Socioeconomic status, hostility, and risk factor clustering in the Normative Aging Study: any help from the concept of allostatic load?

OBJECTIVE: To examine the relationships between socioeconomic status (SES), psychosocial vulnerability (hostility), and allostatic load. Allostatic load refers to the cumulative physiological cost of adaptation to stress.
METHOD: We examined the relationships between SES (as measured by educational attainment), hostility, and allostatic load in the Normative Aging Study, a longitudinal study of community-dwelling men aged 21 to 80 years and free of known chronic medical conditions at entry in the 1960s. In 1986, the revised Minnesota Multiphasic Personality Inventory was administered by mail, from which a hostility measure was derived by summing the scores from three Cook-Medley subscales: Hostile Affect, Hostile Attribution, Aggressive Responding. An index of allostatic load was constructed from data collected during physical exams conducted between 1987 and 1990 (i.e. measures reflecting "wear and tear" on the cardiovascular, endocrine, and metabolic systems). Cross-sectional relationships between education, hostility, and allostatic load were examined in 818 men.
RESULTS: Separate linear regression analyses indicated that lower levels of educational attainment and greater hostility were both associated with higher allostatic load scores (p < .05 and p < .01, respectively). Less education was also associated with higher hostility (p < .001). When allostatic load was regressed simultaneously on education and hostility, the effect of education was attenuated, while hostility (p < .05) maintained an independent effect.
CONCLUSIONS: Our findings suggest that lower levels of education and greater hostility are associated with greater "wear and tear" on the body. The effects of education on allostatic load may be mediated by hostility.