Children suffering from chronic disease and receiving long-term glucocorticoid therapy suffer over years from sever growth retardation and profoundly altered body composition. They consist in a marked increase in fat mass and decrase in lean body mass. Published studies have shown that Growth Hormone (GH) treatement in children with Idiopathic Arthrisis can improve body composition by increasing lean mass and by preventing increase in fat mass.

The aim of the present protocol is to evaluate whether the increase in lean body mass observed during Gh treatement is associated with changes in muscle strengh and mass and muscle energetic metabolism.

 

In order to be able to evaluate the effect of GH on the muscle a comparative group ins needed. Therfore it will be proposed to delay in group of patients the start of Growth Hormone (GH) treatement by 6 months. As most publications have shown a maximum effect of GH within the first year treatement, six months should be enough to evaluate short-term effect of GH on the muscle. Therefore, this study will be a randomized trial : immediate start of Growth Hormone (GH) treatement versus start of Growth Hormone treatement 6 months later. After 6 months all children will be treated with GH. Therfore, The follow-up will be onne year after baseline.

 

Primary objective : Evaluation of short-term GH effect on muscle metabolism in children with growth retardation related to long-term glucocorticoid therapy.

Secondary objectives :

- Evaluation of short-term GH effet on muscle mass

- Evaluation of short term GH effect on muscle strength

- Evaluation of short-term GH effect on body composition.