Laboratory diagnosis of growth hormone deficiency in children

Abstract

This chapter reviews the evidence base for current practices in using biochemical growth hormone (GH) testing to make decisions about treating a child or adolescent with GH for the purpose of normalizing or improving adult stature. The discrepancies in measuring GH by different methodologies using different standards or different provocative stimuli and the consequent difficulty of having to make a decision based on a single diagnostic threshold are reviewed. Moreover, normative data show that the diagnostic thresholds for peak GH response currently in use in most industrialized countries are well within the range seen in healthy, normally growing children. This drastically decreases the diagnostic specificity of GH testing and misclassifies non-GH-deficient short children who can expect very modest benefit from GH treatment. I propose that full disclosure of the modest effect expected from treating children who test below the payer-accepted threshold but still well within the reference range established by normative data be considered standard of care.