Abstract 20147: Association of Post Traumatic Stress Disorder and Carotid Intima Media Thickness: The Influence of Familial Factors
Introduction: Post traumatic stress disorder (PTSD) is related to an increased risk of cardiovascular disease, but the mechanisms are unclear. Possible pathways include increased adrenergic tone and unhealthy behaviors. Genetic and familial factors may also confound this association. We sought to better understand these mechanisms in a genetically informative cross-sectional study of PTSD and carotid intima media thickness (IMT) in male veteran twins.
Methods: We examined 460 middle-aged male twins without a previous coronary artery disease from the Vietnam Era Twin Registry. A diagnosis of lifetime symptoms of PTSD was made using the Structured Clinical Interview for the Diagnosis of Psychiatry Disorders. Traditional cardiovascular risk factors were measured during an in-person assessment. Carotid IMT was measured using B-mode ultrasound. Analysis using mixed-effect regression models adjusted for familial and genetic factors and other potential confounders.
Results: The mean age was 55 years, 95% were Caucasian, and 13.0% had a lifetime history of PTSD. Twins with lifetime PTSD had more lifetime depression (51% vs 20%), were slightly older (56.8 vs 54.8 years), and had a higher Framingham risk score (6.7 vs 5.9) than those without PTSD. In models adjusted for cardiovascular risk factors and depression, carotid IMT did not significantly associate with PTSD in individual twins (p=0.27) or within PTSD discordant twin pairs (37 pairs). It did, however, significantly associate with PTSD amongst pairs of twins (unadjusted p=0.003, adjusted p=0.03, for trend), such that if a pair in which one of the two twins had lifetime PTSD, each of them had higher carotid IMT than pairs without PTSD. If both twins have PTSD, then the IMT is even higher (figure).
Conclusion: We found evidence that familial factors are important in explaining the association between lifetime PTSD and increased carotid IMT, even when controlling for unhealthy behaviors related to PTSD.
- © 2010 by American Heart Association, Inc.