Reserve it for the GH deficient

  Growth hormone (GH) has been in clinical use for four decades and there has been much rediscovery of wheels in the past 30 years.1 Childhood growth is GH dependent. Velocity is related to the amplitude of pulsatile GH secretion in an asymptotic manner so that children with very little GH grow very slowly and a small replacement dose has a large effect on growth acceleration. The more GH a child secretes, the more normally he or she grows, the bigger is the dose of GH needed to have a significant effect, but any child given GH in adequate amounts grows more quickly.2

To maintain peak concentrations of GH, the pituitary has to increase production as the child grows. This may not happen in some children who then grow poorly in the middle childhood years. When growth is complete and the demand for GH drops, they have ample GH for adult life, which is why most patients do not continue to require treatment. Lack of puberty may give rise to another transient GH insufficient state.

The indication for GH replacement is GH deficiency, congenital or acquired, permanent or transient. GH should be introduced as soon as the failure of its secretion has been identified. The dose is dictated by the clinical situation but there is a tendency to maximise doses at the start of treatment in order to restore lost growth in the least time, with probable long term benefit.3

Normal children, children with Turner's syndrome, renal failure, skeletal dysplasia, etc, all grow more quickly when given GH, but results on adult heights are not all that exciting. This is not surprising as none of the children are GH deficient and GH does nothing for the severity of their underlying conditions. In 50% of patients, predicted height …