Abstract

Background: Affective disorders, including bipolar depression (BDD), have high medical comorbidity, especially cardiovascular disease (CVD). The link between BDD and CVD is bidirectional, with involvement of inflammation. Inflammation in BDD may promote endothelial dysfunction and arterial stiffness. This study utilized noninvasive Applanation Tonometry (AT) to examine the link between inflammation, endothelial dysfunction, and CVD risk in BDD patients. It was an exploratory study as part of a study aimed at testing the hypothesis that modulation of inflammation improves treatment resistance.
 
Methods: BDD subjects (N=47) enrolled in a double-blind study to receive Escitalopram (ESC) + Celecoxib (CBX) or ESC + Placebo (PBO) for eight weeks. ESC was given at daily doses of 20-30 mg and CBX at 400 mg. AT was used to measure the Augmentation Index (AIx). Healthy subjects served as controls.
 
Results: BDD subjects had a higher mean AIx at baseline than healthy subjects but after controlling for confounding variables, no difference emerged. There was no correlation between severity of depression and augmentation index at baseline.  CBX did not decrease AIx over the study period. Age is a significant confounding variable for AIx in all subjects, but young BDD subjects had significantly higher AIx than young healthy subjects.  
 
Conclusions: AIx is a marker of endothelial dysfunction and arterial stiffness. Several factors impact AIx, including natural aging, and inflammation. Among young BDD patients, the contributory effect of age is minimized, and the effect of depression unmasked.  It is important to understand the inflammatory effects of depression, as contributory to CVD risk.  

Key words: Bipolar depression, inflammation, treatment resistance, endothelial dysfunction, arterial stiffness, cardiovascular disease