The ketotic effects of glucocorticoid and growth hormone in man.

The ketotic effects of both glucocorticoid and growth hormone were assessed in normal man. Experimental protocols, previously shown to induce marked ketosis in diabetic man, were utilized to explore the metabolic effects of these two stress hormones in subjects with normal insulin secretory capacity. Glucocorticoid was administered orally as 1 mg of dexamethasone at 24 and 8 h prior to study. Growth hormone was administered subcutaneously at a dosage of 1 mg, 12 h prior to study. During the 90-min study of the ketotic activity of these hormones, plasma nonesterified fatty acids were acutely increased by heparin administration to support hepatic ketogenesis. This technique permitted an assessment of the ketotic activity of glucocorticoid and growth hormone independent of their lipolytic activity. The results of this study demonstrate that glucocorticoid may cause minimal hyperketonemia in spite of hyperinsulinemia in normal man. However, this effect is accompanied by a glucocorticoid-induced instability in basal ketone body and nonesterified fatty acid concentration. In contrast, no effect of growth hormone on plasma ketone body concentration or insulin levels was observed. These results in normal man contrast to the marked ketosis previously induced by these two stress hormones in diabetic man.