Abstract 183: Depressive Symptoms and Incident Stroke in Black and White Participants in the REGARDS Study

Abstract

Background and Purpose: Research suggests that depression may contribute to stroke risk independent of other known risk factors. Most studies examining the impact of depression on stroke have been conducted with predominantly white cohorts, though blacks are known to have higher stroke incidence than whites. The purpose of this study was to examine depressive symptoms as a risk factor for incident stroke in blacks and whites, and determine whether depressive symptomatology was differentially predictive of stroke among blacks and whites. Methods: The REasons for Geographic and Racial Differences in Stroke (REGARDS), is a national, population-based longitudinal study designed to examine risk factors associated with black-white and regional disparities in stroke incidence. Among 30,239 participants (42% black) accrued from 2003-2007, excluding those lacking follow-up or data on depressive symptoms, 27,557 were stroke-free at baseline. As of the January 2011 data closure, over an average follow-up of 4.6 years, 548 incident stroke cases were verified by study physicians based on medical records review. The association between baseline depressive symptoms (assessed via the Center for Epidemiological Studies Depression scale, 4-item version) and incident stroke was analyzed with Cox proportional hazards models adjusted for demographic factors (age, race, and sex), stroke risk factors (hypertension, diabetes, smoking, atrial fibrillation, and history of heart disease), and social factors (education, income, and social network). Results: For the total sample, depressive symptoms were predictive of incident stroke. The association between depressive symptoms and stroke did not differ significantly based on race (Wald X 2 = 2.38, p = .1229). However, race-stratified analyses indicated that the association between depressive symptoms and stroke was stronger among whites and non-significant among blacks. Conclusions: Depressive symptoms were an independent risk factor for incident stroke among a national sample of blacks and whites. These findings suggest that assessment of depressive symptoms may warrant inclusion in stroke risk scales. The potential for a stronger association in whites than blacks requires further study.