 95% CI 1.3-4.4, p <.01). In this cross-sectional analysis, elevated cortisol was not associated with worse cardiac function.
Conclusions: In patients with CHD,depression is associated with elevated cortisol levels.