Inflammatory cytokines, socioeconomic status, and acute stress responsivity

Socioeconomic status is a major determinant of coronary heart disease (CHD). Proinflammatory cytokines are implicated in the etiology of CHD, and are also sensitive to emotional stress. We hypothesised that concentration of interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-alpha), and interleukin-1 receptor antagonist (IL-1Ra) would be inversely related to socioeconomic status, and that cytokine responses to stress would be associated with SES. One hundred and twenty-five middle-aged men and 105 women from the Whitehall II epidemiological cohort were tested, and socioeconomic status was indexed by grade of employment, with participants divided into high, intermediate, and low status groups. Plasma concentrations at rest of TNF-alpha, IL-1Ra, and IL-6 (women only) were associated with socioeconomic status, with lower levels in the high status group, but the effect was non-linear. There was no relationship between socioeconomic status and cytokine responses to stress, but sex differences were observed, with men showing greater TNF-alpha, and women greater IL-6 and IL-1Ra increases. The role of inflammatory cytokines in mediating psychosocial influences on CHD is discussed.