Growth hormone: uses and abuses

6.2 million people in the USA sustain a bone fracture each year.
Systemic administration of growth hormone (GH) may promote fracture
healing. Insulin-like growth factor-1(IGF-1), also known as somatomedin-C,
seems to be mediating the effect of GH on the skeleton (1). IGF-1 promotes
bone matrix formation (type I collagen and non-collagenous matrix
proteins) by acting on the fully differentiated osteoblasts (2).

Andreassen and Oxlund (2003), using a rat tibial diaphyseal fracture
model, administered GH systemically during the first 3 weeks of healing;
increased callus formation and enchanced fracture strength up to 11 weeks
after cessation of GH treatment (3).
Furthermore, Bail et al (2002) studied the effect of systemic
administration of GH using a fracture healing and distraction osteogenesis
model in Yucatan micropigs. Biomechanical testing, quantitative computed
tomography (qCT), histomorphometric analysis, and serum levels of IGF-1
all showed that administration of homologous recombinant porcine GH led to
an increase in serum IGF-1, stimulation of fracture healing and
acceleration of ossification of bone regenerate in distraction
osteogenesis (4). However clinical trials are needed before the safety and
effectiveness of GH as a therapeutic option in fracture healing in humans
is established (3,4).

1. Copeland KC, Underwood LE, Van Wyk JJ. Induction of immunoreactive
somatomedin C human serum by growth hormone: dose-response relationships
and effect on chromatographic profiles. J Clin Endocrinol Metab.
1980;50(4):690-7.

2. Cheryl A. Conover. Insulin-like Growth factors and the Skeleton.
In Skeletal Growth Factors, Canalis E.(ed), Lippincott
Williams&Wilkins, Phil. 2000.

3. Andreassen TT, Oxlund H. Local anabolic effects of growth hormone
on intact bone and healing fractures in rats. Calcif Tissue Int.
2003;73(3):258-64.

4. Bail HJ, Kolbeck S, Krummrey G, Schmidmaier G, Haas NP, Raschke
MJ. Systemic application of growth hormone for enhancement of secondary
and intramembranous fracture healing. Horm Res. 2002;58 Suppl 3:39-42

Competing interests:
None declared