Body mass index and sleep disorders after moderate-to-severe traumatic brain injury - a national TBI model systems study.

Objective: To examine the relationship between body mass index (BMI), newly developed sleep disorders and functional outcome after moderate-to-severe traumatic brain injury (msTBI).

Methods: Retrospective data from the TBI Model Systems National Database was analyzed, focusing on the independent association between BMI, sleep disorder diagnosis, and functional outcome as measured by the Extended Glasgow Outcome Scale (GOSE) at 1-year post-injury. Linear and logistic regression were used.

Results: Out of 2,142 participants, 84% reported no sleep disorder (NSD), 9% reported a sleep disorder before TBI (PreSD), and 7% developed a sleep disorder after TBI (PostSD). Over 50% of participants were overweight or obese. After adjusting for demographic and clinical characteristics, a one-unit increase of BMI at the time of rehabilitation admission was associated with 3.7% higher odds of PostSD (OR [95%CI]: 1.037 [1.007, 1.068],  = 0.015). PostSD was associated with a 53.6% higher chance of unfavorable GOSE compared to NSD (OR [95%CI]: 1.536 [1.069-2.207],  = 0.02) and an 81.7% higher chance compared to PreSD (OR [95% CI]: 1.817 [1.137-2.905],  = 0.01).

Conclusion: Being overweight/obese and developing a sleep disorder had adverse effects on functional outcome, emphasizing the importance of addressing sleep and lifestyle factors in post-msTBI rehabilitation.