Large amounts of lifetime exposure to traumatic stress - even when it doesn't result in post-traumatic stress disorder - boosts inflammation levels in heart disease patients, a new study suggests.
The findings are important because it's known that heart disease patients with higher levels of inflammation tend to fare worse, according to the researchers at the University of California, San Francisco and the San Francisco VA Medical Center.
They looked at the exposures to 18 types of traumatic events experienced by nearly 1,000 patients aged 45 to 90 with cardiovascular disease. All the traumatic events involved either experiencing or witnessing a direct threat to life or physical well-being.
The more traumatic stress patients experienced in a lifetime, the more likely they were to have elevated levels of inflammatory markers in their bloodstream. When the surviving patients were checked again five years later, those who reported the highest levels of traumatic stress at the start of the study still had the highest levels of inflammation.
The study was recently published online in the journal Brain, Behavior and Immunity.
What the study showed
"Even though we lost some study participants because they died, we still observed the same relationship in those who remained," lead author Aoife O'Donovan, a fellow in psychiatry at UCSF and the VA Medical Center, said. "This suggests that it wasn't just the people who were the most sick at the outset who were driving this effect."
The researchers also found that the association between large amounts of traumatic stress in a lifetime and elevated levels of inflammation remained even after they adjusted for mental health disorders such as post-traumatic stress disorder (PTSD), anxiety and depression.
"Not everyone who is exposed to trauma develops PTSD," senior investigator Dr Beth Cohen, a VA physician and an assistant professor of medicine at UCSF, said in the news release.
"This study emphasises that traumatic stress can have a long-term negative impact on your health even if you don't go on to develop PTSD. It also tells us that, as clinicians, we need to think about not just which diagnostic box someone might fit into, but what their lifetime trauma exposure has been," she explained.
While the study found an association between trauma and higher inflammatory markers, it did not prove that trauma directly worsens inflammation or heart disease.
Stress and your heart
The U.S. National Institute of Mental Health has more about stress.
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