Background: Increased rates of depression are reported in coronary artery disease (CAD). In heart disease, depression increases disability, reduces quality of life, and increases mortality.
Hypothesis: The study was undertaken to examine the relationship between depression and thyroid axis function in patients with CAD.
Methods: In all, 73 patients with CAD, consecutively admitted to a cardiac rehabilitation hospital, were assessed for depression using the Hospital Anxiety and Depression scale (HADS). Blood was drawn for assessment of thyroid axis hormones and the N-amino terminal fragment of the pro-B-type natriuretic peptide (NT-pro BNP).
Results: The patients with CAD with depressive symptoms had a higher prevalence of cardiac failure (p = 0.04), higher NT-pro BNP concentrations (p = 0.02), and lower free triiodothyronine (T3) concentrations (p = 0.04) than patients with CAD but without depressive symptoms. They also showed a strong trend (p = 0.058) toward a higher incidence of the low T3 syndrome. Higher NT-pro BNP concentrations were related to lower total T3 concentrations (r = -0.294, p = 0.011) and to higher reverse T3 concentrations (r = 0.353, p = 0.002). In men, higher scores of depression were related to lower total T3 concentration (r = -0.289, p = 0.034) and to higher NT-pro BNP concentration (r = 0.380, p = 0.005).
Conclusion: These findings suggest that symptoms of depression in patients with CAD are associated with changes in thyroid axis function and with cardiac impairment, especially in men.