Purpose and Hypothesis

1. State/Trait Depression and Hostility as Predictors of Interleukin-6 Levels in African Americans Mana Ali, BA¹, Denee T. Mwendwa, PhD¹, Joneis Thomas, PhD¹, Clive O. Callender, MD², Alfonso Campbell Jr., PhD¹ Howard University1 and Howard University Hospital2 Washington, DC 20059 Background Discussion Design and Methodology • This study offers insight into the biopsychosocial correlates of cardiovascular disease in African Americans. • Consistent with previous research, state/trait depression and hostility, unadjusted, were significantly correlated with log transformed IL-6. After controlling for age, gender, BMI and blood pressure, only hostility emerged as a significant correlate of log transformed IL-6. • In a hierarchical multiple regression analysis, hostility emerged as a significant predictor of IL-6 after controlling for age, gender, BMI and blood pressure. This model accounted for 28% of the variance in IL-6. • Our sample did not endorse a high level of depressive symptoms, which may explain why depression was not a significant predictor after controlling for biosocial variables. • Cardiovascular disease (CVD) is the leading cause of morbidity and mortality in the United States and disproportionately affects African American men and women (American Heart Association 2009; Yancy, 2005). • Depression and hostility have been associated with adverse health consequences and increased risk of cardiovascular disease (Everson-Rose & Lewis, 2005 ). • Interleukin-6 (IL-6), a protein that promotes cells’ inflammatory response, is a biological correlate of CVD (Kato et al, 1999; Ikeda et al, 2001). • Depression and hostility have been associated with elevated levels of IL-6 (Maier & Watkins, 1998; Suarez, 2003). Participants: The participants were a community based sample of African Americans, 18 to 73 years of age, who reside in the Washington, DC Metropolitan Area. Setting: The study site was Howard University Hospital’s General Clinical Research Center (GCRC) located in Washington, DC. Tests and Measures: Informed consent was obtained. Participants were administered self-report measures to assess state depression (Beck Depression Inventory- II (BDI-II) (Beck, 1996), trait depression (Neo Personality Inventory-Revised (NEO-PI-R) (Costa & McCrae, 1992) and hostility (Cook Medley Hostility Scale (CMS) (Cook & Medley, 1954). Participants also underwent a medical examination, which included measurements of body mass index (BMI) and blood pressure. Weight and height measurements were used to calculate BMI. Blood pressure was measured via a sphygmomanometer. Plasma IL-6 were measured by enzyme-linked immunosorbent assay (ELISA). Purpose and Hypothesis Results Purpose: The purpose of this research is to understand how mood states impact the inflammation process and CVD risk in African Americans. More specifically, the goal is to establish whether state/trait depression and hostility are significantly correlated with and predictive of IL-6. Hypothesis: We predict that state/trait depression and hostility will be positively correlated with IL-6. These psychological constructs will also be independent predictors of IL-6. Implications Correlations Log Transformed IL-6 Adjusted (Age, Gender, Unadjusted BMI, Blood Pressure) • The clinical implication of this finding is that hostility in African Americans plays a critical role in the inflammatory response process, which increases the risk for CVD. • Negative mood states need to be routinely assessed, and treated as indicated, because of the adverse consequences for cardiovascular health. Sample Characteristics (N=180) *p ≤ 0.05; **p ≤ 0.01 Regression Analyses Males n=86 (48%) Females n=94 (52%) Mean Age (years)=45.37 Mean BMI=31.24 Mean Systolic Blood Pressure (mm Hg)=132.62 Mean Diastolic Blood Pressure (mm Hg)=78.72 BDI-II/State Depression mean= 8.02 NEO-PI-R/Trait Depression mean=50 CMS Hostility mean=23.4 Acknowledgment • This research is part of a larger study entitled “Stress and Psychoneuroimmunological Factors in Renal Health and Disease” that is funded by The National Center on Minority Health and Health Disparities under grant #1P20MD000512-04, “A Research Center to Reduce Ethnic Disparities in ESRD.” *Dependent Variable: IL-6