Chronic Stress, Daily Stressors, and Circulating Inflammatory Markers

Objectives: Acute laboratory stressors elicit elevations in serum levels of interleukin-6 (IL-6) and C-reactive protein (CRP). Chronic stressors, such as family dementia caregiving, promote a state of chronic low-grade elevation in circulating inflammatory markers. The recurrent daily stressors associated with chronic stress may lead to repeated and sustained activation of the physiological stress systems. The present study evaluated the possibility that greater exposure and reactivity to daily stressors fueled increased levels of circulating inflammatory markers among family dementia caregivers, compared with noncaregiving controls.

Methods: This cross-sectional study included 53 caregivers and 77 noncaregiving controls. A semistructured interview assessed the occurrence of daily stressors in the past 24 h. A blood sample provided data on two inflammatory markers, C-reactive protein (CRP) and interleukin-6 (IL-6).

Results: Caregivers were more likely to experience multiple stressors in the past 24 h than noncaregiving controls. The occurrence of multiple daily stressors was associated with greater serum IL-6 and CRP levels. The greater occurrence of daily stressors in the past 24 h partially mediated the relationship between dementia caregiving and CRP levels.

Conclusion: These results suggest that the cumulative effect of daily stressors promotes elevations in inflammatory markers. Greater exposure to daily stressors may be a psychobiological mechanism leading to elevations in CRP levels among family dementia caregivers.