Insulin-like growth factors (IGFs) and IGF-binding proteins in nephrotic syndrome children on glucocorticoid.

Growth failure is often seen in nephrotic children who fail to respond to glucocorticoid therapy or are glucocorticoid dependent. The underlying mechanism responsible for such growth defect remains poorly understood although long-term glucocorticoid use or nephrotic syndrome (NS) has been indicated to independently affect growth. Recent clinical evidence has suggested that changes in the serum levels of insulin-like growth factors (IGFs) and IGF-binding proteins (IGFBPs) among these children. The loss of insulin-like growth factor-I (IGF-1) and IGFBP-3 found in nephrotic children may directly prompt growth defect and retardation. In addition, glucocorticoid is believed to be associated with overt elevation of serum IGF-I levels suggesting potential development of IGF resistance, one of the main factors responsible for persistent growth retardation. Growth hormone therapy has been shown to effectively reconcile this IGF resistance. The present review will discuss the complex relationship among IGF, IGFBPs, and glucocorticoid in children with NS.