Effect of exogenous growth hormone and exercise on lean mass and muscle function in children with burns

We tested the hypothesis that the administration of recombinant human growth hormone (rHGH) and exercise would increase lean body mass (LBM) and muscle strength in burned children to a greater extent than rHGH or exercise separately. Children, ages 7-17 yr, with >40% body surface area burned, were randomized into groups. One group (GHEX, n = 10) participated in a 12-wk in-hospital physical rehabilitation program supplemented with an exercise program and received 0.05 mg·kg^-1·day^-1 of rHGH. A second exercising group (SALEX, n = 13) received saline. A third group (GH, n = 10) received a similar dose of rHGH as GHEX and participated in a 12-wk, home-based physical rehabilitation program without exercise. The fourth group (Saline, n = 11) received saline and participated in a 12-wk, home-based physical rehabilitation program without exercise. The mean (±SE) percent change in lean body mass after 12 wk was not significantly different between GHEX (9.0 ± 2.1%), SALEX (5.4 ± 1.6%), and GH (5.8 ± 1.8%) groups (P = 0.33). However, the mean percent change in muscle strength was significantly greater in the GHEX (36.2 ± 5.4%) and SALEX (42.6 ± 10.0%) groups than in the GH (-7.4 ± 4.7%) or Saline (6.7 ± 4.4%) groups (P = 0.008). In summary, rHGH GHEX, SALEX, and GH alone produced similar improvements in LBM. However, muscle strength was only increased via exercise.