We carried out contemporaneous daytime blood sugar and growth hormone (HGH) determinations in eight juvenile and six middle-aged diabetics under both poor and good metabolic control. A continuous blood sampling technic was used. The following results were obtained:
1. HGH values in poorly controlled diabetics were higher and more fluctuating than in normals of a corresponding age.
2. After good control was reached, a significant HGH decrease was observed in all patients but one. In this condition HGH levels were normalized in middle-aged diabetics but not in juvenile ones. In the latter group HGH values, even if decreased, were persistently higher than in controls of the same age.
3. No difference was observed between newly diagnosed diabetics and patients known to have had diabetes for some years.
Our data support the suggestion that HGH abnormalities in diabetes are a consequence of the metabolic disturbance.