Abstract P123: The Association of Inflammatory Markers with Subsyndromal Depression the Multi-Ethnic Study of Atherosclerosis
Objective. Subsyndromal (mild) depression can be a disabling condition that has been associated with increased cardiovascular risk, yet mechanisms governing this association are unclear. Some studies indicate that clinical depression is associated with higher levels of inflammation, yet this association has not been explored in subsyndromal depression. Therefore we examined the association between inflammatory markers and subsyndromal depression.
Methods. Blood levels of C-reactive protein (CRP), interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF) were measured in a cross-sectional analysis of 6814 participants from the Multi-Ethnic Study of Atherosclerosis (MESA). Based on scores from the Center for Epidemiologic Studies Depression Scale (CES-D), participants were classified as depressed (≥16), subsydromally depressed (8-15), or normal (<8). The inflammatory markers were highly skewed and, therefore, log-transformed. Inflammatory markers with subsyndromal and depression groups were entered into multivariable regression model adjusting for demographic, behavioral, biological and comorbid confounders.
Results. The mean age was 62.1 (SD=10.2) and 53% were women. Twenty four percent had subsyndromal depression and 13% were depressed. Thirty nine percent were Caucasian, 28% were African-American, 22% Hispanic and 12% Chinese-American. In unadjusted analyses, and compared to normals, there was a suggestion oftrend towards a significant association of subsyndromal depression with lnCRP (β=0.06 p=0.06), but not lnIL-6 (β= 0.03 p=0.18) or lnTNF (β= 0.05 p=0.23). Moreover, there was a significant association of depressed individuals with lnCRP (β= 0.06 p<0.001) and lnIL-6 (β= 0.10 p<0.001), but not for lnTNF (β= 0.05 p=0.23). After adjusting for demographics, the association of depression with lnCRP was attenuated (β= 0.00 p=0.96) but remained significant for lnIL-6 (β= 0.06, p=0.01). Final adjustment for smoking, alcohol intake, walking for exercise, as well as for BMI, lipids, glucose, blood pressure, comorbid antihypertensives and antidepressants resulted in non-significant associations of depression with lnCRP (β= -0.06, p=0.13) and lnIL-6 (β=0.02, p=0.45).
Conclusion. While there is no association between subsyndromal depression and inflammatory markers, the significant association of depression with CRP and IL-6 appears to be explained by various biological and behavioral covariates. Future studies are needed to examine the association of novel inflammatory markers with the different spectrum of mood states.
- © 2013 by American Heart Association, Inc.