The Biological and Physiological Response to Caregiver Burden

Thursday, 15 July 2010: 9:10 AM

Michele C. Clark, PhD, RN
School of Nursing, University of Nevada in Las Vegas, Las Vegas, NV
Hoang Thanh Nguyen, PhD
LifeStat LLC, Kemah, TX
Carolyn Leach, MSN, CNP, RN
Diabetes and Endocrine Department, Children's Hospital and Clinics of Minnesota, Minneapolis, MN

Learning Objective 1: discuss the influence of caregiver burden and dormant vulnerabilities (sociotropy and autonomy) on proinflammatory mediators.

Learning Objective 2: understand interrupting the influence of burden is an important strategy in reducing the levels of proinflammatory mediators, important precursors to chronic disease.

Purpose: When dormant vulnerabilities (personality factors sociotropy and autonomy) are activated by a stressor (caregiver burden), these personality factors become mediators to caregiver depression. However, these personality factors have not been examined in relation to physiological biomarkers. The purpose of the current study was to investigate whether personality factors influence caregivers’ levels of proinflammatory mediators when high levels of caregiver burden are present.

Methods: A cross-sectional convenience sample (n = 106) of primarily female (55%) caregivers completed questionnaires for depression, burden, and personality factors. Serum levels of interleukin-1 receptor antagonist (IL-1ra), interleukin-6 (IL-6), tumor necrosis factor (TNF), and C-reactive protein (CRP) were also evaluated. The relationship between personality factors and proinflammatory mediator levels was modeled using logistic regression using the Wald test.

Results: The effect of sociotropy was consistently greater than the effect of Il-1ra and IL-6 in predicting depression. However, those caregivers with high sociotropy and CRP values of ≥ 10 had more than a 6-fold increase in depression risk compared to caregivers with lower CRP values. Caregivers with TNF levels in the top quartile had a 3-fold increase in depression risk compared to caregivers with TNF levels in the lower quartiles. In contrast to sociotropy, autonomy had no significant effect on proinflammatory mediator levels. However, when burden was added to the model, TNF and CRP remained significant, and the odds for depression for caregivers with high level of these pro-inflammatory mediators were 4-5-fold higher than caregivers with lower levels of these mediators.

Conclusion: These data suggest that caregivers with high burden are at high risk for depression and are more likely to have increased proinflammatory mediator levels. Because of these increased proinflammatory mediator levels and their link with chronic disease, health care providers need to develop strategies to prevent these elevated levels in caregivers with high burden.