Elucidating Mechanisms of Hypertension Risk in PTSD
Abstract
Post-traumatic stress disorder (PTSD) is a psychiatric illness that develops in some people that have experienced or witnessed a traumatic event (such as combat, natural disasters, serious accident, sexual violence, etc.). People with PTSD experience intense, distressing, and intrusive thoughts, flashbacks, and dreams related to their trauma that may persist for months or years after the traumatic event. These symptoms interfere with social and occupational functioning and have a significantly negative impact on quality of life. In addition to mental health effects, PTSD leads to negative physical health effects as well. Multiple large, well-designed population studies have shown that people with PTSD have a much higher risk of developing hypertension (i.e., high blood pressure) later in life. This is important because hypertension is a leading cause of heart attack, heart failure, strokes, kidney disease, early death, and other health threats. Although we know that individuals with PTSD have a much higher risk of developing hypertension, the biological reasons why PTSD leads to higher blood pressure is not known and has not been adequately studied. Up to nearly one in five young military Veterans in the post-9/11 era suffer from PTSD and are at much higher risk of developing high blood pressure because of their PTSD diagnosis. Therefore, it is imperative that we do the research now to understand why PTSD leads to hypertension so that we can develop effective treatments and preventative strategies to improve health outcomes in this vulnerable population. One way in which PTSD might lead to higher risk of high blood pressure is due to alterations in the body’s response to stress. People with PTSD have many episodes of stress that are related to their past trauma such as flashbacks and nightmares. The normal reaction to stress is to increase the sympathetic nervous system (the body’s flight or fight response) and decrease the parasympathetic nervous system (the body’s rest and digest response). The activation of the flight or fight response increases adrenaline levels, which increase the blood pressure and heart rate and is designed to help the body react to the stressful situation. However, in PTSD, this system is hyperactive. Dr. Park (Partnering Principal Investigator PI) and Dr. Marvar (Initiating PI) previously discovered that this response of the fight or flight response is greatly exaggerated in military Veterans with PTSD. During stress, PTSD patients have a greater increase in the fight or flight response (sympathetic nervous system) and blood pressure than those without PTSD. This causes negative reactions in the body that can increase the risk of developing hypertension later in life. Our goal is to study this pathway by which exaggerated activation of the flight or fight response leads to high blood pressure later in life. Over-activation of the fight or flight response also activates several pathways that can directly increase the risk of high blood pressure. First, adrenaline can stimulate the immune system to increase inflammation in the body. Dr. Park has previously shown that inflammation in the resting state is higher in PTSD. We know from large population studies that inflammation increases hypertension risk. However, we are not sure when and where this inflammation is coming from in PTSD. Dr. Marvar has shown that a certain inflammation marker (IL-6) increases suddenly and dramatically during stress in mice that behave like they have PTSD. In this proposal, he will use sophisticated molecular techniques and animal behavior models to determine what cells and pathways are responsible for generating this inflammation during stress in mice with PTSD. To understand if inflammation is increasing in the same way during stress in humans, Dr. Park will test whether IL-6 increases during stress that is related to PTSD symptoms. This is done by applying virtual reality combat exposure (VRCE) that depicts militar
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Dec 28, 2022
- Source ID
- W81XWH2210438
Entities
People
- Jeanie Park
Organizations
- Emory University
- United States Army