Growth hormone treatment (GH) is recommended in children born small for gestational age (SGA) who fail to catch-up. SGA is a heterogeneous condition as reflected in the varied response to GH treatment. Variable generation and resistance to Insulin-like growth factor-1 (IGF-1), the most important circulating mediator of GH action may underpin this heterogeneity. An association between the variants in the genes related to lower insulin sensitivity and reduced IGF-1 and growth response to GH therapy in SGA children have been reported recently. The hypothesis of this study is that insulin sensitivity may be causally linked to the response to GH therapy, and adjuvant therapy with an insulin sensitizer may improve IGF-1 generation, decrease IGF-I resistance and optimise growth response.