What is Traumatic Brain Injury(TBI)?
Traumatic brain injury (TBI) is a global health problem, with an estimated incidence of 64 to 74 million cases per year worldwide, and is a leading cause of morbidity and mortality. Poor clinical outcomes may be due to the direct sequelae of TBI, pre-TBI comorbidities, or a combination of these factors. In addition, large-scale studies of American-style football players and military veterans have demonstrated that prior TBI is associated with multisystem chronic conditions, suggesting that recurrent severe head injuries may be associated with long-term health and functional status.
The development of chronic medical comorbidities after TBI can complicate the course of recovery and increase health care costs and mortality. A number of registry-based studies have demonstrated an increased risk of cardiovascular and metabolic disorders, as well as epilepsy, stroke, and depression,9-11 in the chronic phase of TBI recovery. However, most previous studies were based on self-report, focused on older age groups, or included patients with TBI and preexisting comorbidities, which precluded isolating the association of TBI severity with subsequent development of comorbidities and mortality, particularly in individuals who were otherwise healthy at the time of injury.
In a 2021 study, we found a higher risk for developing multisystem medical and behavioral comorbidities in previously healthy patients who sustained concussions. Notably, the risk of postconcussion comorbidities was higher in patients younger than 40 years old compared with age-matched unexposed patients. However, it is unclear whether our findings apply to more severe subtypes of TBI and whether post-TBI comorbidities are associated with mortality risk. A better understanding of the interplay between TBI and the development of medical and neurologic comorbidities can have important implications for preventive care, prognosis, and targeted screening in a high-risk population.
Traumatic Brain Injury May Up Risk for Developing Comorbidities
Traumatic brain injury (TBI) of any severity is associated with an increased risk of chronic cardiovascular, endocrine, and neurologic comorbidities, according to a study published online on April 28 in JAMA Network Open.
Saef Izzy, M.D., from Brigham and Women’s Hospital in Boston, and colleagues conducted a longitudinal cohort study using hospital-based patient registry data to examine the incidence of cardiovascular, endocrine, neurological, and psychiatric comorbidities in patients who experienced mild TBI (mTBI) or moderate-to-severe TBI (msTBI) from 2000 to 2015. Patients were matched to an unexposed group without head injuries. The analyses included 4,351 patients with mTBI, 4,351 with msTBI, and 4,351 unexposed individuals.
The researchers found that compared with unexposed individuals, those with mTBI and msTBI had significantly higher risks of cardiovascular, endocrine, neurologic, and psychiatric disorders. In particular, in both mTBI and msTBI groups, hypertension risk was increased (hazard ratios, 2.5 and 2.4, respectively); the risk of diabetes was also increased in both groups (hazard ratios, 1.9 and 1.9, respectively), as was the risk of ischemic stroke or transient ischemic attack (hazard ratios, 2.2 and 3.6, respectively).
In the TBI subgroups, all comorbidities emerged within a median of 3.49 years after injury. The risk of mortality was increased for individuals with msTBI versus unexposed individuals (9.9 versus 5.7 percent); increased mortality was seen in association with postinjury hypertension, coronary artery disease, and adrenal insufficiency (hazard ratios, 1.3, 2.2, and 6.2, respectively).
