Effect of Obese Body Mass Index on Clinical Outcomes and Inflammatory Blood Biomarkers following Sport-Related Concussion in Collegiate Athletes and Military Cadets: Findings from the NCAA-DoD CARE Consortium

Background: Obesity is associated with chronic circulatory inflammation; higher acute inflammation is associated with worse outcomes from concussion. The purpose of this study is to evaluate the effect of obese body mass index (BMI; ≥ 30.0) on clinical outcomes (e.g., symptoms, neurological exam, neurocognitive testing) and inflammatory blood biomarkers at multiple recovery time points in collegiate athletes and military cadets with sport-related concussion (SRC). Methods: The National Collegiate Athletic Association and US Department of Defense Concussion Assessment, Research and Education (CARE) Consortium is a prospective, longitudinal cohort study of collegiate student athletes and military cadets from 30 academic institutions. Athletes and cadets were baseline tested prior to their first athletic season, and retested following concussion at 24 h postinjury, after reporting symptom resolution, and following clearance for unrestricted return-to-play (uRTP; n = 3002). A representative cohort was selected for a subanalysis of inflammatory blood biomarkers (n = 547) at similar time points: (i.e., baseline, postinjury, 24 h postinjury, asymptomatic, and 7 days following uRTP; n = 547). Results: Participants with obesity had a lower number of symptoms endorsed, symptom severity, and psychological symptom scores at baseline (p < 0.0001–0.004) but higher symptom scores at postinjury (p < 0.0001–0.0001). Participants with obesity had worse verbal memory, visual memory, and visual motor speed (p < 0.0001) scores at all postinjury time points compared with participants without obesity. Participants with obesity had higher C-reactive protein (CRP) and interleukin 1-RA (IL-1RA) than participants without obesity at all time points (p < 0.05). Participants with obesity had higher interleukin 6 (IL6) from 24 h to after uRTP, higher IL8 from postinjury to 24 h, and higher vascular endothelial-like growth factor (VEGF) at postinjury. Conclusions: Obese BMI modified clinical response to SRC and participants with obese BMI had a different inflammatory profile than participants without obese BMI.