History of Sudden Unexpected Loss Is Associated With Elevated Interleukin-6 and Decreased Insulin-Like Growth Factor-1 in Women in an Urban Primary Care Setting

Address correspondence and reprint requests to: Benjamin P. Chapman, PhD, E-mail: Ben_Chapman{at}URCM.Rochester.edu.

	Abstract

Objective: To investigate the hypothesis that a history of sudden unexpected loss including number of losses and type of loss (death due to unnatural versus natural causes) would be associated with the magnitude of dysregulation. The sudden unexpected death of a loved one confers risk of morbidity and mortality, perhaps due to dysregulation in the immune/inflammatory and endocrine systems. Methods: Female primary care patients aged 40 years (n = 75) completed questionnaires, a clinical interview, and a blood draw. Interleukin (IL)-6 and insulin-like growth factor (IGF)-1 were assayed, using standard enzyme-linked immunosorbent assay protocols and anticytokine antibody pairs. Results: History of sudden loss was positively associated with IL-6 (mean = 4.07 pg/mL; log₁₀ values, B = 0.314, p = .009) and negatively associated with IGF-1 (mean = 97.05 ng/mL; B = -0.277, p = .023). A linear relationship parsimoniously captured the association between ordered categories of lifetime loss (0, 1, 2–5, 5+) and increases in log₁₀ IL-6 (B = 0.107, p = .005) and decreases in IGF-1 (B = -0.116, p = .005). Adjusting for illness burden, depressive symptom severity, and obesity did not change the observed associations. The hypothesized effect of type of loss was not supported. Conclusions: These preliminary findings encourage further investigations to elucidate pathways from sudden unexpected loss to biomarker changes that increase risk for morbidity and mortality.

Key Words: interleukin-6, insulin-like growth factor-1, psychoneuroimmunology, sudden unexpected loss, primary care