Individualized low-dose growth hormone (GH) treatment in GH-deficient adults with childhood-onset disease: Metabolic effects during fasting and hypoglycemia

Growth hormone (GH) has insulin-antagonistic effects, and GH secretion is a ugmented during fasting and hypoglycemia. In the present study, 10 patients aged 21 to 28 years with childhood-onset GH deficiency (GHD) were studied during a 24-hour fast and a hypoglycemic glucose clamp before and after 9 m onths of GH replacement. During the 24-hour fast, blood glucose, serum insu lin, and serum free fatty acid (FFA) levels were measured. In the hypoglyce mic clamp, the counterregulatory hormones (plasma catecholamines, serum glu cagon, and serum cortisol), serum insulin-like growth factor (IGF) binding protein-1 (IGFBP-1), serum FFA, and glucose uptake were measured. The GH do se was adjusted to the response of serum IGF-I, and the median GH dose was 0.14 IU/kg/wk (range, 0.08 to 0.19). At the end of the study, serum IGF-I l evels were normalized in all but one patient, in whom serum IGF-I was above the normal range. Nine months of GH treatment did not cause any significan t changes in the blood glucose level, insulin to glucose ratio, or serum FF A level during the 24-hour fast, and none of the patients experienced hypog lycemia either before or after GH treatment. However, GH therapy resulted i n increased insulin resistance during hypoglycemia, without changes in the counterregulatory hormonal responses, serum IGFBP-1, or serum FFA. Copyrigh t (C) 1999 by W.B. Saunders Company.