Objective. To determine the effects of stress hormones on insulin-like growth factor 1 (IGF-1). Methods. Insulin induced hypoglycemia ( < 3 mmol/l) and clonidine induced depression of noradrenergic tone were used to assess the acute effects of cortisol, human growth hormone (hGH), and norepinephrine (NE). Results. Despite the increase of hGH during hypoglycemia, a statistically significant decrease of IGF-1 was observed along with the expected rise of cortisol and NE. To eliminate the role played by NE, NE tone was depressed by administering clonidine. A statistically significant decrease of IGF-1 was also observed. Conclusion. Acute cortisol release or a NE decrease induce low IGF-1 levels.
