Individual and neighborhood socioeconomic status and inflammation in Mexican American women: what is the role of obesity?

OBJECTIVE: Inflammation may represent a biological mechanism underlying associations of socioeconomic status (SES) with cardiovascular disease. We examined relationships of individual and neighborhood SES with inflammatory markers in Mexican American women and evaluated contributions of obesity and related heath behaviors to these associations.
METHODS: Two hundred eighty-four Mexican American women (mean age = 49.74 years) were recruited from socioeconomically diverse South San Diego communities. Women completed measures of sociodemographic characteristics and health behaviors, and underwent a physical examination with fasting blood draw for assay of plasma C-reactive protein (CRP), interleukin 6 (IL-6), and soluble intercellular adhesion molecule 1 (sICAM-1). Neighborhood SES was extracted from the US Census Bureau 2000 database.
RESULTS: In multilevel models, a 1-standard deviation higher individual or neighborhood SES related to a 27.35% and 23.56% lower CRP level (p values < .01), a 7.04% and 5.32% lower sICAM-1 level (p values < .05), and a 10.46% (p < .05) and 2.40% lower IL-6 level (not significant), respectively. Controlling for individual SES, a 1-standard deviation higher neighborhood SES related to a 18.05% lower CRP level (p = .07). Differences in body mass index, waist circumference, and dietary fat consumption contributed significantly to SES-inflammation associations.
CONCLUSIONS: The findings support a link between SES and inflammatory markers in Mexican American women and implicate obesity and dietary fat in these associations. Additional effects of neighborhood SES were not statistically significant; however, these findings should be viewed tentatively due to the small sample size to evaluate contextual effects. Trial Registration ClinicalTrials.gov identifier: NCT00387166.