Comparison between a physiological and a pharmacological stimulus of growth hormone secretion: response to stage IV sleep and insulin-induced hypoglycaemia.

Peak growth hormone (GH) response to insulin-induced hypoglycaemia was compared with peak GH concentration during the first cycle of stage IV sleep in 75 children. 65 children had concordant results: in 38 GH concentrations were greater than 15 mU/l and in 27 less than this value. Results were discordant in 10 children. Results of sleep sampling under electroencephalographic control of the assessment of GH secretion are comparable to conventional pharmacological studies in terms of efficiency, sensitivity, and percentage false-negatives. Sleep sampling has the advantage of being a physiological test of secretion.