An audit of the laboratory interpretation of growth hormone response to insulin-induced hypoglycaemia in the assessment of short stature in children

Introduction Measurement of serum growth hormone (GH) concentration in response to insulin-induced hypoglycaemia remains an important investigation in the assessment of pituitary disease. Methods In this audit, laboratories were presented with aliquots of sera with GH concentrations likely to be found in an insulin stress test (IST). They were invited to analyse the specimens for GH and comment on their results. Results and discussion A number of laboratories appeared to be using out-of-consensus cut-off concentrations that sometimes were unrelated to the bias of their GH assay. The specimens were chosen to mimic those seen in an IST that was clearly not indicative of GH deficiency, so there was reasonable consensus in the interpretation of results. However, five laboratories (9(.)6%) did indicate that their results were equivocal.