Pitfalls of insulin-like growth factor-i and growth hormone assays.

Accurate measurement of growth hormone (GH) and insulin-like growth factor-I (IGF-I) are the key to correct diagnosis of acromegaly and GH deficiency. Unfortunately, there is much variation involved when these hormones are measured at different sites and using different assay methods. There is an ongoing global effort to standardize the measurement process to obtain more comparable results in the future. This review discusses common pitfalls in the measurement of GH and IGF-I and guides laboratories in their analyses of these hormones.