Association between posttraumatic stress disorder and inflammation: A twin study

• Type of Material: Article
• Authors: Laura Plantinga, Emory University; J. Douglas Bremner, Emory University; Andrew Miller, Emory University; Dean P Jones, Emory University; Emir Veledar, Emory University; Jack Goldberg, University of Washington; Viola Vaccarino, Emory University
• Language: English
• Date: 2013-05-01
• Publisher: Elsevier: 12 months
• Publication Version: Author Accepted Manuscript (After Peer Review)
• Copyright Statement: © 2013 Elsevier Inc.
• License: Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International
• Final Published Version (URL): http://dx.doi.org/10.1016/j.bbi.2013.01.081
• Title of Journal or Parent Work: Brain, Behavior, and Immunity
• ISSN: 0889-1591
• Volume: 30
• Start Page: 125
• End Page: 132
• Grant/Funding Information: The United States Department of Veterans Affairs has provided financial support for the development and maintenance of the Vietnam Era Twin Registry.; This study was supported by K24HL077506, R01 HL68630, R01 AG026255, and National Institutes of Health (NIH)/National Institute of General Medical Sciences Institutional Research and Academic Career Development Awards Grant 5K12 GM000680 from the NIH; by the Emory University General Clinical Research Center MO1-RR00039; and by Grant 0245115N from the American Heart Association.
• Keywords: ATHEROSCLEROSIS RISK; Vietnam veterans; VIETNAM; MAJOR DEPRESSIVE DISORDER; Twins; Posttraumatic stress disorder; Neurosciences & Neurology; C-REACTIVE PROTEIN; Cardiovascular disease; Life Sciences & Biomedicine; Inflammation; SYMPTOMS; Science & Technology; CARDIOVASCULAR-DISEASE; Immunology; PTSD; HEART-RATE-VARIABILITY; INTERLEUKIN-6; PSYCHOSOCIAL STRESS; Neurosciences; Psychiatry
• Research Categories: Health Sciences, Immunology; Biology, Neuroscience; Psychology, Clinical

Abstract

The association of posttraumatic stress disorder (PTSD) with cardiovascular disease risk may be mediated by inflammation. Our objective was to examine the association between PTSD and measures of inflammation and to determine whether these associations are due to shared familial or genetic factors. We measured lifetime history of PTSD using the Structured Clinical Interview for DSM-IV in 238 male middle-aged military veteran twin pairs (476 individuals), selected from the Vietnam Era Twins Registry, who were free of cardiovascular disease at baseline. We assessed inflammation using levels of high-sensitivity C-reactive protein (hsCRP), interleukin 6 (IL-6), fibrinogen, white blood cells, vascular cell adhesion molecule-1, and intercellular adhesion molecule-1 (ICAM-1). Geometric mean levels and percent differences by PTSD were obtained from mixed-model linear regression analyses with adjustment for potential confounders. Within-pair analysis was conducted to adjust for shared family environment and genetics (monozygotic pairs). Overall, 12.4% of participants had a lifetime history of PTSD. Adjusted mean levels of hsCRP and ICAM-1 were significantly higher among those with vs. without PTSD [hsCRP: 1.75 vs. 1.31. mg/l (33% difference); ICAM-1: 319 vs. 293. ng/ml (9% difference)]. Adjustment for depression rendered the association of PTSD with hsCRP non-statistically significant. For IL-6, no consistent association was seen. Within-pair analysis produced associations that were similar in direction for all three markers but lesser in magnitude for hsCRP and IL-6. There was no evidence of interaction by zygosity. Elevated hsCRP and ICAM-1 are associated with PTSD, and these associations may be confounded by shared non-genetic, antecedent familial and environmental factors.