Growth hormone-induced nitrogen retention in children of short stature.

The decrease in urinary nitrogen excretion (i.e. increased nitrogen retention) following intramuscular injection of human growth hormone (HGH) has been used to differentiate hypopituitary dwarfism from other types of short stature. While small decreases can be demonstrated in almost all children who are given HGH, in the hypopituitary child the decrease is greater and more prolonged. Using a standardized test of nitrogen retention in response to HGH, Prader, Illig, Szeky, and Wagner (1964) recorded very little overlap when the results in a group of 12 hypopituitary dwarfs were compared with those of 7 non-hypopituitary dwarfs and 4 children of normal stature. In the first Lawson Wilkins Memorial Lecture, Hubble (1966) reported no overlap of results using a similar HGH nitrogen retention test in a group of 10 dwarfed children, 6 of whom had hypopituitarism. This series of patients has now been extended to 22 cases. The results of