Adding Glucagon-Stimulated GH Testing to the Diagnostic Fast Increases the Detection of GH-Sufficient Children.
BACKGROUND/AIMS
The evaluation of children with unexplained hypoglycemia may include a diagnostic fast. However, low growth hormone (GH) concentration during hypoglycemia is not specific to GH deficiency (GHD). The aim of this study was to determine if serial GH measurement following glucagon administration, in the setting of a diagnostic fast, would increase the number of children identified as not having GHD.


METHODS
We conducted a retrospective chart review of children who had serial GH measurements performed after glucagon administration at the end of a diagnostic fast. Glucagon was administered at the end of the fasting study, and GH was measured every 30 min for 210 min.


RESULTS
Of the 29 children in this series, only 3 (10%) had GH concentrations >7 ng/ml at the end of the fast, which increased by 16 (55%) after serial GH testing. The percentages of samples with GH concentrations >7 ng/ml were: 10% at baseline, and 25, 39, 41, 41, 33, 43, and 0% every 30 min thereafter.


CONCLUSION
Additional GH measurements after glucagon administration following a diagnostic fast can improve the identification of children without GHD and thereby save them unnecessary GH stimulation testing and potential GH treatment.