Comparison of insulin and 2-deoxy-D-glucose-induced glucopenia as stimulators of growth hormone secretion

Abstract

Responses of plasma growth hormone after insulin-induced hypoglycemia and 2-deoxy-D-glucose (2-DG)-induced glucopenia were studied in 10 normal, 6 obese, 8 acromegalic, 6 addisonian, and 2 hypopituitary subjects. After insulin hypoglycemia, the mean increases of growth hormone above basal levels were: normal 27.6, addisonian 38.8, obese 2.3, active acromegalic 9.9, and inactive acromegalic subjects 3.1 mμg./ml. After 2-DG-induced glucopenia, the mean increases of growth hormone above basal levels were: normal 19.1, addisonian 25.6, obese 0.6, active acromegalic 6.5 and inactive acromegalic subjects 2.7 mμg./ml. No increase was noted with either stimulus in a hypopituitary subject. Both stimuli were effective in releasing growth hormone from the pituitary. The increase in growth hormone levels was higher and more consistent after insulin-induced hypoglycemia than after 2-DG-induced glucopenia. 2-DG, however, did produce a more sustained increase in growth hormone levels. In those subjects who have impaired insulin sensitivity, 2-DG—which acts by inducing cellular glucopenia—should be useful in evaluating pituitary growth hormone reserve.