Younger veterans who sustain traumatic brain injury (TBI) may have a greater risk of cardiovascular disease (CVD) in the future, a new study has revealed. 

And with the median age of veterans with TBI found to be only 27, the research team said the CVD risk has long-term health implications. 

“We found that post-9/11 veterans with a history of TBI were more likely to develop CVD than veterans without TBI,” said senior author Dr Mary Jo Pugh, a research scientist with VA Salt Lake City.  

“Furthermore, there was evidence to suggest a dose-response, whereby more severe TBI was associated with higher CVD risk.”

The Department of Defense (DOD) – which led the study along with VA – considers TBI a signature injury of the wars in Iraq and Afghanistan, with around one in five of the 4.5 million service men and woman who served after 9/11 sustaining at least one TBI. 

The association between TBI and subsequent CVD has not been previously examined in post-9/11 veterans – although a greater risk of stroke has been previously established – with the team in this study looking at the health data from more than 1.5 million veterans. More than 300,000 veterans were found to have a history of TBI.

In the study, veterans with TBI were found to be younger and were more likely to be male. The group with brain injuries was also more likely to have been enlisted, have served in the Army or Marines, served on active duty, have been deployed, and have been exposed to combat. 

Veterans with TBI were also more likely to have a history of smoking, substance use disorder, obesity, insomnia, and anxiety than those without brain injury.

“In addition to overall cardiovascular disease, we found that TBI increased the risk of each individual disease, including heart attack, stroke, peripheral artery disease, and cardiovascular death,” said first author Dr Ian Stewart, of the Uniformed Services University. 

“While the majority of research examines inflammation shortly after [brain] injury, there is some evidence to suggest changes to the immune system for months, or even years, after a traumatic event. 

“Since inflammation has been associated with both CVD and cardiovascular risk factors (such as hypertension), it is possible that this represents one pathway by which an episode of TBI can result in subsequent CVD.

“Our results give further evidence for this point of view by demonstrating that patients with TBI are at an increased risk of adverse cardiovascular outcomes for years after the initial event.”

This is important for medical teams and veterans themselves to understand, said Dr Stewart, because there are strategies to help prevent cardiovascular disease, such as losing weight, eating healthy foods, exercising regularly, and quitting smoking.

”Given the relatively young age of the study group, these results suggest that there may be an increased burden of CVD as these veterans age and develop other CVD risk factors,” said Dr Pugh. 

“Future studies are needed to determine if the increased risk associated with TBIs is modifiable.”

Dr Stewart recommends that future research will involve designing a randomised clinical trial to identify medical care or lifestyle modifications that can decrease cardiovascular risk and improve outcomes. 

“The men and women who have volunteered to serve our country, and sustained a TBI in that service, deserve nothing less than our whole-hearted effort,” he said.