The GH/IGF-1 Axis in Growth and Development: New Insights Derived from Animal Models

Longitudinal growth in humans follows a unique pattern that is characterized by rapid fetal growth, deceleration immediately after birth, a prolonged childhood growth phase, an additional deceleration prepubertally, and a dramatic adolescent growth spurt leading ultimately to stagnancy in adulthood [1]. Linear bone growth, which accompanies longitudinal body growth, occurs during development and the childhood years until epiphyseal fusion occurs after puberty [2]. Growth is dynamic in nature and is influenced by nutritional, neuronal, and hormonal factors [3].