Abstract 388: Muscle Sympathetic Nervous Activity in Depressed Patients Before and After Treatment with Sertraline.
Depression is associated with an increased risk for cardiac morbidity and mortality. Depression and severity of depressive symptoms are also associated with increased sympathetic nervous activity. There is some evidence that antidepressants decrease sympathetic nerve activity. We tested the hypothesis that depressed patients with high scores of depressive symptoms (HD) would have augmented muscle sympathetic nervous system activity (MSNA) at rest and during mental stress when compared to depressed patients with low scores of depressive symptoms (LD) and normal controls (NC). In addition, sertraline would decrease MSNA in depressed patients. Ten HD, 9 LD and 11 NC age and body weight matched were studied. Muscle sympathetic nerve activity (MSNA) was directly measured from the peroneal nerve using microneurography for 3 minutes at rest and 4 minutes during Stroop color word test. Sympathetic measurements were performed at baseline in the 3 groups and repeated after treatment with sertraline in the HD and LD groups. Resting MSNA was significantly greater in the HD compared to the LD and NC (29.1±2.9 vs. 19.9±1.6 and controls had 22.2±2.0 bursts/min, p<0.03). There was a significant positive correlation between resting MSNA and Montgomery and Asberg Depression Rating Scale among depressed patients. Sertraline significantly decreased resting MSNA in the LD group and MSNA during mental stress in LD and HD groups. Sertraline significantly decreased resting heart rate and heart rate response to mental stress in the HD group. Moderate to severe depression is associated with increased sympathetic nervous system activity. Sertraline treatment reduces resting MSNA and HR levels at rest and during mental stress in depressed patients.