110. Beta-Adrenergic sensitivity and somatic symptoms of depression in heart failure patients

Abstract

Background: Depression is prevalent in heart failure (HF) and is considered a powerful predictor of rehospitalization and mortality. Dysregulated sympathetic activity associated with depression may be one pathway. We investigated the relationship between depressive symptoms and alterations in leukocyte beta-adrenergic sensitivity in response to an acute exercise task in HF-patients. Methods: NYHA II–III HF-patients ( n = 13) were assessed for symptoms of depression using the Beck’s Depression Inventory (BDI), sub-categorized into somatic (BDI-s) and cognitive (BDI-c) symptoms. Participants underwent a 15 min bicycle ergometry task using a modified Bruce protocol. Beta-adrenergic receptor sensitivity was measured by quantifying leukocyte cyclic-AMP levels pre- and post-isoproterenol stimulation. Repeated measures analysis-of-variance (MANOVA) was used to measure changes in beta- adrenergic sensitivity in relation depressive symptoms. Results: There was a significant time effect ( p = .006) with increases in stimulated cAMP levels in response to exercise in the HF-patients. Moreover,there was a time x-somatic symptoms interactions ( p = .016) for stimulated cAMP. Although HF-patients with elevated somatic symptoms of depression appeared to have elevated basal stimulated cAMP levels, they responded less to the exercise task then those with low somatic symptoms of depression. Conclusions: HF-patients with low BDI-s had an increase in beta-receptor sensitivity due to exercise. However in HF-patients with high BDI-s, elevated basal and reduced stimulated cAMP level response to exercise suggest sympathetic dysregulation. This is consistent with the hypothesis that depression is related to over-activation of the sympathetic–adrenal–medullary system, causing dysregulation of beta-adrenergic activity. Further study is needed to identify clinical implications and HF-disease prognosis.