Increased proapoptotic serum activity in patients with chronic mood disorders

BACKGROUND: Growing evidence suggests that endothelial dysfunction may be present in patients with chronic mood disorders. We hypothesized that circulating factors in the sera of patients with chronic mood disorders could induce vascular endothelial damage that in turn may be responsible for increased vascular risk. In this study, we sought to determine whether serum of patients with chronic mood disorders could directly induce apoptosis in human endothelial cells. METHODS: We examined the proapoptotic activity by an ex vivo proapoptotic activity assay in the serum of 100 individuals: 25 patients with major depressive disorder (MDD) and no lifetime diagnosis of anxiety disorder, 25 patients with bipolar disorder (BPD) with a current comorbid anxiety disorder, 25 patients with BPD and no anxiety, and 25 age- and gender-matched healthy controls. RESULTS: The proapoptotic serum activity of all mood disorder patients was significantly higher than that of the control group (all p values<0.01). This association was found to be independent from potential confounders including age, gender, smoking status, body mass index, blood pressure parameters, family history of cardiovascular disease, serum creatinine, plasma glucose, total cholesterol, triglycerides, NT-proBNP, and C-reactive protein (beta=0.44, t=2.93, p=0.012). CONCLUSIONS: Together our findings indicate that chronic mood disorders are associated with higher proapoptotic serum capacity. Although subject to future confirmation, it is possible that the increased systemic proapoptotic activity of the serum in these patients could exert deleterious vascular effects resulting in endothelial dysfunction.