Growth Hormone Responses Following Double Pulse Oral Glucose Administration in Various Clinical States

Abstract

The 8-h double pulse oral glucose test is proposed as an alternative screening procedure for determining the adequacy of growth hormone (GH) release. The second pulse of glucose is timely in suppressing GH release and delaying it for a more predictable controlled elevation. Peak GH (mean ± sd) values following the double pulse glucose test were 17 ± 10.2, 16.5 ± 2.2, and 1.3 ± 0.5 ng/ml in normal controls, short stature patients and GH deficient patients, respectively. Peak GH values following insulin hypoglycemia were 36.9 ± 13.8, 21.9 ± 23.0 and 1.8 ± 1.1 ng/ml in normal controls, short stature patients and GH-deficient patients. Peak GH values during a 5-h oral glucose tolerance test were 16.4 ± 6.0 and 10.2 ± 3.3 ng/ml in normal controls and short patients, respectively. These differences in peak GH values between the various clinical and control groups were not significantly different except for the greater GH peak values reached in short patients in the double pulse glucose test compared to the 5-h oral glucose tolerance test. The rise in GH following double pulse oral glucose is more timely predictable than after the 5-h oral glucose test and involves less professional time than the insulin tolerance test as it does not require close medical supervision.