The influence of age and gender on resting energy expenditure in severely burned children

Abstract

Introduction: Recent evidence suggests that female severely burned children have higher endogenous anabolic hormone levels and a shorter ICU stay compared with males. The purpose of this study was to analyze the influence of age and gender on resting energy expenditure (REE) in severely burned children from acute hospitalization through 12 months postburn.

Methods: A total of 100 pediatric patients with > 40% total body surface area (TBSA) burn were enrolled in a prospective study and followed by indirect calorimetry measurements. The REE was expressed as actual REE kcal/d, percent of predicted REE, and REE/ body mass index (BMI). Statistical analysis was performed by Student t test and one-way ANOVA for repeated measures. Significance was accepted at P < 0.05.

Results: The measured REE was significantly higher in males versus females at all time points (P < 0.05). The percent of predicted REE was significantly higher in males versus females during the acute hospitalization, at discharge, 6 and 9 months postburn (P < 0.05). The REE/BMI showed a significant difference between males and females at the acute and discharge time period (P < 0.05). In children 3 to 9.9 years of age, the measured REE and the percent of predicted REE were significantly higher in males versus females during the acute study, at discharge and 6 months postburn (P < 0.05). The measured REE at discharge, 9 and 12 months postburn for children >10 years of age was significantly higher in males compared with females (P < 0.05).

Conclusion: Data show that female children exert a decreased hypermetabolic response compared with male children, which may improve burn outcomes in females.

FIGURE 1. Pattern of the REE over time. A, Acute REE and REE at discharge were significantly increased compared with 6, 9, and 12 months. B, Percent of predicted REE showed a significant decrease from the acute study to 6, 9, and 12 months postburn. C, The normalization of the REE to body mass index (BMI) showed a significant decrease from the acute study at 9 and 12 months postburn. *Significant difference compared with acute and discharge (P < 0.05).

FIGURE 2. Resting energy expenditure over time: females versus males. A, The measured REE was significantly higher in males versus females at all time points. B, Percent predicted REE showed a significant difference between males and females during the acute study, at discharge, 6 and 9 months postburn. C, Normalization of the REE to BMI showed a significant difference between males and females from acute to 9 months postburn. *Significant difference compared with acute and discharge (P < 0.05).

FIGURE 3. Resting energy expenditure patients stratified for age. A, The measured REE for patients <3 years of age were significantly lower at all time points when compared with the patients from 10 to 18 years and at acute, discharge and at 12 months postburn compared with 3 to 9.9 years. There was a significant difference between patients in the 3- to 9-year age group compared with the 10- to 18-year age group at all time points. B, Percent predicted REE for patients in the <3-year age group was significantly lower compared with the 10- to 18-year group during the acute study and upon discharge. C, Children <3 years of age had the lowest REE/BMI index at all time points compared with 10 to 18 years and at acute, discharge and at 12 months compared with the 3 to 9.9 years. Children 3 to 9.9 years had lower REE/BMI index acutely, at discharge and 6 months postburn compared with 10 to 18 years. *Significant difference between 0 to 2.9 years and 10 to 18 years (P < 0.05). ^†Significant difference between 3 to 9.9 compared with 10 to 18 years (P < 0.05). ^‡Significant difference between 0 to 2.9 compared with 3 to 9.9 years (P < 0.05).

FIGURE 4. Resting energy expenditure females stratified by age. A, REE was significantly lower in the <3-year age group compared with the 10- to 18-year age group at all time periods. REE for patients in the 3- to 9.9-year age group versus the 10- to 18-year age group showed a significant difference in REE acutely, at discharge and at 6 months postburn. B, Percent predicted REE in the <3-year age group compared with the 10- to 18-year age group showed a significant difference at acute and at discharge. In the 3- to 9.9-year age group compared with the 10- to 18-year age group, percent predicted REE was significantly different only during the acute study. C, In the <3-year age group, REE/BMI was significantly lower during the acute study and at discharge compared with the 10- to 18-year age group. The age group 3 to 9.9 years had a significantly lower REE/BMI index acutely when compared with females 10 to 18 years. *Significant difference between 0 to 2.9 years and 10 to 18 years (P < 0.05). ^†Significant difference between 3 to 9.9 compared with 10 to 18 years (P < 0.05). ^‡Significant difference between 0 to 2.9 compared with 3 to 9.9 years (P < 0.05).

FIGURE 5. Resting energy expenditure males stratified by age. A, REE for male children <3 years of age was significantly lower at all study periods when compared with the other 2 age groups. In the 3- to 9-year age group, the REEE was significantly decreased compared with 10- to 18-year age group at all time periods. B, Percent predicted REE was significantly lower in the <3-year age group compared with the 10- to 18-year age group at discharge. C, REE/BMI index showed that male children <3 years of age had significantly lower REE/BMI at all study periods when compared with the other 2 groups. Index was also lower in the 3- to 9-year age group compared with the 10- to 18-year age group from the acute study through 9 months postburn. *Significant difference between 0 to 2.9 years and 10 to 18 years (P < 0.05). ^†Significant difference between 3 to 9.9 compared with 10 to 18 years (P < 0.05). ^‡Significant difference between 0 to 2.9 compared with 3 to 9.9 years (P < 0.05).

FIGURE 6. Resting energy expenditure (females vs. males 3–9 years). A, REE was significantly higher in males during the acute study period, at discharge and 6 months postburn. B, Percent predicted REE was significantly higher in males during the acute study, at discharge and 6 months postburn. C, The REE/BMI index showed no significant difference between males and females in this age group. *Significant difference between females versus males (P < 0.05).

FIGURE 7. Resting energy expenditure females versus males 10 to 18 years. A, REE was significantly higher in males at discharge and at 9 and 12 months postburn when compared with females. B, Percent predicted REE showed no significant difference between males and females at any study period in this age group. C, The REE/BMI index showed a significant difference between males and females at the 9- and 12-month time period. *Significant difference between females versus males (P< 0.05).