Title: How PTSD Can Lead to Earlier Heart Disease
By: Traci Pedersen, Associate News Editor
Date: 29 APR 2020
Source: Experimental Biology - https://experimentalbiology.org/2020/home.aspx
A new study may help explain why patients with post-traumatic stress disorder (PTSD) are more likely to develop heart disease at an earlier age than those without the illness.
The research was supposed to be presented at the American Physiological Society annual meeting in San Diego this month, but the event was canceled due to the COVID-19 outbreak. The abstract is published in The FASEB Journal.
In the study, researchers found evidence of small blood vessel dysfunction which appears to be driven by the sympathetic nervous system — the system behind the fight-or-flight response — along with oxidative stress, an imbalance between free radicals and antioxidants in the bloodstream.
Problems in the small blood vessels are often a precursor to stiffening or narrowing of the larger arteries, which can lead to a heart attack, stroke or other forms of heart disease.
“We have found that blood vessel dysfunction is more prevalent in young adults with PTSD than those without,” said lead study author Jennifer Weggen, a Ph.D. student at Virginia Commonwealth University. “We hypothesize that both oxidative stress and overactivity of the sympathetic nervous system, independently and cooperatively, may ultimately lead to an increased risk of cardiovascular disease.”
In any given year about 8 million U.S. adults suffer from PTSD, a mental health disorder caused by witnessing or experiencing a traumatic event. Prior research has shown that PTSD increases a person’s chances of having heart disease by as much as 50%.
To investigate the path from PTSD to heart disease, the scientists conducted a series of cardiovascular assessments in 16 patients with PTSD and 24 healthy volunteers with similar demographics. The average age in both groups was 24 years old.
The PTSD participants received two assessments and consumed either an antioxidant supplement containing vitamin C, vitamin E and alpha lipoic acid or a placebo beforehand.
Healthy arteries respond to changes in blood flow by constricting and relaxing. The researchers found that all participants had normal responses in the brachial artery, an artery in the arm.
However, the participants with PTSD showed a significantly lower amount of blood flowing through a given portion of the brachial artery during testing which reflects abnormal responses in the smaller vessels further downstream. These patients also had a lower variation in the time intervals between heart beats, a marker of increased sympathetic nervous system activation.
Importantly, those differences essentially disappeared when the participants consumed an antioxidant supplement, suggesting oxidative stress plays a role in both the small vessel dysfunction and the sympathetic nervous system activity.
Free radicals naturally occur in the body as a result of normal physiological processes, but the body makes its own antioxidants to keep them in check. Oxidative stress occurs when the free radicals overwhelm the body’s antioxidant defenses.
“Supplementing with an antioxidant cocktail tipped the balance back to equilibrium, reducing oxidative stress,” said Weggen. However, she warned that antioxidants were used in the study only to understand the potential role of oxidative stress, not to test the supplements as a potential treatment.
“The suggestion of regular use of antioxidants specifically for treatment of PTSD would be premature, as no studies have confirmed its efficacy or safety and appropriate dosage is unknown. Everyone responds differently to antioxidant supplements, and not everyone may reap benefits. Seeking medical guidance would be prudent before taking nutritional supplements,” said Weggen.
Oxidative stress can also be reduced by fortifying the body’s own antioxidant defense systems through lifestyle changes such as exercise, diet, stress reduction and meditation. More studies could help shed light on whether these methods are effective for mediating the oxidant-antioxidant balance in people with PTSD, Weggen noted.