The association of social status and blood pressure with markers of vascular inflammation.

OBJECTIVE Low socioeconomic status (SES) is associated with low-grade inflammation. Vascular inflammation often accompanies high blood pressure (BP) and has clinical implications for future vascular diseases, including atherosclerosis. Elevated plasma levels of soluble intercellular adhesion molecule-1 (sICAM-1) and endothelin-1 (ET-1) are reliable indicators of vascular inflammation. We examined the associations among BP, social status, and sICAM-1 and ET-1 levels in 121 European American and African American men and women. METHODS Social status of the subjects was determined by using the Hollingshead Two Factor Index of Social Position scale, and plasma sICAM-1 and ET-1 levels were assessed using immunoassays. RESULTS Correlation analyses revealed positive correlations among plasma sICAM-1 levels, BP, and social status. Levels of ET-1 were also significantly correlated with BP (p < .01) and social status (p < .001). When subjects were categorized into three social classes, sICAM-1 levels were significantly higher in the lowest social class as compared with the upper (p < .05) or middle (p < .01) class. The levels of ET-1 were higher in the low (p < .01) and middle (p < .05) social classes as compared with the upper class. Multiple hierarchic regression analyses revealed that even after controlling for demographic and health characteristics (gender, ethnicity, age, body mass index, and smoking) and systolic BP, social status accounted for additional variance of sICAM-1 or ET-1 levels. CONCLUSION These results suggest that low-social-status individuals may incur risk for future vascular diseases through vascular inflammation.