Standardization of Growth Hormone and Insulin-like Growth Factor-I Measurement.

Determination of serum levels of GH and IGF-I is crucial for the diagnosis and treatment of GH deficiency and disorders related to GH excess such as acromegaly and pituitary gigantism. However, significant discrepancies in measured GH values among the methods were observed around the world. In Japan, the Study Committee for GH and Its Related Factors of The Foundation for Growth Science standardized GH values measured with various commercially available GH assay kits by creating formulas to adjust them to their averages. The committee also established reference values for IGF-I in Japanese subjects at all ages from childhood to adulthood. Internationally, collaborators have been working on the harmonization of GH measurements.