IGF1 and type 2 diabetes mellitus: It has been reported that hypoxia inducible factor-1 (HIF-1α), the key to mediating hypoxia-responsive genes, and insulin-like growth factor I (IGF-1), which is secreted in the liver, may potentially be synergistic in regulating the vascular endothelial growth factor (VEGF) expression in type 2 diabetes (7).