Cross-Sectional and Longitudinal Associations of Chronic Posttraumatic Stress Disorder With Inflammatory and Endothelial Function Markers in Women

Abstract

Background: Posttraumatic stress disorder (PTSD) may contribute to heightened cardiovascular disease risk by promoting a proinflammatory state and impaired endothelial function. Previous research has demonstrated associations of PTSD with inflammatory and endothelial function biomarkers, but most work has been cross-sectional and does not separate the effects of trauma exposure from those of PTSD.

Methods: We investigated associations of trauma exposure and chronic PTSD with biomarkers of inflammation (C-reactive protein and tumor necrosis factor alpha receptor II) and endothelial function (intercellular adhesion molecule-1 and vascular cell adhesion molecule-1) in 524 middle-aged women in the Nurses' Health Study II. Using linear mixed models, we examined associations of trauma/PTSD status with biomarkers measured twice, 10 to 16 years apart, in cardiovascular disease-free women, considering either average levels over time (cross-sectional) or change in levels over time (longitudinal). Biomarker levels were log-transformed. Trauma/PTSD status (based on structured diagnostic interviews) was defined as no trauma at either blood draw (n = 175), trauma at blood draw 1 but no PTSD at either draw (n = 175), and PTSD that persisted beyond blood draw 1 (chronic PTSD; n = 174). The reference group was women without trauma.

Results: In models adjusted for known potential confounders, women with chronic PTSD had higher average C-reactive protein (B = 0.27, p < .05), tumor necrosis factor alpha receptor II (B = 0.07, p < .01), and intercellular adhesion molecule-1 (B = 0.04, p < .05) levels. Women with trauma but without PTSD had higher average tumor necrosis factor alpha receptor II levels (B = 0.05, p < .05). In addition, women with chronic PTSD had a greater increase in vascular cell adhesion molecule-1 over time (B = 0.003, p < .05).

Conclusions: Increased inflammation and impaired endothelial function may be pathways by which chronic PTSD increases cardiovascular disease risk.

Keywords: Biomarkers; Endothelial cell adhesion molecules; Inflammation; Posttraumatic stress disorder; Trauma; Women.