The effects of oxandrolone and exercise on muscle mass and function in children with severe burns

Abstract

Objectives: Severe burns are associated with a significant loss of muscle and strength. Studies have reported that oxandrolone improves lean body mass in muscle-wasting conditions. Also shown previously in burned children is that an exercise program increases lean body mass and muscle strength. We hypothesized that oxandrolone, in combination with exercise, would increase lean body mass and muscle strength in severely burned children more than oxandrolone alone or exercise alone.

Methods and patients: Fifty-one burned children (> or = 40% total body surface area burned) were randomly assigned to receive oxandrolone alone (0.1 mg/kg per day orally; n = 9), oxandrolone and exercise (n = 14), placebo and no exercise (n = 11), or placebo and exercise (n = 17). Administration of oxandrolone was started at discharge and continued until 1 year after burn. The 12-week exercise training program was started 6 months after burn. Serum hormones, lean body mass, muscle strength, and peak cardiopulmonary capacity were assessed at 6 (baseline) and 9 months after burn. Data were analyzed using a 1-way analysis of variance, and significance was set at P < .05.

Results: The mean percentage of change or increase in weight and lean body mass in the oxandrolone and exercise group was significant compared with placebo and exercise, as well as with the oxandrolone alone group or placebo and no exercise group. Furthermore, lean body mass was significantly improved in the oxandrolone and exercise, oxandrolone alone, and placebo and exercise group compared with the group only receiving placebo. Muscle strength significantly increased in oxandrolone and exercise, placebo and exercise, and the oxandrolone alone group when compared with the placebo and no exercise group. The peak cardiopulmonary capacity was significantly higher in both exercise groups. Insulin-like growth factor 1 was significantly increased in the oxandrolone alone group compared with placebo and exercise and placebo and no exercise. Both exercise groups showed significant changes in insulin-like binding-protein-3 when compared with groups without exercise.

Conclusions: Oxandrolone, in combination with exercise, is beneficial in severely burned children, thus improving their rehabilitation.

FIGURE 1

General design of the study. After randomization, patients received oxandrolone or placebo starting at hospital discharge. Patients then participated in an exercise program between 6 and 9 months after burn or in a home-based standard of care program.

FIGURE 2

Mean percentage changes in weight. Data are presented as mean ± SEM. ^a Significant difference in weight compared with OX, PLEX, and PL (P < .05). ^b Significant difference in weight compared with PL (P < .05).

FIGURE 3

Mean percentage changes in lean mass from 6 to 9 months after burn. Data are presented as mean ± SEM. ^a Significant improvement compared with OX, PLEX, and PL (P < .05). ^b Significant difference compared with PL (P < .05).

FIGURE 4

Mean percent changes in MStr. ^a Significant difference in MStr compared with PL (P < .05). Data are shown as mean ± SEM.

FIGURE 5

Mean percentage changes in peak aerobic capacity. Data are presented as mean ± SEM. ^a Peak aerobic capacity, which was significantly improved in both exercise groups, OXEX and PLEX, when compared with OX and PL (P < .05).

FIGURE 6

Mean percentage changes in IGF-1 from 6 months to 9 months after burn. Data are presented as mean ± SEM. ^a Significant difference in IGF-1 compared with OXEX, PLEX, and PL (P < .05).

FIGURE 7

Mean percentage changes in IGFBP-3 from 6 months to 9 months after burn. ^a Significant difference between the exercise groups, OXEX and PLEX, relative to the groups without exercise, OX and PL (P < .05). Data are presented as mean ± SEM.