Diabetes and Vascular Risk Factors Linked to Poorer Cognitive Recovery After Traumatic Brain Injury: JAMA

A new study published in the Journal of American Medical Association revealed that individuals with diabetes had slower recovery in processing speed and global cognition 2 weeks after traumatic brain injury. Having two or more vascular risk factors was also associated with lower cognitive scores and worse verbal memory and processing speed.

Although vascular risk factors and traumatic brain injury (TBI) are linked to cognitive impairment, it is unclear if those with vascular risk factors have worse cognitive outcomes following TBI. Thus, this study compared the cognitive performance of TBI patients with and without concomitant preinjury vascular risk factors.

The participants with TBI who were enrolled in the Transforming Research and Clinical Knowledge in TBI (TRACK-TBI) research between February 26, 2014, and August 8, 2018, with a 1-year follow-up, were the subject of this prospective cohort research. At 2 weeks, 6 months, and a year after the injury, participants completed a five-test cognitive evaluation; in main analyses, the results were aggregated into a global cognitive factor score, while in secondary analyses, each test was analyzed separately. The relationships were estimated using inverse probability of attrition–weighted generalized estimating equations that controlled for psychiatric history, age, sex, race, ethnicity, education, TBI severity, and prior TBI.

The mean (SD) age of the 1,313 participants was 38.7 (16.4) years; 428 (32.6%) were female; 885 (67.0%) were male; 393 (29.9%) had never smoked; 221 (16.8%) had hypertension; 98 (7.5%) had diabetes; and 116 (8.8%) had hyperlipidemia. Over the first year after the injury, cognitive function improved for both individuals with and without vascular risk factors.

The participants with diabetes had worse executive functioning at two weeks after injury, less improvement on processing speed over the first year after injury, and lower global cognitive factor scores at two weeks after injury (mean z-score difference, −0.25; 95% CI, −0.45 to −0.04) than those without diabetes. The participants with and without smoking, hypertension, and hyperlipidemia did not significantly vary in their cognitive function.

There were comparable improvements in cognitive performance over the first year after injury, but those with two or more vascular risk factors had worse verbal episodic memory immediate recall, executive functioning, and processing speed at 2 weeks after injury (mean difference, −0.21; 95% CI, −0.19 to −0.07) and a lower global factor score at that time.

Overall, 2 weeks after a traumatic brain injury, those with diabetes showed worse executive functioning and global cognitive function, and they recovered less quickly in terms of processing speed throughout the first year following the injury.

Source:

Schneider, A. L. C., Hunzinger, K. J., Brett, B. L., Sandsmark, D. K., Jain, S., Sun, X., Gardner, R. C., Manley, G. T., Diaz-Arrastia, R., Nelson, L. D., TRACK-TBI Study Investigators, Belton, P., Eagle, S., Gopinath, S., Grandhi, R., Keene, C. D., Krishnamoorthy, V., Mac Donald, C., McCrea, M., … Zafonte, R. (2025). Vascular risk factors and 1-year cognitive change among individuals with traumatic brain injury. JAMA Network Open, 8(8), e2525719. https://doi.org/10.1001/jamanetworkopen.2025.25719