P1519Depression, heart rate variability, inflammation, and incident cardiovascular disease in subjects with coronary heart disease risk factors

Abstract

Background: Only a few studies have investigated the relation between depression and cardiovascular disease (CVD) over time, and uncertainties remain on the underlying mechanisms linking depression and subclinical atherosclerosis. It is unclear whether inflammation is a mechanism linking depression to CVD. Purpose(s): The purpose of this study was to examine prospectively whether inflammation explains the relationship between depression and CVD. Method(s): Depression status (Beck Depression Inventory, BDI), selected CHD risk factors, inflammation markers, measures of heart rate variability (HRV), and indices of endothelial function (flow-mediated dilation, FMD) were evaluated in 415 subjects free of CHD, diabetes mellitus, and other life-threatening conditions, with at least two CHD risk factors among the following: older age, male gender, current smoking, hypertension, and dislipidaemia. The main outcome was incidence of CVD events (hospital stays for nonfatal myocardial infarction, stroke, congestive heart failure, and CVD-related mortality)during 10 year of follow-up. Result(s): Overall, 51.7% of the participants were males, aged 57.6+8.8 years on average (minimum 30, maximum 70). Almost half were ypertensive,43.9% were dyslipidemic, 30.4% current smokers, and 23.1% showed a depressive symptomatology (BDI >10). Compared with subjects without depression, subject with depression had a 70% higher CRP (p=0.0008) and more likely to have altered HRV and their FMD was severely impaired (adjusted odds ratio of 1% increase 14 0.72; 95% CI: 0.61-0.86).). Depression was a significant predictor of CVD (hazard ratio 2.58, p=0.0009). Adjustment for other patient factors did not substantially affect the results. Addition of CRP decreased the estimate for depression by 13% and addition of HRV decreased it by 4%. Both depression and inflammatory biomarkers remained independent predictors of outcome. Conclusion(s): Despite their robust association with depression, HRV, systemic inflammatory, explain only a small portion of the association between depression and CVD incidence.