GLOSSARY

IGF-Binding Proteins (IGFBPs)
IGF-binding proteins bind IGF ligands and regulate their distribution, persistence and access to receptors. The principal high-affinity family includes IGFBP-1 through IGFBP-6, which have distinct regulation and tissue roles.

More than passive transport

Binding can limit immediate receptor access or preserve and deliver ligand in particular contexts. Proteolysis and interactions with extracellular structures modify these effects.

Different metabolic responses

Insulin, nutrition, GH and tissue conditions influence specific binding proteins differently. Measuring one IGFBP does not describe the entire binding environment.

Clinical boundary

IGFBP results can assist selected endocrine assessments, but they are not universal measures of growth or nutritional adequacy. Interpretation requires age, physiology, disease context and the specific binding protein measured.