The 24-hour growth hormone secretion in a boy with giantism.

The endocrinological and radiological findings in a 7.5-year-old boy with giantism are reported and compared with an age and sex matched normal tall boy. A 24-h GH profile demonstrated a persistently elevated GH concentration (mean GH concentration: giant 19.3 mU/l; tall boy 5.4 mU/l) with loss of the dominant GH periodicity of 3 h seen in the boy with tall stature and substitution with one of 8 h. These data support the view that giantism and acromegaly are similar diseases occurring prior to and following epiphyseal fusion, respectively.