Diagnosis of Growth Hormone Deficiency Remains a Judgment Call - and That Is Good

Abstract

The diagnosis of growth hormone deficiency (GHD) still does not reflect evidence-based and generally accepted practice, and reliance on growth hormone stimulation testing (GST) leads to a high rate of false-positive diagnosis of idiopathic-isolated GHD (IIGHD). While searching for more definitive indicators of GHD is attractive, it should not distract from currently available steps to reduce erroneous IIGHD diagnoses. This paper describes opportunities to improve the accuracy of the GST which include: (1) meticulous selection of candidates for GST, since a low prevalence of GHD among short children in general is a major factor undermining the test's diagnostic accuracy; (2) departure from traditional pass/fail diagnostic GH cutoffs toward, instead, formulation of diagnoses along a continuum that spans actual GHD - > provisional GHD - > not GHD; (3) response to the provisional diagnosis of IIGHD based on GST with additional post-test observation or alternative growth-promoting interventions rather than immediate human growth hormone treatment; (4) re-examination and often correction of a prior IIGHD diagnosis with the onset of puberty. Modern medicine is increasingly offering diagnostic tests that aim to eliminate the need for provisional diagnoses. But a pitfall of such a "definitive" test for GHD would be the temptation to respond to its results definitively. Given the nuances, variations, and fluctuations in GH axis function over time, children evaluated for growth concerns are still best served by clinical judgment that combines thoroughness, patience, flexibility, and healthy skepticism into the diagnosis of GHD.

Keywords: False positive; Growth hormone testing.