Socioeconomic and psychosocial predictors of interleukin-6 in the MIDUS national sample.

OBJECTIVE: To investigate whether psychosocial factors (i.e., depression, anxiety, and well-being) moderated educational gradients in interleukin-6 (IL-6) levels using data from the Survey of Midlife Development in the U.S. (MIDUS). The influences of educational attainment and psychosocial factors on IL-6 in middle aged and older adults were also examined. DESIGN: Telephone interviews and mail surveys were utilized to collect educational attainment and psychosocial information from respondents (N = 1028). Respondents also participated in an overnight clinic visit, during which health information and a fasting blood sample were obtained. MAIN OUTCOME MEASURES: Serum levels of IL-6. RESULTS: Greater educational attainment predicted lower levels of IL-6 independent of age and gender, although this effect was attenuated after taking health behaviors, body mass index, waist-to-hip ratio, and chronic illnesses into account. Psychological well-being interacted with education to predict IL-6, such that for those with less education, higher well-being was associated with lower levels of IL-6. CONCLUSION: The findings indicate a strong association between education and inflammation, which can be further moderated by psychosocial factors. The health benefits associated with psychological well-being were particularly evident for individuals with low educational attainment.