Association Between Anxiety and C-Reactive Protein Levels in Stable Coronary Heart Disease Patients

Background: Anxiety is highly prevalent among patients with stable coronary heart disease (CHD). However, the biologic effects that may connect these two seemingly unrelated disorders is not well understood. Objective: This study aimed for a comprehensive evaluation of anxiety in stable CHD patients, in addition to cardiac biomarkers such as C-reactive protein (CRP), troponin T, and amino-terminal pro-B-type brain natriuretic peptide. Method: The study included 43 CHD patients with anxiety disorder and 42 CHD patients without psychiatric disorder given the Structured Clinical Interview for DSM-IV. Results: Regression analyses showed an association between anxiety (anxiety disorder, not otherwise specified) and CRP levels, despite model adjustment for various related demographic and clinical variables. Anxiety was associated with CRP levels. Conclusion: There are significant associations between anxiety and CHD risk, with a potential biologic link between anxiety and elevations in a biomarker with powerful prognostic risk, namely CRP. It is not clear whether this association is directly causal or relates to other medical processes among patients with heightened anxiety. The findings suggest that the current focus on depressive disorders with respect to biomarkers and CHD outcomes should be broadened to include anxiety disorders, as well. (Psychosomatics 2009; 50: 347-353)