Socioeconomic position, race/ethnicity, and inflammation in the multi-ethnic study of atherosclerosis.
BACKGROUND
Low socioeconomic position is known to be associated with cardiovascular events and atherosclerosis. Reasons for these associations remain a topic of research. Inflammation could be an important mediating mechanism linking socioeconomic position to cardiovascular risk.


RESULTS
This cross-sectional study used data from the baseline examination of the Multi-Ethnic Study of Atherosclerosis (MESA), a study of 6814 men and women 45 to 84 years of age. Race- and ethnicity-stratified regression analyses were used to estimate associations of household income and education with C-reactive protein and interleukin-6 before and after adjustment for infection and medication use, psychosocial factors, behaviors, adiposity, and diabetes mellitus. Low income was associated with higher concentrations of interleukin-6 in all race/ethnic groups. Percent differences associated with 1-SD-lower income were 9% (95% confidence interval [CI], 7 to 11), 6% (95% CI, 1 to 10), 8% (95% CI, 4 to 11), and 8% (95% CI, 3 to 13) for whites, Chinese, blacks, and Hispanics. Low levels of education were associated with higher levels of interleukin-6 only among whites and blacks (percent difference in interleukin-6 associated with 1-SD-lower education: 9% [95% CI, 6 to 12] among Whites, and 7% [95% CI, 3 to 10] among blacks). Similar patterns were observed for C-reactive protein. Adiposity was the single most important factor explaining socioeconomic position associations, especially among blacks and whites. A smaller effect was seen for psychosocial factors and behaviors in all race groups.


CONCLUSIONS
Both household income and education are associated with inflammation, but associations vary across race/ethnic groups. Associations likely result from socioeconomic position patterning of adiposity and other factors.
Ranjit
Nalini
N
Center for Social Epidemiology and Population Health, University of Michigan, Ann Arbor 48104, USA. nranjit@umich.edu
Diez-Roux
Ana V
AV
Shea
Steven
S
Cushman
Mary
M
Ni
Hanyu
H
Seeman
Teresa
T
D000368:Aged; D000369:Aged, 80 and over; D050197:Atherosclerosis / Q000191:economics* / Q000208:ethnology* / Q000378:metabolism / Q000473:pathology; D015415:Biomarkers / Q000378:metabolism; D003430:Cross-Sectional Studies; D005006:Ethnicity / Q000208:ethnology* / Q000235:genetics; D005260:Female; D006801:Humans; D007249:Inflammation / Q000191:economics / Q000208:ethnology / Q000235:genetics; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D044469:Racial Groups / Q000208:ethnology* / Q000235:genetics; D012307:Risk Factors; D012959:Socioeconomic Factors
D015415:Biomarkers