Traumatic Brain Injury - Unacknowledged Risk Factor in Cardiovascular Diseases

Long-term associations between Traumatic Brain Injury (TBI) and cardiovascular disease, highlight that nervous system dysfunction, neuro-inflammation, changes in the brain-gut connection, and post-injury co-morbidities may raise the risk of //cardiovascular and cognitive dysfunction in TBI survivors (military, sports personnel) compared to the general population ().

This new review paper by investigators from Mass General Brigham was published in The Lancet Neurology.

Association Between Traumatic Brain Injury & Long-Term Risk of Heart Diseases

Traumatic brain injury (TBI) is a leading cause of long-term disability and premature death, especially among military personnel and those playing contact sports. Substantial research has examined acute and chronic neurological consequences of TBI; however, non-neurological conditions associated with TBI are understudied.

‘The study raises a clarion call to conduct future cardiovascular research, surveillance, and intervention in Traumatic Brain Injury (TBI) survivors who may have increased cardiovascular risk. #braininjury #cardiovascularrisk #betteranalysis’

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“Despite decades of extensive traumatic brain injury focused research, surprisingly, there has been minimal progress in mitigating long-term outcomes and mortality following injuries. The cardiovascular effects of TBI may be a missing link in advancing our efforts to improve long-term quality of life and reducing mortality rates in TBI patients,” said first author Saef Izzy, MD, MBChB, of the Stroke and Cerebrovascular Center of Brigham and Women’s Hospital, a founding member of the Mass General Brigham healthcare system.

“We have the opportunity to identify and improve targeted screening for high-risk populations, build preventative care strategies, and improve outcomes for survivors of TBI,” he said.

Existing research has identified a strong link between TBI and neurological conditions, such as Alzheimers disease and dementia. However, the mechanisms driving neurological disease after TBI remain poorly understood, despite decades of research.

Izzy and co-authors from Spaulding Rehabilitation Hospital, Massachusetts General Hospital, Brigham and Women’s Hospital, and elsewhere suggest that non-neurological effects of TBI, such as cardiovascular, cardiometabolic, and endocrine dysfunction, may act as intermediaries contributing to neurological disease decades after TBI. For example, hypertension, hyperlipidemia, diabetes, and hypopituitarism can negatively affect cognitive function and are established risk factors for dementia.

These cardio-metabolic risk factors have also been found to be more prevalent in those with a history of TBI, as demonstrated in over a dozen studies on military personnel, athletes, and the general patient population, which are summarized by the authors of the review.

Wake Up Call for Early Assessment of Cardiovascular Risk in TBI Survivors

There are many potential links between TBI and cardiovascular and cognitive dysfunction. Neuroinflammatory pathways triggered by TBI could predispose individuals to atherosclerosis. Weight gain and sleep disturbances after an injury could pose independent or additive risks.

Disruptions to connections between the nervous and gastrointestinal systems could throw off the balance of microbes in the gut, contributing to cognitive and cardiovascular effects. Investigators are actively pursuing research related to the role of the gut microbiome and are also working to create new models of TBI to further study the biological mechanisms underlying cardiovascular disease.

It remains unclear how single versus repetitive injuries, age at injury, TBI severity, and other co-morbidities impact cardiovascular risk. This is in part due to methodological limitations to current research, such as retrospective study designs and reliance on self-reported health data. Prospective studies can clarify what risk factors and biomarkers may be most relevant to cardiovascular dysfunction post-TBI.

The author concluded: “There is a growing recognition that many systems interact to produce multilevel dysfunction after TBI, with a series of nuanced comorbidities. Clinicians can begin to treat some of these conditions, and in the future, management guidelines can more directly address the cardiovascular health of TBI survivors.”

Reference:

Cardiac Dysfunction in Adult Patients with Traumatic Brain Injury: A Prospective Cohort Study - (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6306140/)

Source: Eurekalert