Objective and subjective stress, personality, and allostatic load.

INTRODUCTION: Despite the understanding of allostatic load (AL) as a consequence of ongoing adaptation to stress, studies of the stress-AL association generally focus on a narrow conceptualization of stress and have thus far overlooked potential confounding by personality. The present study examined the cross-sectional association of objective and subjective stress with AL, controlling for Big Five personality traits. METHODS: Participants comprised 5,512 members of the Copenhagen Aging and Midlife Biobank aged 49-63 years (69% men). AL was measured as a summary index of 14 biomarkers of the inflammatory, cardiovascular, and metabolic system. Objective stress was assessed as self-reported major life events in adult life. Subjective stress was assessed as perceived stress within the past four weeks. RESULTS: Both stress measures were positively associated with AL, with a slightly stronger association for objective stress. Adjusting for personality traits did not significantly change these associations. CONCLUSIONS: The results suggest measures of objective and subjective stress to have independent predictive validity in the context of personality. Further, it is discussed how different operationalizations of stress and AL may account for some of the differences in observed stress-AL associations.