Factors Associated With Energy Expenditure And Energy Balance In Acute Sport-Related Concussion

Context: Sport-related concussion (SRC) is characterized by a pathologic neurometabolic cascade that results in an increased intracranial energy demand and a decreased energy supply. Little is known about the whole-body energy-related effects of SRC.Objective: To examine factors associated with whole-body resting metabolic rate (RMR), total energy expenditure (TEE), energy consumption (EC), and energy balance (EBal) in student-athletes acutely after SRC and healthy matched control individuals.Design: Case-control study.Setting: University research laboratory.Patients or Other Participants: Student-athletes diagnosed with SRC (n = 28, 50% female, age = 18.4 +/- 1.8 years, body mass index [BMI] = 24.1 +/- 4.1 kg/m(2)) assessed -72 hours postinjury and a matched control group (n = 28, 50% female, age = 19.4 +/- 2.9 years, BMI = 24.7 +/- 4.78 kg/m(2)).Main Outcome Measure(s): Resting metabolic rate was measured via indirect calorimetry. Participants reported their physical activity and dietary intake for 3 days, which we used to estimate TEE and EC, respectively, and to calculate EBal (EC:TEE ratio). Resting metabolic rate, TEE, and EC were normalized to body mass. Group and group-by-sex comparisons were conducted for RMR.kg(-1), TEE.kg(-1), EC.kg(-1), and EBal using independent t tests with the a priori alpha = .05. Associations of age, sex, concussion history, BMI, and symptom burden with RMR.kg(-1) and EBal were explored with linear regression models.Results: Total energy expenditure.kg(-1) was lower (P < .01; mean difference 6 SD = -5.31 +/- 1.41 kcal.kg(-1)) and EBal was higher (P < .01; 0.28 +/- 0.10) in SRC participants than in control participants. Both sexes with SRC had lower TEE.kg(-1) than did the control participants (P values <= .04); females with SRC had higher EBal than controls (P = .01), but male groups did not differ. Higher RMR.kg(-1) was associated with history of concussion (adjusted R-2 = .10, beta = 0.65). Younger age (beta = -0.35), fewer concussions (beta = -0.35), lower BMI (beta = -0.32), greater symptom duration (beta = 1.50), and lower symptom severity (beta = -1.59) were associated with higher EBal (adjusted R-2 = .54).Conclusions: Total energy expenditure.kg(-1) and EBal appeared to be affected by acute SRC, despite no differences in RMR.kg(-1). Sex, concussion history, BMI, and symptom burden were associated with acute energy-related outcomes.