The association between body mass index and physical function in adult burn survivors: A Burn Model System National Database study.

INTRODUCTION: An area of rehabilitation research in burns is the impact of co-morbidities on disease trajectory. Obesity is a comorbidity of increasing public health concern, but its role remains controversial regarding burn injury and physical recovery. Our aim was to evaluate the association between body mass index (BMI) categories as a measure of obesity at discharge and self-reported physical function (PF) during recovery of adult burn survivors. METHODS: This is a retrospective study on data collected by four major US burn centers, which contribute to the Burn Model System National Database. The data included BMI obtained at hospital discharge and self-reported PF-mobility, using the PROMIS measures assessed at 6, 12, and 24 months after burn. Subjects were classified into weight status categories based on BMI: underweight (BMI <18.5), normal weight (18.5 ≤ BMI <25), overweight (25 ≤ BMI <30), obesity class 1 (30 ≤ BMI <35), obesity class 2 (35 ≤ BMI <40), and obesity class 3 (BMI ≥40). Mixed-effects linear regression models were used to assess the association between BMI categories and PF scores over time, adjusted for patient and injury characteristics. RESULTS: A total of 496 adult burn patients aged 47 ± 16 years were included, with mean total body surface area (TBSA) burned of 18 ± 19 % and mean BMI at discharge of 28 ± 7 kg/m2. PROMIS PF scores significantly improved over time in the recovery phase after burn (time effect, p < 0.001). Compared to overweight burn patients, normal-underweights exhibited lower PF score by an average of 4.06 units (p = 0.001) but scores increased linearly by an estimated 0.17 units per month (p = 0.01) over the 24 months after discharge. Similarly, compared to overweight burn patients, class 1 obese reported lower PF score by a mean 2.67 units (p = 0.07) but PF increased linearly by 0.15 units per month (p = 0.07) over the 24 months after discharge. These findings were independent of the effects of age at discharge, sex, TBSA burned, and hand and leg burn. CONCLUSION: Being overweight was associated with improved and faster recovery of PF scores compared to normal, underweight, and obese burn patients during long-term recovery. Hence, our data suggests that long-term recovery and restoration of PF in adult burn survivors is not compromised by a small excess in body weight.

The Historical Evolvement of Movement and Exercise Training in Patients with Severe Burns and Their Potential Effects on Grafts, Scars, and Function.

Exercise training for burn patients has become a major part of rehabilitation programs within the last decades. One of the main reasons for prolonged and long-term increased morbidity and mortality in this population is a persistent catabolic state with subsequent loss of lean body mass (LBM). A combination of resistance and aerobic exercises as well as stretching has shown to improve physical function by enhancing cardiopulmonary fitness, LBM, and strength and thus leading to ameliorated long-term outcomes of patients recovering from burns. In this literature review, we show an outline of the implementation of exercise training over the last decades into standardized care for patients with burns.